Arthrofibrosis of the Knee David Magit, MD Abstract Andy Wolff, MD Better understanding of surgical timing, improved surgical Karen Sutton, MD technique, and advanced rehabilitation protocols has led to Michael J. Medvecky, MD decreased incidence of motion loss after anterior cruciate ligament injury and reconstruction. However, motion loss from high-energy, multiligament injuries continues to compromise functional outcome. Prevention, consisting of control of inflammation and early motion, remains the key element in avoiding motion loss. However, certain techniques, such as manipulation under anesthesia in conjunction with arthroscopic lysis of adhesions, are reliable treatment options. Open surgical débridement is rarely necessary and should be considered only as a salvage procedure. A greater understanding of the pathogenesis of arthrofibrosis and related inflammatory mediators may result in novel therapies for treating the patient with motion loss. Dr. Magit is Orthopaedic Surgeon, The Greenwich Sports and Shoulder oss of knee motion is a devastat- tients with arthrofibrosis.1 Service, Orthopaedic and Neurosurgery Ling consequence of both single- Arthrofibrosis represents a wide Specialists PC, Greenwich, CT. Dr. and multiligamentous injury and spectrum of disease, ranging from lo- Wolff is Fellow, Steadman Hawkins their reconstruction. Increased recog- calized to diffuse involvement of all Clinic, Vail, CO. Dr. Sutton is Resident, nition of this problem in the past two compartments of the knee and of the Department of Orthopaedics and decades has led to better prevention extra-articular soft tissues. Preven- Rehabilitation, Yale University School of and improved management of these tion of motion loss remains essential Medicine, New Haven, CT. Dr. Medvecky injuries. Despite these advances, to successful outcome. In the patient is Assistant Professor, Department of however, motion loss remains a prob- who experiences motion loss despite Orthopaedics and Rehabilitation, Yale lematic consequence of knee liga- preventive measures, treatment op- University School of Medicine. ment injury. tions include static or dynamic brac- None of the following authors or a The incidence of motion loss var- ing, manipulation under anesthesia, member of their immediate families has ies according to the degree of injury. and arthroscopic or open débride- received anything of value from or owns Motion loss is less severe after single- ment. In recalcitrant cases, arthrode- stock in a commercial company or ligament, low-energy injury than af- sis in the older patient or total knee institution related directly or indirectly to ter high-energy, multiligament in- arthroplasty may be required. the subject of this article: Dr. Magit, Dr. jury. The etiology of motion loss is Wolff, Dr. Sutton, and Dr. Medvecky. multifactorial, involving a combina- Normal Knee Motion Reprint requests: Dr. Magit, The tion of mechanical and biologic fac- Greenwich Sports and Shoulder tors. Major risk factors include tech- Normal knee motion involves a Service, Orthopaedic and Neurosurgery nical errors during intra-articular combination of longitudinal axial, ro- Specialists PC, 6 Greenwich Office ligament reconstruction and extra- tation, varus/valgus angulation, and Park, 10 Valley Drive, Greenwich, CT articular procedures, injury severity, flexion/extension arcs. Flexion and 06831. timing of surgery, delayed postoper- extension can be categorized into ative physical rehabilitation, hetero- three sub-arcs: terminal extension, J Am Acad Orthop Surg 2007;15:682- topic ossification, prolonged immo- active function, and passive flexion. 694 bilization, infection, and complex The arc of terminal extension, also Copyright 2007 by the American regional pain syndrome. Recently, called “screw home,” begins at the Academy of Orthopaedic Surgeons. authors have begun to examine pos- limit of passive extension. This arc sible genetic differences among pa- moves from 10° of flexion to 5° of hy- 682 Journal of the American Academy of Orthopaedic Surgeons David Magit, MD, et al Figure 1 Knee motion can be measured by the standard goniometric method (A) or by measuring the heel-height difference (B). (Panel A reproduced and panel B adapted from Schlegel TF, Boublik M, Hawkins RJ, Steadman JR: Reliability of heel-height measurement for documenting knee extension deficits. Am J Sports Med 2002;30:479-482.) perextension. The arc of terminal ex- gait. Without flexion beyond 125°, Measuring Motion Loss tension is rarely used in normal gait the patient may report an inability but is thought to allow for quadriceps to squat. Small flexion deficits in Proper care for the patient with re- muscle relaxation during the stance the athlete, however, can produce cent ligamentous knee