Osteotomy.Pdf

Table of Contents

About the Authors 5 Introduction 7 Basic Knee Anatomy 9 Understanding Lower Limb Malalignment 12 The Basics 12 Primary, Double, and Triple Varus 14 The Influence of Gait (How We Walk) on Forces in the Knee 18 What Happens in the Arthritis Process in the Knee Joint? 20 The Demise of Articular Cartilage 20 Types of Knee Arthritis 21 The Knee Examination 22 History 22 Where Does It Hurt? 22 Range of Knee Motion 23 Knee Ligament Tests 23 Meniscus Tests 25 Knee Joint Crepitus 25 The Patellofemoral Joint 26 Lower Limb Alignment and Gait Analysis 26 Muscle Strength and Function 26 Imaging Studies (X-rays, MRI) 26 Conservative Treatment: What You Should Have Already Tried 28 A Few Comments 28 Mild Arthritis Pain 29 Moderate Arthritis Pain 29 Severe Arthritis Pain 29 Choosing an Orthopaedic Surgeon in the United States 30 High Tibial Osteotomy for Varus (Bowed Leg) Malalignment 31 Indications 31 Contraindications 32 Timing of Knee Ligament Reconstruction if Required 33 Preoperative Planning 34 Choosing Between an Opening Wedge and Closing Wedge Procedure 35 Initial Steps for Both Osteotomy Procedures 36 Opening Wedge Osteotomy 37 Closing Wedge Osteotomy 40 Possible Complications 41 Expected Results 41 Distal Femoral Osteotomy for Valgus (Knock-Knee) Malalignment 42 Indications 42 Contraindications 43 Preoperative Planning 44 How the Operation May Be Done 44 Possible Complications 46 Expected Results 46 Limb Alignment Osteotomy Versus Partial Knee Replacement 46 Common Associated Operative Procedures 47 ACL Reconstruction 47 PCL Reconstruction 48 Posterolateral Reconstruction 49 Articular Cartilage Restoration 51 Meniscus Repair 52 Meniscus Transplantation 53 Preparing for Surgery 53 Getting Your House Ready 53 Food and Medications 55 Practice the Exercises You Will Do After Surgery 56 Mental Preparation 56 The Night Before Surgery 57 The Day of Surgery 57 Recovering From Surgery 59 Prevention of Blood Clots in Your Leg (Deep Venous Thrombosis) 59 Our Postoperative Physical Therapy Program 59 Home Exercises 67 Ankle Pumps 67 Range of Knee Motion 67 Patellar Mobilization 67 Hanging Weights 68 Rolling Stool 68 Wall Slides 68 Quadriceps Isometrics: Full Extension 69 Quadriceps Isometrics: Multi-angle 69 Straight Leg Raise: Hip Flexion 70 Straight Leg Raise: Hip Extension 70 Straight Leg Raise: Hip Abduction 70 Straight Leg Raise: Hip Adduction 70 Straight Leg Raises With Resistance Band 71 Mini-squats 72 Hamstring Curls, Active 73 Knee Extension, Active-Assisted 73 Knee Extension, Active 73 Wall Sits 73 Heel Raises 74 Toe Raises 74 Lateral Step-ups 74 Step-downs, Stable and Unstable Surface 74 Hamstring Stretch 75 Calf Stretch 75 Iliotibial Band Stretch 75 Quadriceps Stretch 76 Health, Fitness Club Exercise Machines 76 Leg Press 76 Hip Abduction/Adduction 77 Multi-Hip 77 Knee Extension 77 Hamstring Curls 78 Upper Body Weight Training 78 Core Training 78 Stationary Bicycle 78 Cross-Country Ski 79 Elliptical 79 Pool Training 79 Water Walking and Other Basic Aquatic Exercises 79 Swimming (Straight Ahead Kicking) 79 Frequently Asked Questions 80 Acronyms and References 81 Appendix 1. Gait Retraining Program for Severe, Painful Knee Hyperextension 86 5 About the Authors

Dr. Frank Noyes is an internationally recognized orthopaedic surgeon and researcher who has specialized in the treatment of knee injuries and disorders for nearly 4 decades. He is the founder and chairman of the Cin- cinnati SportsMedicine and Orthopaedic Center and its nonprofit research foundation. Dr. Noyes completed his orthopaedic training at the University of Michigan Medical Center. He then received a 4-year clinical and research appointment as an orthopaedic surgeon in the United States Air Force, was commissioned as a Lieu- tenant Colonel, and began his landmark research into knee ligament injuries, the effects of immobilization, biomechanics of ligaments, prevention of ACL injuries in the female athlete, the diagnosis of many knee injuries and problems, and the results of treatment for a variety of knee disorders. Along with Dr. Edward Grood, Dr. Noyes established one of the first biomechanics laboratories in the United States at the University of Cincinnati College of Engineering. The laboratory was subsequently named in his honor as the Noyes Tissue Engineering and Biomechanics Laboratory.

Dr. Noyes has won every conceivable award for his clinical and laboratory research from societies such as the American Academy of Orthopaedic Surgeons, the American Orthopaedic Society of Sports Medicine, the Orthopaedic Research and Education Foundation, as well as the University of Cincinnati. He was inducted into the American Orthopaedic Society for Sports Medicine’s Hall of Fame in 2008. Dr. Noyes has been selected by his peers as one of the Best Doctors in America every year since 1992.

Dr. Noyes has published over 260 clinical and scientific research studies and textbook chapters. These publica- tions detailed surgical techniques and clinical outcomes on many different types of knee injuries and disorders. He edited a textbook entitled, “Noyes’ Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes” which was written for orthopaedic surgeons, physical therapists, and other sports medicine health care professionals. Dr. Noyes is also a co-editor of “ACL Injuries in the Female Athlete. Causes, Impacts, and Conditioning Programs”, a textbook written for sports medicine health care professionals, coaches, and trainers involved with female athletes.

Sue Barber-Westin has directed clinical research studies for Dr. Noyes’ research Foundation for nearly 3 decades. In the mid 1980’s, she authored one of the first studies that measured problems during single-leg hop- ping tests in patients with ACL injuries, “Quantitative Assessment of Functional Limitations in Normal and Anterior Cruciate Ligament-Deficient Knees.” She has co-authored 140 articles in medical journals and text- books, focusing on the clinical outcome of various knee operative procedures, the methods used to determine the results of clinical investigations, differences in neuromuscular indices between male and female athletes, effects of neuromuscular training in female athletes, and prevention of ACL injuries in female athletes. Sue is the associate editor of “Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes” and is the co-editor for “ACL Injuries in the Female Athlete. Causes, Impacts, and Conditioning Programs”. Sue has personally undergone 4 knee operations and played competitive junior and collegiate tennis.

In 2004, Sue and Dr. Noyes were members of the clinical research team that won the Clinical Research Award from the Orthopaedic Research and Education Foundation. They are frequently invited to speak at national and international conferences and review articles for orthopaedic and sports medicine journals. Noyes and Barber-Westin have written several other eBooks for patients:

1. ACL Injury: Everything You Need to Know to Make the Right Treatment Decision

2. ACL Injury Rehabilitation: Everything You Need to Know to Restore Knee Function and Return to Activity 6 3. Knee Meniscus (Cartilage) Tears: Everything You Need to Know to Make the Right Treatment Decision

4. Patellar (Kneecap) Pain and Problems: Everything You Need to Know to Make the Right Treatment Deci- sion

5. Operations for Knee Arthritis: What To Do When All Else Has Failed To Stop Your Knee Pain

6. Knee Arthrofibrosis: Everything You Need to Know to Recognize, Treat, and Prevent Loss of Knee Motion After Injury or Surgery

7. Partial Knee Replacement: Everything You Need to Know to Make the Right Treatment Decision

8. PCL and Posterolateral Knee Ligament Injuries: Everything You Need to Know to Make the Right Treatment Decision

9. The Unstable Patella (Kneecap): Everything You Need to Know to Make the Right Treatment Decision 7

Introduction

Lower limb malalignment, often referred to as bowed legs or knock-knees, can cause knee pain and limitations, especially as we grow older. In adults, a bow-legged or knock-kneed position indicates a malalignment of the lower extremity - the entire leg from the hip to the ankle. The medical terms used to describe these conditions are varus for bowed legs and valgus for knock-knees.

Both varus and valgus malalignment are frequently seen in very young children and are usually corrected naturally with growth and physical maturation. In adults, lower limb malalignment may occur to one or both legs and be either a congenital disorder or happen as a result of a knee injury. The main problem with lower limb malalignment is the development of osteoarthritis in one area of the knee that causes pain, swelling, and limitations with recreational sports and eventually, with normal daily activities.

Varus (bowed leg), the more common malalignment condition, may cause pain in the inner (medial) portion of the knee joint. Knee symptoms may be worsened with obesity or overuse of the knee joint, and can become a serious problem if the medial meniscus (cartilage) tears and requires partial or complete removal (called a meniscectomy). Valgus malalignment (knock-knee) may cause pain in the outer (lateral) area of the knee and can worsen upon removal of the lateral meniscus.

Osteoarthritis may occur from varus or valgus malalignment because there is an abnormal amount of stress and pressure placed on just the inner (varus) or outer (valgus) part of the knee joint. A good analogy to this problem is the wearing of a portion of a tire on a car that is out of proper alignment. If the alignment is not fixed, the tire will wear out on one side, shortening its expected lifespan.

Fortunately, there are operations that have gained wide acceptance as treatment options for younger active patients who have painful osteoarthritis in one portion of the knee due to varus or valgus malalignment. An operation called an osteotomy may be performed in which bone in either the femur (thigh bone) or tibia (shin bone) is cut and the leg is properly aligned by the surgeon. The operation commonly done for varus malalignment is called a high tibial osteotomy (HTO). This surgical procedure most frequently involves producing an “opening wedge” of bone which aligns the knee joint and transfers a major portion of the weight-bearing loads to the lateral (outside) area of the knee joint. Valgus malalignment is corrected with an operation referred to as a distal femoral osteotomy, which is designed to transfer a major portion of the weight-bearing loads to the medial (inner) part of the knee. In rare instances, a surgeon may recommend a tibial osteotomy (called a lateral opening wedge) to realign a knock-knee.

Osteotomy may be performed in patients with some arthritic damage to one area of the knee joint, but is not indicated in individuals who have severe damage, widespread arthritis, or when a “bone-on-bone” situation exists in which little or no joint space is left between the femur and tibia. In these individuals, either a partial knee replacement or total knee replacement is the better option. Osteotomy is frequently required to restore proper alignment to the lower limb before other operations may be done, such as a meniscus transplant or cartilage restoration procedure, as will be discussed.

Currently, no eBooks exist that provide detailed information on either tibial or femoral osteotomy. After treating patients for nearly 4 decades with knee problems, we decided to write this eBook to try to help individuals understand these operations and what to realistically expect if they decide to undergo surgery. This eBook provides information on basic knee anatomy, what causes lower limb malalignment, the process of arthritis in the knee, the factors that go into deciding whether or not to have an osteotomy, how the operations are performed, success rates in terms of pain relief and increased function, how to prepare for surgery, and physical therapy 8 required after surgery. In addition, exercises to do at home and in a fitness club are described in detail. This eBook should not be used for self-diagnosis and treatment of lower limb malalignment. Only a qualified orthopedist or sports medicine-trained physician can make a definitive diagnosis of this problem. For medical professionals, we recommend our textbook “Noyes’ Knee Disorders. Surgery, Rehabilitation, Clinical Out- comes” for more comprehensive information regarding the diagnosis and treatment of knee arthritis, as well as other knee problems such as knee ligament tears, patellofemoral problems, preventing knee ligament injuries in the female athlete, meniscus injuries, and cartilage restoration procedures. 9

Basic Knee Anatomy

The knee is a hinge joint. It is made up of 4 bones that are held together by ligaments, tendons, and muscles. The femur (or thigh bone) is the large bone in the thigh. The tibia (or shin bone) is the large bone in the lower leg and the fibula is the smaller bone in the lower leg that lies parallel to the tibia. The patella (or knee cap) is the small bone in the front of the knee that glides up and down as the knee bends and straightens. It is located in front of the femur and glides through a groove called the trochlear (or patellar) groove.

There are 2 types of cartilage in the knee joint: the meniscus (fibrocartilage) and articular cartilage (hyaline cartilage). The meniscus is a C-shaped structure that is located between the weight-bearing ends of the femur (femoral condyle) and tibia (tibial plateau). There are 2 menisci in each knee, the medial meniscus (located on the inner side) and the lateral meniscus (located on the outer side). The menisci are located on the top of the tibia. You may have heard someone say they “tore their cartilage”, which usually means they have torn their meniscus. 10

Articular cartilage is a smooth protective lining or layer of tissue that is located on the ends of bones where they meet in the knee. In the knee joint, articular cartilage is located on the end of the femur, the top of the tibia, and on the undersurface of the kneecap. This type of cartilage allows the bones to glide smoothly and the knee to flex and straighten easily. The term arthritis basically refers to the breakdown or damage to articular cartilage.

There are 2 joints, or articulations, in the knee. The tibiofemoral joint is the area where the femur and tibia meet. The patellofemoral joint is the portion of the knee where the patella and femur meet.

There are 3 compartments in the knee. These compartments represent the areas where 2 bones meet and include all of the surrounding soft tissues in that portion of the knee. These are the medial tibiofemoral compartment (where the femur and tibia meet on the inside portion of the knee), the lateral tibiofemoral compartment (where the femur and tibia meet on the outside portion of the knee), and the patellofemoral compartment (where the patella and femur meet in front of the knee).

Ligaments connect bones and help provide stability to joints. There are 4 main ligaments in the knee. The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) cross each other in the center of the knee. They each connect the femur to the tibia. The medial collateral ligament (MCL) is located on the medial (or inner) side of the knee and it also connects the femur to the tibia. The lateral collateral ligament (LCL) is located on the lateral (or outer) side of the knee and it connects the femur to the fibula.

Each ligament has a main job in helping to keep the knee stable when we walk, run, go up and down stairs, kneel, and do any weight-bearing activity. In addition, the muscles and other soft tissues in the knee joint help provide stability.

The ACL prevents the tibia from excessive forward motion (called anterior tibial translation) and too much inward twisting or rotation (called internal tibial rotation). The PCL keeps the tibia from moving too far backward. The MCL and LCL act to control the knee’s sideways stability and rotation. The LCL and posterolateral structures (PLS, which include the popliteus muscle-tendon-ligament unit, the popliteofibular ligament, and the posterolateral capsule) help block knee hyperextension, or keep the knee from bending too far backwards.

There are smaller ligaments that also exist in the knee, such as the meniscotibial ligament that attaches the edges of the menisci to the top of the tibia. The transverse ligament connects the lateral meniscus to the medial meniscus. The medial patellofemoral ligament attaches the inner edge of the patella to the medial portion of the femur. The popliteofibular ligament and fabellofibular ligament connect the femur to the top of the fibula.

There are other important structures in the knee you may have heard of, such as tendons that connect muscles to bone. The quadriceps tendon connects the quadriceps muscles (the large muscles that are in front of the thigh) to the kneecap. The patellar tendon (also called the patellar ligament) connects the quadriceps muscle and kneecap to the upper part of the tibia to bend and extend the knee joint. The hamstrings muscles at the back of the thigh attach to the tibia at the back of the knee via the semitendinosus, gracilis, and biceps tendons. 11

The muscles that are involved with bending and straightening the knee and also in helping to provide stability to the knee are the quadriceps and hamstrings. The quadriceps are 4 muscles that are located in the front and sides of the thigh (called the rectus femoris, vastus lateralis, vastus intermedius, vastus medialis). They help straighten the knee. The hamstrings are the muscles at the back of the upper leg (called the biceps femoris, semitendinosus, gracilis, semimembranosus) that flex or bend the knee.

Other muscles are also important in providing stability during walking, running, and the like. These include the muscles in the hip (gluteus maximus, gluteus medius, piriformis, adductor muscles) and in the calf (gastrocnemius and soleus).

The iliotibial band is a large band of thick tissue located on the outside of the thigh. It extends from the hip to the knee. This structure also helps to stabilize the knee joint during activities such as running. 12

Understanding Lower Limb Malalignment

The Basics

In order to understand why lower limb malalignment may cause pain and arthritic damage in the knee joint, it is necessary to briefly describe how the knee normally works to absorb forces that are continually experienced during any weight-bearing activity. There are tremendous forces placed on the knee when we do just about anything, such as:

Climbing up stairs or walking: 3 times body weight (150-lb person = 450 lbs with every step)

Going down stairs: 5 times body weight (150-lb person = 750 lbs with every step)

Running: 7 times body weight (150-lb person = 1050 lbs with every step)

In a knee with normal alignment, the body’s weight basically goes up almost through the middle of the joint and is distributed fairly evenly across the medial and lateral compartments. On average, the weight-bearing forces are shared 60%-40%, with the medial side absorbing a little more of the load than the lateral side. If you look back at the Basic Knee Anatomy section to the illustration showing the knee joint looking down on top of the tibia (left leg), you will notice that the medial meniscus is larger than the lateral meniscus. This size difference is most likely due to this normal distribution of weight-bearing forces between the medial and lateral compartments.

It is important to understand that many structures - bones, soft tissues (such as ligaments), and muscles - work in harmony to balance and share the tremendous impact forces sustained by the knee joint. In addition, the manner in which a patient walks (referred to as the gait cycle or gait pattern) influences how loads are distributed within the knee joint. Any injury or deficiency of the structures around the knee, or an abnormal gait pattern, may alter an individual’s lower limb alignment and/or change the way weight-bearing forces are distributed. We will discuss further in the next section the potential impact of the loss of a meniscus or knee ligament function on lower extremity alignment. Finally, arthritic degeneration of a compartment of the knee can lead to a change in lower limb alignment. A frequent problem is loss of the joint space that normally exists between the femur and tibia in the medial compartment, which may result in a varus malaligned position.

The alignment of the lower extremity is measured on an x-ray performed with the patient standing that goes from the hip to the ankle. A line is drawn from the center of the femoral head (in the hip) to the center of the ankle (tibiotalar joint). This is called the “weight-bearing line” (WBL). A second line is drawn on top of the tibia (tibial plateau). Then, a third line is drawn from the medial edge of the tibia to the WBL. As shown on the right, the distance of line A divided by the distance of line B equals the WBL percentage. In essence, 0% corresponds to the far medial border of the tibial plateau and 100% corresponds to the far lateral border. 13

A portion of an x-ray of a leg in normal alignment with a WBL of 50%. The actual x-ray that is read by the surgeon shows the entire lower extremity from the hip to the ankle.

In a bow-legged (varus) limb, the majority of the patient’s body weight passes through the medial (inner) area of the knee. In other words, the WBL goes well into the medial compartment, below 50%.

Illustration of varus malalignment A portion of an x-ray of a leg in A patient with bilateral varus where the WBL (dotted black line) varus malalignment where the malalignment. is 33%. WBL is 20%. The actual x-ray that is read by the surgeon shows the entire lower extremity from the hip to the ankle. 14

The opposite occurs in valgus malalignment (knock-knees), where most of the loads pass through the lateral (outer) area of the knee. The WBL is calculated in the same manner, and will be above 50%.

A portion of an x-ray of a leg in valgus A patient with valgus malalignment on malalignment where the WBL is 70%. The the left lower extremity. actual x-ray that is read by the surgeon shows the entire lower extremity from the hip to the ankle.

