Irreducible dislocation of the knee joint

Posterolateral knee dislocations are very rare and generally irreducible by closed reduction. It is due to interposition of various portions of medial capsule-ligamentous structure in the knee joint space. In such cases, open reduction is recommended. Only a few cases have been reported in the literature. This article presents an unusual case of irreducible knee dislocation, in which the medial femoral condyle buttonholed through the medial retinaculum and capsular structure. Closed reduction attempt was unsuccessful. Open joint reduction was performed. Direct repair of the medial collateral ligament and retinaculum, and arthroscopic assisted posterior cruciate ligament reconstruction were also performed. Arthroscopic-assisted anterior cruciate ligament reconstruction was carried out in staged operation.     

Irreducible dislocation of the knee joint: two-stage treatment

Closed reduction attempts may be unsuccessful after traumatic knee dislocations on rare occasions. The interposition of the soft tissues on the medial aspect of the joint into the femoral condyle and tibial plateau is shown to be the cause of an unsuccessful reduction. In such cases, open reduction is the recommended method of treatment. In our study, we presented a 16-year-old male with an open knee dislocation after a motorcycle accident. As our closed reduction attempt failed, open joint reduction and repair of the medial collateral ligament and retinaculum was performed in the first stage of treatment. In the second stage, arthroscopic anterior cruciate ligament and posterior cruciate ligament reconstructions were carried out.     

Two cases of irreducible knee dislocation occurring simultaneously in two patients and a review of the literature.

Knee dislocations normally respond to closed reduction; however, a small percentage must be reduced by open operations. A 24-year-old man exhibited typical medial joint-line puckering during repeated reduction attempts and a mild lateral displacement on roentgenograms. A 31-year-old woman had a complete dislocation of her knee, with the femur "buttonholed" through medial soft tissue and entrapped by the joint capsule. Longitudinal incision of the medial joint capsule was the method of reduction. The lateral collateral ligament and both lateral and medial menisci were intact in both cases. However, the medial collateral ligament and the anterior and posterior cruciate ligaments were avulsed from the femur and required fixation.     

Complex instability of the anterior knee

Complex knee instability involves the anterior cruciate ligament (ACL) and one or more major stabilizers of the knee [medial collateral ligament (MCL), lateral collateral ligament (LCL), posterior cruciate ligament (PCL)]. The medial side has a high healing potential and does not need operative treatment in most cases if ACL reconstruction is performed. Reconstruction of the medial ligament complex is indicated in gross instability of the medial meniscus fixation, dislocation of the MCL into the joint, and large dislocated bony avulsions. Injuries on the lateral side do not heal spontaneously and require acute operative treatment (first 2 weeks). Frank knee dislocations and gross multiligament injuries should be reduced acutely, and the integrity of the vascular structures must be examined closely. In a European multicenter study, operative treatment with reconstruction of both cruciate ligaments and functional rehabilitation gave better results than conservative treatment with immobilization of the joint.     

Posterior cruciate ligament rupture alters in vitro knee kinematics

Isolated posterior cruciate ligament injuries usually are treated nonoperatively, although some patients remain symptomatic, and degenerative changes within the patellofemoral joint and the medial compartment of the tibiofemoral joint have been seen in followup studies. In vitro simulation of knee squatting was done to quantify the influence of the posterior cruciate ligament on tibiofemoral and patellofemoral kinematics. For five knee specimens, knee kinematics were measured before and after sectioning the posterior cruciate ligament, and compared using a Wilcoxon signed rank test. The only kinematic parameters that changed significantly after sectioning the posterior cruciate ligament were the tibial posterior translation and patellar flexion. The posterior translation of the tibia increased significantly between 25 degrees and 90 degrees flexion. The average increase in the posterior translation exceeded 10 mm at 90 degrees flexion. The patellar flexion increased significantly from 30 degrees to 90 degrees flexion. The average patellar flexion increase peaked at 4.4 degrees at 45 degrees flexion. Increased tibial translation could adversely influence joint stability. Increased patellar flexion could increase the patellofemoral joint pressure, especially at the inferior pole, leading to degenerative changes within the patellofemoral joint.     

Complete knee dislocation without posterior cruciate ligament disruption. A report of four cases and review of the literature.

