Anterior Knee Pain in the Sporting Population Patellar Tendinopathies - Part 3

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

ABSTRACT

Increase your success rate in treating patients with anterior knee pain.

AKP can be one of the most difficult conditions to manage. The success rate of most treatment regimens has been poor and the condition frequently recurs.

This three-part, online course will equip you with the latest tools to deal effectively with this and other related sports injuries.

You’ll learn about assessing the knee in part one; part two will introduce you to the new integrated treatment approach; and part three deals with patellar tendinopathy

1. NOMENCLATURE appearance. There are clefts in the matrix and

Patellar tendinopathy was first referred to as occasional necrotic collagen fibers with small “jumper’s knee” due to its frequency in vessel ingrowth. This histopathological jumping sports (e.g. basketball, volleyball, picture, which is called “tendinosis” is identical and high, long and triple jumps).1 However, in tendons with both macroscopically evident the condition also occurs in sportspeople who partial tears and those without.4 change direction, and may occur in These regions of tendon degeneration sportspeople who do not perform either correspond with areas of increased signal on jumping or change of direction. The term MRI and hypo-echoic regions on ultrasound.2 “patellar tendonitis” is a misnomer as the

pathology underlying this condition is not an inflammatory “tendonitis”.2 On balance,

“patellar tendinopathy” is probably the most

appropriate general label for this condition.3

PATHOLOGY AND PATHOGENESIS OF PATELLAR TENDINOPATHY

Normal tendon is white and glistening but the

patellar tendon of patients undergoing surgery

for patellar tendinopathy contains abnormal tissue adjacent to the lower pole of the patella

(Fig 1). Figure 1: Arrow highlights a region of grey tendinosis within the otherwise glistening Under the light microscope, symptomatic white patellar tendon. Skin and subcutaneous fat have been retracted. patellar tendons do not consist of tight parallel REPRINTED WITH PERMISSION OF SAGE PRESS FROM collagen bundles, but instead are separated SHELBOURNE KD ET AL. RECALCITRANT PATELLAR TENDINOSIS IN ELITE ATHLETES. AM J SPORTS MED by a large amount of ground substance that 2006;34(7):1141-6

gives them a disorganised and discontinuous 1

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

3. CLINICAL FEATURES The features of patella tendinopathy are It is important to reproduce the patient’s pain outlined in Table 2 (in Part 1). The patient on examination. Functional activity, such as a complains of anterior/inferior knee pain squat or hop, reproduces the pain, and these aggravated by activities such as jumping, tests are superior to palpation as a method for changing direction, and decelerating. The monitoring recovery. An additional method of most common site of tendinopathy is the deep monitoring the clinical progress of patellar attachment of the tendon to the inferior pole tendinopathy is the use of the Victorian of the patella. Distal lesions are less common Institute of Sport Assessment VISA-P and mid-substance lesions are rarely questionnaire (Table 1 on Page 5)6,7. This reported.5 The tendon is tender on palpation simple questionnaire takes less than five at the inferior pole, occasionally extending minutes to complete and patients are able to into the body of the tendon. There is complete it themselves. frequently associated thickening of the tendon. The most effective position for INVESTIGATIONS palpation is shown in Figure 2. Expert Ultrasound examination and MRI are the clinicians also assess possible precipitating investigations of choice in patellar factors, such as weakness of the lower limb tendinopathy, although these imaging musculature including calf, quadriceps, and modalities do not have 100% sensitivity and gluteal muscles, and shortening or increased specificity for the condition.8 (Figure 3a). tone of the gastrocnemius/soleus, quadriceps, Ultrasound examination with Doppler (Fig 3b) and hamstring muscles. to assess vascularity in and around the tendon is more sensitive than MRI9 (Fig 3c).

Figure 3: Ultrasound and MRI images of patellar tendinopathy in athletes. Figure 2: Palpation of the patellar tendon. a. Ultrasound image (normal left) and Pressure on the superior pole of the patella thickened tendon regions). Arrowheads tilts the inferior pole, allowing more precise point to the posterior/deep edge of the palpation of the tendon origin. patellar tendon. 2

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

recognise that tendinopathy that has been present for months may require a considerable period of rehabilitation before symptoms disappear.