Primary, Double, and Triple Varus

As we mentioned earlier, the amount of varus malalignment is dependent not only on the alignment of the bones, but also on the condition of other important structures in the knee joint. The loss of the medial meniscus from an injury - or loss of the function of important ligaments in the knee - can worsen the extent of the varus and cause all kinds of additional problems. Just to repeat the major functions of the knee ligaments, the ACL prevents the tibia from excessive forward motion. The PCL keeps the tibia from moving too far backward. The MCL and LCL act to control the knee’s sideways stability and rotation. The LCL/PLS help block knee hyperextension, or keep the knee from bending too far backwards.

Many years ago, Dr. Noyes devised a classification system that specified the exact causes of varus malalignment. There are 3 categories:

Primary varus, where the amount of varus is due to just the alignment of the bones. Over time, with loss of the normal amount of joint space between the medial femur and tibia, the amount of varus angulation may increase. 15 Double varus, where the amount of varus is due to 2 factors: the alignment of the bones and an abnormal amount of separation between the femur and tibia on the lateral side of the knee from injury or deficiency of the LCL and posterolateral structures (PLS). In some individuals, a large amount of primary varus will, over time, cause the PLS to become slack even though no injury occurred to the knee, thereby converting the knee from a primary varus to a double varus condition.

Illustration of a patient with normal alignment on the right side and double varus malalignment on the left side. The lateral joint space in the left knee opens up 8 mm when the patient stands, 4 mm more than the Illustration of double varus opposite side. malalignment. The lateral compartment will open or separate during any weight-bearing activity. The WBL is 20%.

Triple varus, where the amount of varus is due to 3 factors: the alignment of the bones, an abnormal amount of separation between the femur and tibia on the lateral side of the knee from injury or deficiency of the LCL and PLS, and a varus recurvatum position of the limb. Varus recurvatum indicates that the knee goes far back into hyperextension and bows outward, shown to the right. 16 It is important to note that the LCL/PLS work to prevent several problems from happening: excessive opening or separation between the lateral femoral condyle and lateral tibial plateau, external rotation of the tibia, knee hyperextension (bending too far backwards), and varus recurvatum.

In triple varus knees, the lateral compartment will separate during any weight-bearing activity, even more than that seen in double varus knees.

Illustration of triple varus malalignment. The lateral compartment will open or separate during any weight-bearing activity. The WBL is 5%. 17

It is a frequent finding in triple varus knees that either the ACL or PCL are also severely damaged (along with the LCL and PLS) and not functioning. In fact, our decades of experience with these complicated problems have shown many different combinations of problems in varus-aligned knees.

Many years ago, Dr. Noyes began noticing patients who had a normally aligned leg in which the ACL was torn, along with the medial meniscus. These individuals were treated with removal of the torn section of the medial meniscus. Either the ACL tear was not fixed, or it was reconstructed but the surgery failed and the patients had a non-functional ACL. Over time, the injured legs gradually went into a varus position. With the loss of the medial meniscus that normally provides a cushion between the tibia and femur, the medial side of the knees developed arthritic damage. The knees became greatly unstable, painful, and swollen. These patients typically required an osteotomy to correct the varus malalignment and, in some cases, an ACL reconstruction. In some individuals, a meniscus repair or transplant was also performed in an attempt to preserve or restore the important functions of this structure.

A patient with a normally aligned right knee, but a varus-aligned left knee from an old injury in which the medial meniscus was removed and the ACL tear was not reconstructed.

Although not as common, we have also treated patients with the problem of primary varus that was made worse by an injury to the LCL and PLS. These ligament injuries were frequently either not diagnosed properly or not surgically reconstructed. Over time, the triple varus knee condition developed that led to significant problems with any sports activity (recreational or competitive) and often, normal daily activities. These patients were usually treated with an osteotomy first. Then, several months later, if the LCL and PLS remained deficient, a ligament reconstruction was performed to restore ligament function.

There are other cases where patients had primary varus, but did not have any knee problems until an injury was sustained to the medial meniscus. If a good portion of the meniscus tissue was removed, the amount of varus increased over time, gradually causing deterioration of the medial portion of the knee.

Finally, we have noted and published several papers regarding failure of knee ligament reconstructions for the ACL, PCL, and LCL/PLS. One of the major factors that caused these operations to fail was the fact that varus lower limb malalignment was not corrected with an osteotomy and the lateral ligaments (LCL/PLS) were not reconstructed. The opening of the lateral joint from the bowed leg position produced an overload and failure of the ACL graft. In fact, this problem appeared to be a major factor of ligament failure in 16% of the 153 patients in our ACL revision studies and in 30% of the 82 patients in our PCL and LCL/PLS revision studies. 18

X-ray of a knee with tears to the PCL, LCL, and PLS and varus malalignment. The ligament tears were reconstructed, but the primary varus problem was not corrected with an osteotomy. The surgery failed and the patient was referred to our center for further treatment. The abnormal amount of opening between the femur and tibia on the lateral side of the knee (LJO) can be clearly seen.

As you can see, problems with lower limb malalignment can become quite complicated and that is why a comprehensive knee examination is required so the surgeon can precisely determine all of the problems that exist. We will discuss all that is required in this examination in detail later in this eBook.

The Influence of Gait (How We Walk) on Forces in the Knee

We previously mentioned that the manner in which we walk, called the gait cycle or gait pattern, influences how weight-bearing forces impact the knee joint. Changes from a normal gait pattern may happen because of congenital varus malalignment, or due to a serious knee ligament injury that is not surgically corrected. Ab- normal lower limb alignment - both varus and valgus - produces substantial alterations in the forces about the knee joint and increase the risk of arthritic damage.

The gait cycle begins when one foot contacts the ground and ends when that foot contacts the ground again. There are 2 major phases in the gait cycle: the stance phase (the interval in which the foot is on the ground, about 60% of the gait cycle) and the swing phase (the time in which the foot in not in contact with the ground, about 40% of the gait cycle). The cycle begins at initial foot contact in the stance phase and proceeds through the swing phase until the cycle ends.

Loads are placed on the body with the initial contact, or the instant the foot touches the ground. The gait cycle has periods of time when both feet are in contact with the ground at the same time (about 10% of the cycle) and periods where just one foot is in contact. When walking, there is always at least 1 foot on the ground. How- ever, during running, there may be one foot on the ground or neither foot in contact with the ground.

There are many categories within the 2 major phases of the gait cycle and we will not go into too much detail here. Basically, the stance phase consists of heel strike (initial contact), foot flat (loading response), mid-stance, and toe off (terminal stance). The swing phase consists of pre-swing, initial swing, mid-swing, and terminal swing. An experienced orthopaedic surgeon or physical therapist can visually assess each individual phase as a patient walks to determine if an obvious problem exists. There are also sophisticated gait analysis laboratories that can provide a comprehensive analysis of an individual’s gait characteristics.

The ankles, knees, hips, and trunk all change position during the phases of the gait cycle to allow locomotion while maintaining stability. Throughout the entire stance phase, ground reaction forces produce “moments” of force that are sustained within the joints. In the knee joint, an external adduction moment is produced which tends to rotate the tibia internally. A high knee adduction moment increases forces on the medial compartment of the knee and only adds to the problems in varus malalignment in terms of increasing the risk of arthritic 19 deterioration. The position of the foot when it contacts the ground influences this moment - patients with a “toe-in” gait have a higher knee adduction moment than patients with a “toe-out” gait because the WBL passes further medially to the knee joint. There is also an increase in the inversion moment experienced about the ankle joint, as shown below.

Ankle and knee adduction moments are influenced by the angle of the foot on ground contact. The example on the right shows how a low foot angle (“toe-in” gait) on ground contact produces higher knee adduction moments.

A frequent finding in double and triple varus knees is what is termed a varus thrust during the stance phase of walking. In these patients, the knee literally thrusts or bows outward with every step. In triple varus knees, the knee may also hyperextend abnormally during walking.

In some individuals, the gait abnormalities are severely disabling and cause marked pain and instability. In others, these problems only happen after walking for a long period of time when the muscles become fatigued. It is important for these patients to go through a period of physical therapy before osteotomy and ligament reconstructive procedures to correct these gait problems and improve muscle strength. This is because the resump- tion of a varus thrust and/or knee hyperextension gait after surgery may cause failure of the operations. We have published an article that describes a gait retraining program, which is summarized in Appendix 1. This program requires an experienced physical therapist to teach and guide the patient in order to achieve a normal gait pattern.

We have frequently mentioned that the major problem with lower limb malalignment is the possible development of arthritic deterioration in one compartment of the knee (medial for varus, lateral for valgus). Next we will describe what happens in this arthritic process. 20 What Happens in the Arthritis Process in the Knee Joint?

The Demise of Articular Cartilage

Articular cartilage, often referred to as the “joint lining”, is a tissue that is found on the ends of bones in joints that move freely such as knees, hips, wrists, and shoulders. It provides a resilient and compressible surface, or one that is able to recover its shape (called compliance) after being stressed or compressed. Articular cartilage provides the sliding surface that allows joint motion. It also protects the knee joint by helping to distribute loads that are applied during weight-bearing activities, thereby limiting the amount of stress that is absorbed by the underlying subchondral and cancellous bone. As we have previously discussed, lower limb alignment and other structures in the lower extremity also have a role in increasing or decreasing forces, such as the menisci, ligaments, and muscles.

Arthritis in the knee joint refers to the breakdown, degeneration, and eventual loss of articular cartilage that is frequency accompanied with damage to the underlying bone. Over time, there is a loss of the normal amount of space between the bones in the knee joint that is usually occupied by the cartilage as it becomes thin and is lost. In patients with varus or valgus malalignment, this occurs between the end of the femur (femoral condyle) and the top of the tibia (tibial plateau). With a loss of the cartilage lining, increased pressures are placed on the underlying supporting bone that responds by becoming thicker and harder (this process is called sclerosis). Bone spurs may develop at the periphery (ends) of the joint. It is important for you to understand what articular cartilage is and its importance in the knee joint in order to understand the arthritis process.

Articular cartilage is made up of water (70%), type II collagen (about 15%), proteoglycans (about 15%), and chondrocytes (about 1%). Chondrocytes are cells that are responsible for the production of the cartilage matrix, which consists of collagen and proteoglycans. The structure of articular cartilage is described in medical text- books as a series of zones, each of which varies according to the alignment, number, size, and shape of chondrocytes. These zones are called the superficial (tangential), transitional (middle), radial (deep), and calcified. The calcified cartilage zone contains what is termed the tidemark, a line that indicates the boundary between noncalcified and calcified cartilage. Just under this area is subchondral bone, with cancellous bone located underneath. 21

Cancellous bone contains red bone marrow where the production of stem cells occurs. Stem cells are responsible for replacing cells in the body that have been damaged or have died. The bone marrow contains hemato- poletic stem cells that create blood cells (red, white, and platelets) and stromal stem cells that create bone cells (osteoblasts), cartilage cells (chondrocytes), fat cells (adipocytes), and connective tissue.

Articular cartilage does not contain nerves and has no real ability to repair or restore itself when injured. This is because there are relatively few cells in the tissue, the metabolic rate is low, and the ability of chondrocytes to form new cartilage matrix is greatly limited. When injury to cartilage occurs, the cells increase in number and provide greater matrix components. However, the native original cartilage is not regenerated.

In osteoarthritis, articular cartilage deteriorates as a result of increased water content, reduced number of chondrocytes, reduced concentration of proteoglycan, and a breakdown of the matrix. Even if the body at- tempts to repair damaged articular cartilage, it usually fails because the repair tissue does not have the same biomechanical properties and structure of normal cartilage. Inflammatory diseases or infection can also cause degeneration of articular cartilage.

Types of Knee Arthritis

There are many types of arthritis that may affect joints, the most common being osteoarthritis, post-traumatic arthritis, and rheumatoid. Rheumatoid arthritis is an autoimmune disorder whereby the body’s immune system mistakenly attacks healthy tissue in joints and organs. It leads to chronic inflammation and may destroy the cartilage in many different joints in the body. It may begin at any age and usually occurs in both knees, along with the wrists, fingers, feet, and ankles.

Osteoarthritis is the most common form of knee arthritis. It is a slow, progressive disease in which the knee joint degenerates as the articular cartilage wears away. The underlying subchondral bone may become damaged. There is also a loss of the normal amount of space in the tibiofemoral compartments and/or the patellofemoral compartment. This is what is usually found in middle-aged and elderly patients. It is also referred to as degenerative joint disease, or wear-and-tear arthritis.

Post-traumatic arthritis occurs after an injury to the knee, such as a fracture or tear to a ligament or meniscus. It is similar to osteoarthritis in that it involves loss of articular cartilage. However, this is more frequently found in younger patients, especially those involved in athletics.

Here is a photograph taken at arthroscopy of a normal knee, without any arthritic damage. 22 Now, take a look at what severe damage to the articular cartilage and joint surface looks like. This patient is a candidate for a knee replacement procedure and not an osteotomy.

The Knee Examination

History

As we mentioned previously, a thorough knee examination is required to measure not only the amount of malalignment that exists in your knee, but also to detect any other problems such as lax or completely deficient ligaments that require treatment. The physician will first take a thorough history to find out when your knee symptoms began or if you ever had a knee injury. You will be asked about what specific problems you are having such as pain, swelling, and instability (giving-way).

If you did not have an injury, but your knee just started to hurt, it is important to determine what activities cause your symptoms to start, what makes your problems worse, and what helps relieve them. You will be asked if going up and down stairs, kneeling, squatting, walking long distances, or playing sports aggravate your knee problems. If you had an injury, questions will be asked about when it occurred, what exactly happened, and if you have had more than one injury.

You will also be asked if you have had knee surgery in the past. If this is the case, it is very helpful if you can obtain a copy of the operative note and any photographs that were taken during the operation. Have these on hand for your current physician to review during your appointment.

Pain in the knee may come from different problems. Therefore, your physician should perform many clinical examination tests and techniques while you are standing, sitting, and lying down.

Where Does It Hurt?

The physician will palpate, or feel, various areas on and around your entire knee joint. This will be done while you are sitting with your leg relaxed, and then with your knee bending and straightening. The physician is try- ing to determine exactly where your knee hurts. Sometimes, the pain is in a specific location and in other cases, it occurs in many different places or just “all over” (called diffuse pain).

To give you an idea of what the physician is feeling, some of the structures include the medial and lateral reti- naculum (soft tissues on both sides of the knee cap), the fat pad, the iliotibial band, the medial patellofemoral ligament, the patellar tendon, the medial and lateral menisci (joint lines), the quadriceps tendon, the insertions of these tendons, the insertions of the vastus medialis oblique and vastus lateralis oblique muscles, the tibial insertion of the patellar tendon, and the saphenous nerve. Your physician will check to see if you have any swelling in your soft tissues or a neuroma present. A neuroma is a small “knot” of nerve tissue or endings that can be painful. 23

Range of Knee Motion

Your physician should measure the amount of motion in both of your knees, or how much they bend and extend. This is referred to as range of knee motion. When the knee is straight, that is referred to as 0 degrees. When the knee is fully flexed, it usually goes to about 135-140 degrees, although this varies between individuals. Many patients with knee arthritis have a loss of the normal amount of motion in their knee joint. Of partic- ular concern is when the knee cannot reach full extension (become fully straight) that results in limping.

Knee Ligament Tests

A Lachman test is one of the most common tests done to determine if your ACL is torn. You will be asked to lie down on an examination table on your back and to completely relax. With your injured knee slightly bent, the physician will hold your thigh still with one hand and gently pull on your tibia (shin bone) with the other hand to estimate the forward motion of the tibia in relation to the femur. Normally, a knee has just a few millimeters of forward movement and then a firm stop or endpoint is felt by the physician, which represents the ACL working to prevent any more excessive movement (anterior tibial translation). The physician estimates the amount of forward movement, which is done in millimeters, and compared to the movement of the opposite, normal knee. The result of this test may be scored as either normal (0-2 mm increase), nearly normal (3-5 mm increase), abnormal, (6-10 mm increase) or severely abnormal (6-10 mm increase).

The Lachman test may also be done with an instrument called a KT-2000 (knee arthrometer). This device produces an actual measurement of the amount of forward motion of the tibia. It is done on both the injured leg and the opposite leg. The difference in the amount of motion measured of the forward movement of the tibia determines if the ACL is damaged. If more than 5 mm of increased movement is found in your injured leg compared to the other leg, the ACL is indeed torn. The KT-2000 is also used to determine the total increase of posterior tibial translation (backwards movement) at 30 and 90 degrees of knee flexion.

Other physical examination tests may be done to determine if your ACL has been injured. These are called the pivot-shift and flexion-rotation tests. These tests include a rotational movement and are more complicated to perform, especially if you are having pain and your knee is swollen. The results are usually scored on a scale of 0-3 where 0 means your ACL is working normally, 1 indicates a partial tear (or a loose-jointed knee), and 2 or 3 mean your ACL is completely torn and not functioning.

A posterior drawer test will be done to determine if your PCL has been injured. You will be asked to lie on your back with your injured knee flexed to 90 degrees and your feet resting flat on the exam table. The physician 24 may sit on your feet to make sure your hamstring muscles are relaxed. Then, the physician will apply a force to push your tibia backward. Normally, a knee has just a few millimeters of movement and then a firm stop or endpoint is felt by the physician, which represents the PCL working to prevent any more excessive backwards movement (called posterior tibial translation). The physician estimates the amount of backward movement, which is done in millimeters, and compared to the movement of the opposite, normal knee. The result of this test may be scored as either normal (0-2 mm increase), nearly normal (3-5 mm increase), abnormal, (6-10 mm increase) or severely abnormal (6-10 mm increase).

The posterior drawer test A knee with a chronic PCL tear

A varus stress test will be used to determine if your LCL/PLS is injured. You will be asked to lie on your back on an exam table with your injured leg resting just off of the table, as shown in the photograph below. With your knee kept straight, the physician will push your ankle medially and feel with his/ her fingers if any “gap” or opening occurs on the lateral side of your knee joint between the femur and tibia. This test is also done with your knee slightly bent (30 degrees). The physician estimates the amount of joint opening on the lateral (outside) part of the knee and compares it to the opposite, normal knee. The result of this test may be scored as either normal (0-2 mm increase), nearly normal (3-5 mm increase), abnormal, (6-10 mm increase) or severely abnormal (6-10 mm increase).

Another test that will be done to determine if your LCL/PLS are injured is the external rotation-internal rotation “dial test”. You will be asked to lie on your back, with both knees bent and feet kept together. Then, the physician will turn both of your feet outward as shown in the photograph below. The physician will compare the amount of rotation of the tibial tubercle between your injured and opposite, normal leg. This test is done twice, first with your knees flexed to 30 degrees and then to 90 degrees. The result of this test may be scored as either normal (< 5 degrees increase), nearly normal (6-10 degrees increase), abnormal, (11-19 degrees increase) or severely abnormal (> 20 degrees increase). 25 A valgus stress test will be used to determine if your MCL has been injured. You will be asked to lie on your back on an exam table with your injured leg resting just off of the table, as shown in the photograph below. With your knee kept straight, the physician will push your ankle laterally and feel with his/her fingers if any “gap” occurs on the medial side of your knee joint between the femur and tibia. This test is also done with your knee slightly bent (30 degrees). The physician estimates the amount of joint opening on the medial (inside) part of the knee and compares it to the opposite, normal knee. The result of this test may be scored as either normal (0-2 mm increase), nearly normal (3-5 mm increase), abnormal, (6-10 mm increase) or severely abnormal (6-10 mm increase).

Meniscus Tests

There are tests and techniques that your physician may perform if a meniscus tear is suspected, which is a frequent injury that occurs with knee ligament tears. These include palpating, or feeling, what is called the tibiofemoral joint line to see exactly where the pain is coming from.

