Primary reconstruction of injuries of the capsular ligament of the knee joint

Whether operative or conservative treatment is indicated for acute knee ligament injuries depends on the lesions of the cruciate ligaments: complex instability with rupture of one or both cruciate ligaments and injuries to the lateral or medial ligamentous structures should be treated by operation. Surgical treatment of an isolated rupture of the anterior cruciate ligament is recommended only for the young active patient. Surgery is performed by way of a single anterolateral incision with standard medial and if necessary, lateral arthrotomies. Ruptures of the cruciate ligaments are reconstructed with absorbable sutures, which are passed through bone channels. Augmentation with an absorbable allograft is used in most reconstructions of the cruciate ligaments. A knee brace with limited range of motion is used for postoperative rehabilitation. Our long-term results after operative reconstruction of acute instabilities of the knee joint show that ligamentous stability was achieved in most cases, but the functional results were impaired by pain and limited range of motion.     

Comparison of magnetic resonance imaging with operative findings in acute traumatic dislocations of the adult knee

OBJECTIVES: To compare magnetic resonance imaging (MRI) with examination under anesthesia and with surgical findings in evaluating soft tissue injuries in acute traumatic knee dislocations in adults. DESIGN: Retrospective analysis. SETTING: Level I trauma center. PATIENTS: For a single surgeon, all patients who underwent MRI before surgical treatment for knee dislocations (ten individuals). INTERVENTION: Incompetent ligaments were repaired or reconstructed. MAIN OUTCOME MEASUREMENTS: MRI of knee dislocations was compared with clinical examination under anesthesia and with intraoperative findings at arthrotomy in ten cases. Pertinent positive and negative findings were recorded, and accuracy, sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Two mid-grade sprains of the anterior cruciate ligament were erroneously read as complete tears. One rupture or avulsion of each the biceps tendon, the lateral collateral ligament, and the posterolateral and posteromedial corners were considered intact on MRI. The MRI studies erroneously identified tears of the lateral collateral ligament and medial meniscus in one case each. Otherwise, the study was highly accurate. CONCLUSIONS: MRI is useful for defining the presence of ligamentous injuries in knee dislocations; however, clinical examination under anesthesia is more accurate.     

Strain gauge analysis of knee ligaments

Mercury strain gauges were sutured onto the tibial collateral anterior and posterior cruciate ligaments to quantitatively determine the relative strain or deformation of each of these ligaments as a function of joint position. The results were obtained on 5 amputation specimens by subjecting them to flexion, extension, rotation, valgus--varus and anteroposterior forces. The tibial collateral ligament is most lax in full flexion and stretches with extension, valgus and external rotation. The cruciate ligaments are most lax at 35 degrees flexion and stretch with both flexion and extension. Internal rotation and varus stretch and anterior cruciate ligament. These principles allow us a better understanding of injury patterns. The most advantageous position for immobilization following acute injuries or reconstructions is better understood knowing that minimal tension on ligamentous fibers occurs as follows: Anterior cruciate, 35 degrees; Posterior cruciate, 35 degrees; Tibial collateral ligament, 45--90 degrees (or as much flexion as the patient will tolerate).     

Der Kniebandschaden als Begleitverletzung bei Femurschaftfrakturen

Knee ligament injuries associated with femoral shaft fractures can severely influence the functional results of treatment. In a follow-up of 59 operatively treated femoral shaft fractures 18.6% of the patients revealed ligamentous damages. In all cases one or both of the cruciate ligaments were injured. Especially polytraumatized car front-seat passengers are at higher risk with 30.8% ligament ruptures. While only 61.6% of the ligament injuries were primarily diagnosed, the testing of knee joint stability after osteosynthesis of a femoral fracture is essential. Furthermore arthroscopy should be performed if there is any hint of ligamentous damage. The ruptures of the anterior cruciate ligament and the ligamentous avulsion fractures can be successfully treated on by operative means.     