Conservative management of patellar tendinopathy requires appropriate strengthening and motor control exercises, load reduction, correcting biomechanical errors, and soft tissue therapy. More invasive treatments include injection with substances that either affect the vessels (sclerotherapy Figure 3: Ultrasound and MRI images of with polidocanol), or theoretically improve patellar tendinopathy in athletes. b. Ultrasound image with Doppler showing tendon repair (platelet-rich plasma [PRP] abnormal vascularity (blue and red injections) or matrix structure (prolotherapy). signal) near the junction of the patellar tendon and the patella (arrowhead). Surgery is only indicated after a considered

and lengthy conservative program has failed.

This section outlines the physiotherapy approach of targeted exercise therapy, correction of factors that might be contributing to excessive load on the tendon, and soft tissue treatment, before outlining medical treatments including medication, injections and surgery.

RELATIVE LOAD REDUCTION – MODIFIED ACTIVITY AND BIOMECHANICAL CORRECTION

Figure 3: Ultrasound and MRI images of There are numerous ways of reducing the load patellar tendinopathy in athletes on the patellar tendon without resorting to c. MRI (appearance of patellar tendinopathy) complete rest of immobilization. Relative rest

means that the patient may be able to 4. TREATMENT continue playing or training if it is possible to Treatment of patellar tendinopathy requires reduce the amount of jumping or sprinting, or patience and a multifaceted approach. It is the total weekly training hours. Some essential that the practitioner and patient continued load on the tendon is critical to 3

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3 maintain tendon integrity and absolute rest is Hamstring shortening (decreased sit and contraindicated. reach test) is associated with an increased prevalence of patellar tendinopathy. Strengthening and correcting biomechanics to Weakness of the gluteal, quadriceps, and calf improve the energy-absorbing capacity of the muscles leads to fatigue and aberrant limb should be directed at both the affected movement patterns that may alter forces musculotendinous unit and the hip and ankle. acting on the knee during activity. Therefore, The ankle and calf are critical in absorbing the proximal and distal muscles also need initial landing load that reduces the load assessment in patients with patellar transmitted to the knee10. Biomechanical tendinopathy. studies reveal that only about 40% of landing STRENGTHENING energy is transmitted proximally11. Thus, the There are at least six reports of effective calf complex must function well to prevent strengthening exercises for patellar more load than necessary transferring to the tendinopathy.14, 15-19 These can be divided into patellar tendon. two groups – those reporting eccentric

exercises on a decline board and those using Better landing techniques can decrease other exercises. patellar tendon load. Compared with flat-foot landing, forefoot landing generates lower Overview of management of patellar tendinopathy ground reaction forces and, if this technique is combined with a large range of hip or knee  A patient presenting with persistent painful patellar tendinopathy for the first flexion, vertical ground reaction forces can be time may require 3-6 months to recover. A patient with a longstanding history may 11 reduced by a further 25%. Landing with require 6 -12 months to return, pain-free, weight further forward that uses all available to competition without recurrence. dorsiflexion may also decrease patellar tendon  Relative tendon unloading is critical for treatment success. This is achieved by 12,13 load. activity modification assisted by biomechanical correction. Biomechanical correction requires assessment  Progressive strengthening is the of both anatomical and functional treatment of choice. Effective exercise prescription requires thorough shortcomings. Anatomical variants that can assessment of the patient’s functional contribute to patellar tendinopathy include capacity and a skilful approach to increasing demand on the tendon. limited ankle dorsiflexion and hallux rigidus.  After successful patellar tendon surgery, There are numerous functional biomechanical it takes between 6 and 12 months to abnormalities. Inflexibility of the hamstring, return to full competitive sport. Thus, the treating physician must be sure that an quadriceps, and calf muscles, as well as appropriate conservative treatment program has failed before suggesting a restricted ankle range of motion, are likely to tendon needs surgery. increase the load on the patellar tendon. 4