Complete knee dislocation usually causes disruption of both the anterior and posterior cruciate ligaments. Four cases of complete knee dislocation without posterior cruciate ligament (PCL) disruption are reported. All cases involved either anterior or anteromedial dislocation with anterior cruciate ligament disruption and collateral ligament injury, but without posterior cruciate disruption. This is an uncommon finding in complete dislocation of the knee. The PCL may occasionally be spared significant injury in anterior type dislocations, however, thus favorably affecting treatment options.     

腘绳肌腱移植包埋法重建内侧髌股韧带治疗复发性髌骨脱位

目的 :探讨腘绳肌腱移植包埋法重建内侧髌股韧带治疗复发性髌骨脱位的疗效。方法 :2008年3月至2013年6月间收治复发性髌骨脱位67例,其中男28例,女39例;年龄10~42岁,平均22岁。临床表现为膝关节不稳感,"打软腿",髌骨错位感,膝前疼痛等。67例均行腘绳肌腱移植包埋法重建内侧髌股韧带。术前后采用Lysholm评分及Q角变化对疗效进行评估。结果:术后67例均获随访,随访时间4~60个月,平均(27.5±13.4)个月。术后切口均愈合良好,无髌骨脱位或半脱位发生。Lysholm评分由术前76.35±2.86提高到术后82.71±2.29;Q角从术前(18.75±2.33)°降至术后(13.28±1.75)°。结论:腘绳肌腱移植包埋方法重建内侧髌股韧带可以提供足够的张力,恢复髌骨稳定性,改善膝关节功能。     

Akagi胫骨前后轴在全膝关节置换术中的定位作用

目的 分析膝关节CT片上Akagi胫骨前后轴与髌腱中内1/3点、髌腱内侧缘等解剖标志的相互关系,确定全膝关节置换术中胫骨假体旋转定位的参照轴线.方法 对40名青年健康志愿者行膝关节伸直中立位CT检查.Akagi胫骨前后轴定义为CT片上垂直于外科经上髁轴且经过后十字韧带中点的直线.于胫骨平台平而及预定截骨平面标记胫骨前后轴及其与髌腱相交点、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线,分别测量胫骨前后轴与髌腱相交点内侧髌腱占髌腱总宽度的比例、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线同胫骨前后轴之间的夹角.结果 在胫骨平台平面,胫骨前后轴经过髌腱内侧缘外侧10.1%±8.3%处;在预定截骨平面,胫骨前后轴经过髌腱内侧缘外侧0.2%±10.0%处.在预定截骨平面,后十字韧带中点与髌腱内侧缘连线和胫骨前后轴的夹角为0.1°±2.7°,后十字韧带中点与髌腱中内1/3点连线和胫骨前后轴的夹角为10.3°±3.6°.结论 全膝关节置换术中,当以胫骨结节中内1/3点为标准行胫骨假体旋转放置时,有导致胫骨假体相对于股骨假体过度外旋的可能.后十字韧带中点与髌腱内侧缘连线几乎与Akagi胫骨前后轴重叠,可以作为全膝关节置换术中胫骨假体旋转定位的参照轴线.     

Rupture of superficial pes anserinus and partial rupture of patellar ligament as rare concomitant lesions of complex knee joint injuries

We present a rare case of combined knee joint lesions in a 25 year old patient. Besides the commonly reported injuries of the knee joint due to directly applied valgus force, forceful quadriceps muscle contraction, external rotation at flexed knee causing combined lesions such as rupture of the anterior cruciate ligament, rupture of the posterior cruciate ligament and rupture of the medial collateral ligament, a rare combination of the above mentioned lesions and a rupture of the lateral meniscus, an osteochondral fracture of the lateral femur condylus, a rupture of the medial patellofemoral retinacula as well as a complete rupture of the superficial pes anserinus and a partial rupture of the patellar ligament was encountered.     

膝关节脱位多韧带损伤Ⅰ期修复重建的临床观察

目的:探讨关节镜下Ⅰ期异体肌腱重建并结合关节外微创技术治疗膝关节脱位合并多发韧带损伤的临床疗效。方法:2008年1月至2012年1月共收治48例膝关节脱位患者,排除腘血管损伤,采用关节镜下Ⅰ期重建前后交叉韧带,并结合关节外微创技术修复膝关节韧带损伤。男38例,女10例;年龄20～59岁,平均35.6岁;左膝22例,右膝26例;伤后至手术时间2 d～2周。前交叉韧带(ACL)、后交叉韧带(PCL)、内侧副韧带(MCL)及后外侧复合体(PLC)损伤2例,ACL、PCL及MCL损伤36例,ACL、PCL及PLC损伤10例。合并腓总神经损伤4例。比较术前及末次随访时Lysholm 评分以评价膝关节功能。结果:所有患者获得随访,时间12～30个月,平均(18.2±6.3)个月,患者关节活动度和稳定性明显改善,Lysholm评分由术前40.3±4.1提高为随访时87. 0±6.4.结论:关节镜下应用同种异体肌腱Ⅰ期重建膝关节脱位并多韧带损伤,能较好地恢复关节稳定性,保留关节功能。术前训练指导及术后个体化康复是膝关节功能恢复的关键。     