急性完全性前交叉韧带损伤的膝关节镜下早期重建治疗

目的　探讨膝关节镜下对急性完全性前交叉韧带 (ACL)断裂的早期重建治疗 ,以尽早恢复膝关节稳定性。　方法　ACL急性断裂早期在关节镜下应用挤压螺钉固定骨 髌腱 (中 1/ 3) 骨复合体自体移植重建ACL ,止点重建或缝合修复治疗内侧副韧带断裂。　结果　 1998年 2月～ 1999年 3月共治疗急性完全性ACL断裂合并内侧副韧带断列患者 10例 ,术后平均随访 10个月 ,近期效果良好。　结论　急性ACL损伤早期可以在关节镜下完成重建 ,手术创伤小 ,治疗及时 ,可同时处理合并损伤 ,能早期恢复膝关节稳定性和运动功能。     

Isolierte und kombinierte Kniebandverletzungen

Complex knee ligament injuries are characterized by simultaneous rupture of the anterior cruciate ligament (ACL) and/or the posterior cruciate ligament (PCL) and at least one collateral ligament. Isolated injury to the medial collateral ligament (MCL) and PCL have a high healing capacity and can be treated conservatively in many cases. Ruptures of the MCL can also be treated conservatively in complex injuries if the cruciate ligaments are reconstructed. Ruptures of the lateral structures usually need surgical reconstruction. Indications for acute surgical repair include meniscus dislocation, entrapment of collateral ligament portions in the joint, knee dislocation with severe knee instability, and displaced bony avulsions. The anatomy of the knee ligaments must be carefully respected in surgical reconstruction. Acute repair of collateral ligament injuries is possible only in the first 2 weeks after trauma. Acute arthroscopy is indicated only in combination with reconstructive surgery.     

Ruptur des vorderen Kreuzbands

Rupture of the anterior cruciate ligament (ACL) is the most common ligamentous knee injury. The knee is stabilized by the cruciate ligaments and the collateral ligaments. The ACL originates from the inner surface of the lateral condyle of the femur, runs in an anterior medial direction and inserts at the tibial plateau in the intercondyle area. The most common injury is an indirect knee trauma, typically a joint torsion in sports. Patients often describe a snapping noise followed by hemarthrosis. Concomitant injuries are lesions of the medial collateral ligament, the medial meniscus (unhappy triad) and chondral fractures. The age peak is between 15 and 30 years with a higher incidence in females. The cardinal symptom of the ACL rupture is the giving way phenomenon. The clinical diagnosis is provided by a positive Lachman test, a positive pivot shift test and the anterior drawer test. Fractures can be excluded by X-ray examination. Magnetic resonance imaging (MRI) allows the evaluation of the internal knee structures. ACL repair is carried out by arthroscopically assisted bone-tendon-bone or semitendinosus grafting techniques. Early rehabilitation is important for a good functional outcome.     

Reconstruction of knees with combined cruciate deficiencies: a biomechanical study

BACKGROUND: Clinical results of dual cruciate-ligament reconstructions are often poor, with a failure to restore normal anterior-posterior laxity. This could be the result of improper graft tensioning at the time of surgery and stretch-out of one or both grafts from excessive tissue forces. The purpose of this study was to measure anterior-posterior laxities and graft forces in knees before and after reconstructions of both cruciate ligaments performed with a specific graft-tensioning protocol. METHODS: Eleven fresh-frozen cadaveric knee specimens underwent anterior-posterior laxity testing and installation of load cells to record forces in the native cruciate ligaments as the knees were passively extended from 120 degrees to -5 degrees with no applied tibial force, with 100 N of applied anterior and posterior tibial force, and with 5 N-m of applied internal and external tibial torque. Both cruciate ligaments were reconstructed with a bone-patellar tendon-bone allograft. Only isolated cruciate deficiencies were studied. We determined the nominal levels of anterior and posterior cruciate graft tension that restored anterior-posterior laxities to within 2 mm of those of the intact knee and restored anterior cruciate graft forces to within 20 N of those of the native anterior cruciate ligament during passive knee extension. Both grafts were tensioned at 30 degrees of knee flexion, with the posterior cruciate ligament tensioned first. Measurements of anterior-posterior knee laxity and graft forces were repeated with both grafts at their nominal tension levels and with one graft fixed at its nominal tension level and the opposing graft tensioned to 40 N above its nominal level. RESULTS: The anterior and posterior cruciate graft tensions were found to be interrelated; applying tension to one graft changed the tension of the other (fixed) graft and displaced the tibia relative to the femur. The posterior cruciate graft had to be tensioned first to consistently achieve the nominal combination of mean graft forces at 30 degrees of flexion. At these levels, mean forces in the anterior cruciate graft were restored to those of the intact anterior cruciate ligament under nearly all test conditions. However, the mean posterior cruciate graft forces were significantly higher than the intact posterior cruciate ligament forces at full extension under all test conditions. Anterior-posterior laxity was restored between 0 degrees and 90 degrees of flexion with both grafts at their nominal force levels. Overtensioning of the anterior cruciate graft by 40 N significantly increased its mean force levels during passive knee extension between 110 degrees and -5 degrees of flexion, but it did not significantly change anterior-posterior laxity between 0 degrees and 90 degrees of flexion. In contrast, overtensioning of the posterior cruciate graft by 40 N significantly increased posterior cruciate graft forces during passive knee extension at flexion angles of <5 degrees and >95 degrees and significantly decreased anterior-posterior laxities at all flexion angles except full extension. CONCLUSIONS: It was not possible to find levels of graft tension that restored anterior-posterior laxities at all flexion positions and restored forces in both grafts to those of their native cruciate counterparts during passive motion. Our graft-tensioning protocol represented a compromise between these competing objectives. This protocol aimed to restore anterior-posterior laxities and anterior cruciate graft forces to normal levels. The major shortcoming of this tensioning protocol was the dramatically higher posterior cruciate graft forces produced near full extension under all test conditions.     

