Journal of the American Academy of Orthopaedic Surgeons 120 Instability of the proximal tibiofibu- lar joint is rarely reported, and descriptions in the literature are few. The clinical scenario ranges from idiopathic subluxation of the joint with no history of trauma to high- energy traumatic dislocations that may be associated with long bone fractures. Injury to the proximal tibiofibular joint is most commonly seen in athletes whose sports require violent twisting motions of the flexed knee, such as wrestling, para- chute jumping, judo, gymnastics, skiing, rugby, football, soccer, track, baseball, basketball, racquetball, and roller skating. 1-6 One case of bilater- al, recurrent proximal tibiofibular dislocation involved an avid jet skier who while skiing remained in the kneeling position with the knees hyperflexed. 7 Some authors think that proximal tibiofibular injuries may be more common than previ- ously thought and that the diagnosis often may be missed. 8,9 The differ- ential diagnosis can be complex and may require excluding entities such as biceps femoris tendinitis, hyper- mobile or torn meniscus, or postero- lateral rotatory instability. Under- standing instability of the proximal tibiofibular joint, its etiology, and its symptoms can help in evaluating the symptomatic patient. Anatomy of the Proximal Tibiofibular Joint The proximal tibiofibular joint is a synovial membrane–lined, hyaline cartilage articulation that, in 10% to 12% of people, communicates with the knee joint. 10-13 The joint capsule is thicker anteriorly than posteri- orly, and there are anterior and pos- terior ligamentous attachments 2,10-13 (Fig. 1). The anterior portion of the proximal anterior tibiofibular joint is stabilized by three broad ligamentous bands that pass ob- liquely upward and attach to the anterior aspect of the lateral tibial condyle. 2,11,13 The posterior proxi- mal tibiofibular ligament, composed of two thick ligamentous bands, passes obliquely from the fibular head to the posterior aspect of the lateral tibial condyle. The posterior band is covered and reinforced by the popliteus tendon. 2,11,13 The pos- terolateral structures of the knee (lateral collateral ligament, arcuate ligament, fabellofibular ligament, popliteofibular ligament, and popli- teus muscle) are thought to help sta- bilize the proximal tibiofibular joint. 14,15 The biceps femoris tendon inserts on the styloid process and upper surface of the head of the fibula and stabilizes anterior move- ment of the fibular head. 2,10,16 An extension of the deep layer of the bi- ceps femoris tendon passes anterior to the anterior proximal tibiofibular ligaments, inserting into Gerdy’s Dr. Sekiya is Lieutenant Commander, Medical Corps, United States Navy, Bone and Joint/Sports Medicine Institute, Department of Orthopaedic Surgery, Naval Medical Center, Portsmouth, VA. Dr. Kuhn is Associate Professor, Division of Sports Medicine, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI. Reprint requests: Dr. Kuhn, Box 0363, 24 Frank Lloyd Wright Drive, Ann Arbor, MI 48106-0363. Copyright 2003 by the American Academy of Orthopaedic Surgeons. Abstract Injury to the proximal tibiofibular joint is typically seen in athletes whose sports require violent twisting motions of the flexed knee. Instability of this joint may be in the anterolateral, posteromedial, or superior directions. With acute injury, patients usually complain of pain and a prominence in the lateral aspect of the knee. A closed reduction should be attempted in patients with acute dislocation. If this is unsuccessful, open reduction and stabilization of the joint with repair of the injured capsule and ligaments can be done. Patients with chronic dislocation or subluxation report lateral knee pain and instability with popping and catching, which may be confused with lateral meniscal injury. Symptoms of subluxation may be treated nonsurgically with physical therapies such as activity modification, supportive straps, and knee strengthen- ing. For patients with chronic pain or instability, surgical options include arthrodesis, fibular head resection, and proximal tibiofibular joint capsule reconstruction. J Am Acad Orthop Surg 2003;11:120-128 Instability of the Proximal Tibiofibular Joint Jon K. Sekiya, MD, and John E. Kuhn, MD Jon K. Sekiya, MD, and John E. Kuhn, MD Vol 11, No 2, March/April 2003 121 tubercle, and reinforces the joint. 