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

Three papers suggested that exercise-based ischemic pressure and sustained myofascial interventions such as squatting, isokinetics tension to tight muscles or trigger points in and weights reduce the pain of patellar the quadriceps, hamstring and calf muscles tendinopathy.15,16,20 Studies have investigated can be performed. the effectiveness of exercise on 25º decline CRYOTHERAPY board (Fig 4a) – a method specifically loading the extensor mechanism of the knee by Cryotherapy (e.g. ice) is a popular adjunct to increasing the moment arm of the knee17. treatment; however, if the patient finds no clinical benefit from this modality, there is no Two trials reported improvements in pain, rationale for persisting. function, and return to sport with exercise, although time frames for improvement PHARMACOTHERAPY varied.14,18 Compared with surgery, eccentric Studies of pharmacotherapy in the treatment exercise on a decline board provided similar of patellar tendinopathy are limited to outcomes at 12 months.19 Other studies have phoresis, as few studies have investigated investigated heavy load strengthening and oral medications. The use of aprotinen in report equally good results.21 Importantly, tendinopathy has some evidence, but is not strengthening exercises when sportspeople recommended because of possible are competing gave no improvement in pain anaphylaxis after injection. Recently, the use or jump performance among the treatment of aprotinen during cardiac surgery has been group compared with those who undertook no discontinued because of increased risk of exercise.22,23 This information can be used adverse effects. In one study, ionto-phoresis within an educational context when working with corticosteroid improved outcome with a sportsperson who is reluctant to modify compared with phonophoresis, suggesting it his or her training regimen. may introduce corticosteroid into target tissue more effectively than phonophoresis25. When and how a strengthening program should begin is discussed in the box on Page 6. The model for tendinopathy proposed by Cook and Purdam suggests that early-stage SOFT TISSUE THERAPY (reactive) tendinopathy could respond to A popular treatment for patellar tendinopathy medications that reduce cell activity and is the use of friction; however, this lacks a protein production26. Ibuprofen, doxycycline, logical theoretical construct. Studies that and green tea are hypothesized to improve compared soft tissue therapy/transverse pain and pathology in tendinopathy. In later friction with other treatments demonstrated stages of pathology, injection therapies may little benefit in reducing pain.20,24 Digital be more relevant.

TABLE 1: Victorian Institute of Sport Assessment (VISA) questionnaire (English version, this is available in numerous languages. 1. For how many minutes can you sit pain-free? POINTS 0 min 100 min

0 1 2 3 4 5 6 7 8 9 10

2. Do you have pain walking downstairs with a normal gait cycle? POINTS Strong No Pain Severe Pain 0 1 2 3 4 5 6 7 8 9 10

3. Do you have pain at the knee with full active non -weight bearing knee extension? POINTS Strong No Pain Severe Pain 0 1 2 3 4 5 6 7 8 9 10

4. Do you have pain when doing a full weight – bearing lunge? POINTS Strong No Pain Severe Pain 0 1 2 3 4 5 6 7 8 9 10

5. Do you have problems squatting? POINTS Unable No problems

0 1 2 3 4 5 6 7 8 9 10

6. Do you have pain during or immediately after doing 10 single-leg hops? POINTS Strong No Pain Severe Pain 0 1 2 3 4 5 6 7 8 9 10

7. Are you currently undertaking sport or other physical activity? POINTS 0  Not at all

4  Modified training ± modified competition

7  Full training ± competition but not at same level as when symptoms began

10  Competing at the same or higher level as when symptoms began

8. Please complete EITHER A, B, or C in this question

 If you have no pain while undertaking sport please complete Q8A only

 If you have pain while undertaking sport but it does not stop you from completing the activity, complete Q8B only

 If you have pain that stops you from completing sporting activities, please complete Q8C only. A. If you have no pain while undertaking sport, for how long can you train/practise? POINTS

Nil 1 -5 min 6 - 10 min 11 - 15 min > 15 min 0 7 14 21 30

B. If you have some pain while undertaking sport, but it does not stop you from completing your training/practise, for how long can you train/practice?