Biomechanics of the anterior cruciate ligament:Physiology,rupture and reconstruction techniques

The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.     

Two-stage reconstruction with autografts for knee dislocations

Traumatic knee dislocations are severe injuries that involve damage to the anterior cruciate ligament, the posterior cruciate ligament, and the lateral or medial ligamentous structures. There are no established methods of treatment. The objective of the current study was to report the clinical outcome of a two-stage autologous reconstruction on nine knees (eight patients). The mean followup was 40.1 months. The first stage of the reconstruction was done at a mean of 2 weeks after the injury, and the posterior cruciate ligament was reconstructed by an arthroscopically assisted technique using contralateral autogenous hamstring tendon as the graft material. Three months later, the second stage of the reconstruction was done for the ligaments that had not healed with conservative treatment. Arthroscopically assisted anterior cruciate ligament reconstruction was done on all of the knees using the ipsilateral autogenous hamstring tendon or bone-patellar tendon-bone as the graft material. At the same time, a medial collateral ligament reconstruction using an autogenous semitendinosus tendon was done on one knee, and reconstruction of the posterolateral ligamentous structures using a biceps tendon was done on three knees. Each of the knees that was reconstructed was capable of full extension, and the mean degree of passive flexion was 139.5 degrees +/- 5.2 degrees. The mean side-to-side difference in anteroposterior total laxity (KT-1000 arthrometer, manual maximum) was 2.3 +/- 1.9 mm. None of the knees had lateral or medial instability. All of the injured ligaments were able to be reconstructed with autografts, and severe contracture was able to be prevented. A good clinical outcome can be achieved when two-stage reconstruction is used for traumatic knee dislocations.     

Two-phase surgical treatment of anteromedial knee injuries

The treatment of severe anteromedial knee injuries over the years has undergone various types of approach, changing from proposals, such as combined surgical repair of the anterior cruciate ligament and medial compartment, to the more current protocol which involves conservative treatment of the peripheral injury and later reconstruction of the anterior cruciate ligament. However, in serious ruptures of the medial ligament compartment, conservative treatment does not make it possible to recover peripheral stability, thus transferring abnormal forces onto the anterior cruciate pro-ligament graft which can gradually deteriorate the transplant itself. Thus in severe anteromedial injuries a treatment with two distinct surgical phases is proposed, using direct immediate suture of the peripheral compartment and, after a period of rehabilitation, later replacement of the anterior cruciate ligament by arthroscope graft. Given the obtained results and the few complications observed in 25 cases, it is probable that this therapeutic scheme can be proposed in selected cases of severe ligament laxity of the medial compartment associated with rupture of the anterior cruciate ligament.     