13,16 The lateral collateral ligament helps to secure the fibular head to the tibia. It extends from the lateral as- pect of the fibular head just anterior to the styloid and attaches to the posterior aspect of the lateral fem- oral condyle between the lateral femoral epicondyle and the supra- condylar process, immediately above the groove for the popliteus. 2,11,13,15 The lateral collateral ligament is tight from 0° to about 30° of flexion. With knee flexion, the proximal fibula moves anteriorly with relaxation of the lateral collateral ligament and biceps femoris tendon. With knee extension, the proximal fibula is pulled posteriorly because these same structures are tightened. 10,17 This anterior-posterior motion is more evident in young children than in adults. 10 As a result of the laxity in the joint capsule with flexion, injuries to this joint generally occur with the knee in a flexed position. Classification of Anatomic Variation A number of studies have demon- strated an association between par- ticular anatomic variations of the proximal tibiofibular joint and the potential for developing instabil- ity. 2,4,10,11,18 Two general anatomic variants have been identified. 4,10 A horizontal variant (Fig. 2, A) has <20° of joint inclination relative to the horizontal plane, and the fibular head is seated in a groove behind a prominent lateral tibial ridge that enhances its stability against anterior dislocation. 2,4,10 The surface area of the horizontal joint is planar, circu- lar, and relatively large, averaging 26 mm 2 . An oblique variant (Fig. 2, B) is defined by any angle of inclination >20°. 10,11 The oblique type of joint is highly variable in its surface area, configuration, and inclination. 10 This angle of inclination, which can reach up to 76°, and the decreased surface area of the joint, averaging 17 mm 2 , is thought to predispose the oblique anatomic variant to instability. 3,4 Figure 1 Anatomy of the proximal tibiofibular joint. Lateral collateral ligament Biceps femoris tendon Popliteofibular ligament Anterior proximal tibiofibular ligament Popliteus muscle Popliteus tendon Arcuate ligament Lateral collateral ligament Anterior proximal tibiofibular ligament Arcuate ligament Popliteus tendon Popliteal tendon Biceps femoris tendon Posterior proximal tibiofibular ligament Anterior Posterior Lateral A B Figure 2 Lateral radiographs demonstrating anatomic variation of the proximal tibiofibular joint. The slope of the proximal tibiofibular articulation is a risk factor for the development of instability. A, Horizontal articulation (<20° from the horizontal). B, Oblique orientation (>20° from the horizontal), which is more likely to have instability develop. 10° 34° Instability of the Proximal Tibiofibular Joint Journal of the American Academy of Orthopaedic Surgeons 122 The proximal tibiofibular joint allows for the external rotation of the fibula that naturally occurs with ankle dorsiflexion. However, the amount of rotation varies. The oblique variant of articulation is more constrained and has less rota- tional mobility than the horizontal variant. As a result, forced ankle dorsiflexion is thought to increase torsional loads in the fibula in pa- tients with oblique proximal tibio- fibular joints, predisposing the fibula to a higher risk of fracture or dislo- cation. 10 Classification of Instability Patterns Ogden 4,11 described four types of in- stability of the proximal tibiofibular joint: atraumatic subluxation, antero- lateral dislocation, posteromedial dislocation, and the rare superior dislocation. Subluxation of the proximal tibiofibular joint involves excessive and symptomatic anterior- posterior motion without actual dis- location of the joint. 4,9,11 Patients with subluxation of the proximal tibiofibular joint typically have no history of inciting trauma or injury. Atraumatic subluxation of the joint may be seen in patients with gener- alized ligamentous laxity. Anterolateral dislocation is the most common dislocation of the proximal tibiofibular joint and in- volves injury to the anterior and posterior capsular ligaments. The dislocation frequently is associated with injury to the lateral collateral ligament 4,9,11 (Fig. 3). Usually this injury results from a fall on a hyper- flexed knee with the foot inverted and plantarflexed, such as landing with a flexed knee caught under the body. 1-5,10,11,13,19-22 For an anterior dislocation to occur, the proximal fibula must first displace laterally to the edge of the bone buttress of the lateral tibial metaphysis. 