Nil 1 -5 min 6 - 10 min 11 - 15 min > 15 min 0 4 10 14 20 OR

C. If you have pain that stops you from completing your training/practise, for how long can you train/practise? POINTS

Nil 1 -5 min 6 - 10 min 11 - 15 min > 15 min 0 2 5 7 10

TOTAL SCORE /100

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

TABLE 2: Strengthening program for treatment of patellar tendinopathy TIMING TYPE OF OVERLOAD ACTIVITY 0 – 3 Strength and strength endurance Hypertrophy and strengthen the effected months muscles Focus attention on all anti-gravity muscles 3 – 6 Power and speed endurance Weight-bearing speed-specific loads months 6 + months Combinations dependent on sport (e.g. load, Sport-specific rehabilitation speed)

Figure 4a: Patellar tendon eccentric strength training exercises. Single-leg squat on decline Figure 4c: Patellar tendon eccentric strength board. training exercises. Lunge with weights.

INJECTION THERAPY

Neovascularisation (Fig 3b) is a cornerstone of

degenerative tendon pathology and is the target of treatment by Alfredson and

Ohberg.27 In a high-quality randomized

control trial of elite athletes with patellar

tendinopathy, investigators found that

sclerosing injections with polidocanol resulted

in a significant improvement in knee function and reduced pain.28

Figure 4b: Patellar tendon eccentric strength training exercises. Lunge 7

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

WHEN SHOULD PATELLAR TENDON STRENGTHENING BEGIN?

Therapists often have concerns as to when and Thus, exercises that target the quadriceps how they should begin a strengthening program. specifically (such as single-leg extensions) may Even sportspeople with the most severe case of have a place in the rehabilitation of patellar patellar tendinopathy should be able to begin tendinopathy. Similarly, when the sportsperson some weight-based strength and other exercises is ready, increase the load on the quadriceps by (such as calf strength and isometric quadriceps having the patient stand on a 25º decline board work) in standing. However, the sportsperson to do squats. Compared with squatting on a flat who has not lost a lot of knee strength and bulk surface, this reduces the calf contribution during can progress quickly to the speed part of the the squat. program. The therapist should progress the regimen by

Both pain and the ability of the adding load and speed and then endurance to musculotendinous unit to do the work should each of those levels of exercise. Combinations guide the amount of strengthening to be done. such as load and speed, or height and load, then If pain is a limiting factor, then the program follow. These end-stage exercises can provoke must be modified so that the majority of the tendon pain, and are only recommended after a work occurs without aggravating symptoms prolonged rehabilitation period, and when the within 24 hours of the exercise. A subjective sport demands intense loading. In several clinical rating system, such as the VISA sports, it may not be necessary to add questionnaire (Table 1 on Page 5), administered potentially aggravating activities such as jump at about monthly intervals, will help both the training to the rehabilitation program, whereas therapist and the patient measure progress. in volleyball, for example, it is vital.

If pain is under control, it is essential to monitor Finally the overall exercise program must the ability of the limb to complete the exercises correct aberrant motor patterns such as stiff with control and quality. Exercises should only landing mechanics (discussed above) and pelvic be progressed if the previous work load is easily instability. For example, weight-bearing managed, pain is controlled, and function is exercises must be in a functionally required satisfactory. range, and the pelvis position must be

monitored and controlled at all times. The Sportspeople with patellar tendinopathy tend to common errors in rehabilitation strength “unload” the affected limb to avoid pain, so they programs are listed in Table 3 below. commonly have not only weakness but also abnormal motor patterns that must be reversed.