Effects of joint load on the stiffness and laxity of ligament-deficient knees. An in vitro study of the anterior cruciate and medial collateral ligaments

We measured the effects of serial section of the medial collateral ligament and anterior cruciate ligament and of the anterior cruciate ligament and medial collateral ligament on anterior-posterior force-versus-displacement and tibial torque-versus-rotation response curves for seven fresh frozen cadaver knees at zero and 20 degrees of flexion before and after application of as much as 925 newtons of compressive load on the tibiofemoral joint. Section of the anterior cruciate ligament always increased anterior laxity in an unloaded specimen; joint load reduced this increase by a greater amount at zero degrees than at 20 degrees of flexion. Joint load was more effective in limiting anterior laxity in anterior cruciate-deficient specimens at low levels of applied anterior force; at higher levels of applied force, the effects of joint congruency were overcome and ligament restraints came into play. Section of the medial collateral ligament increased anterior laxity in an unloaded knee only for specimens in which the anterior cruciate ligament had been previously sectioned; joint load eliminated this increase at full extension but did not do so at 20 degrees of flexion. The medial collateral ligament was the more important of the two ligaments in controlling torsional laxity. Secondary section of either ligament (the other ligament having been sectioned first) produced a greater increase in laxity than did primary section of that ligament in an intact knee. Increases in torsional laxity due to primary section of either ligament were unaffected by the application of joint load. Joint load reduced increases in laxity that were due to secondary section of the medial collateral ligament.     

High-energy knee dislocation without anterior cruciate ligament disruption in a skeletally immature adolescent

Knee dislocations are rare injuries in any age group, but even more unusual in skeletally immature individuals. Such injuries often occur from high-energy mechanisms and are commonly associated with disruption of both anterior and posterior cruciate ligaments. Although there are several previous reports of knee dislocation without disruption of the posterior cruciate ligament, there is only one report citing 3 cases of knee dislocation with the anterior cruciate ligament remaining intact, each occurring in skeletally mature individuals. We present a high-energy knee dislocation in a skeletally immature girl without anterior cruciate ligament disruption. We also discuss the evaluation, management, and outcome. Treatment of this condition with arthroscopically assisted posterior cruciate ligament reconstruction using tibialis anterior allograft 2 weeks after the acute injury resulted in complete functional recovery.     

膝关节韧带损伤的MRI诊断价值

目的:探讨膝关节韧带损伤的MRI特点与诊断价值。方法:收集2008年6月至2010年2月经MRI检查的74例膝关节损伤患者,男47例,女27例;年龄12～76岁,平均37.3岁;病程2h～10d。临床表现为膝关节肿胀、疼痛,关节不稳、伸屈活动障碍,外翻试验、抽屉试验阳性,膝内侧明显压痛。对其MRI表现进行回顾性分析。结果:74例韧带损伤,其中前交叉韧带19例,后交叉韧带18例,外侧副韧带13例,内侧副韧带24例。韧带完全断裂12例,其中8例交叉韧带MR表现为韧带的连续性中断、断端回缩,局部或弥漫性肿胀,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号;4例侧副韧带MR表现为韧带连续性中断或韧带肿胀增粗,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号。部分纵形撕裂62例,MR表现为韧带连续性完整,韧带增粗,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号。经手术、关节镜检查确诊44例,与MRI诊断相符41例。结论:MRI能诊断膝关节韧带损伤,是一种理想的诊断膝关节外伤的检查方法,宜作为常规检查。     

Knee dislocations: where are the lesions? A prospective evaluation of surgical findings in 63 cases