Your knee will be rotated and flexed to its maximum position by the physician to detect if pain occurs in the meniscus. Many times, a knee with a meniscus tear cannot be fully extended and pain occurs with deep flexion.

Knee Joint Crepitus

Your physician will also see if you have what is called crepitus, or cracking, in your patellofemoral and tibiofemoral compartments. Your physician will place their hand directly on your kneecap and ask your to bend and straighten your knee through its full range of motion several times over the exam table. Pressure will be applied to see if this causes pain. Crepitus usually indicates some damage to the articular cartilage, but may also be due to impingement of the anterior fat pad, the synovial plica, or from an inflammed synovium. 26 The Patellofemoral Joint

Your physician will determine how your kneecap moves, or tracks, within the trochlear groove as you bend and straighten your knee. He or she will determine if the soft tissues that help keep your kneecap in place are damaged or not working properly. Tests will be done to see if your kneecap moves too far to the right or left, or can be tilted abnormally. You will be asked to extend (straighten) your knee and then make a hard quadriceps muscle to determine how far your kneecap moves laterally (toward the outside of your leg). This is to determine what is called dynamic quadriceps muscle balance and is done in both legs at the same time. Your physician will also determine an important angle known as the Q angle. This is the angle formed by drawing one line from the anterior superior iliac spine to the middle of the patella, and a second line from the middle of the patella to the tibial tubercle.

Lower Limb Alignment and Gait Analysis

Your physician will determine your overall lower limb alignment first visually while you are standing and walking. It is important to detect what is called a varus recurvatum position, which indicates severe knee hyperextension (knee bends backwards) and bowing. This is done while you are lying down and standing. A visual analysis will be done of your gait (walking) pattern, as we just described in the previous section. Your physician will note if your legs move in the same manner when you walk, or if the knee that is hurting moves differently that the other or causes you to limp. Special emphasis will be placed on the presence of a varus thrust or knee hyperextension during the stance phase of walking.

Muscle Strength and Function

The function, strength, and flexibility of your leg and hip muscles will be determined. These muscles include the quadriceps, hamstrings, gastrocnemius, soleus, hip flexors and extensors, and hip abductor and adductors. Sometimes, using simple hop tests in place will determine if problems in the function of your muscles exist. Your physician will look for muscle atrophy in your thigh and calf, indicated by a decrease in size of the muscle and your ability to tighten the muscle.

Imaging Studies (X-rays, MRI)

There are several different types of x-rays that should be taken of your knees, called anteroposterior, weight-bearing 45-degree posteroanterior (Rosenberg) lateral, and axial (Merchant). Some of the x-rays will be taken while you are standing and others, while you are sitting or lying down.

These images help determine the amount of joint space that exists in your patellofemoral and tibiofemoral compartments. In order to be a candidate for an osteotomy, there should be some joint space remaining in the affected compartment of your knee. For instance, in varus knees, there should be joint space in the medial compartment as shown to the right.

X-ray showing a small loss of joint space in the medial compartment between the medial femoral condyle and tibial plateau. MJS = medial joint space, WBL = weight-bearing line. 27

To the right is an x-ray of a patient who is not a candidate for an osteotomy, but a partial knee replacement because there is complete loss of the joint space between the medial femoral condyle and tibial plateau.

Full standing x-rays that show both of your entire lower extremities (hips to ankles) are required to precisely measure lower limb alignment. We described previously how the weight-bearing line is measured in the Un- derstanding Lower Limb Malalignment section.

Lateral x-rays are used to measure the height and position of your patella. It is important to determine if a patella infera (patella pulled downward from its normal position) or patella alta (patella rides higher than the normal position) condition exists. Either of these abnormalities will affect the decision of whether to perform osteotomy and if so, which exact procedure is indicated.

A stress x-ray may be done if your surgeon detected damage or deficiency of the ligaments on the lateral side of your knee (LCL and PLS). The amount of lateral joint opening or separation between the lateral femoral condyle and lateral tibial plateau is very important to measure before an osteotomy in double and triple varus knees, as it will affect the calculation of the amount of bone to be resected or inserted in order to achieve a proper alignment correction. Here is an x-ray of a patient with a significant amount of lateral compartment opening, or separation.

A magnetic resonance imaging (MRI) test may be ordered if your surgeon wishes to obtain more information regarding the condition of your knee. MRI is a common test that shows all parts of the knee, including the ligaments, menisci, and other soft tissues that cannot be seen on an x-rays. MRI is a noninvasive test that does not use any harmful rays and may be done in either a partially closed or open scanner. There are sophisticated MRI images that show the cartilage lining. These are technically known as fast-recovery fast spin-echo images that are obtained using a cartilage-sensitive pulse sequence that allows for high-contrast resolution between articular cartilage, subchondral bone, and joint fluid. These images allow the thickness, size, and location of articular cartilage lesions to be determined. 28 Conservative Treatment: What You Should Have Already Tried

A Few Comments

While this eBook focuses on osteotomy for mild to moderate knee arthritis pain, we will briefly outline our recommendations for conservative treatment of this problem. If you have not already gone through a course of such treatment, this approach may be considered first before undergoing surgery.

Our conservative treatment approach is basically designed for “wear and tear” arthritis of varying degrees and consists of lifestyle changes (weight control or loss, avoidance of activities that can aggravate the knee), medications (from over-the-counter to prescription anti-inflammatory to injections), physical therapy, and supplements. We try to use the least amount of medication possible. In many cases of mild to moderate arthritis, the use of occasional over-the-counter pain and anti-inflammatory medications, along with modification of activities and weight loss, is often effective in controlling pain and swelling.

The proper precautions regarding the use of various medications should be discussed with your physician. There are risks with taking nonsterodial anti-inflammatory medications (NSAIDs), including those related to gastrointestinal (nausea, bleeding, ulcers) and cardiovascular (stroke, heart attack) problems. These risks only occur in a small amount of patients, but it is still important that you are informed. Consult with your physician before taking any pain medication, especially if you are already on other medication for problems such as high blood pressure or cholesterol.

Weight Control Understand that for every pound of weight loss, there is 4-6 pounds of reduced pressure on the knee. Our recommendations for weight control are: Decrease size of portions. Decrease fat intake. Substitute for red meat, avoid saturated fats, substitute oils for polyunsaturated types (olive, canola, peanut). Increase vegetable and fruit intake. Learn to count calories. Avoid unhealthy snacks and sweets. Use meal supplements (Slim Fast, Ensure). Seek counseling if required. Try a low carbohydrate diet.

Aggravating Activities The following are considered aggravating activities to the arthritic knee joint that has moderate to severe damage and should be avoided as much as possible. The goal is to limit any activity that produces pain or swelling during or up to 24 hours after the activity. If there is no pain or swelling, then the activity listed is probably safe.

Standing longer than 30-60 minutes at a time. Sitting in one position longer than 30 minutes at a time; includes excessive driving. Walking longer than 69-90 minutes at a time without resting or elevating the leg. Stairs, inclines/declines. Kneeling/squatting. Lifting. Machine operation. Twisting/turning. Sports. 29

Mild Arthritis Pain

Patients with mild arthritis pain are encouraged to lose weight (if they are overweight) or maintain their current weight if they are within the normal range, avoid aggravating activities, decrease high- or moderate-impact sports activities by 50%, and participate in low-impact aerobic exercise. They may occasionally use over- the-counter pain and anti-inflammatory medications such as Tylenol, Aleve, or Advil as needed.

The supplement glucosamine-chondroitin sulfate is used by many patients; however, this may only help one in three individuals. If used, try the supplement alone if possible for 4 weeks, then determine if you have experienced a benefit. This supplement may decrease pain but have not been shown to rebuild damaged joint cartilage. Ice is used for knee swelling and after exercise.

Moderate Arthritis Pain

Patients with moderate arthritis pain are encouraged to lose weight (if they are overweight) or maintain their current weight if they are within the normal range, avoid aggravating activities, decrease sports activities by 50- 75%, and participate in low-impact aerobic exercise. They may require prescription anti-inflammatory medications intermittently, depending on physician guidelines.

Recurrent knee pain and joint swelling may indicate the consideration of a knee injection using either a steroid or synthetic lubricant such as Synvisc. A knee injection is only recommended when anti-inflammatory medications, diet, and avoidance of aggravating activities are no longer effective. This treatment usually results in good relief of knee pain and swelling in three out of four patients for many months because the medication, 90% of which remains in the knee joint, decreases the inflammation in the knee better than oral medications.

Physical therapy is encouraged to help patients remain active and maintain normal motion in their knee. Flexibility and strengthening exercises to maintain joint mobility are important and may be performed at home daily. This is one of the benefits of having a physical therapy evaluation so that a specific exercise, strength, and flexibility program may be prescribed. All knee-related exercises and fitness machines are low-impact to the knee joint. The supplement glucosamine-chondroitin sulfate is used by many patients; however, this may only help one in three individuals. If used, try the supplement alone if possible for 4 weeks, then determine if you have experienced a benefit. This supplement may decrease pain but have not been shown to rebuild damaged joint cartilage. A knee brace may be helpful. Ice is used for knee swelling and after exercise.

Severe Arthritis Pain

Patients with severe arthritis pain are encouraged to lose weight (if they are overweight) or maintain their current weight if they are within the normal range, avoid aggravating activities, decrease sports activities by 75% or completely, and participate in low-impact aerobic exercise. They may require ambulatory aids such as a cane for assistance. A knee brace may be helpful. They may need to consider changing their occupation if it involves aggravating activities to the knee joint. They may also need to permanently change their participation 30 in recreation and sports.

Prescription anti-inflammatory medications may be used intermittently for symptoms. In general, oral ste- roids are avoided or only used briefly for severe symptoms. Narcotics are not used in our clinic because they become addictive. Recurrent knee pain may indicate the consideration of a knee injection using either a steroid or synthetic lubricant such as Synvisc. Physical therapy is encouraged to help these patients remain active and maintain normal motion in their knee. Flexibility and strengthening exercises to maintain joint mobility are important and may be performed at home daily. This is one of the benefits of having a physical therapy evaluation so that a specific exercise, strength, and flexibility program may be prescribed.

Choosing an Orthopaedic Surgeon in the U.S.

Although you may not have a hard time finding an orthopaedic surgeon in your community, finding one who can perform an osteotomy may be difficult.

We recommend that you see a board-certified and fellowship-trained orthopedist for any serious knee operation. The training of an orthopaedic surgeon takes many years of undergraduate college, medical school, and residency education. Most surgeons finish residency training around the age of 30. Then, some choose 1-2 years of additional education known as a sports medicine or joint replacement fellowship in order to receive still more training in order to diagnose complex injuries and perform modern operations.

Orthopaedic surgeons may elect to become “board certified”. This means they must pass rigorous examinations above and beyond those required in medical school and residency. This certification is optional in the United States. Board certified surgeons actively participate in education and stay up to date with the latest advances in medicine and patient care.

Seeing a board certified and fellowship-trained orthopedist is especially important if you decide to have an osteotomy because this is not an operation for a physician who has not had specialized, advanced training. The success of this operation is based on 3 things: first, the ability of the surgeon to diagnose all of the specific problems (there may be many, as discussed) that exist and secondly, to do the operation correctly. Third, the physical therapy program must restore the best knee function possible. It really is a lengthy process and all of these issues share an equal role in the overall success or failure of the operation to get you back to activities.

The American Orthopaedic Society for Sports Medicine has a list of orthopaedic surgeons at http://www. sportsmed.org. As you can see from this society’s website, “Members must demonstrate continuing active research and educational activities in the field of sports medicine. Such activities may include service as a team physician at any level of competition, educating persons involved with the health of athletes, service to local, regional, national and international competitions, and the presentation of scientific research papers at sports medicine meetings.”

If you live in a large city with a major university or sports medicine center, that is one place to search for a board certified, fellowship trained orthopaedic surgeon. As well, you may know someone who underwent major knee surgery and had a successful result and seeing his or her surgeon is certainly a good place to start. It might help to consider “interviewing” a potential surgeon before you decide on who will perform your osteotomy. Some questions to ask are:

How many osteotomies have you done in your career, and about how many do you do each year? 31

Do you keep track of the results of your patients who undergo osteotomy?

Where will my physical therapy be done? Who will my therapist be, and how long have you worked with the therapist? (Most surgeons have a few physical therapists they know and trust to work with patients who undergo major knee surgery. What you do not want is for the surgeon to leave finding a therapist in your hands!)

Do you or my therapist have a list of exercises that I will need to do after surgery? Will I see my therapist before the operation to learn about the exercises? Will I be doing exercises at home? How often?

Can I talk to someone in your insurance department about my coverage, both for the operation and physical therapy visits?

How soon will I see you and my therapist after surgery? (We recommend 24-48 hours to make sure your muscles are working properly, the incision looks good with no signs of infection, and you understand the exercises you should be doing.)

High Tibial Osteotomy for Varus (Bowed Leg) Malalignment

Indications

HTO is a widely accepted operation in younger, active patients with varus malalignment (bowed legs). The basic goal of the operation is to realign a major portion of the weight-bearing loads to the lateral part of the knee; in other words, to “unload” the medial compartment which already has arthritic damage. The recommendation for HTO comes from the orthopaedic surgeon’s careful physical examination, the patient’s symptoms, x-ray evidence of malalignment and arthritis, and an analysis of the patient’s gait. Careful patient selection is critical and it is important to understand that there are no guarantees of the results of the operation.

The predominant indication for HTO is lower limb varus bony malalignment (WBL < 50%) in patients under the age of 50 who have medial tibiofemoral joint pain and wish to maintain an active lifestyle. Candidates may have mild to moderate symptomatic arthrosis in the medial compartment. There must be some remaining cartilage and joint space in the medial compartment, and intact lateral meniscus and articular cartilage in the lateral compartment.

HTO is also indicated to achieve normal limb alignment before other major knee operations are performed, such as medial meniscus transplantation, articular cartilage restorative procedures, and ligament reconstructions. We will discuss these procedures later in this eBook.

The patient must agree to comply with the rehabilitation program after HTO, which is lengthy and requires an experienced and knowledgable physical therapist. Crutches are used for about 6 weeks after surgery and it takes several months for the patient to fully recover normal muscle strength and the ability to return to recreational activities.

The patient must accept the goals of the HTO, which are to allow an active, pain-free lifestyle for a certain amount of time that includes low-impact recreational sports, but not high-loading activities involved with twisting, turning, jumping, and pivoting. The knee arthritis will eventually progress over ensuring years and, therefore, the goal is to buy as much time as possible in younger patients before a partial or total joint replacement is required. 32

Contraindications

It is important for the surgeon to have experience with HTO to be able to determine if a patient is an appropriate candidate for this procedure. For instance, if too much arthritic damage has already occurred to the medial compartment (more than a 15 by 15 mm area of exposed bone on both the tibial and femoral surfaces), or if there is no longer any space left between the femur and tibia (a “bone-on-bone” situation), then this operation is not indicated. As a general rule, articular cartilage should be present over the majority of the medial joint surfaces.

Body weight above a normal body mass index (BMI) is a frequent contraindication. For every pound of body weight, a multiple of 4-8 times (the patient’s weight) is placed at the knee joint with activities of daily living or sports, as we discussed previously. The limb realignment surgery will not be effective because the overall body weight loads are still excessive. This is a frequent problem in former athletes who competed in the 225- 250 pound weight range. A complete change in lifestyle and eating habits is required to achieve a normal BMI before surgery. If the patient regains a significant amount of weight after surgery, the knee pain may return and the result will not be successful.

If the patient has arthritic damage or a loss of joint space in the lateral compartment, or previously had the lateral meniscus removed, then HTO is not indicated. In addition, if the patient has severe arthritic damage to the patella, then this operation should not be performed. Another contraindication is a significant limitation of knee flexion (> 10 degrees from normal) or knee extension (> 15 degrees from normal).

If the patient has lost bone stock, resulting in concavity of the medial tibial plateau, they are not a candidate for HTO. Patients greater than 50 years of age are better suited for partial or total joint replacement than osteotomy.

A condition known as lateral tibial subluxation is another contraindication for HTO. In this situation, the center of the top of the tibia (tibial plateau) and the center of the end of the femur are at different points, as shown below. A difference of 10 mm between these two points indicates HTO should not be performed.

Lateral tibial subluxation. The red dots show the center of the tibial plateau and the center of the end of the femur. 33

Patients who have either severe patella infera (patella pulled downward from its normal position) or severe patella alta (patella rides higher than the normal position) are not candidates. The position of the patella rela- tive to the femur is measured on a lateral x-ray and the “vertical height” is measured as shown in the artist’s illustration to the right.

Osteotomy may lead to a complication of a shortened patellar tendon (patella infera) if there is a problem with rehabilitation after the surgery that decreases the normal mobility of the patella and allows the formation of excessive scar tissue. Below is an example of a patella infera that occurred years ago in a young patient after an ACL reconstruction. This complication happened from poor rehabilitation, loss of quadriceps strength, and formation of dense scar tissue around the patella. The x-ray on the right (B) was taken upon her initial consultation at our Center.

X-rays of a 14-year old female athlete showing the normal vertical height of her patella (A), and the 22% decrease in its vertical height following an ACL reconstruction done elsewhere (B).

Patella infera was a frequent complication decades ago. Fortunately, today’s modern physical therapy programs that include immediate knee motion and strengthening exercises, usually prevent this from happening.

HTO, especially the opening wedge technique, should not be done in patients that use nicotine products in any form. Nicotine decreases the body’s ability to heal at the osteotomy site, which may lead to a non-union of the bone and need for corrective surgery. All nicotine products must be stopped 6 weeks before surgery and not resumed postoperatively.

Medical contraindications to osteotomy include diabetes, rheumatoid arthritis, autoimmune diseases, malnutrition states, poor circulation, and any infection.

Timing of Knee Ligament Reconstruction if Required

In patients who are candidates for osteotomy and also have one or more knee ligaments that may require reconstruction, the surgeon must decide on whether to perform both procedures at the same time or stage them separately. This decision is based on several factors.

In primary varus knees, the HTO and ACL (or PCL) reconstruction may be performed at the same operation. 34 Primary varus knees do not have deficiency of the LCL/PLS, so this is not an issue. It is also reasonable to perform the HTO first and then determine, after the patient has recovered from the surgery, if instability symptoms persist, thereby requiring ACL reconstruction. In our experience, the vast majority of these patients that have a cruciate tear have ACL deficiency. PCL ruptures are rare and usually do not create instability; however, in some patients, problems are present that necessitate PCL reconstruction. The decision process involves carefully evaluating each patient in terms of their future activity goals for both athletics and occupational duties, as well as their current symptoms (before the osteotomy) of pain and instability.

In double varus knees, we prefer to perform the HTO first and, after adequate healing of the osteotomy, determine if any ligament reconstructive procedures are required. We have found that not all double varus knees require a ligament reconstruction of the deficient LCL/PLS. This is because a successful HTO decreases loads in the lateral and posterolateral tissues, thereby allowing these structures to shorten and return to a functional state. Some double varus patients who have a deficient ACL (or PCL) also are not symptomatic and do not require ligament reconstruction. Our study showed that approximately 1 in 3 double-varus ACL-deficient knees did not have instability symptoms after the HTO and, therefore, did not require an ACL reconstruction. However, if symptoms of instability persist on return to light recreational activities, ligament reconstruction is performed.