Strength training must graduate quickly to incorporate single-leg exercises (Figure 4) as the sportsperson can continue to unload the 8 affected tendon when exercising using both legs. ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

TABLE 3: Why rehabilitation programs fail at various stages Early failure Late failure Insufficient strength training Failure to monitor the patient’s symptoms Progression of rehabilitation program too rapid Rehabilitation and strength training end on return to training, instead of continuing throughout the return to sport Inappropriate loads during rehabilitation (too little, too No speed rehabilitation much) Plyometrics training performed inappropriately, not tolerated, or unnecessary

“quick fix” for patellar tendinopathy.31

Corticosteroid injections have been compared to placebo, and corticosteroid improved There is no consensus as to the optimal symptoms so much so that all 12 athletes who surgical technique to use, with surgeons had placebo injection subsequently had performing either a longitudinal or a corticosteroid injections. However, 50% of transverse incision over the patellar tendon, athletes in the corticosteroid group failed to and generally excising abnormal tissue. Some 29 recover and were referred to surgery . surgeons excise the paratenon, while others suture it after having performed a longitudinal Blood injection therapy (autologous blood, tenotomy and excision of the tendinopathic platelet-rich plasma) has been used clinically, area. There has been some enthusiasm for but there are only a few controlled trials. possible arthroscopic debridement of the Compared with standard physiotherapy anterior portion of the fat pad adjacent to the treatment, platelet-rich plasma had similar patellar tendon, and results published to date outcomes at six months30. appear similar to those of patients undergoing

32,33 open surgery. Removal of the fat pad usually makes no difference and might SURGERY increase a patient’s symptoms. The first randomized trial that compared A systematic review of 10 studies of surgery surgical treatment and conservative for patellar tendinopathy reported that management of patellar tendinopathy was techniques, rehabilitation and outcomes published in 2006.31 There were no significant varied considerably; poorer outcomes were differences in outcome between groups; thus reported for surgery that involved the patella, surgical intervention provided no benefit over when the peritendon was closed, and when conservative management. Consequently, the immobilization was standard after surgery.34 clinical implication is that surgery is not a

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

We recommend surgery only after a thorough, 5. OTHER COMMON CAUSES OF high-quality conservative program has failed. INFERIOR KNEE PAIN

Surgeons must advise patients that, while FAT PAD IRRITATION/IMPINGEMENT (INSIDIOUS symptomatic benefit is very likely, return to ONSET) sport at the previous level cannot be We distinguish insidious onset of fat pad pain guaranteed (60 -80% likelihood).32,35 Time to from the condition first described by Hoffa in return to the previous level of sport, if 1903. Hoffa referred to a relatively uncommon achieved at all, is likely to take between six condition where the infrapatellar fat pad was and twelve months.32,35 impinged between the patella and the femoral

condyle due to a direct blow to the knee. More PARTIAL PATELLAR TENDON TEAR commonly, fat pad irritation occurs with The term “partial tear” refers to a sudden repeated or uncontrolled hyperextension of significantly painful episode, which may be the knee. The condition can be extremely associated with disability; this corresponds to painful and debilitating, as the fat pad is one a tear of an area of pathology in the patellar of the most pain sensitive structures of the tendon. If the partial tear is very large, knee.36 causes major disability, and shows no improvement in two to three weeks, early The insidious onset often goes unrecognised. surgery may be justified to stimulate some The pain is often exacerbated by extension healing response in the tendon. manoeuvres, such as straight-leg raises and prolonged standing, it needs to be recognised A small partial tear of the patellar tendon is early so that appropriate management can be soften diagnosed by ultrasonography and is implemented. difficult to differentiate from an area of tendinosis. Alternatively, it may be an Clinical findings include localised tenderness incidental finding on ultrasound examination. (at the inferior pole of the patella, deep and This type of partial tear is part of the both sides of the tendon) and puffiness in the continuum of tendinosis and can be managed fat pad with the inferior pole of the patella conservatively. The indication for surgery of a appearing to be (or actually being) displaced small partial tear is failed conservative posteriorly. Pain may be reproduced with management. active knee extension, passive overpressure in extension, or during squats. Contracting

the quadriceps with the knee extended may aggravate the pain during the acute phase.

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

There may be VMO weakness. Patients often boys as they approach puberty. It is much present with hyperextension of the knees more common among boys (at about age 13 - (genu recurvatum) associated with increased 15); it results from excessive traction on the anterior pelvic tilt. Thus, treatments should be soft apophysis of the tibial tuberosity by the based on the assessments outlined in the powerful patellar tendon. section “Facets that may contribute to pain” (see Part 2) and directed to improve the control, strength, and endurance of local (vasti) proximal and distal muscles, as well as retraining to avoid uncontrolled and excessive terminal knee extension manoeuvres.