OBJECTIVE: To evaluate soft-tissue injury patterns in a large series of patients with knee dislocations to identify frequency and associations that may aid in surgical planning. DESIGN: Prospective clinical study. SETTING: Two institutions, both level I trauma centers. PATIENTS: Sixty patients with 63 dislocatable knees. RESULTS: Cause of injury was motor vehicle injury in 34 patients, sports in 23 patients, and falls in 3 patients; 71% of knees studied had bicruciate injuries. Eight knees had associated major intraarticular fractures. Vascular disruption occurred in 14% of knees. Peroneal nerve palsies occurred in 14% of knees. All injured knees with complete peroneal nerve palsies had anterior cruciate ligament, posterior cruciate ligament, and lateral collateral ligament disruptions. The incidence of vascular injury was the same for patients injured in sports as for those injured in road trauma. Reattachable ligamentous avulsions occurred in 19% for anterior cruciate ligament, 51% for posterior cruciate ligament, 64% for medial collateral ligament, and 84% for lateral collateral ligament injuries. Certain injury patterns also had a high association of tendon and capsule avulsions. Proximal lateral collateral ligament injuries were commonly associated with popliteus tendon avulsions and seldom with distal biceps avulsions. Distal lateral collateral ligament injuries were commonly associated with distal biceps avulsions and seldom with popliteus tendon avulsions. Reattachable meniscal capsular avulsions off the tibia occurred predominantly when the collateral ligament injury was a distal avulsion. CONCLUSIONS: This study showed a wide variety of injury patterns. Knees had to have at least two ligaments injured to be dislocatable but not necessarily both cruciate ligaments. Sports injuries have the same pattern of injury as motor vehicle accidents, suggesting similar forces of injury. The study demonstrates a high incidence of reattachable avulsion injuries to ligaments and soft tissues in dislocatable knees. These may not be as easily dealt with if surgery is delayed beyond 3-4 weeks.     

Medial collateral ligament healing one year after a concurrent medial collateral ligament and anterior cruciate ligament injury: An interdisciplinary study in rabbits

The optimal treatment for concurrent injuries to the medial collateral and anterior cruciate ligaments has not been determined, despite numerous clinical and laboratory studies. The objective of this study was to examine the effect of surgical repair of the medial collateral ligament on its biomechanical and biochemical properties 52 weeks after such injuries. In the left knee of 12 skeletally mature New Zealand White rabbits, the medial collateral ligament was torn and the anterior cruciate ligament was transected and then reconstructed. This is an experimental model previously developed in our laboratory. In six rabbits, the torn ends of the medial collateral ligament were repaired, and in the remaining six rabbits, the ligament was not repaired. Fifty-two weeks after injury, we examined varus-valgus and anterior-posterior knee stability; structural properties of the femur-medial collateral ligament-tibia complex; and mechanical properties, collagen content, and mature collagen crosslinking of the medial collateral ligament. We could not detect significant differences between repair and nonrepair groups for any biomechanical or biochemical property. Our data support clinical findings that when the medial collateral and anterior cruciate ligaments are injured concurrently and the anterior cruciate ligament is reconstructed, conservative treatment of the ruptured medial collateral ligament can result in successful healing.     

Healing of the transected anterior cruciate ligament in the rabbit

Healing of the anterior cruciate ligament was studied in 170 male rabbits. One group included immature animals that had open epiphyses, and a second group consisted of only mature animals. In one knee of each animal, the anterior cruciate ligament was transected either completely or partially, and in the contralateral knee a sham operation was carried out. Mechanical testing and histological studies of the ligaments were done immediately postoperatively and at two weeks, six weeks, three months, and one year. As we expected, there was no regeneration after complete transection of the anterior cruciate ligament, and all of the animals in which this procedure was done had severe osteoarthrosis of the joint at three months. Postoperatively, the partially sectioned ligaments exhibited one-third of the strength of the ligaments on the side on which the sham operation had been done in the immature animals and one-fourth of the strength of the ligaments on the side on which the sham operation had been done in the mature animals. Subsequently, there was secondary complete rupture of 20 per cent of the partially sectioned ligaments. The remaining 80 per cent of the partially sectioned ligaments were clearly weaker two weeks after the operation than immediately postoperatively, but this was also true on the side on which the sham operation had been done. At six weeks, the initial postoperative strength of the partially sectioned ligaments had been regained. At one year, the ligaments of the immature animals were two-thirds as strong as those on the contralateral side, and those of the mature animals were three-fourths as strong as those on the contralateral side. The ligaments were markedly elongated, especially in the mature animals. At three months, stiffness of the ligaments returned to normal. Histologically, the defect was filled with tissue that was still somewhat different from normal ligamentous tissue.     