injury or phase. The arc of active function marked changes in performance. reconstruction requires accurate de- ranges from 10° to approximately Loss of flexion ≥10° can affect run- tection of motion loss. The most 120°, which covers the range needed ning speed. Severe flexion deficits common method involves placing a for most activities of daily living, in- <90° affect the ability of even the goniometer over the lateral knee cluding sitting and stair climbing. most sedentary patient to sit or joint line in the midsagittal position, The arc of passive flexion begins at climb stairs. using the greater trochanter and lat- approximately 120° and continues to eral malleolus as reference points the passive limit of an applied exter- Extension Loss (Figure 1, A). Several studies have nal force. Typically, passive flexion is Extension loss is poorly tolerated demonstrated high inter- and in- 140° in men and 143° in women. and can be more difficult to manage traobserver reliability with this However, flexion to 165° is seen in than loss of flexion. As little as 5° of method.4 A second method involves societies in which full kneeling or extension loss can produce a notice- measuring the heel-height differ- squatting is common, such as in Ja- able limp during ambulation, strain ence, which is done with the patient pan, India, and the Middle East.2 the quadriceps muscle, and contrib- in the prone position (Figure 1, B). In ute to patellofemoral pain. During general, 1 cm of heel-height differ- ence correlates to 1° of knee flexion Flexion and Extension weight bearing on a flexed knee, the contracture. This technique may be Deficits quadriceps muscle force required to stabilize the knee is 75% of the load helpful in detecting subtle degrees of Flexion Loss on the femoral head at 15° of flexion, motion loss (<10°).5 The functional effects of knee 210% at 30°, and 410% at 60°.3 With motion loss vary depending on pa- increased joint contact pressure, the Classification of Motion tient activity. In general, flexion to clinical consequences are increased Loss 125° is adequate for completing ac- quadriceps muscle activity and fa- tivities of daily living and usually tigue, and, ultimately, patellofemo- Determining the true incidence of does not adversely affect normal ral arthrosis. motion loss can be difficult, given Volume 15, Number 11, November 2007 683 Arthrofibrosis of the Knee 16 Table 1 motion loss. Sisto and Warren reported motion problems in 6 of 20 Sprague Pathoanatomic Classification of Motion Loss patients (30%). Shapiro and Freed- 17 Group Pathoanatomy man reported a 57% incidence of postdislocation motion loss. In this 1 Discreet bands or a single sheet of adhesions traversing the study, patients required an additional suprapatellar pouch procedure to restore motion. 2 Complete obliteration of the suprapatellar pouch and peripatellar gutters with masses of adhesions 3 Multiple bands of adhesions or complete obliteration of the Risk Factors for Motion suprapatellar pouch with extracapsular involvement with Loss bands of tissue from proximal patella to anterior femur Technical Errors Reproduced with permission from Sprague NF III, O’Connor RL, Fox JM: Proper graft placement in ACL re- Arthroscopic treatment of postoperative knee fibroarthrosis. Clin Orthop Relat Res 1982;166:165-172. construction is essential to reducing motion loss.18 Graft placement ante- rior to the native ACL insertion on Table 2 the tibia results in impingement on Classification of Motion Loss of the Knee Based on Deviation From Full the roof of the intercondylar notch in Flexion and Extension extension. Lateral placement on the tibia produces impingement on the Group Extension Flexion Severity lateral wall of the intercondylar 1 <5° >110° Mild notch. Placement too far anterome- 2 5°-10° 90°-110° Moderate dially has been shown to limit flex- 19 3 >10° <90° Severe ion. On the femoral side, the most common error is graft placement too Reproduced with permission from Del Pizzo W, Fox JM, Friedman ML, et al: far anterior, which causes excessive Operative arthroscopy for the treatment of arthrofibrosis of the knee. Contemp Orthop 1985;10:67-72. strain on the graft, leading to limited flexion and potential graft failure.20,21 Other sources of graft impinge- the number of available classification extension loss >10° with patella in- ment include the intercondylar schemes. Sprague et al6 defined mo- fera. notch and adjacent posterior cruci- tion loss based on a pathoanatomic ate ligament (PCL). Whereas moder- distribution (Table 1). Later classifi- Incidence of Motion ate notch impingement can cause cation schemes focused on knee Loss pain, effusion, and extension loss, range of motion (ROM). Del Pizzo et severe impingement can cause abra- al7 graded motion