In triple varus knees, the ACL (or PCL) and LCL/PLS are always reconstructed after the HTO. These knees require 2 to 3 grafts to replace the deficient ligament structures, which is a major operation. To perform the HTO and ligament reconstructions simultaneously would greatly increase the risk of complications, resulting in an unfavorable outcome.

Preoperative Planning

The surgeon must make precise measurements to determine the amount of angular correction required to redistribute weight-bearing forces into the lateral compartment. The WBL is measured from the full standing x-rays that show both entire lower extremities (hips to ankles), as we previously discussed. If is very important to measure the amount of opening or separation between the femur and tibia in the lateral compartment because this will affect the calculation used to determine the amount of bone to be resected or inserted. Finally, what is termed the tibial slope is measured on lateral x-rays. Tibial slope refers to the angle created by drawing one line across the tibial plateau and a second perpendicular line down the middle of the tibia, as shown below.

X-rays of abnormal tibial slope (top yellow line, left), which was corrected with an opening wedge tibial osteotomy (top yellow line, right). 35

Our preference is not to change the tibial slope during osteotomy, unless a distinct abnormality exists. This is currently a topic of debate and research among orthopaedic surgeons. While some surgeons believe that the tibial slope should be changed in knees with ACL or PCL-deficiency because it would avoid the need for cruciate ligament reconstruction or improve the results of ligament reconstruction, we disagree because there are no clinical studies that have proven this theory.

The calculations for bone cuts and resection continue during the osteotomy. Special x-rays called intraoperative fluroscopy are taken at different stages of the operation to ensure that the amount of desired correction is obtained. Some surgeons also use computerized navigation to assist in making precise measurements throughout the operation.

Choosing Between an Opening Wedge and Closing Wedge Procedure

The two most common operations for correcting varus malalignment are referred to as an opening wedge HTO and a closing wedge HTO. There are advantages and disadvantages of both procedures and it is important that the surgeon has experience in order to choose the most appropriate technique for each patient.

Because some of the steps in the operations are quite different, there are distinct cases where an opening wedge osteotomy is advantageous. These include knees that have a large amount of varus (more than 12 degrees), knees with chronic deficiency of the medial ligament structures or the LCL/PLS, and knees with a pre-existing patella alta. The opening wedge osteotomy is advantageous because it does not involve a fibular osteotomy (that is performed in the closing wedge procedure), there is less soft tissue dissection, and it is easier for the surgeon to change the amount of bone resection to achieve the desired angular correction at surgery.

The disadvantage of opening wedge osteotomy is that the osteotomy gap must be filled in with bone to stimu- late healing and union of the tibia. There is a low risk of nonunion or delayed union at the gap site, which can cause the correction to collapse and the limb to go back into a varus position. A longer period of crutch pro- tection is required. The superficial attachment of the MCL must be cut and then reattached at the conclusion of the operation. We use very strong osteotomy locking plates to stabilize the osteotomy. In addition, we use allograft bone from a human donor to fill in the gap. This avoids the requirement of a bone graft harvest procedure that would normally be performed at the iliac crest (pelvis).

The closing wedge osteotomy has the advantages of fast healing and earlier weight-bearing postoperatively. The superficial attachment of the MCL does not have to be cut (as is required in the opening wedge osteotomy). There is less chance for the osteotomy position to shift as the patient resumes weight-bearing.

The disadvantages of closing wedge osteotomy include the need for more soft tissue dissection (than required in the opening wedge procedure). In addition, both the tibia and fibula are cut. It is more difficult to change the amount of bone resection (if required) to achieve the desired angular correction at surgery. Dissection is required close to the peroneal nerve, which can potentially be damaged.

The opening wedge osteotomy has markedly increased in popularity among orthopaedic surgeons in the past decade. The majority of clinical and laboratory studies published in the last 10 years have focused on this technique. As we previously discussed, this is mostly due to the heightened precision of the procedure and the ease in adjusting the angular correction at surgery. The technique is “less invasive”, with fewer soft tissues cut, no disturbance to the peroneal nerve, and no cutting of the fibula required. The use of fluoroscopy during the operation adds to the accuracy required to achieve the desired correction. 36 We do note that there are other types of osteotomies performed for varus malalignment. These include dome osteotomy, progressive callus distraction, chevron osteotomy, and combined osteotomy. These are rarely performed today and, therefore, not included in this eBook.

Initial Steps for Both Osteotomy Procedures

The evening before and the morning of surgery, the patient washes their body and the leg to be operated on with antibacterial soap. We start this body wash procedure 3-4 days before surgery. We recommend Hibiclens (chlorhexidine) bottled soap.

The knee to be operated on is verbally identified by the patient. The surgeon marks his or her initials on the thigh of the correct knee before entering the operating room, with a nurse observing the procedure. The identification process is repeated with all operative personnel with a “time out” before surgery to again verify the knee undergoing surgery, procedure, allergies, antibiotic infusion, and special precautions that apply. All personnel provide verbal agreement. The signed limb is visible to the surgeon after the sterile drapes have been applied to the leg.

The patient is placed under anesthesia. An arthroscopic examination is then performed. An arthroscope is a small fiber-optic camera that is inserted into the knee through very small puncture wounds (called portals) that allows the surgeon to see the inside of the joint via a television set in the operating room. With the patient asleep, the knee is taken through the same tests that were done in the clinic to assess the integrity of the ligaments. Using the arthroscope, the surgeon watches what happens inside the knee as it goes through these tests. The surgeon also sees and documents all damage to the articular cartilage surfaces and the condition of the menisci.

The “gap” test is done during the arthroscopic examination. Triple varus knees that have 12 mm or more of joint opening at the edge of the lateral tibiofemoral compartment will usually require a staged posterolateral reconstructive procedure. On the next page is a photograph taken during arthroscopy of a triple varus knee with chronic tears of the LC/PLS. You can see the amount of gapping or opening that occurred on the lateral side of the knee during the varus stress test. 37

Arthroscopic photographs of the gap test in a knee with tears to the ligaments on the lateral side. On the left, the separation or gapping on the lateral side of the knee is seen from the tip of the probe to the femur. On the right, a normal, small amount of space is shown on the other side of the knee (medial).

Here is an artist’s illustration of the results of the gap test in one knee with tears to the LCL/PLS and a normal knee.

Associated meniscus tears are either repaired if possible or partially removed if required. A general debridement of loose tissues and inflamed synovium is performed.

Opening Wedge Osteotomy

A skin incision 5 cm (about 2 inches) long is required for this operation. Here is an example of the appearance of the incision after it has healed.

The surgeon dissects the soft tissues, partially detaches tendons and fascia, and transects the tibial attachment of the superficial MCL. Guide pins are placed where the tibia will be carefully cut in a wedge fashion. The placement of the guide pins is verified by fluroscopy. The tibial bone is carefully cut and the fracture site slowly spread to form a wedge. The anterior portion of the wedge or “gap” created in the tibia is one-half the size of the posterior portion. This important step maintains the normal tibial slope. 38 Illustration of the wedge or gap in the tibia where the bone has been removed (red lines). The anterior portion of the gap = A1 and the posterior portion = A2. The tibial slope is 10 degrees, which is normal.

Fluroscopy is used to verify that the desired limb alignment will be achieved by the size of the wedge of bone that has been removed.

Then, 3 triangular wedges of bone are inserted tightly into the gap. We prefer to use allograft bone to avoid a separate incision and harvest of the patient’s bone at the iliac crest (pelvis). A locking plate and screws are secured to the tibia and verified with fluroscopy. This method of fixation maintains the corrected alignment after surgery as the fracture site heals. X-rays are used to confirm the final alignment and tibial slope.

The superficial MCL fibers are sutured and secured to either the plate or to suture anchors. The tendons and fascia are reattached and the wound is closed in layers. The patient’s neurovascular status is immediately checked in the operation room.

Surgeons who are familiar with computerized navigation for knee joint replacement may use this same tech- nology to assist with determining how much bone to remove and to guide plate fixation. Shown next is a screen from the computer that displays the preoperative measurements that were made on a patient’s knee in the operating room just before surgery. The WBL is the red line, showing the distinct varus malalignment. 39

Computerized navigation screen showing Computerized navigation screen shows the measurements of a varus-aligned knee before corrected alignment, with the WBL (red line) in HTO. The WBL (red line) is far in the medial the lateral compartment. compartment.

In many Centers, fluroscopy is used instead of computerized navigation, which is only required for more difficult limb alignment procedures.

Illustration of an opening wedge HTO with the bone graft inserted into the fracture site. 40 Closing Wedge Osteotomy

In the closing wedge technique, an oblique skin incision is made.

The peroneal nerve, which is close to the area of dissection, is always identified and partially dissected.

A small wedge of bone is taken out of the fibular neck, 2-3 mm less than the amount that will next be taken out of the upper tibia.

The surgeon uses guide pins and fluoroscopy throughout the procedure to determine the angular correction that has been obtained.

Then, the tibial osteotomy is performed and confirmed with fluoroscopy.

As with the opening wedge procedure, the posterior tibial slope is usually not altered.

The osteotomy gap is closed by the surgeon by applying a gentle valgus force over a few minutes. The tibia fracture site is secured with a plate and screws, as shown in the x-ray to the right. 41 Possible Complications

Overall, this is a safe operation and the occurrence of complications is small, in the 1-5% range. The most common problems after HTO are failure of the bone to completely heal or failure of the operation to achieve the desired amount of correction of the lower limb varus malalignment. These problems may happen because of weak internal fixation, a progressive loss of articular cartilage or joint space in the medial compartment, or stretching out of the posterolateral structures. Failure to achieve appropriate angular correction may also occur from difficulty in verifying the osteotomy calculations during the operation.

A tibial plateau fracture may occur when the osteotomy fracture line progresses into the joint. This problem is uncommon after opening wedge osteotomy.

Neurovascular injuries are very rare. Damage to the peroneal nerve may happen during the dissection in a closing wedge osteotomy or from the use of a cast or bandage which is applied too tightly after surgery. Com- partment syndrome (muscle swelling and altered blood supply) may occur following closing wedge osteotomy but, again, this is a rare problem.

Muscle weakness and limitations of knee motion (arthrofibrosis) have been reported following HTO. A rehabilitation program that includes immediate knee motion, patellar mobilization, and muscle strengthening exercises begun the day after surgery (leg raises, multi-angle isometrics, electrical muscle stimulation) will decrease the incidence of these problems.

A change in the vertical height of the patella may occur after either opening or closing wedge osteotomy. The use of immediate knee motion exercises and strong internal fixation, along with maintenance of normal posterior tibial slope, have helped alleviate this complications.

The fixation device (plate and screws) may cause pain that is not alleviated over time. The hardware may be removed after approximately 9 months if required.

There is a 1-2% chance of developing an infection that will require treatment. There are other risks with surgery, including those related to anesthesia, development of blood clots, deep vein thrombosis, etc. These are small, but do exist. There are inherited forms of excessive blood clotting that occur in 3-5% of the population. Always tell your surgeon if you or any member of your family has a history of blood clots.

Expected Results

We have performed hundreds of HTOs in our Center and have published our clinical outcomes and experience required to achieve a low complication rate and high patient satisfaction rate. We carefully screen patients to ensure that this is the right operation for their knee and lifestyle situation. Every effort is made to communicate the expected results and the patient’s responsibilities to avoid a complication.

Typically, we see a significant decrease in pain and limitations with daily activities that so many patients com- plain of before surgery. Our studies how that approximately 70% of our patients return to low-impact recreational activities such as bicycling or swimming without problems. The closing wedge procedure was found in one of our studies to be successful in 75-80% of patients 4-5 years after surgery in terms of maintenance of the angular correction achieved. In another study, the opening wedge osteotomy was found to allow a somewhat faster return to activities of daily living and had a very low complication rate. We believe that the com- bination of HTO and cartilage restoration procedures (to be discussed later in this eBook) might help achieve even better results and provide a longer period of time before the patient must undergo further surgery. These 42 procedures include meniscus transplantation, osteochondral autograft transfer, and autologous chondrocyte implantation.

A recent literature review from researchers in Germany summarized mid- and long-term clinical data from 44 studies that encompassed 3,539 closing wedge and 435 opening wedge osteotomies. At 5-8 years postoperatively, 91% of the osteotomies had not required revision to total knee replacement, and at 9-12 years, 84% remained functional. At 5-8 years, 64% of the knees were rated excellent or good in terms of symptoms with daily activities. This percentage dropped to 45% at 10-years after surgery.

There have been few studies published to date that provided survival rates after opening wedge osteotomy. At 5 years, this procedure was reported in 3 investigations to still be working in 84-97% of patients. At 7-10 years, the survival rate reported in 2 studies was 85-91%. We expect in the near future for more data to be published because this procedure has gained favor with surgeons over the last 10 years for all of the reasons we previously discussed.

One investigation compared short-term outcomes and complications between opening and closing wedge osteotomies in 12 studies. There were no differences in the incidence of infection, deep vein thrombosis, peroneal nerve palsy, nonunion, or failure. There was a greater incidence of change in posterior tibial slope and patellar height after opening wedge osteotomies. Other authors have also noted this complication and recent studies advocate the importance of maintaining the posterior tibial slope to lessen these problems.

In regard to return to sports activities, an investigation was performed to determine what types of sports and what percent of patients participated after HTO. Nine studies were included, with varying results due to the difference in years of follow-up. In general, return to recreational sports such as tennis, bicycling, and jogging was possible in the majority of patients up to 10 years after surgery. Few surgeons encouraged or allowed return to highly competitive athletics.

Factors that may help the long-term clinical outcome of osteotomy include age at surgery of less than 50 years, normal body weight, and only mild arthritic degeneration detected on x-rays. In addition, patient counseling and appropriate expectations of the activity level that may be resumed after surgery is highly important. Technical factors for the surgeon and rehabilitation team include accurate preoperative planning, use of locking plate and screws for rigid internal fixation, and immediate rehabilitation after surgery that includes knee motion, patellar mobilization, and muscle strengthening exercises. We acknowledge that there is still a need to continue to study the long-term results and validate this operation in patients who have painful medial compartment arthritis, as recommended by the American Academy of Orthopaedic Surgeons clinical practice guidelines (Treatment of Osteoarthritis of the Knee, 2nd edition, 2013).

Distal Femoral Osteotomy for Valgus (Knock-Knee) Malalignment

Indications

A distal femoral osteotomy is a widely accepted operation for active patients under the age of 50 who have valgus malalignment, or “knock-knees”, and pain in the lateral (outside) portion of their knee. The basic goal of the operation is to realign the weight-bearing loads just over to the medial portion of the knee; in other words, to “unload” the lateral compartment which has already incurred arthritic damage. 43

A patient with valgus malalignment on the operating table, ready for surgery.

The recommendation for distal femoral osteotomy comes from the orthopaedic surgeon’s careful physical examination, the patient’s symptoms, x-ray evidence of malalignment and arthritis, and an analysis of the patient’s gait. Careful patient selection is critical and it is important to understand that there are no guarantees of the results of the operation.

Patients considered for this operation are usually active and wish to remain so by avoiding a partial or total knee replacement for as long as possible. Candidates may have mild to moderate symptomatic arthrosis in the lateral compartment. There must be adequate joint space in both the lateral and medial compartments, and intact articular cartilage.

Femoral osteotomy is frequently performed to achieve normal lower limb alignment before or along with an articular cartilage restoration procedure, such as osteochondral autograft transfer or autologous chondrocyte implantation. Patients may also receive a lateral meniscus transplant if they previously had this structure removed.

The patient must agree to comply with the rehabilitation program after surgery, which is lengthy and requires a knowledgable physical therapist. Crutches are used for 8 weeks after surgery and it takes several months for the patient to fully recover normal muscle strength and the ability to return to low-impact sports.

The patient must accept the goals of the osteotomy, which are to allow an active, pain-free lifestyle for a certain amount of time that includes low-impact recreational sports, but not high-loading activities involved with twisting, turning, jumping, and pivoting. The knee arthritis will eventually progress over ensuing years and, therefore, the goal is to buy as much time as possible in younger patients before a partial or total joint replacement is required. It is noted that occasionally the surgeon will decide to correct valgus malalignment with a lateral opening wedge tibial osteotomy. There is disagreement among surgeons on the role of this operation that is beyond the scope of this eBook.

Contraindications

It is important for the surgeon to have experience with osteotomy to be able to determine if a patient is an appropriate candidate for this procedure. For instance, if too much arthritic damage has already occurred to the lateral compartment (more than a 15 by 15 mm area of exposed bone on both the tibial and femoral surfaces), or if there is no longer any space left between the femur and tibia (creating a “bone-on-bone” situation), then 44 this operation is not indicated. As a general rule, articular cartilage should be present over the majority of the lateral joint surfaces.

If the patient has arthritic damage or a loss of joint space to the medial compartment, or previously had the medial meniscus removed, then femoral osteotomy is not indicated.

As well, if the patient has severe arthritic damage to the patella or is overweight (obese), then this operation should not be performed. Another contraindication is a limitation of knee flexion (> 10 degrees from normal) or knee extension (> 15 degrees from normal). Patients greater than 50 years of age are better suited for partial or total joint replacement than osteotomy.

Distal femoral osteotomy, especially the opening wedge technique, should not be done in patients that use nicotine products in any form. This is due to the problems that may occur with healing of the bone cuts and fracture with nicotine ingestion already discussed. All nicotine products must be stopped 6 weeks before surgery and not resumed postoperatively.

Medical contraindications include diabetes, rheumatoid arthritis, autoimmune diseases, malnutrition states, circulation problems, or any infection.

Preoperative Planning

The surgeon must make precise measurements to determine the amount of angular correction to redistribute forces into the medial compartment. The WBL is measured from the full standing x-rays that show both entire lower extremities (hips to ankles), as we previously discussed. If is very important to detect any separation between the femur and tibia in the medial compartment because this will affect the calculation used to determine the amount of bone to be resected or inserted.

The calculations for bone cuts and resection continue during the osteotomy. As we described for HTO, intraoperative fluroscopy images are taken at stages during the operation to ensure that the amount of desired correction is obtained. Some surgeons also use computerized navigation to assist in making precise measurements throughout the operation.

How the Operation May Be Done

The patient is placed under anesthesia. An arthroscopic examination is then performed. An arthroscope is a small fiber-optic camera that is inserted into the knee through very small puncture wounds (called portals) that allows the surgeon to see the inside of the joint via a television set in the operating room. With the patient 45 asleep, the knee is taken through the same tests that were done in the clinic to assess the integrity of the ligaments. Using the arthroscope, the surgeon watches what happens inside the knee as it goes through these tests. The surgeon also sees and documents all damage to the articular cartilage surfaces and the condition of the menisci. Associated meniscus tears are either repaired if possible or partially removed if required. A general debridement of loose tissues and inflamed synovium is performed.

There are two procedures for distal femoral osteotomy: a closing wedge and an opening wedge. The basic con- cepts for these procedures are the same as those described for HTO, only they are performed at the end of the femur, just above the knee joint. If you did not read the section on “Choosing Between an Opening Wedge and Closing Wedge Procedure”, please do so at this time.

In the closing wedge technique, a small triangular wedge of bone is taken out of the distal portion (lower end) of the femur, just above the knee. The remaining bone is brought together and secured with a plate and screws. Although historically this technique was performed most often, recent advances in the opening wedge technique now make this procedure the favored choice for many surgeons for correcting valgus malalignment. The majority of clinical and laboratory studies published in the last 10 years have focused on this technique. As we previously discussed, this is mostly due to the heightened precision of the procedure and the ease in adjusting the angular correction at surgery. The use of intra-operative fluoroscopy adds to the accuracy required to achieve the desired correction.