4 With the knee in extreme flexion, both the lat- eral collateral ligament and biceps femoris tendon are relaxed, predis- posing the proximal tibiofibular joint to lateral displacement and in- jury. 4,7 Further twisting of the body transmits a torque to the fibula, which dislocates the proximal end laterally, with the peroneal muscles, extensor hallucis longus muscle, and extensor digitorum longus muscle pulling the proximal fibula anteri- orly. 2,4,13,23 Posteromedial dislocations, often associated with peroneal nerve in- juries, usually involve either a direct blow (such as from a car bumper or a horseback rider’s knee striking a gatepost) or a twisting injury that tears the capsule and surrounding ligaments, including the lateral col- lateral ligament. 4,10,11 As the fibula displaces posteriorly, it also dis- places medially along the posterolat- eral tibial metaphysis 4 (Fig. 4). Other mechanisms of injury typically involve twisting of the leg with a violent contraction of the biceps femoris muscle, pulling the head of the fibula posteriorly. 13,22 Superior dislocations are classically associated with a concomitant high- energy ankle injury and superior migration of the entire fibula. 11 The result is an injury to the interosseous membrane between the tibia and fibula (Fig. 5). Atraumatic superior dislocation of the proximal tibiofibu- lar joint also has been associated with congenital dislocation of the knee. 4 Figure 3 A, Anterior and lateral views of anterolateral dislocation (arrows) of the proximal tibiofibular joint. Note that the fibula on the lateral view is anterior to the posterior cortex of the tibia (dotted line). B, Anterior and lateral radiographs of an anterolateral dislocation (arrows). A B Jon K. Sekiya, MD, and John E. Kuhn, MD Vol 11, No 2, March/April 2003 123 Evaluation Clinical Presentation Patients with subluxation of the proximal tibiofibular joint most com- monly report pain on the lateral side of the knee that is exacerbated by direct pressure over the fibular head. 4 Typically there is no history of trauma, and the condition is fre- quently bilateral. 9 Subluxation of the proximal tibiofibular joint may be associated with generalized ligamen- tous laxity, muscular dystrophy, or Ehlers-Danlos syndrome. 4,8,9,24 Patients in whom hypermobility is the source of symptomatic subluxa- tion of the proximal tibiofibular joint typically are preadolescent, often female, and can expect a decrease in symptoms with skeletal matur- ity. 4,9,24-26 Patients with generalized ligamentous laxity that persists into their late forties and fifties may con- tinue to have symptoms as they age. 9 Subluxation of the proximal tibio- fibular joint also has been described in patients with osteomyelitis, rheu- matoid arthritis, septic arthritis, pre- vious below-knee amputations, osteochondroma, or growth distur- bances about the knee, and in run- ners who recently have increased their mileage. 4,8,11,22,27 Patients with an acute dislocation of the proximal tibiofibular joint Figure 4 A, Anterior and lateral views of posteromedial dislocation (arrows) of the proximal tibiofibular joint. The dotted lines indicate the posterior cortex of the tibia. B, Anteroposterior and lateral radiographs of a posteromedial dislocation (arrows). A B Figure 5 A, Anterior and posterior views of superior dislocation (arrows) of the proximal tibiofibular joint. B, Anteroposterior and lateral radiographs of a superior dislocation (arrows). The associated tibia fracture (asterisks) indicates a high-energy injury. A B * * * * Instability of the Proximal Tibiofibular Joint Journal of the American Academy of Orthopaedic Surgeons 124 complain of pain and prominence or swelling in the lateral aspect of the knee. 2,3,5,20,22,28 Many are unable to bear weight because of the pain. 5,21,22 Motion of the ankle aggravates the lateral knee pain. 3 Knee motion also is very painful, and patients may be unable to fully extend the knee. 5,28 Transient peroneal nerve symptoms may be present, especially with pos- teromedial dislocation. 