A popular clinical approach consists of treating the posteriorly tilted patella by taping across the superior surface of the patella, to lever Figure 5: Fat pad unloading tape. Tape is the inferior pole forward and relieve applied in a “V” from the tibial tuberosity to the joint lines. The fat pad region is pinched impingement of the fat pad (See Part 2). to unload the fat pad while applying the tape. Unloading the fat pad may be required to This tape is often combined with taping of the superior pole of the patella (Part 2) in the relieve the symptoms further. treatment of fat pad impingement. This elevates the inferior pole of the patella.

To unload the fat pad, a “V” tape is placed It occurs in association with high levels of below the fat pad, with the point of the “V” at activity during a period of rapid growth and is the tibial tuberosity coming wide to the medial associated with a change in the tendon. and lateral joint lines. As tape is being pulled Longitudinal imaging of the tendon in towards the joint line, the skin is lifted adolescents without pain shows that the towards the patella, thus shortening the fat attachment transitions to a normal pad (Fig 5). Muscle training and improving attachment through a structure that can be lower limb biomechanics are the basis of interpreted as osteochondritic.38 As with all clinical management. Our clinical impression tendon-related pain, the clinician must be is that surgery should be avoided. To date, careful not to make a diagnosis based only on there have been no randomised controlled imaging findings. 37 trials of surgery for this condition. Treatment consists of reassurance that the condition is self-limiting. Whether or not to OSGOOD-SCHLATTER LESION play sport depends on the severity of Osgood-Schlatter lesion is an osteochondrosis symptoms. Children with mild symptoms may that occurs at the tibial tuberosity in girls and wish to continue to play some or all sport; 11

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3 others may choose some modifications to (“housemaid’s knee”) presents as a superficial their programs. If the child prefers to cease swelling on the anterior aspect of the knee. sport because of pain that decision should be This must be differentiated from an effusion of supported. However, the amount of sport the knee joint. played does not seem to affect the time taken for the pain to disappear. Taping has excellent Acute infective pre-patellar bursitis, common results in reducing recovery time. in those who kneel a lot, should be identified and treated quickly.

SINDING-LARSEN-JOHANNSON LESION Infrapatellar bursitis can cause anterior knee Sinding-Larsen-Johansson is a rare lesion; it pain that may mimic patellar tendinopathy; is one of the group of osteochondroseis found this bursa forms part of an enthesies organ of in adolescents. It is an unimportant the distal insertion and, thus, can be differential diagnosis in young patients with challenging to treat. pain at the inferior pole of the patella.

QUADRICEPS TENDINOPATHY Treatment of mild cases of bursitis includes non-steroidal anti-inflammatory drugs Pain arising at the quadriceps tendon at its (NSAIDs). More severe cases require attachment to the patella occurs mainly in aspiration and infiltration with a corticosteroid older sports people, and in weightlifters as the agent and local anaesthesia, followed by quadriceps tendon is loaded more in a deeper appropriate treatment of the enthesis if squat. It is characterised by tenderness along appropriate. Unloading patellar taping the superior margin of the patella and pain on techniques may be useful. resisted quadriceps contraction. Treatment follows the same principles as treatment of patellar tendinopathy. Differential diagnosis is suprapatellar pain of PFJ origin and bipartite patella. Ruptures of the entire quadriceps attachment to the patella are not uncommon and require surgery and extensive rehabilitation.

BURSITIS

There are a number of bursae around the knee joint; these are shown in Figure 6. The most commonly affected bursa is the pre- patellar bursa. Pre-patellar bursitis Figure 6: Bursae around the knee joint

ANTERIOR KNEE PAIN IN THE SPORTING POPULATION PATELLAR TENDINOPATHIES - PART 3

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38. Ducher G, Cook J, Spurrier D et al. Ultrasound imaging of the patellar tendon attachment to the tibia during puberty: a 12 month follow-up in tennis players. Scand J Med Sci Sports 2010;20(1):e35-40