In the opening wedge technique, the femur is carefully cut and the fracture site slowly spread open. Then, triangular wedges of bone are tightly inserted into this area. The bone comes from the patient’s own pelvic iliac crest; allograft (donor) bone is not recommended because it slower to heal the fracture site compared to autograft (the patient’s own) bone. This part of the operation requires a separate 2-inch incision to be made on the iliac crest. A small piece of bone is removed that the surgeon cuts into carefully sized triangles according to the size required to fill the gap in the femur. This may produce postoperative pain and discomfort for 3-4 weeks at the pelvis harvest site. However, it is important to harvest the bone from this area because the patient’s own bone accelerates the fracture healing process and lessens the risk of delayed healing or loss of correction.

A locking plate and screws are secured to the wedges of bone to help them heal into the patient’s femur. Fluros- copy during the operation allows the surgeon to see the progress of the procedure.

As with the opening wedge HTO, the tibiofemoral slope is not changed. At the end of the operation, more x-rays are taken to show the plate and screws surrounding the bone that was “wedged” into the fracture. 46 Possible Complications

The complications that may occur after a distal femoral osteotomy are similar to those described after HTO. Overall, this is a safe operation and the occurrence of a complication is small, in the 1-5% range. The most common problems are failure of the bone to completely heal or failure of the operation to achieve the desired amount of correction of the malalignment. These problems may occur due to weak internal fixation or delayed union in which the correction is not maintained. In addition, over ensuring years after surgery, there may be further loss of articular cartilage or joint space in the lateral compartment. Failure to achieve appropriate angular correction may also occur from difficulty in verifying the osteotomy calculations during the operation. Neurovascular injuries, muscle weakness, and limitations of knee motion (arthrofibrosis) may occur. The fixation device (plate and screws) may cause pain that is not alleviated over time. The hardware may be removed after approximately 9 months if necessary.

Expected Results

Only a few long-term clinical studies have been published on the outcome of distal femoral osteotomy. This is because this operation is not done nearly as often as HTO. Four studies followed 136 patients who received a closing wedge femoral osteotomy for 10 years postoperatively. These investigations found the following survival rates (meaning the patients were doing well and had not required total knee replacement): 90%, 87%, 82%, and 64%. To date, 3 studies reported 15-year survival rates after this procedure of 45%, 49%, and 79%.

Two studies provided 7-year survival rates after opening wedge femoral osteotomy in 41 patients of 82-91%.

We expect in the near future for more data to be published because this technique has gained favor with many surgeons over the last several years. Considering the fact that this operation’s goal is to buy time and provide pain relief with regular daily activities until partial or total knee replacement is required, the 7 and 10-year survival rates justify its use in correctly indicated patients. We acknowledge that the American Academy of Orthopaedic Surgeons clinical practice guidelines (Treatment of Osteoarthritis of the Knee, 2nd edition, 2013) was not able to provide a recommendation for this operation due to the small number of published studies.

Limb Alignment Osteotomy Versus Partial Knee Replacement

With the fairly recent development of successful partial knee replacement operations, the role of osteotomy has declined for patients in their 40’s and 50’s. As we previously discussed, patients who have already worn out the entire portion of the medial or lateral area of the knee to where a “bone-on-bone” situation exists are not candidates for osteotomy. There are other patients who have some joint lining left, but it is thin and moderate arthritis symptoms exist on one side of their knee joint. A partial knee replacement - also referred to as a unicompartmental knee replacement - is a better option for all of these patients. It is important to understand that the other areas of the knee joint should be normal or nearly normal in terms of the condition of the articular cartilage and joint spaces. 47

On the right is an illustration of a medial unicompartmental knee replacement, with components placed into the knee joint.

The advantages of a partial replacement compared to an osteotomy include less time spent on crutches (2-3 weeks), a more rapid return to daily and work activities, and easier rehabilitation. Only the damaged compartment is replaced with metal and plastic; the rest of the healthy bone and surrounding tissue is left alone. There is less concern of requiring an early second operation in the event the arthritis would progress that sometimes happens after an osteotomy.

The disadvantage of a partial knee replacement is that, in some patients (5-10%), the replacement becomes loose or pain gradually occurs elsewhere in the knee joint due to progressive arthritis. In these patients, a total knee replacement is then required. For more information, see our eBook “Partial Knee Replacement: Everything You Need to Know to Make the Right Treatment Decision”.

Common Associated Operative Procedures

ACL Reconstruction

As we have mentioned previously, there are some patients who have varus malalignment and a torn or completely deficient ACL. The decision of whether to reconstruct this important ligament is based on the patient’s symptoms and future activity goals. Problems with instability, or the knee collapsing and giving-way, necessitate a reconstruction regardless of the patient’s involvement with sports activities. In addition, patients who wish to resume recreational sports after osteotomy typically undergo ACL reconstruction in order to avoid future reinjuries. It is important to prevent future injuries and giving-way episodes because further damage may be sustained to the knee joint.

There are different ways of reconstructing the ACL, but the modern method involves replacing the ligament with a tendon graft that comes from either the patient’s own tissues (autograft) or donor tissues (allograft). Autografts are the most commonly used tissues and consist of portions of the patellar tendon, the hamstrings tendons (semitendinosus and gracilis tendons), or the quadriceps tendon. When allografts are selected for this operation, they usually come from either the patellar tendon or the Achilles tendon. Less frequently used allograft tendons are the hamstrings (semitendinosus), tibialis anterior, tibialis posterior, and peroneus longus.

The diagram on the next page shows the basic elements of an ACL reconstruction using a patellar tendon autograft. The operation requires 1 or 2 small incisions that are 8-10 cm (about 3-4 inches) long. Approximately 9-10 millimeters (the central one-third) of the patellar tendon is harvested, along with a small piece of bone from the patella and tibia. This produces what is called a bone-tendon-bone graft because there is bone on each end of the graft that will be fixed into tunnels in the femur and tibia. The next step of the operation involves carefully drilling the tunnels and it is crucial that the surgeon places them in the exact location where the patient’s own ACL was located. If the tunnels are not in the correct position, the graft may stretch out or fail. The graft is inserted and should fit snugly in the tunnels. The graft is secured to bone in both of the tunnels using various devices such as medical grade screws, sutures, pins, or screw-suture posts. 48

For further information on ACL reconstruction and postoperative rehabilitation, see our eBooks “ACL Injury: Everything You Need to Know to Make the Right Treatment Decision” and “ACL Injury Rehabilitation: Every- thing You Need to Know to Restore Knee Function and Return to Activity”.

PCL Reconstruction

Complete tears to the PCL are rare. Although this injury may not cause problems initially, the patient may develop considerable limitations over time with sports and even with regular daily activities. PCL reconstruction is required in patients with lower limb malalignment that either have a tear to another major knee ligament, the desire to return to athletics, or have frequent pain and instability.

There are many different ways of reconstructing the PCL, but the modern method involves replacing the ligament with a tendon graft that comes from either the patient’s own tissues (autograft) or donor tissues (allograft). Autografts are the most commonly used tissues and consist of portions of the patellar tendon, the hamstrings tendons (semitendinosus and gracilis tendons), or the quadriceps tendon. When allografts are selected for this operation, they usually consist of either the patellar tendon, the Achilles tendon, or the quadriceps tendon. Less frequently used allograft tendons are the hamstrings (semitendinosus), tibialis anterior, tibialis posterior, and peroneus longus.

To the right is an illustration of one of the more commonly performed PCL reconstructive procedures. Shown is a single-strand quadriceps tendon-bone graft placed into one tunnel in the femur and one tunnel in the tibia. The bone is fixed to the patient’s own bone in the tibia with an interference screw and the tendon is fixed by sutures to the patient’s femur. 49 Another reconstructive technique places a 2-strand quadriceps tendon-bone graft into 2 tunnels in the femur and one tunnel in the tibia. The bone plug is placed in the tibia. Two strands are used in large patients to restore the large PCL attachment.

For further information on PCL reconstruction and postoperative rehabilitation, see our eBook “PCL and Posterolateral Knee Ligament Injuries: Everything You Need to Know to Make the Right Treatment Decision”.

Posterolateral Reconstruction

There are several options for repairing or reconstructing torn or deficient tissues in the posterolateral region of the knee. As we described previously, this part of the knee contains the LCL and posterolateral structures (PLS, which include the popliteus muscle-tendon-ligament unit, the popliteofibular ligament, and the posterolateral capsule). The LCL/PLS are often torn along with the PCL and/or the ACL. It is possible to sustain a tear to just the LCL/PLS, but this is a rare injury. And, as we previously discussed, knees with varus malalignment may develop deficiency of the LCL/PLS over time from the abnormal loads that are placed on these structures during weight-bearing activities.

In double and triple varus knees, we usually perform the HTO first. Then, after the patient has recovered adequately, an examination is performed to determine if another operation is required to restore normal function in the posterolateral region. The type of procedure that is required is initially determined from findings on the clinical examination. Then, just before the operation begins, the patient is placed under anesthesia and the ligament tests are repeated. The “gap” test is done as we described under the Initial Steps for Both Osteotomy Pro- cedures section. Finally, the operation begins and the surgeon carefully dissects the LCL, PLS, and surrounding tissues to make the final determination of the damage that exists.

In most cases, we perform what is termed an anatomic reconstruction of the LCL in which a graft is placed in the exact same location as the completely deficient (or even non-existent) ligament. The insertion sites of the LCL on the femur and fibula are identified and tunnels created. We use a patellar tendon autograft harvested from the patient’s opposite knee or a patellar tendon allograft for this procedure, as shown below. On occasion, other allograft tissues such as an Achilles tendon-bone may be used. 50 In some knees, 2 grafts are required to restore normal function of the LCL/PLS. The first graft is placed as just described. Then, a second graft is inserted to rebuild what is called the popliteal-muscle-tendon-ligament unit and popliteofibular ligament. We prefer to use an Achilles tendon-bone allograft for this procedure. The bone portion of the popliteus graft is placed at the femoral insertion site, the graft is placed beneath the LCL graft, and passed in a tibial tunnel. Graft fixation is done with interference screws. The popliteus graft is sutured to the LCL graft and the posterolateral capsule is advanced or plicated (tightened).

In some knees, the LCL/PLS are intact but lax and have not been replaced by scar tissue. All tissues appear normal, except they are slightly elongated (stretched out). In these cases, a simpler operation may be done to restore the normal function of the PLS. The procedure (called a proximal advancement) involves removing the bone femoral attachment site of the LCL, popliteus muscle tendon, and anterior portion of the gastrocnemius muscle tendon. The bone portion is then moved (advanced) and relocated in the proximal direction of the LCL.

The bone and attachments of the LCL, Fixation of the new bone at- popliteus tendon, and anterior gastrocne- tachment site of the postero- mius tendon after osteotomy. lateral structures is done with a staple and screw.

For further information on LCL/PLS reconstruction and postoperative rehabilitation, see our eBook “PCL and Posterolateral Knee Ligament Injuries: Everything You Need to Know to Make the Right Treatment Decision”. 51 Articular Cartilage Restoration

We previously discussed the role of articular cartilage and the process of arthritis in the knee joint under The Demise of Articular Cartilage section. There are a variety of operative procedures that may be considered to help alleviate the pain and limitations that accompany this problem. The decision of the appropriate procedure to perform is based on the extent of damage that exists to the articular cartilage. The most common operations that are performed are microfracture/abrasion, osteochondral autograft transfer (also called mosaicplasty), and autologous chondrocyte implantation (ACI). In the worst cases, where there is no remaining articular cartilage, a partial or total knee replacement is indicated.

Osteotomy is frequently done either with or before osteochondral autograft transfer or ACI. The realignment procedure is required to relieve pressures on the damaged compartment of the knee so that the articular cartilage procedure may be successful.

The osteochondral autograft transfer procedure involves the transfer of small cylinder plugs of bone and normal articular cartilage from areas of the knee that do not bear much body weight (usually from the edges of the femoral condyles) to a full-thickness articular cartilage defect. Cartilage defects that are relatively small (2-3 cm2) and surrounded by normal appearing cartilage are well suited for this operation.

ACI was developed to treat medium to large areas of articular cartilage damage. This procedure typically requires two operations. Cartilage tissue is biopsied and taken out of the knee from areas that do not bear much body weight, such as the outer edge of the femoral condyles. The tissue is sent to a laboratory where the chondrocytes are separated out and then multiplied by growing in a culture. After 4-6 weeks, millions of chondrocytes have been produced which are then ready to be implanted into the knee. The second operation involves an incision made in the knee where the cells will be implanted. Either perioste- um harvested from the patient’s lower leg or a collagen patch is sewn over the articular cartilage defect. We use a collagen patch to cover the defect. Then, the cells are injected underneath the patch. Fibrin glue is used to completely seal the patch. This procedure is referred to as “first generation” ACI. 52

In an effort to improve the results reported with first generation ACI, other operative techniques developed to restore or regenerate damaged articular cartilage are under investigation. The goals of these newer operations are to perform the procedure with just the use of an arthroscope (eliminating the need for an incision), reduce costs, reduce complications, and improve the quality of the cartilage that grows into the defect. The overall goal is the production of more hyaline cartilage instead of the traditional mix of hyaline and fibrocartilage that has been reported following first generation ACI operations.

So-called “second” and “third” generation ACI procedures have been described and early clinical studies published. The procedures and products used vary widely and nearly all are not currently available in the U.S. Most of the newer procedures still require two operations; however, techniques have recently been published that involve just one procedure. The basis of these newer techniques is tissue engineering and cell therapy in which the expansion or multiplication of the patient’s cells in the laboratory is improved in hopes of obtaining the goal of better quality hyaline cartilage that fills the defect.

If you are interested in further information regarding ACI and all of the procedures available for articular cartilage restoration, see our eBook “Operations for Knee Arthritis: What To Do When All Else Has Failed To Stop Your Knee Pain”.

Meniscus Repair

Meniscus tears are a frequent finding in knees with lower limb malalignment. In varus malalignment, the abnormal forces in the medial compartment make the medial meniscus susceptible to tearing. The opposite occurs in valgus malalignment, where the lateral meniscus is predisposed to tearing. The medial and lateral meniscus are vital for normal knee function. Each one acts as a spacer between the end of the femur (femoral condyle) and the top of the tibia (tibial plateau). During weight-bearing activities, the menisci provide shock absorption, distributing forces across a large area of the knee joint. The menisci also help contribute stability to the knee joint. Some researchers have theorized that the menisci assist in overall lubrication of the articular cartilage surfaces.

It is now well known that removal of some (partial meniscectomy) or all (total meniscectomy) of either meniscus frequently leads to or accelerates the process of arthritis in the knee. Removal of either meniscus results in greater pressures and stresses on the tibial plateau. The area in the knee where weight-bearing forces is normally distributed shrinks by about 50%. In addition, the forces increase 2- to 3-fold.

There are different types of meniscus tears and, fortunately, many can be repaired or sewn together instead of removed. This can be performed at the same time as an osteotomy. In our opinion, it is always better to repair meniscus tears as long as the appropriate indications exist. In our practice, the candidates for a meniscus repair are patients with unresolved knee joint line pain who are less than 50 years of age, or in their fifties and athleti- cally active. The meniscus tear must be in a location which either has a blood supply or in which a blood supply can be brought to the repair site using special techniques at surgery. The meniscus tissue must appear normal and not degenerative or have a lot of fragmentation. Below are photographs taken during arthroscopic surgery of a meniscus tear and repair.

For further information on meniscus tears and repairs, see our eBook “Knee Meniscus (Cartilage) Tears: Everything You Need to Know to Make the Right Treatment Decision”. 53

Meniscus Transplantation

When a meniscus has been removed and symptoms develop such as pain and swelling that limit normal activities, a transplant (also called allograft) may be done in certain cases. In this operation, a meniscus transplant is taken from a human donor and implanted into the patient’s knee using advanced operative techniques.

A lateral meniscus transplant placed in the knee A medial meniscus transplant placed in the knee using a tibial slot and central bone bridge using a two-tunnel technique. technique.

We believe the best candidate for a meniscus transplant is an active individual under the age of 50 who has had a total meniscectomy, has pain that limits daily activities, and does not have severe arthritic damage in the knee. There must be adequate space between the femur and tibia on standing x-rays (of at least 2 mm) and the body mass index must be within normal range (under 30). Patients with varus or valgus malalignment must agree to under osteotomy before or at the same time as the meniscus transplant.

The patient candidate must also accept that meniscus transplantation has a limited amount of time that it will work and that the overall goal is to buy time until a partial or total knee replacement is required. They must be willing to follow the lengthy rehabilitation program, which lasts for about 6 months after the operation, and agree not to return to high-impact sports activities. For further information on meniscus transplantation, see our eBook “Knee Meniscus (Cartilage) Tears: Everything You Need to Know to Make the Right Treatment Decision”.

Preparing for Surgery

We realize that differences may exist between what your surgeon might recommend and what we tell our patients in terms of getting ready for osteotomy surgery. However, we believe that the information we will share with you is valuable and will make your life easier, especially in the first week or two after surgery.

Getting Your House Ready

There are important steps to take to prepare for your surgery. Preparation of your home, purchase of appropriate medications and food, and arranging for assistance for the first week after surgery should all be done well before you go to the hospital. We recommend to our patients that they take the first week off from school or work to stay home and rest. Make the necessary arrangements with teachers, school administrators, or your 54 employer as required.

We ask our patients to have someone in their home assisting them at all times for at least the first week after surgery. We cannot stress how important this is, as for the first few days you will be on strong pain medication and will not be up to doing basic things such as cooking or cleaning. Your doctor and hospital staff will ask you to avoid making any major decisions for the first few days due to the effects of the anesthesia and pain medication.

During the first week after surgery, you should be lying down on a bed or couch with your leg elevated above your heart as often as possible to help control swelling. The only exceptions are when you are doing your exercises or attending to personal bathroom needs. This is a critical time period to control pain and swelling, and the constant elevation of your leg is quite helpful.

Try to arrange your sleeping room on the first floor of your house. If you live in an apartment or residence on another floor, we recommend you plan on staying put in your home for the majority of time the first week after surgery. You will be on crutches and we recommend avoiding stairs as much as possible the first week after surgery. A slip or fall could be disastrous for your knee or other parts of your body!

Set up a bed or a foldout couch in either a bedroom or other room on the first floor if possible, and put a good sized table next to it so you can keep medication, ice bags, water bottles, food, etc. right next to you. Place a towel over the table so you won’t have to worry about spilling water or food. Also, if there is a couch or recliner with a leg rest on the first floor, make sure there is a table next to it also for your supplies and cover it with a towel.

Have a good stock of books, magazines, movies, etc. on hand that can keep you occupied while you are resting on the bed or couch. Put fresh batteries in the remote control for your television! Charge up any item you plan on using, such as your music listening device, cell phone, and laptop computer.

If there will be someone living or staying with you the first week, they can get fresh clothes when you need them. If you may have time periods where you will have to be alone, have clean clothes ready close to where you will be spending most of your time. It will be somewhat difficult to put shoes on initially until you regain flexion in your knee. So have slippers, flip-flops, or shoes that you can slip on and off easily readily available.

Hopefully, you have a bathroom on the first floor or close to where you will be sleeping that you can use for at least the first week after surgery. Move all of your supplies into this bathroom, including toothbrush, tooth- paste, comb, brush, shaver, shaving cream, soaps, make-up, etc. Make sure you have an ample supply of toilet paper and tissue paper!