4,9,13,22,28,29 With high-energy trauma, this injury has been associated with concomi- tant fractures of the tibial plateau or shaft (Fig. 5, B), ipsilateral femoral head or shaft, distal femoral epiph- ysis, or ankle, and with knee disloca- tions. 4,30 Proximal tibiofibular dislo- cations often are missed in the initial evaluation of the polytrauma patient with associated fractures. 4 Recurrent or chronic dislocation of the proximal tibiofibular joint can be associated with a wide range of symptoms, most commonly insta- bility of the lateral knee and clicking or popping, which often can be mis- taken for lateral injury of the menis- cus. 1,3,5,20,26-28 In addition, the diag- nosis may be confused with other, better described and recognized lat- eral injuries or disorders, such as lateral collateral ligament injury, biceps femoris tendinitis, posterolat- eral rotatory instability, or iliotibial band syndrome. 8 Although patients usually have no difficulty with activities of daily living, symptoms may develop during sports move- ments that require sudden changes in direction. These movements may produce symptoms of giving way and the sensation of recurrent dislo- cation. 19 Some patients complain of difficulty climbing stairs. 25 The differential diagnosis for in- stability of the proximal tibiofibular joint requires excluding a variety of pathologic conditions related to the lateral side of the knee. Patients may present with a locking or catch- ing sensation, 25,26 suggesting menis- cal tears or a discoid lateral menis- cus. Posterolateral rotatory instabil- ity also is worth considering be- cause many patients present with a feeling that the knee is giving way or is unstable. 25,26 Other less com- mon conditions that may be con- fused with proximal tibiofibular joint instability include exostoses and intra-articular loose bodies in the popliteus tendon sheath, both of which may produce similar symp- toms of popping and catching if tendinous structures are subluxat- ing over the mass. Physical Examination When associated with significant trauma, acute injuries of the proxi- mal tibiofibular joint frequently are missed, so examining this joint is important as part of a comprehen- sive knee examination. It is also im- portant to assess the integrity of the ankle and determine the functional status of the peroneal nerve. Typi- cally, isolated proximal tibiofibular injuries will not present with a knee effusion; however, there may be a prominent lateral mass. 4 With an- terolateral dislocation, there is usu- ally severe pain near the proximal fibula and along the course of the stretched biceps femoris tendon, which may appear to be a tense, curved cord. 4 Pain at the lateral knee is accentuated by dorsiflexing and everting the foot. Pain also is accentuated as the flexed knee is extended. In chronic injuries, or in patients with atraumatic subluxation of the proximal tibiofibular joint, the opti- mal method for examining the joint requires flexing the knee to 90°, which relaxes the lateral collateral ligament and biceps femoris tendon. The knee is palpated for tenderness, and laxity is assessed by translating the fibular head anteriorly and pos- teriorly, grasping it between the thumb and index finger 25 (Fig. 6). It is helpful to ask the patient if this translation reproduces the symp- toms or causes apprehension. It also may be helpful to elicit the Ra˘dules- cu sign, 27 which requires the patient to lie prone. With one hand stabiliz- ing the thigh and the knee flexed to 90°, the leg is rotated internally with the other hand in an attempt to sub- luxate the fibula anteriorly. The proximal tibiofibular joint is usually stable with the knee in full exten- sion; if it is not, injury to the lateral collateral ligament and posterolat- eral structures is likely. 4,9,23 Examination in all patients with suspected proximal tibiofibular injuries should include an assess- ment of the integrity of the lateral collateral ligament and posterolat- eral structures of the knee. These structures frequently are injured with a proximal tibiofibular dislo- cation or may be important in the differential diagnosis. In addition, tenderness at the popliteus tendon or biceps femoris tendon should be elicited. Tendinitis of these struc- tures may produce painful symp- toms at the posterolateral corner of the knee. Imaging Studies Plain radiographs should be taken of the knee in true anteroposterior and lateral views. Comparison radio- Figure 6 Technique for examining the proximal tibiofibular joint. The knee is flexed; the examiner grasps the fibular head and assesses anterior and posterior translation, comparing the involved knee with the normal side. Jon K. Sekiya, MD, and John E. Kuhn, MD Vol 11, No 2, March/April 2003 125 graphs of the contralateral knee can substantially improve the ability to diagnose instability of the proximal tibiofibular joint. 