Anterior cruciate ligament deficiency alters the in vivo motion of the tibiofemoral cartilage contact points in both the anteroposterior and mediolateral directions

BACKGROUND: Quantifying the effects of anterior cruciate ligament deficiency on joint biomechanics is critical in order to better understand the mechanisms of joint degeneration in anterior cruciate ligament-deficient knees and to improve the surgical treatment of anterior cruciate ligament injuries. We investigated the changes in position of the in vivo tibiofemoral articular cartilage contact points in anterior cruciate ligament-deficient and intact contralateral knees with use of a newly developed dual orthogonal fluoroscopic and magnetic resonance imaging technique. METHODS: Nine patients with an anterior cruciate ligament rupture in one knee and a normal contralateral knee were recruited. Magnetic resonance images were acquired for both the intact and anterior cruciate ligament-deficient knees to construct computer knee models of the surfaces of the bone and cartilage. Each patient performed a single-leg weight-bearing lunge as images were recorded with use of a dual fluoroscopic system at full extension and at 15 degrees , 30 degrees , 60 degrees , and 90 degrees of flexion. The in vivo knee position at each flexion angle was then reproduced with use of the knee models and fluoroscopic images. The contact points were defined as the centroids of the areas of intersection of the tibial and femoral articular cartilage surfaces. RESULTS: The contact points moved not only in the anteroposterior direction but also in the mediolateral direction in both the anterior cruciate ligament-deficient and intact knees. In the anteroposterior direction, the contact points in the medial compartment of the tibia were more posterior in the anterior cruciate ligament-deficient knees than in the intact knees at full extension and 15 degrees of flexion (p < 0.05). No significant differences were observed with regard to the anteroposterior motion of the contact points in the lateral compartment of the tibia. In the mediolateral direction, there was a significant lateral shift of the contact points in the medial compartment of the tibia toward the medial tibial spine between full extension and 60 degrees of flexion (p < 0.05). The contact points in the lateral compartment of the tibia shifted laterally, away from the lateral tibial spine, at 15 degrees and 30 degrees of flexion (p < 0.05). CONCLUSIONS: In the presence of anterior cruciate ligament injury, the contact points shift both posteriorly and laterally on the surface of the tibial plateau. In the medial compartment, the contact points shift toward the medial tibial spine, a region where degeneration is observed in patients with chronic anterior cruciate ligament injuries.     

Segond骨折的诊治分析

目的：探讨Segond骨折的临床特点和手术治疗的方法与时机。方法：自2008年6月至2011年12月收治16例Segond骨折,6例于伤后1周内行关节镜探查发现前交叉韧带完全断裂,半月板损伤;10例于伤后8～10周行关节镜探查,发现4例前后交叉韧带完全断裂,4例前交叉韧带完全断裂,2例前交叉韧带部分断裂,其中前交叉韧带完全断裂的8例合并半月板损伤,前交叉韧带不全断裂的1例半月板未见明显损伤,1例合并腓骨头骨折与外侧副韧带损伤。所有交叉韧带完全断裂和不全断裂的患者在关节镜探查后行交叉韧带重建术,5例半月板损伤患者行半月板缝合或成形术。术后采用Lysholm—Gillquist膝关节评分进行疗效评定。结果：伤后1周内行手术治疗的6例术后3d时膝关节肿胀明显,关节腔穿刺抽吸有淡血性液抽出,术后1周时始佩戴护具下床活动。伤后8-10周内行手术治疗的10例术后3d时膝关节无明显肿胀,关节腔穿刺抽吸无淡血性液抽出,术后3d即佩戴护具下床活动。所有患者术后获随访,时间12—50个月,平均24个月。术后Lysholm—Gillquist膝关节评分高于术前。所有病例获得满意效果。结论：Segond骨折常合并前交叉韧带损伤和半月板损伤,早期正确诊断对治疗十分重要,关节镜下行交叉韧带重建及半月板修复的最佳手术时间宜在术后8-10周内进行。     

Knee dislocation following anterior cruciate ligament disruption without any other ligament tears.

We report a rare case of complete knee dislocation following anterior cruciate ligament (ACL) disruption without any other ligament tears. The pathology of the knee joint was torn ACL, intact other ligaments, osteochondral fractures and bone bruise of the lateral femoral condyle, and torn lateral meniscus. In this case, osteochondral fracture resulting from the anteriorly sublaxiation of the tibia following ACL disruption was considered to prevent from spontaneous reduction. This case suggests that anterolateral knee dislocation and spontaneous reduction may occur in ACL injuries.