You will not be able to drive for a while after surgery. Your surgeon will tell you when you are allowed to drive or operate machinery. The rules we follow are the patient must be off of all prescription pain medications, be able to adequately bend their knee to sit comfortably in the driver’s seat, be 50% weight-bearing, and be able to produce a good quadriceps contraction. Therefore, arrange for someone to drive you to your postoperative appointments to see your surgeon and physical therapist, and any other places you will need to go, for at least a few weeks after surgery. If you have to take a taxi, know the amount of money you will need and obtain the cash before surgery. Try to avoid public transportation. Even if you are on crutches, the chances of being pushed, shoved, or falling are not worth it, as damage can occur to your knee.

Your surgeon and the office staff will advise you on the preoperative hospital or laboratory tests that will be 55 required, which usually are done within a week before surgery at the facility where your operation will take place. You will also undergo a physical examination. This will involve a thorough history of any medical conditions you have had, any other operations you have undergone, and current medications you are taking. It is quite helpful to bring along a list of all of your medications (include the name of the drug and dose you take) or the actual bottles of drugs. If you have had any operations in the past, write these down along with the dates to make this process easier. The examination will most likely involve a chest x-ray, blood pressure and temperature readings, urinalysis, and blood tests. Other tests may be necessary as required by your physician.

Food and Medications

After surgery, we prescribe 2 aspirin to be taken a day (1 in the morning and 1 in the evening) for 5 days, a NSAID for at least 5 days (unless contraindicated for stomach or heart disease issues), and pain medication for the first 2-3 weeks. Before the operation, any other medications you routinely take (such as blood pressure or allergy) are discussed to determine when they may be resumed postoperatively. If, for instance, you normally take aspirin, NSAID, or Advil, you should stop 10 days before surgery. This is to reduce a complication of excessive bleeding during surgery. Also, medications for diabetes (insulin pills) should not be taken the day of surgery.

Well before surgery, make sure you have refilled your routine medications that have been approved by your doctor to be resumed immediately after the operation. You should also purchase whatever medications your surgeon will ask you to take after surgery, including aspirin, anti-inflammatory, and prescription and non-prescription pain drugs. Ask your surgeon what non-prescription pain medication you should take once you are weaned off of the stronger prescription drug. Many patients do not like the “feeling” of prescription pain drugs and try to stop taking them as soon as possible after surgery. You will need to switch to a non-prescription pain medication, such as Tylenol (acetaminophen), Motrin (ibuprofen), or Aleve (naproxen) as determined by your surgeon because the control of pain is of tremendous importance. If your pain is not adequately controlled, you will not be able to do your knee exercises and may have an increased risk of a complication such as muscle atrophy or loss of normal knee motion.

One other item to have on hand from the pharmacy is a laxative. Unfortunately, one side effect of surgery and pain medication is constipation. If you have never taken a laxative before, ask your surgeon for advice. If you already suffer problems with constipation, eat lightly and decrease meats and bulky food 2 days before surgery. We recommend that you eat a yogurt product the week before surgery to lessen the risk of operative antibiotics disturbing normal intestinal flora, causing diarrhea.

In terms of what you will eat and drink after surgery, you will be thirsty the first few days (another side effect of the surgery and pain medication). Plan on having either bottled water or someone who can get you glasses of water as you require. We recommend staying away from carbonated beverages after surgery. Food should be light and easy to digest - avoid heavy sauces, creams, and spices. Try not to consume a lot of sugar and sodium (salt). Reducing your sodium intake may help with the swelling you will have in your knee, or that may develop in your foot/ankle. Make a trip to the grocery store the day before surgery and carefully select items that will be easy on your stomach. You should have someone prepare your meals the first week after surgery. If necessary, you can prepare “comfort food” and freeze it so it can be eaten as you wish. You won’t need (or want) to eat large meals, but you will need to eat some food each time before you take pain medication.

Make sure you have a good supply of gallon-sized plastic bags on hand, or other bags that can be used to hold ice. You will be applying bags of ice to your knee quite frequently. If you do not have a reliable icemaker in your home, purchase a few bags of ice to have on hand for at least the first week after surgery. A bag of frozen vege- 56 tables (for example, peas) may substitute for ice bags. A portable ice wrap machine costs approximately $150- 200 and is highly beneficial. The ice wrap dressing is worn continuously and the temperature is controlled. You will need to take your temperature twice a day for about the first week after surgery, so make sure you have a working thermometer.

If you have pets, make sure you have a good supply of food and any other material (such as cat litter) they may require. If you have a dog that needs to be walked daily, find someone to handle this for you until you are off of crutches and can walk comfortably. If you can, pay any bills that are due or will be due the week after surgery. Have some cash on hand.

Practice the Exercises You Will Do After Surgery

If you have not already worked with a physical therapist before your operation, you will need to find one and have a consultation before surgery. Your surgeon should be able to recommend a physical therapist that he or she is familiar with and trusts to handle your important postoperative exercise program. We believe it is vital to have a good and trusting relationship with your therapist and the support staff (physical therapy assistants, athletic trainers, personal trainers), because you will be spending more time with these individuals than with your surgeon after the operation.

All of our patients see a physical therapist and learn the exercises they will perform at home a few days before their surgery. They are provided with a list of the exercises and how many or how long each one should be done every day. It is extremely important that you begin gentle range of knee motion, ankle pumps, and quadriceps isometrics the day after surgery. Find a place (preferable on the first floor) in your residence where you can do the exercises comfortably and safely.

You will use crutches for approximately6-8 weeks after your surgery, or until the fracture site has healed. Your physical therapist should instruct you on the correct way to use them and make sure they fit you properly. Practice using your crutches (including going up and down stairs) so you are comfortable and confident with them before surgery. Take up any small throw rugs in your house, as these can be hazardous when using crutches. Consider purchasing a backpack to help carry items.

Mental Preparation

An important aspect in getting ready for surgery is the development of a positive attitude and willingness to work hard every day for as long as is required to regain normal function in your knee. Getting the most information you can (such as reading this eBook) about surgery and rehabilitation is quite helpful for this process. This is why we make sure our patients meet with their physical therapist before surgery and have a comfort level with the postoperative process. Don’t hesitate to ask any question, regardless of how you think it may sound, to your medical team. Fears of the operation and lengthy rehabilitation are to be expected. It is helpful to talk through these feelings with your friends, family members, and medical support staff. A complete understanding of what you are about to go through is extremely useful in developing a positive attitude.

Your medical team should provide you with realistic expectations and goals of the surgery. It is important to also realize that the recovery from surgery may take many months.

There are online message and support boards that can be helpful as you deal with your surgery and recovery, such as KneeGuru.com. Don’t hesitate to use these measures for support; however, be cautious and understand that patients recover in different time frames. Always use your own surgeon and physical therapist for deci- 57 sion-making and determination of your progress. Do not become frustrated or lose your motivation because some patients seem to be making better progress than you both before and after surgery.

The Night Before Surgery

Your surgeon will ask you not to eat or drink anything after midnight (or at least 8 hours before surgery). This is called NPO, or nothing by mouth. It includes everything, even water. If you have medication you must and are allowed to take the morning of your operation, it should be done with a very small sip of water. The pur- pose for NPO is to reduce the risk of vomiting during the operation. If you have a cough, fever, or open skin sore, call your surgeon’s office as this may prevent you from having surgery.

Try to get a good night’s sleep! Don’t consume excessive food or beverages (especially alcohol). You want to wake up feeling fresh and ready for the day ahead. If you are very anxious about surgery, your doctor can prescribe a mild evening sedative to help you sleep.

It is important to wash your body and the leg to be operated on with antibacterial soap 3-4 days before surgery, the night before, and the morning of surgery. We recommend Hibiclens (chlorhexidine) bottled soap that you may purchase at a pharmacy. This markedly reduces skin bacteria. If you have had a MRSA (methicillin-resoap thataphylococcus aureus) or other skin infection, be sure to tell your physician. MRSA is a very potent bacteria and may reside or colonize in the interior of your nose, which is detected by a preoperative nose culture swab.

The Day of Surgery

Take a shower the morning of surgery before coming to the hospital. As we just discussed, wash the leg to be operated on with Hibiclens. We ask our patients not to shave the leg that will be operated on. The staff at the hospital will take care of shaving the desired area of your knee and leg so you don’t accidentally cut yourself, which might prevent the operation from occurring that day. Let your doctor know if you have a tape or Iodine allergy or any antibiotic or medicine allergy.

Leave all of your jewelry at home, as none can be worn to the operating room and the hospital staff cannot be held responsible for any lost items. Bring a pair of loose fitting shorts and a shirt that is easy to pull on. Wear tennis shoes and bring socks. Bring items such as elastic TED hose stockings, a brace, and crutches if you were given these ahead of time at your surgeon’s office.

If your surgeon has approved any medication to be taken, do so at this time. Use as little water as possible to swallow the medications.

We ask our patients to arrive at the hospital 90 minutes ahead of the estimated starting time of the operation. You should bring something to read or listen to while you wait. Unless you have the very first starting time of the day, be prepared to wait even longer than your designated starting time. Some operations take longer than anticipated, and it is difficult to know in advance exactly when your surgery will begin.

You will eventually be called back to the “preop” area, which is usually located very close to the operating rooms. Here you will be assigned a nurse who will verify your medical history and current medications. The nurse will ask you if you are allergic to any medications.... and this will happen several times with other hospital staff, so don’t be surprised. Your nurse will immediately check your blood pressure, temperature, and oxy- 58 gen saturation of hemoglobin in the blood (with a small pulse oximeter that is attached to your finger). Do not worry if your blood pressure is higher than normal because this is expected if you are nervous about the operation. Your nurse will begin your intravenous line and attach monitors to allow your vitals to be watched during the operation. These include electrocardiography pads placed on your chest to monitor your heart rhythm, the pulse oximeter, and a blood pressure cuff.

You should have already discussed anesthesia with your surgeon. In addition, the anesthesiologist who will be involved with your operation will meet with you while you are being prepped. The anesthesiologist’s goal is to take you smoothly from your normal, awake, relaxed condition - to sleep in the operating room - to an awak- ened state in the recovery room.

Your anesthesiologist will talk to you about any health problems you may have and their impact on your anesthetic. Feel free to ask any questions at this time. Conditions to be brought to his or her attention include diabetes, heart disease, lung disease, high blood pressure, previous anesthetic complications, or family history of problems with anesthesia. If you are taking any diet medications, please let the anesthesiologist know. A light general anesthesia is commonly used, but there are cases where spinal is recommended. Try not to be afraid of anesthesia, as the hospital staff will follow a specific routine to make this procedure safe and lessen any risks.

In accordance with the Joint Commission on the Accreditation of Healthcare Organizations, we follow the Universal Protocol in order to avoid operating on the wrong knee. In fact, since 2004 in the U.S., preoperative surgical site marking has been mandatory in hospitals and surgical centers. Our patients verbally designate the knee to be operated on. The surgeon then signs the correct knee joint by marking his or her initials on the thigh area. Before the operation begins, a “time-out” is taken at which point all of the surgical personnel repeat the identification of the patient, the correct leg to be operated on, the procedure that will be done, and verify any allergies that exist or special precautions that apply to the patient. Within two hours before surgery, you will receive a dose of antibiotics through the IV as a precaution for postoperative infection. This may be repeated at the end of the operation.

Once you are taken into the operating room, you will move from the transfer bed to the operating room table. Some operating rooms are cold, so be prepared and don’t hesitate to ask for a blanket! Soon, medication will be placed into your IV to put you to sleep. A tube may be placed in your throat while you are asleep as part of the anesthesia process.

When the operation is finished, the medicines that kept you asleep are discontinued and you will wake up in the recovery room. Do not be surprised if your vision is blurry or if your throat is a little sore. A nurse will be with you as you wake up and will ask if you have any pain or nausea. Anesthesia has come a long way and very few patients experience nausea or vomiting after their surgery. Surgeons administer pain medication at the end of the operation, which is called preemptive pain management. The nurse will ask you several times over the next hour or so if you are in any discomfort. Usually, a pain scale of 0 to 10 is used for you to rate your pain. On occasion, a femoral nerve block into the groin is performed if pain becomes a problem.

You will have elastic stocking on your non-operated leg. A large bulky compression dressing will be on your operated leg. You will also have a knee brace on over the dressing. In some instances, you will be able to go home the same day. In some cases where pain or nausea is a problem, the surgeon may decide you should stay overnight at the hospital.

Remember, it is normal to be scared or apprehensive about the surgery and hospital experience. Keep in mind that the hospital staff - nurses, anesthesiologist, and operative team - are all very experienced and will try to 59 keep you as comfortable as possible during the entire process. It is exceedingly rare for a problem to occur, but if something does happen, you should be reassured that the medical professionals will be able to address the issue.

Recovering From Surgery

Prevention of Blood Clots in Your Legs (Deep Venous Thrombosis)

The risk of blood clots in the legs (called deep venous thrombosis), or embolism in the lungs from a clot, is usually low after surgery. If you are overweight, have heart disease, diabetes, or history of blood clots or phlebitis, your risk for this complication is increased. In these cases, you will be placed on a blood thinner medication. Talk to your doctor if you or a member of your family has ever had phlebitis or a blood clot problem.

To lessen the risk of blood clots, we recommend that you move around the house (using your crutches at all times) 6-8 times a day, for about 10 minutes at a time, starting the day of surgery. Take 2 aspirin a day (1 in the morning and 1 in the evening) for 5 days unless you are allergic to aspirin or you have a stomach ulcer or stomach bleeding condition. Use the TED hose stockings to maintain good blood flow. Do ankle pumps for 5 minutes every hour you are awake to increase circulation. Leave the compression dressing on until your postoperative appointment.

Importantly, call your surgeon’s office if you develop any calf or leg pain or swelling that is not alleviated by medication and cold therapy.

If you have experienced phlebitis or a blood clot previously, medication will be prescribed to thin your blood after the operation. In addition, if any members of your family have had blood clots, you will likely undergo screening tests to make sure you do not have an inherited gene disorder that may cause an increase in blood clotting.

For women taking oral contraceptives, be sure and talk with your surgeon to determine if you should stop the medication before surgery. Oral contraceptives may increase the risk of blood clots.

If you are prescribed Coumadin (Warfarin), remember not to eat spinach or green leafy vegetables that act to increase the effect of the medication.

Our Postoperative Physical Therapy Program

Next we will summarize our postoperative physical therapy program. We provide guidelines on what exercises to do according to “phases” of the rehabilitation program. Goals are listed that should be achieved before going from one phase to another. Therefore, while we provide an estimate of the weeks post-injury or post-surgery in which the phases occur, it is important that the goals have been reached and your knee is not having problems with excessive swelling, pain, or instability.

Our patients begin exercises the day after surgery, many of which are done at home. In addition, other exercises and machines are used in the physical therapy clinic. We strongly believe that you should see your surgeon and physical therapist within 48 hours of the operation. During this visit, your wound will be checked to make sure there is no excessive swelling, redness, calf pain, or other problem. Your medical team can determine if 60 your quadriceps muscle has “turned on” and that you can make a muscle and lift your leg off of the exam table. They can also make sure you are doing the initial exercises correctly, including your range of knee motion and patellar mobilization. We strongly disagree with letting you wait a week or more before seeing your surgeon and therapist. Knee surgery is not something to be taken lightly and there are potential complications that may happen. Making sure you are on the right track from the very beginning is important and helpful to your overall recovery.

Instructions for the exercises are provided in the Home Exercises; Health, Fitness Club Exercise Machines; and Pool Training sections. Follow the number of repetitions shown in these instructions. The first time you exercise on machines (such as a stationary bicycle or leg press), have a physical therapist or trainer make sure it is adjusted correctly according to your body dimensions. The therapist or trainer should also help to determine the amount of weight to start with initially and make sure you perform the exercise correctly.

The exercises and machines (called modalities) used during your physical therapy appointments will vary according to what is available at the facility where you will complete your program and your therapist’s knowl- edge. We provide examples of some of the exercises and machines used at our center.

X-rays are obtained after HTO immediately after surgery, 4 weeks postoperatively, and 8 weeks postoperatively. Patients who undergo a femoral osteotomy also have x-rays taken at 16 weeks postoperatively. The x-rays indicate the correction achieved and the amount of bone healing. These are vital to the advancement of the physical therapy program, as will be discussed next. If for some reason the fracture site has not healed in the expected time frame, more x-rays will be obtained as required by the surgeon.

Our formal program lasts for approximately 6 months. At that time, if the patient has progressed as expected, they are released and encouraged to continue their strengthening and cardiovascular program as they desire. They return 3 months later for a check-up, and then yearly with the orthopaedic surgeon.

Phase 1: Weeks 1-2

General Comments:

The important goals the first week after surgery are to control pain and swelling. We recommend that you take the week off of work or school to rest. Stay in bed or on a couch as much as possible with your knee elevated above your heart.

Our patients receive a portable ice compression machine that they use at home for cold therapy. If you do not have such a device, fill 2 gallon-size plastic bags with ice. Place 1 bag on top of your knee and 1 bag underneath your knee (with the brace off, if you have one) for 20 minutes 4-6 times a day. Do not put the bags directly on your skin or incision(s).

Take your temperature twice a day, once in the morning and once in the evening. Call your surgeon’s office if your temperature rises above 101 degrees or if you develop chills or feel feverish.

It is very important to keep your incision(s) clean and dry and away from any material that could cause an infection. Keep your incision(s) away from anything that might transmit bacteria. Do not soak your knee in a bathtub, hot tub, or pool until you receive permission from your surgeon or therapist. 61 We allow our patients to take a shower 2 days after surgery, but they must wrap their leg in plastic to protect the incisions. It is a good idea to place a stool in the shower so you can sit down and prevent a slip, twist, or fall. If you feel weak and unstable, or do not have a stool to put in the shower, wait another day or two. Have someone wash your hair in the kitchen sink and take sponge baths.

Our patient use crutches for approximately 6 weeks after HTO and for 7-8 weeks after femoral osteotomy. A long-leg postoperative brace is used for approximately 9-12 weeks. The following timelines are guided by x-ray evidence of fracture healing and when the patient resumes a normal gait pattern: HTO: allowed to bear 25% of body weight immediately, increased to 50% at 4 weeks, increased to 100% at 6 weeks if x-rays show adequate healing. Femoral osteotomy: allowed toe-touch weight bearing only for 4 weeks, then increased to 25%, then gradually advanced to 100% at 8 weeks if x-rays show adequate healing.

Home Exercises (perform each exercise as indicated): - Ankle pumps, 5 minutes every hour you are awake - Quadriceps isometrics (full extension), 10 reps every hour - Range of knee motion (passive, 0-90°), 3-4 x/day - Patellar mobilization, 3-4 x/day - Knee extension, active-assisted (90-30°), 3 x/day - Hamstring stretch, 3-4 x/day - Calf stretch, 3-4 x/day

Exercises, Modalities in Physical Therapy: - Electrical muscle stimulation, biofeedback (for quadriceps muscle) - Electrical muscle stimulation, cryotherapy (for pain, swelling)

Goals: - Range of knee motion: 0-90° - Crutches, weight-bearing: HTO 25%, femoral osteotomy toe-touch - Adequate quadriceps contraction - Control joint inflammation, effusion

Phase 2: Weeks 3-4

General Comments: During this time period, it is very important to control knee joint pain and swelling and the therapist will want to see you show good quadriceps muscle and leg control while you are doing your exercises. Crutches and the brace are used.