11,31 On the lateral view, the fibular head overlies the posterior border of the tibia. 11 Res- nick et al 11 described a line on lateral radiographs that follows the lateral tibial spine distally along the poste- rior aspect of the tibia and defines the most posteromedial portion of the lateral tibial condyle (Fig. 7). In a normal knee, this line is found over the midpoint of the fibular head. In anterolateral dislocations, the fibular head will be anterior to this line on the lateral view (Fig. 3, B). In pos- teromedial dislocations, all or most of the fibular head is posterior to this line on the lateral view (Fig. 4, B). Oblique views of the knee may be helpful, although this is controver- sial. 11,28,32,33 Axial computed tomog- raphy has been found to be the most accurate imaging modality to detect injury of the proximal tibiofibular joint 32 and is recommended if the diagnosis is suspected but not clearly established based on plain radio- graphs. Treatment of Instability Atraumatic Subluxation Nonsurgical management is usu- ally successful for symptomatic atraumatic subluxation of the proxi- mal tibiofibular joint. For patients with substantial pain, some authors have recommended immobilization in a cylinder cast for 2 to 3 weeks to help diminish symptoms. 4,9 When symptoms of instability persist, a supportive strap or bandage com- bined with lower extremity ham- string and gastrocnemius muscle strengthening may provide some benefit. 5,7,8,25 The strap is placed 1 cm below the fibular head. Care must be taken because if the strap is placed too tightly, it may precipitate a peroneal nerve palsy. It should be worn as needed during activities that produce symptoms. 5,8,25 Ac- tivity modification with avoidance of knee hyperflexion is important in the nonsurgical treatment of sublux- ation. 7,8 In most patients with gen- eralized ligamentous laxity with atraumatic subluxation, the symp- toms are self-limiting and resolve with age; therefore, surgery usually is not needed. Acute Dislocation The initial management of acute proximal tibiofibular joint dislo- cation involves closed reduction, which can be done with either local anesthesia or intravenous seda- tion. 13 Closed reduction is done by placing an appropriately directed force to the fibular head with the knee flexed between 80° and 110°, which relaxes the lateral collateral ligament and biceps femoris ten- don. 4,5,13 There is often an audible pop as the fibula reduces. Some authors believe that it is also help- ful to keep the foot externally rotat- ed, everted, and dorsiflexed, which theoretically relaxes the peroneal, extensor hallucis longus, and ex- tensor digitorum longus muscles. 3,4 Others believe this maneuver is unnecessary. 13 Once reduced, the stability of the knee should be determined with respect to the integrity of the lateral collateral lig- ament and posterolateral struc- tures. Whether to immobilize the pa- tient after successful closed reduc- tion is controversial. Some authors believe that a soft dressing and no immobilization is appropriate, with protected weight bearing on crutches progressing to full weight bearing over 6 weeks. 5,13,20 Others think that immobilization with the knee in the neutral position or slightly flexed for 3 weeks is appropriate. 3,4,28 Inter- estingly, Ogden 4 reported that 57% of patients with acute proximal tibio- fibular dislocations later required surgery for continuing symptoms after failure of treatment with closed reduction and 3 weeks of immobi- lization. Open reduction of the proximal tibiofibular joint should be done when closed reduction fails. 5,13,17,23 This can occur when the proximal fibula is caught anteriorly on the lat- eral tibial ridge with an intact and tight lateral collateral ligament. 23 Following open reduction, the joint should be stabilized in the reduced position with temporary screw fixa- tion or Kirschner wires, combined with a primary repair of the torn capsule and injured ligaments. 5,13,17 Immobilization after surgery typi- cally lasts 6 weeks and should in- clude the ankle joint. After 6 to 12 weeks, the Kirschner wire or screws can be removed. 5,13,17 Other indications for surgical treatment include acute postero- medial dislocations, which have been associated with poor results after nonsurgical management. 4 Although the numbers in his series are small, Figure 7 Lateral radiograph of a normal knee indicating Resnick’s line (broken line) for identifying instability of the proximal tibiofibular joint. In this knee, the line is near the midpoint of the fibular head. Instability of the Proximal Tibiofibular Joint Journal of the American Academy of Orthopaedic Surgeons 126 Ogden 4 believed that patients with this type of dislocation probably should be treated with open reduc- tion, temporary stabilization with a Steinmann pin, and repair of the capsule and lateral collateral liga- ment. Superior dislocations of the proximal tibiofibular joint also typi- cally require surgical intervention because they are invariably associated with a concomitant tibia or ankle fracture. 4 Surgery also is indicated with acute injury to the posterolat- eral structures of the knee because primary repair of these structures has been associated with a favorable outcome. 33 Treatment of Recurrent Symptoms Malreductions or missed disloca- tions may produce degenerative changes of the proximal tibiofibular joint. In such patients, pain is often the primary complaint, and an arthrodesis of the joint can be done. 30 After isolating and protecting the peroneal nerve, the articular surfaces of the proximal tibiofibular joint are denuded of articular cartilage to bleeding subchondral bone. The joint is reduced and fixed with can- cellous lag screws. It is immobilized for 5 weeks; full weight bearing can be started after 8 weeks. 25 Arthro- desis prevents rotation of the fibula, which causes increased rotational stress at the ankle and frequently can lead to pain and instability of the ankle joint. 4,9 Arthrodesis therefore should be avoided, especially in ath- letes and children. 19 If arthrodesis is required, many recommend resect- ing 1.5 cm of the fibula at the junc- tion of the proximal and middle third to avoid overconstraining the fibula. 4,27 An alternative to arthrodesis is fibular head resection. 4 Successful fibular head resection requires exci- sion of the head and neck of the fibula while preserving the fibular styloid and the lateral collateral liga- ment, which is secured to the under- lying tibia. 5,9 When scar is found around the peroneal nerve, a neurol- ysis should be done. 9 In fact, per- oneal nerve symptoms or palsy in chronic subluxation or dislocation of the proximal tibiofibular joint is one indication for fibular head resec- tion. 4,9,29 Unfortunately, fibular head resection also has been associ- ated with the development of chronic ankle pain and knee instability. 7,34 Resection of the fibular head is con- traindicated in athletes because of the possibility of instability from dis- ruption of the posterolateral corner, as well as in children, whose physes are at risk of injury. For patients with symptoms of recurrent instability, reconstruction of the supporting structures of the proximal tibiofibular joint also can be done and has shown promising results in the limited number of published reports. Giachino 19 de- scribed his technique using one half of a posterior strip of biceps femoris tendon still attached distally to the fibular head and a 10-cm rolled strip of deep fascia of the anterolateral compartment of the leg still attached proximally to the fibular head (Fig. 8). The common per- oneal nerve is isolated, the lateral head of the gastrocnemius muscle is retracted, and the soleal attachment to the posterior part of the proximal tibiofibular joint is dissected to expose the posterior surface of the proximal tibia. A hole is then drilled from anterior to posterior in the tibia, and the two new ligaments are wrapped around the head of the fibula with the proximal tibiofibular joint held reduced. The grafts are then passed through the tibial drill hole from posterior to anterior and anchored to the fascia anteriorly. The knee is immobilized for 6 weeks; progressive weight bearing is then advanced. Giachino 