Home Exercises (perform each exercise 3 times a day): - Quadriceps isometrics (multi-angle) - Range of knee motion (passive, 0-110°) - Hanging weights if you do not have 0° of extension, 6-8 x/day - Rolling stool or wall slides if you do not have 90° of flexion, 6-8 x/day - Patellar mobilization - Straight leg raises (hip flexion, hip extension) - Knee extension, active-assisted (90-0°) 62

- Toe raises - Hamstring stretch - Calf stretch

Exercise Machines: - Cardiovascular (1-2 x/day for 10 minutes): - Upper body cycle

Exercises, Modalities in Physical Therapy: - Electrical muscle stimulation, biofeedback (for quadriceps muscle) - Electrical muscle stimulation, cryotherapy (for pain, swelling)

Goals: - Range of knee motion: 0-110° - Crutches, weight-bearing: HTO 25%, femoral osteotomy 25% at 4 weeks - Control joint inflammation, effusion - Reminder: use ice for 20 minutes at a time as needed for swelling

Phase 3: Weeks 5-6

General Comments: Your therapist and surgeon will advise you on weight-bearing rules. You should have no pain and no or only slight swelling and x-rays should show healing of the osteotomy site.

Home Exercises (perform each exercise 2-3 times a day): - Quadriceps isometrics (multi-angle) - Range of knee motion (passive, 0-130°) - Hanging weights if you do not have 0° of extension, 6-8 x/day - Rolling stool or wall slides if you do not have 110° of flexion, 6-8 x/day - Patellar mobilization - Straight leg raises (hip flexion, hip extension), with ankle weight - Wall sits - Knee extension, active (90-30°) if x-rays show healing of osteotomy - Mini-squats, if x-rays show healing of osteotomy - Toe raises, if x-rays show healing of osteotomy - Hamstring stretch - Calf stretch

Exercise Machines: Strength: - Leg press, if x-rays show healing of osteotomy - Upper body weight training - Core training Cardiovascular (2 x/day for 10 minutes): - Stationary bicycle - Upper body cycle 63 Pool Training (may do instead of stationary bicycle, 2 x/day for 10 minutes): - Water walking

Exercises, Modalities in Physical Therapy: - Electrical muscle stimulation, biofeedback (for quadriceps muscle) - Electrical muscle stimulation, cryotherapy (for pain, swelling)

Goals: - Range of knee motion: 0-130° - Crutches, weight-bearing: HTO 100% at 6 weeks, femoral osteotomy 25-50% - Good muscle control - Control joint inflammation, effusion - Medical team recognizes and treats any complications (loss of knee motion, pain syndromes, patellofemoral problems) - Reminder: use ice for 20 minutes at a time as needed for swelling

Phase 4: 7-8 Weeks

General Comments: During this time period, you should have no pain or swelling and show good muscle control with your exercises and gait. You should have 0-135° of knee motion. If the femoral osteotomy fracture site has healed according to x-rays, you may wean off your crutches. HTO patients should demonstrate a normal gait pattern. The brace is still used.

Home Exercises (perform each exercise 2 times a day): - Straight leg raises (all if x-rays show osteotomy healed), with weight or resistance band - Knee extension, active (90-30°), if x-rays show healing of osteotomy - Mini-squats, if x-rays show healing of osteotomy - Step-downs: 2-4” block if allowed full weight bearing - Wall sits - Mini-squats, if x-rays show healing of osteotomy - Lateral step-ups, if x-rays show healing of osteotomy - Toe raises, if x-rays show healing of osteotomy - Hamstring stretch - Calf stretch

Exercise Machines: Strength: - Leg press - Multi-hip or hip abduction/adduction, if x-rays show healing of osteotomy - Upper body weight training - Core training Cardiovascular (choose one, 1-2 x/day for 15 minutes): - Upper body cycle - Stationary bicycle, if x-rays show healing of osteotomy

Pool Training (may do instead of cardiovascular machine, 1-2 x/day for 15 minutes): 64 - Water walking

Exercises in Physical Therapy: - Balance board (2-legged), stable vs. unstable surface, if x-rays show healing of osteotomy - Single-leg stance (level surface), if x-rays show healing of osteotomy

Goals: - Range of knee motion: 0-135° - Walk normally, full weight bearing - Control joint inflammation, effusion - Increase muscle endurance - Reminder: use ice for 20 minutes at a time as needed for swelling

Phase 5: 9-12 Weeks

General Comments: You should have no pain or swelling, be able to walk without pain or limping, and have no problems with the exercise program. You should have 0-135° of knee motion. In all patients, x-rays should show adequate healing of the osteotomy site.

Home Exercises (perform each exercise 1-2 times a day): - Straight leg raises (all), with weights or resistance band - Mini-squats - Wall sits - Lateral step-ups - Step-downs - Hamstring curls, active - Hamstring stretch - Calf stretch - Quadriceps stretch - Iliotibial band stretch

Exercise Machines: Strength: - Leg press - Multi-hip or hip abduction/adduction - Knee extension - Hamstring curls - Upper body weight training - Core training Cardiovascular (choose one, 1 x/day for 15-20 minutes): - Stationary bicycle - Walking - Stair machine - Ski machine - Elliptical 65 Pool Training (choose one instead of cardiovascular machine, 1 x/day for 15-20 minutes): - Water walking - Swimming (straight leg kicking)

Exercises in Physical Therapy: - Balance board (1-legged), stable vs. unstable surface - Single-leg stance (unstable platform)

Goals: - Increase strength and endurance - Increase balance and coordination - Range of motion: 0-135° - Reminder: use ice for 20 minutes at a time as needed for swelling

Phase 6: 13-26 Weeks

General Comments: You should have no pain or swelling, be able to walk without pain or limping, and have no problems with the exercise program. Your therapist should perform a manual muscle test of your leg and hip muscles, with the goal of scoring a 4+/5.

Home Exercises (perform each exercise 1-2 times a day): - Straight leg raises (all), with weights or resistance band - Mini-squats - Wall sits - Hamstring curls, active - Hamstring stretch - Calf stretch - Quadriceps stretch - Iliotibial band stretch

Pool Training (choose one instead of cardiovascular machine, 3 x/week for 20 minutes): 66 - Water walking - Swimming (straight leg kicking)

Exercises in Physical Therapy: - Balance board (1-legged), stable vs. unstable surface - Single-leg stance (unstable platform)

Goals: - Increase strength and endurance - Range of motion: 0-135° - Reminder: use ice for 20 minutes at a time as needed for swelling 67 Home Exercises

Ankle Pumps

While lying down with your legs elevated above your heart, pump your ankles up and down continuously.

Range of Knee Motion

This exercise is performed passively, which means that the muscles in your operated leg are relaxed and your knee is moved either by your therapist, assistant, or with your other leg. To perform this exercise at home, hang your legs over a bed, counter, or chair and use your opposite (non-operated) leg to assist in bending and straightening your knee. Place the foot of the opposite leg in front of the leg of the operated knee and push back for flexion. Place the foot of the opposite leg in back of the foot of the operated knee and pull up for extension. Go back as far as you can for flexion, hold for 5 seconds, then go up as far as you can for extension. Repeat for 10 minutes at a time.

Patellar Mobilization

You may either have an assistant perform this exercise or use your own hands. Move your kneecap as far as possible to the right and the left, holding each position for 10 seconds. Perform for 5 minutes after you complete your range of knee motion exercises. 68 Hanging Weights

This is an excellent exercise if you are having difficulty getting your knee straight. Sit up in bed, on a couch, or on a table with your back well supported. Prop up your foot and ankle (of your operated knee) on a towel or other item to elevate the lower leg, allowing your knee to drop into extension. Hold this position for 10-15 minutes at a time and perform 6-8 times a day. Add weight (up to 20 pounds) on the lower part of your thigh to provide more pressure if needed.

Rolling Stool

This is an excellent exercise if you are having difficulty getting your knee to bend. Sit on a small stool with wheels and move forward with your knee flexed to the maximum position possible. Hold that position for approximately 1 minute or as long as you can. Then, roll the stool forward without moving your foot position on the floor to gain a few more degrees of flexion and hold that position for as long as possible. Relax your knee for 2 minutes and repeat. This exercise may also be done using a large physioball. Perform for 10-12 minutes at a time and repeat 6-8 times a day.

Wall Slides

This is another good exercise if you are having difficulty getting your knee to bend. Lie on your back on a bed or the floor and place the foot of your reconstructed knee on a wall. Place the foot of your opposite leg on top of the foot of the reconstructed knee and use it to gently flex your knee in a gradual manner by sliding down the wall. Then, reverse the position of the feet and slide them back up the wall to the starting position. Perform for 10-12 minutes at a time and repeat 6-8 times a day. 69 Quadriceps Isometrics: Full Extension

Sit up in bed, on a couch, or on a table with your back well supported. Keeping your knee as straight as possible, contract or squeeze your thigh muscle and raise your leg off of the bed or couch a few inches. Do not allow your knee to go into hyperextension. Hold for 10 seconds, then lower the leg back down and relax. Repeat 10 times. As you become stronger, see how long you can keep your leg off of the bed or couch. Challenge yourself to hold your leg for 30, 45, 60 seconds and so on. Perform on both legs.

Quadriceps Isometrics: Multi-Angle

Sit up in bed, on a couch, or on a table with your back well supported. Use pillows placed under your knee to change the angle of the knee joint. The goal is to put the knee at approximately 90° (A), 60° (B), and 30° (C) as shown below. For each joint angle, contract or squeeze your thigh muscle for 10 seconds, then lower the leg back down and relax. Repeat 10 times for each angle. Rest for 1 minute between sets. Perform on both legs. 70 Straight Leg Raise: Hip Flexion

Lie on your back. Tighten your thigh muscle, keep your knee as straight as possible, and lift your leg straight up off of the bed or floor. Hold for 3 seconds, then lower the leg back to the starting position. Perform 1 set of 10 repetitions, rest for 30 seconds, and repeat the exercise 2 more times for a total of 30 repetitions. Add weight around your ankle as the exercise becomes easy to complete. Perform on both legs.

Straight Leg Raise: Hip Extension

Lie on your stomach. Keeping your knee straight, lift your leg toward the ceiling. Hold for 3 seconds, then lower the leg back to the starting position. Perform 1 set of 10 repetitions, rest for 30 seconds, and repeat the exercise 2 more times for a total of 30 repetitions. Add weight around your ankle as the exercise becomes easy to complete. Perform on both legs.

Straight Leg Raise: Hip Abduction

Lie on your side, the opposite of the leg that is painful. Keeping your knee straight, lift the leg up sideways toward the ceiling. Hold for 3 seconds, then lower the leg back to the starting position. Perform 1 set of 10 repetitions, rest for 30 seconds, and repeat the exercise 2 more times for a total of 30 repetitions. Add weight around your ankle as the exercise becomes easy to complete. Perform on both legs. Only begin this exercise when x-rays show the osteotomy site has healed.

Straight Leg Raise: Hip Adduction

Lie on your side, the one that is painful. Bend the opposite leg and place the foot on the ground in front of the other knee as shown below. Lift your leg toward the ceiling, keeping the knee straight and the toes pointed straight ahead. Hold for 3 seconds, then lower the leg back to the starting position. Add weight around your ankle as the exercise becomes easy to complete. Per- form on both legs. Only begin this exercise when x-rays show the osteotomy site has healed. 71 Straight Leg Raises With Resistance Band

Only begin these exercises when x-rays show the osteotomy site has healed.

In these exercises, you will perform the same motion that is done during straight leg raises, except you are standing with a resistance band or rubber tubing tied around your ankle/lower leg. Secure the other end of the band or tubing around a heavy object. You will change the position of your feet in order to work the hip adductors, abductors, flexors, and extensors as shown in the photographs below.

To help maintain balance, hold onto an object and slightly bend the leg that is not being exercised. Move the foot with the band in the desired direction out as far as possible to ensure the band is tight.

Perform 3-5 sets of 30 repetitions, moving the band as fast as possible. Rest for 1 minute between sets. Perform on both legs.

Hip adduction. Hip abduction. Starting position (A) and ending position (B) Starting position (A) and ending position (B) 72

Hip flexion. Hip extension. Starting position (A) and ending Starting position (A) and ending position (B) position (B)

Mini-squats

Only begin this exercise when x-rays show the osteotomy site has healed. From a standing position, squat down to a 45-degree angle. Hold for a few seconds and then slowly rise back up. Perform 3 sets of 20 repetitions each. This exercise may also be done on an unstable surface, such as foam, cushion, or rocker board. 73 Hamstring Curls, Active

Only begin this exercise when x-rays show the osteotomy site has sufficiently healed.

This exercise may be performed either from a standing position or lying on your stomach. Attach a small ankle weight (with the amount of weight determined by your physical therapist) and bend your knee from 0-90 degrees behind you as shown below. Perform 3 sets of 10 repetitions. Rest for 1 minute between sets. Perform on both legs.

Knee Extension, Active-Assisted

Sit up with your back well supported. Begin with your knee flexed to 90 degrees. Place the foot of the opposite leg underneath the other heel and use it to lift the leg so your knee comes up to 30 degrees. Then, tighten the thigh muscles of your leg as hard as possible, completely remove the opposite foot, and lower your leg slowly back to the 90-degree starting position. Perform 3 sets of 10 repetitions. Rest for 30 seconds between sets. Per- form on both legs. Add ankle weight when able, begin with 5-10 pounds and perform 3 to 5 sets of 10 repetitions.

Knee Extension, Active

Only begin this exercise when x-rays show the osteotomy site has sufficiently healed. Sit up with your back well supported. Begin with your operated knee flexed to 90 degrees. Using only that leg, lift so the knee comes up to 0 degrees of extension, hold for a few seconds, then slowly lower back to the starting position. Perform 3 sets of 10 repetitions. Rest for 30 seconds between sets. Perform on both legs. Add ankle weight when able, begin with 5-10 pounds and perform 3 to 5 sets of 10 repetitions.

Wall Sits

Wear gym shoes for this exercise. Stand in front of a wall and place your feet about 2 feet away from the wall. Then, sit against the wall until your knees are flexed to 60-70 degrees. Feel the quadriceps muscles in both legs with your hands, which should feel equal. Wait until you feel a burn in your quadriceps and then hold this position as long as possible to achieve fatigue. Then, carefully stand up, rest for 2-5 minutes, then repeat the exercise. Perform 4 times a day. As you progress, you may place a ball between your knees and squeeze it as hard as possible for the entire exercise. You may also sit a little lower, to 90 degrees if possible, provided no pain is felt in your kneecap or patellar tendon. 74 Toe Raises

Only begin this exercise when x-rays show the osteotomy site has healed. From a standing position, come up onto the toes of your feet, raising your heels completely off of the ground. Hold for 1-2 seconds and then slowly return to the starting position. This may also be done using just one foot (single-leg). Hold onto a stable object for balance and control if necessary. Perform 3 sets of 10 repetitions. Increase repetitions as you are able.

Heel Raises

Only begin this exercise when x-rays show the osteotomy site has healed. From a standing position, raise the toes of your feet as high as possible while keeping the heels on the ground. Hold for 1-2 seconds and then slowly return to the starting position. Hold onto a stable object for balance and control if necessary. Perform 3 sets of 10 repetitions. Increase repetitions as you are able.

Lateral Step-ups

Only begin this exercise when x-rays show the osteotomy site has healed. Stand next to a step or low platform. Place one foot up on top of the platform. Then, bring your other foot up, lightly tap this foot on the platform and return it back to the starting position. Lower and raise the foot by bending and straightening your knee, maintaining good balance and posture. Repeat 10-15 times and then do the same for the opposite side. You may increase the difficulty of this exercise by holding free weights in your hands. The height of the step or platform should be no more than 12 inches and may be lower if any pain is felt in the kneecap during the exercise.

Step-downs, Stable and Unstable Surface

Only begin this exercise when x-rays show the osteotomy site has healed. Begin by standing on a step or low platform. Step down slowly on one leg, then step up backwards leading with the opposite leg. Repeat 10-15 times and then do the same for the opposite side. You may increase the difficulty of this exercise by holding free weights in your hands. The height of the step or platform should be no more than 12 inches and may be lower if any pain is felt in the kneecap during the exercise. This exercise may also be done by stepping onto any unstable surface, including foam, a cushion, or rocker board. 75 Hamstrings Stretch

Sit with your leg lying straight in front of you and bend the opposite knee so that the foot is resting against the inner portion of the other thigh as shown below. Keep- ing your back straight, slowly lean forward until you feel a stretch in your hamstrings. Hold each stretch for 30 seconds and repeat 5 times on each leg.

Calf Stretch

Sit on a bed or recliner with a foot rest with your back well supported. Take a large towel and roll it up so that is long and thin as shown below. Wrap the middle of the towel around the toes of your leg. While keeping your knee straight, use the towel to bend your toes back toward you until you feel a stretch in your calf muscles. Hold each stretch for 30 seconds and repeat 5 times on each leg.

Iliotibial Band Stretch

Sit on the floor, bend your right knee, and keep the left knee straight and flat on the floor. Cross the foot of the right side over the left knee as shown below. Place one hand on the floor behind the hips and use the other arm to press the chest toward the knee and foot. This stretch may be done lying on the back to support the spine and neck. Hold each stretch for 30 seconds and repeat 5 times on each leg. 76 Quadriceps Stretch

From a standing position, grab a foot or ankle and lift it up behind your body. Gently pull the lower leg and foot up, directly behind the upper leg. Do not twist inward or outward. Hold each stretch for 30 seconds and repeat 5 times on each leg.

Health, Fitness Club Exercise Machines

Listed below are some simple exercises you may do at a health club to help strengthen the muscles of your legs and hips and improve your cardiac fitness. We strongly believe that you should be under the care of a physical therapist that can guide and progress your exercise program and make sure that the strength training does not cause further knee pain.

Always do the stretches shown in the Home Exercise section last in your exercise sessions. If any of these exercises cause pain in your kneecap, stop immediately.

The first time you exercise on the machines described below, have a physical therapist or trainer make sure the machine is adjusted correctly according to your body dimensions. The therapist or trainer should also help to determine the amount of weight to start with initially.

Leg Press

Beginning at 70 degrees (A), extend your knees slowly to 10 degrees (B), hold for 1-2 seconds, and slowly return to 70 degrees. Make sure you do this exercise only from 70-10 degrees! Do not press your knees out until they are fully extended, and do not allow your knees to bend all of the way back. Push up through your heels and not your toes. Complete 3 sets of 10 repetitions. Rest for 30 seconds between sets. Gradually increase the amount of weight as you are able. 77 Hip Abduction/Adduction

Only begin this exercise when x-rays show the osteotomy site has healed. If your fitness facility only has a hip abduction/adduction machine (and not a multi-hip cable machine), then use this to work these muscles. However, if your facility has a multi-hip cable machine, use that instead. On the abduction/adduction machine, be sure to work your legs together, moving gradually and holding the abduction or adduction position for 1-2 seconds before returning to the starting position. Complete 3 sets of 10 repetitions. Rest for 30 seconds between sets. Gradually increase the amount of weight as you are able.

Multi-Hip

Only begin this exercise when x-rays show the osteotomy site has healed. A multi-hip machine allows all of the hip muscles to be exercised, including the hip flexors, extensors, abductors, and adductors. Use good posture (keep your back straight) throughout the exercises and hold onto the support bars to ensure you are working just your hip muscles. Complete 3 sets of 10 repetitions in all 4 direc- tions on both sides. Rest for 30 seconds between sets. Gradually increase the amount of weight as you are able.