19 re- ported good results in two cases without recurrent symptoms of pain or instability, with a return to previ- ous activity level. Alternatively, a 20 × 2–cm strip of iliotibial band, still connected to its insertion on Gerdy’s tubercle, can be tubularized and passed from ante- rior to posterior through a drill hole in the tibia at a level just proximal to Gerdy’s tubercle (Fig. 9). The graft is passed through the posterior cap- sule and arcuate complex, then through a drill hole from posterior to anterior in the reduced fibula at the fibular head/neck junction. The graft is placed deep to the lateral col- lateral ligament from anterior to posterior and tightened, then se- cured to itself and the posterior cap- sule. 1 Complications of the surgical treatment for proximal tibiofibular joint instability include injury to Figure 8 Reconstruction of the proximal tibiofibular joint with biceps femoris ten- don. The posterior half of the biceps femoris tendon is used, leaving the inser- tion on the fibular head. The tendon is routed from posterior to anterior through the tibia (arrow). A strip of the fascia from the anterolateral compartment may be used to augment this reconstruction. (Adapted with permission from Giachino AA: Recurrent dislocations of the proximal tibiofibular joint: Report of two cases. J Bone Joint Surg Am 1986;68:1104-1106.) Biceps femoris tendon Fascia Jon K. Sekiya, MD, and John E. Kuhn, MD Vol 11, No 2, March/April 2003 127 the peroneal nerve. 20,29,32 Arthro- desis of the proximal tibiofibular joint has been associated with late ankle pain and instability. 4,9 Re- section of the proximal fibula has been associated with the develop- ment of knee instability 34 and chronic ankle pain. 7 Recurrence of instability and swelling over the proximal fibula also have been described. 29,32 Summary Proximal tibiofibular dislocation is most commonly seen with sports involving violent twisting motions of the flexed knee. Injury to the joint can be classified into either subluxation or dislocations in the anterolateral, posteromedial, and superior directions. Subluxation of the joint, common in preadolescent girls with no history of trauma, often resolves with skeletal maturity. For subluxation symptoms, nonsurgical therapy with activity modification, supportive straps, and a knee- strengthening program usually is successful. After an acute injury, patients usually complain of pain and prominence in the lateral aspect of the knee. In addition to a thor- ough physical examination, antero- posterior and lateral radiographs of the injured and the contralateral uninjured knees are helpful in mak- ing the diagnosis. With acute dislo- cation, a closed reduction should be done with the knee flexed to ap- proximately 90°. If this is unsuc- cessful, open reduction and stabi- lization of the joint with repair of the injured capsule and ligaments should be done. With chronic dis- location or subluxation, patients report lateral knee pain with insta- bility and popping or catching, which may be confused with lateral meniscal injury. A number of surgi- cal options are available for chronic pain or instability, including ar- throdesis, fibular head resection, and proximal tibiofibular recon- structive procedures. A B Figure 9 Reconstruction of the proximal tibiofibular joint with iliotibial band. A, A 20-cm strip of the anterior portion of the iliotibial band is routed through the tibia, exits posteriorly, and is then routed through the fibular head. B, As the graft exits the anterior fibular head, it is placed deep to the fibular collateral ligament and tightened, then sutured in place. (Adapted with permission from Shapiro GS, Fanton GS, Dillingham MF: Reconstruction for recurrent dislocation of the proximal tibiofibular joint: A new technique. Orthop Rev 1993;22:1229-1232.) References 1. Shapiro GS, Fanton GS, Dillingham MF: Reconstruction for recurrent dis- location of the proximal tibiofibular joint: A new technique. Orthop Rev 1993;22:1229-1232. 2. Ogden JA: Dislocation of the proximal fibula. Radiology 1972;105:547-549. 3. Thomason PA, Linson MA: Isolated dislocation of the proximal tibiofibular joint. J Trauma 1986;26:192-195. 4. Ogden JA: Subluxation and disloca- tion of the proximal tibiofibular joint. J Bone Joint Surg Am 1974;56:145-154. 5. 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