Knee Extension

Beginning at 90 degrees (A), extend slowly to 30 degrees (B), hold for 1-2 seconds, and slowly return to 90 degrees. Make sure you only do this exercise from 90-30 degrees! Do not extend your knees out past 30 degrees, as this will place excessive forces on your kneecap. Complete 3 sets of 10 repetitions. Rest for 30 seconds between sets. Gradually increase the amount of weight as you are able. You may either use both legs to move the bar up and down, use both legs to push the bar up and one leg to bring the bar back down, or use just one leg to move the bar up and down. Perform equal sets on both legs. 78 Hamstring Curls

Beginning at 0 degrees (A), flex slowly to 90 degrees (B), hold for 1-2 seconds, and slowly return to 0 degrees. Make sure you do this exercise from 0-90 degrees! Complete 3 sets of 10 repetitions. Rest for 30 seconds between sets. Gradually increase the amount of weight as you are able. You may either use both legs to move the bar down and up, use both legs to push the bar down and one leg to bring the bar back up, or use just one leg to move the bar down and up. Perform equal sets on both legs.

Upper Body Weight Training

It is important during your rehabilitation to include exercises to strengthen the muscles in your arms, shoulders, chest, and upper back. There are many options available that use either free weights or weight machines. The major upper body muscle groups that should be exercised include the deltoids, pectorals, triceps, biceps, trapezius, rhomboids, and latissimus dorsi. Work with your therapist or a trainer at your fitness facility to develop this aspect of your training program. Your program should be tailored to the sport or activity you wish to return to upon your medical release.

Core Training

The “core” is the area of your body that includes your pelvis, abdomen, and lower back. Core strength is crucial to maintain postural support and movement of the trunk. Core stability contributes to athletic performance. In fact, poor core strength may cause injury. The muscles in the abdomen and lower back may be strengthened in many different ways, using either weight machines or exercises such as sit-ups, crunches, bicycle kicks, supine bridges, planks, etc. Work with your therapist or a trainer at your fitness facility to develop this aspect of your training program. Your program should be tailored to the sport or activity you wish to return to upon your medical release.

Stationary Bicycle

Only begin this exercise when x-rays show the osteotomy site has sufficiently healed. A stationary bicycle offers a cardiovascular exercise option that we allow provided it does not cause kneecap pain. It is important to adjust the seat height correctly so that your knee is just slightly bent when the pedal is in the lowest position. We recommend using low resistance and a level setting. If you begin to experience knee 79 cap or patellar tendon pain during or after riding the bicycle, stop and talk to your therapist.

Cross-Country Ski

Only begin this exercise when x-rays show the osteotomy site has healed. This is an excellent machine to use for cardiovascular fitness because it has very little impact on your knee and it also works muscles in your core and upper body. At first, make sure your stride is short, you use the level setting (no incline), and a low resistance. If you begin to experience kneecap pain during or after using this machine, stop and talk to your therapist.

Elliptical

Only begin this exercise when x-rays show the osteotomy site has healed. This is an excellent machine to use for cardiovascular fitness and has the additional benefits of applying very little impact on your knees (and other joints as well) while working the muscles in your core and upper body. At first, make you use the level setting (no incline) and a low resistance. If you begin to experience kneecap or patellar tendon pain during or after using the elliptical, stop and talk to your therapist.

Pool Training

Water Walking and Other Basic Aquatic Exercises

Walk in a pool with the water at least waist-high, forwards and backwards. Gradually increase your speed, the length of your steps, and the distance covered. Make sure you walk with high knee steps, exaggerated from your normal walking appearance. You can also march across the pool. Partial squats and lunges can be done in shallow water in the same manner as they are done on land. There are a variety of exercises that may be done in the pool to increase strength and flexibility, many of which require buoyant or other aquatic equipment. A kick board may be used when walking to increase the amount of resistance. A noodle may be used to support the upper body while doing bicycle kicking. Knee flexion curls may be done with a buoyant circle. Knee extension resistance exercises may be done by placing a noodle under the bottom of a foot and pressing down. In addition, the upper extremity and core muscles may be exercised in a variety of ways in the pool. These including performing arm circles under water, first with the palms up and then with the palms facing down. A buoyant device can be placed between your legs and freestyle swimming done using just your arms. If you have access to a pool and enjoy training in the water, work with your therapist to develop a comprehensive program to be used in conjunction with your other land-based exercises.

Swimming (Straight Ahead Kicking)

If you would like to swim, use only straight ahead kicking, as in freestyle and backstroke. Consider adding a mask and snorkel to make breathing easier. You may also use flippers and perform simple flutter kicking to further strengthen your legs. 80 Frequently Asked Questions

1. How have tibial (HTO) and femoral osteotomy changed over time to reduce the complication rates and improve the success rates?

There have been several factors in preoperative planning, operative techniques, and postoperative rehabilitation that have made a real difference in the results of osteotomy. These include increased precision in the calculations required to achieve the desired angular correction, such as the use of computerized navigation and special x-rays taken throughout the operation to ensure the varus or valgus malalignment is corrected. Small- er incisions are used, with less dissection of tissues which means a less invasive operation. The fracture sites are secured with high strength locking plates that allow earlier weight-bearing, reducing the amount of time patients spend on crutches. These plates also decrease the problems with healing of the fracture sites, known as nonunion or delayed union. Typically, in our clinic, patients are allowed full weight-bearing at 6 weeks after HTO and at 7-8 weeks after femoral osteotomy.

2. What are the overall success rates of these operations?

Overall, we have noted that 70-80% of patients have a significant improvement in their symptoms and knee function. Many can return to recreational sports that allow an active lifestyle for many years after surgery. The majority can do their daily activities without problems. However, we always advise our patients that if there is already arthritis in knee joint that it will progress. About 20% of patients will not have a long-term benefit and may require a partial or total knee replacement.

3. As a younger patient who needs a major ligament reconstruction, why do I have to have a HTO first to realign my leg ?

The problem with performing any knee ligament reconstruction in a malaligned lower limb is that there is a very high chance the new graft will stretch out and fail. This happens because varus malalignment creates abnormally high forces on the lateral side of the knee. This means there is an abnormal amount of space between the femur and tibia with any weight-bearing activity and this joint opening places tremendous loads on the healing graft. The malalignment must be corrected and we usually prefer to do this first and then proceed with the ligament reconstruction a few months later, if it is still required.

4. Why is it necessary to bone graft an opening osteotomy?

In opening wedge osteotomies, a space or gap is created in either the tibia or femur. This gap must be filled with bone or the angular correction will collapse. In HTO, we have found that allograft bone (from a donor) works very well. For femoral osteotomies, we prefer to use bone from the patient’s hip to fill the gap. This is because there are larger forces on the femur and an increased risk of delayed healing or even no healing of the fracture site.

5. What is rate of nonunion that requires subsequent surgery? 81

In our HTO studies, no further bone grafting or surgery for bone healing problems was required. We believe this was due in part to the type of fixation we used to stabilize the fracture site. We do inform patients that there is a 1-5% chance of a delayed union that requires the patient to spend a longer amount of time on crutches.

6. Overall, how advantageous is it to correct malalignment?

We and many other orthopaedic surgeons believe it is very advantageous to have an osteotomy. Several studies have shown that these operations buy many years before patients need further surgery such as a partial or total knee replacement. This is particularly helpful in younger patients who wish to remain active and avoid knee replacement for as long as possible. In addition, it is well known that lower limb malalignment must be corrected in order for knee ligament surgery to be successful. Patients who require a meniscus transplant or articular cartilage restoration procedure need to have varus or valgus malalignment corrected or the procedure will most likely fail.

7. How soon will I start rehab?

In our clinic, patients begin rehabilitation the first day after surgery. It is very important during the first week to control pain and swelling, which may be done with appropriate medications, ice, and elevation of the limb. It is also important to “turn on” the muscles in the leg which may be accomplished with the assistance of modalities (such as electrical muscle stimulation) guided by a physical therapist. Our entire 6-month rehabilitation program is detailed in this eBook. The early start of knee motion, patellar mobilization, and muscle strength exercises reduces the risk of complications such as excessive scarring and muscle atrophy.

8. Is there a chance the osteotomy will require an early correction with another operation if the alignment does not come out as planned?

There is a small chance (1-2%) that the osteotomy will not exactly achieve the alignment desired by the surgeon. In these cases, another operation is required to re-adjust the alignment. Sometimes a settling occurs at the bone fracture ends of just 3-4 millimeters, which changes the alignment that was initially obtained at surgery. It is important for the surgeon to determine in the first 3-4 weeks after surgery that the desired correction has been achieved and maintained. It is actually very straightforward to change the correction early after the osteotomy because all of the dissection has already been performed.

Acronyms and References

ACI, autologous chondrocyte implantation ACL, anterior cruciate ligament BMI, body mass index HTO, high tibial osteotomy LCL, lateral collateral ligament MCL, medial collateral ligament MRI, magnetic resonance imaging MSA, methicillin-resoap thataphylococcus aureus 82

NPO, nothing by mouth NSAID, non-steroidal anti-inflammatory PCL, posterior cruciate ligament PLS, posterolateral structures WBL, weight-bearing line

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We have noted in our experience that some patients with chronic insufficiency of the LCL and PLS and varus malalignment of the lower extremity may develop a gait abnormality that is characterized by excessive knee hyperextension during the stance phase of the gait cycle. Patients who have a knee hyperextension gait display varying amounts of abnormal gait mechanics, knee symptoms, and functional limitations. Some may demonstrate a markedly abnormal gait that is severely disabling and limits ambulation, requiring crutch or cane support. Others may have less noticeable problems, with the abnormal knee hyperextension occurring only after excessive walking (or other weight bearing activities) and muscle fatigue.

Patients with this gait problem may experience knee instability during routine daily activities. Pain is frequently located in the medial tibiofemoral compartment, but may also occur in the posterolateral tissues.

In addition, there is an increased risk of failure of knee ligament reconstructions if this gait abnormality is not corrected before surgery. This is due to the excessively high tensile forces from high knee extension and adduction moments which are expected to return during weight bearing activities after surgery. Therefore, gait retraining to correct the hyperextension pattern is vital to help resolve symptoms and reduce the risk of failure of future ligament reconstructive procedures.

The loss of the normal knee flexion and extension patterns throughout the stance phase noted in patients with hyperextension gait abnormalities has important functional implications. During the initial loading phase, normal amounts of knee flexion are required for the knee joint to absorb shock. A limb that is hyperextended transfers body weight directly from the femur to the tibia, resulting in abnormally high compressive forces. The usual muscle energy absorption and cushioning effect a flexed knee provides is lost.

The thrusting hyperextension motion at the knee is associated with an abnormally high adduction moment, which tends to increase medial tibiofemoral compartment compressive forces and lateral distraction forces. The increased compressive forces cause pain in the medial tibiofemoral compartment and posterolateral soft tissues.

We have used a specific gait retraining program at our Center for knee hyperextension abnormalities for over two decades. The program requires 2-4 initial clinical sessions (held preferable every other week) with an experienced physical therapist who instructs the patient on the abnormal gait mechanics that occur and the adaptations required to restore a normal gait pattern. The patient is instructed to practice at home for at least 2-4 hours daily. In addition, the patient undergoes muscle strengthening and neuromuscular coordination training as part of the comprehensive rehabilitation process.

In order to have a successful outcome, the patient must be compliant with the time commitment and constant motivation required of this program. A family member is also taught the same instructions so that they can observe and assist with the patient’s retraining at home. It is also helpful to video the patient’s abnormal and corrected gait to aid the education process.

The initial focus of the retraining process is placed on the knee hyperextension in order for the patient to understand that this is the primary problem that must be corrected. 87

Illustration of gait abnormalities that occur before retraining. Filled grey structures represent the corrected, retrained positions at the trunk, upper body, hip, knee, foot, ankle, and toes.

The patient is instructed to maintain 5 degrees of flexion with every step. This requires walking in a very slow and deliberate manner. A good visual aid is the mental image of a woman walking in high heels, which produces 5-8 degrees of knee flexion. In addition, a 1- to 2-inch elevated heel may be used to help maintain flexion throughout stance phase. The therapist should be aware that problems may occur as the patient practices this flexed-knee stance because it may aggravate pre-existing patellar pain, which must be treated promptly.

The second step of the training involves educating the patient on the abnormal ankle and foot motions that occur along with knee hyperextension. The patient practices elevating the heel and pushing off with the forefoot and toes in the midstance phase to avoid knee hyperextension. Excessive ankle plantar flexion is limited and early ankle dorsiflexion is encouraged to maintain forward progression of the tibial and flexion of the knee joint. It is helpful to have the patient notice and feel the pressure against the forefoot during the end of stance phase. With the first and second steps, the patient is taught to say “knee-foot” with each stance cycle as a reminder of the normal gait pattern.

The third step analyzes the hip and body trunk position. The fourth and final step of the retraining program determines whether an abnormal lower limb alignment (varus or valgus thrust), or an external or internal rotational knee subluxation occurs during stance. This is important because a primary cause of a patient’s abnormal knee hyperextension may be instability of the knee with flexion, so that coronal plane or rotational transverse plane subluxations occur.

In these patients, a functional knee brace and additional gait retraining may be required. In some cases, a heel wedge may be used to place the knee in slight flexion in order to minimize the midstance hyperextension which can occur with poor quadriceps control. A significant varus or valgus malalignment may require use of an unloading brace or a lateral or medial heel wedge. 88 Here are tips for the physical therapist to conduct a successful gait retraining program, broken down according to anatomic regions.

Trunk - Upper Body 1. Maintain erect position, avoid forward loading position which shifts body weight anteriorly to knee joint during stance phase. 2. Avoid excessive medial-lateral sway during stance phase, which induces varus-valgus moments about the knee and hip.

Hip 1. Avoid excessive hip flexion during stance phase which encourages knee hyperextension and fatigues hip extensors. 2. For valgus lower limb alignment, avoid excessive internal femoral rotation. Encourage external femoral rotation and walking on lateral foot border. Avoid “knock-knee” position (important for valgus thrusts). 3. For varus lower limb alignment, avoid external femoral rotation. Encourage internal femoral rotation, “knock-knee” position.

Knee 1. Avoid any knee hyperextension throughout stance phase by always maintaining a knee-flexion position. 2. Practice knee flexion-extension control walking in a slow manner; often begin with crutches. Initially use an excessive knee-flexion position. 3. Gradually resume a more normal walking speed, after flexion-extension control and a more normal gait pattern is resumed. 4. Look for increase in patellofemoral pain. 5. Look for varus or valgus thrust with knee flexion-position. 6. Look for external or internal rotational tibiofemoral subluxations when flexion position resumed.

Ankle 1. Avoid excessive plantar flexion. Maintain dorsiflexion using soleus muscle to induce early heel rise (rocker-action) to encourage forward tibial progression and knee flexion. 2. Initially use excessive dorsiflexion and walking aids (elevated heel) to increase early heel-off in stance phase.

Foot 1. Encourage push-off against forefoot and toes along with early heel-off in stance phase to assist knee flexion during stance phase. 2. With associated varus alignment, encourage toe-out position. For valgus alignment, encourage toe-in position.

In addition to gait retraining, voluntary hip and lower extremity muscle control is critical to help minimize hyperextension gait. Normal gait requires adequate push-off from the gastrocsoleus complex, sufficient quadriceps contraction in midstance, hip and knee flexion during swing, and an upright posture. Defects in any of these mechanisms may lead to gait alterations. Therefore, gait retraining should include exercises to target the specific muscles during gait, pre-gait activities to methodically force the patient to think about functionally using these muscles, and then practicing the new gait pattern for it to eventually become the learned default pattern to avoid the hyperextension gait mechanism.

In some patients with varus malalignment, there is an associated internal tibial torsion and toe-in gait. The 89 patient may voluntarily decrease the varus thrust by purposely walking with a toe-out gait; however, when the patient is not practicing, the toe-in gait resumes. The same situation applies to a valgus knee alignment with a pronated toe-out gait. The gait retraining therefore is primarily to address knee hyperextension in which most patients will achieve a beneficial response to the program.

There are many strengthening exercises that assist with gait retraining. These include toe raises that may be progressed from using double stance to eccentric/ negative repetitions (up with two legs/ down with a single leg), and eventually to single ankle plantar flexion lifting. Other options are to move from the floor to the edge of a step or to add additional weight for increasing the work load. The exercise can also be combined with traditional step-up exercises.

Quadriceps strengthening may be done initially with the straight leg plus raise exercise. With the patient in the seated position, the quadriceps is contracted, the leg is lifted approximately 6 inches off the table or chair, held for 15 seconds, and then lowered and relaxed for 45 seconds. This one-minute cycle is maintained and progressed in ratios (1:3, 1:2, and eventually, 1:1), and then progressed from 5 to 10 repetitions, with additional ankle weight being added to increase the difficulty of the exercise.

Wall sits are an excellent method of facilitating quadriceps activation. Active isometric hip adduction during the wall sit by compressing a ball between the knees may assist vastus medialis oblique recruitment. It is also important to improve hip abduction control. This may be done by placing a heavy elastic exercise band proximal to the knee and performing “clam shells” in either a side-lying or long sitting (hook) position. Three to five sets of 10 repetitions are performed. 90 Balance and proprioception are important components of a gait retraining program. Activities such as weight shifting, tandem balance, single leg balance (stable and unstable), and rocker board (front-to-back and side-to- side) are effective.

Each of the following factors contributes to a symmetric gait pattern: adequate pushoff, midstance quadriceps control, hip and knee flexion, and maintenance of an upright posture. An activity known as “cup walking” may be used in order to encourage the patient to break down the actual gait cycle into more manageable tasks. Cups or cones are set up in 2 staggered rows with symmetric stride lengths. The patient walks or marches over the cups, emphasizing each of the earlier four mentioned tasks. This activity allows the clinician to observe the gait cycle to determine where emphasis needs to be placed.

Common compensatory mechanisms that patients exhibit include circumduction of the lower extremity, inadequate pushoff, midstance hyperextension, lack of coordinated hip and knee flexion, positive Trendelen- burg sign, and forward flexed trunk. The clinician must be able to identify these problems in order to teach the patient and their support family or friends how to observe the deficiency and to perform the corrective strate- gy. The normal automatic nature of gait now becomes a “thinking” activity for the patient. The patient is asked to exaggerate the gait cycle by stepping over the cups. This methodical approach allows the patient to apply a part of the gait cycle to the entire, normal gait pattern. Gait retraining activities such as this must be repeated thousands of cycles over time in order to create a “new default” gait pattern.

As time progresses, another gait activity may be used requires the patient to wear a heavy elastic band around the distal thighs (~2 finger widths above the patella), and then produce a marching pattern to provide a resisted gait cycle.

With a central line on the floor, the patient (while marching) must maintain right foot strike on the right side of the line, and left foot strike on the left side of the line. This movement into swing ensures that adequate hip flexion and hip abduction muscu- lature are used during the gait cycle. In addition, the stance limb requires adequate pushoff of the gastrocnemius, as well as a voluntary quadriceps contraction to prevent a hyperextension episode. This resisted gait activity can be completed in a forward, backward, and lateral direction. Each direction allows the clinician to emphasize what muscle groups are used to allow for adequate voluntary muscle control. Again, these activities require voluntary thought processes to focus on recruiting the quadriceps to avoid the hyperextension mechanism from occurring.

In the authors’ experience, after approximately 2-4 sessions, the patient will understand the abnormal mechanics and recognize when the hyperextension patterns occur. As already discussed, mental reminders, such as “knee bent, toe pushoff” are helpful in this stage. After approximately 4 weeks of training, the patient should convert to a more normal gait pattern. However, it may require 2-3 months to complete the training process to the point where a normal gait pattern becomes routine on a sub- conscious level and the patient does not resume the hyperextension gait pattern when walking quickly.