Patellaluxationen

Dislocation of the patella represents a frequent knee problem in childhood and adolescence. There are traumatic, recurrent, habitual and chronic forms. Many anatomical variations, which promote patellar dislocation, are known. The first traumatic dislocation is primarily treated conservatively with the exception of concomitant osteochondral fragments or very large soft tissue damage which justify surgical interventions. Recurrent, habitual and chronic dislocations are best cured surgically by vastus medialis advancement, reconstruction of the medial patellofemoral ligament, strengthening of the medial retinaculum together with a lateral release and by fixation of the patella using tendon grafts or medialisation of the insertion of the patellar ligament. To improve the femoropatellar groove by trochleoplasty is a different surgical concept. The long-term results following medialisation of the patellar ligament insertion or trochleoplasty are good with regards to patellar stability but mediocre in terms of avoiding degenerative changes in the patellofemoral joint.     

Stability after medial collateral ligament release in total knee arthroplasty.

Six knees from cadavers were tested for change in stability after release of the medial collateral ligament with posterior cruciate-retaining and substituting total knee replacements. Load deformation curves of the joint were recorded in full extension and 30 degrees, 60 degrees, and 90 degrees flexion under a 10 N-m varus and valgus torque, 1.5 N-m internal and external rotational torque, and a 35 N anterior and posterior force to test stability in each knee. The intact specimen and posterior cruciate ligament-retaining total joint replacement were tested for baseline comparisons. The superficial medial collateral ligament was released, followed by release of the posterior cruciate ligament. The knee then was converted to a posterior-stabilized implant. After medial collateral ligament release, valgus laxity was statistically significantly greater at 30 degrees, 60 degrees, and 90 degrees flexion after posterior cruciate ligament sacrifice than it was when the posterior cruciate ligament was retained. The posterior-stabilizing post added little to varus and valgus stability. Small, but significant, differences were seen in internal and external rotation before and after posterior cruciate ligament sacrifice. The posterior-stabilized total knee arthroplasty was even more rotationally constrained in full extension than the knee with intact medial collateral ligament and posterior cruciate ligament.     

Neglected irreducible posterolateral knee dislocation

Knee dislocations are rare injuries. Posterolateral knee dislocations are only a small subset of them. There is a paucity of literature regarding the management of such neglected cases. We report here, a case of neglected irreducible posterolateral knee dislocation treated with open reduction and isolated posterior cruciate ligament reconstruction followed by gradual rehabilitation with good outcome at 3 years followup.     

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.     

关节镜辅助下解剖重建内侧髌股韧带治疗习惯性髌骨脱位

目的 :观察内侧髌股韧带重建术治疗习惯性髌骨脱位的疗效。方法 :回顾性分析2009年6月至2014年12月25例习惯性髌骨脱位患者在关节镜辅助下行内侧髌股韧带重建术的临床资料,其中男10例,女15例;平均年龄18.4岁(15~25岁);术前有运动外伤史15例,慢性损伤史7例,无明显诱因3例;左膝11例,右膝14例;脱位次数3~10次。术后进行相应的功能锻炼。依据膝关节活动度、Lysholm评分、Kujala评分、Insall评定法以及髌骨恐惧试验、髌骨研磨试验对术后临床效果进行评价。结果:25例均获得随访,时间12~48个月,平均24.8个月。术后所有患者切口愈合良好,无感染、再脱位等相关并发症。末次随访时患者膝关节活动度(122.60±5.42)°,高于术前的(105.40±5.93)°;Lysholm评分91.44±5.53,高于术前的64.12±7.49;Kujala评分92.44±2.69,高于术前的57.88±5.10;Insall评定法评定优19例,良5例,可1例。结论:关节镜辅助下解剖重建内侧髌股韧带治疗习惯性髌骨脱位疗效确切,有助于临床症状的缓解和膝关节功能的改善。     

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.     

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 dislocation: treatment of high-velocity knee dislocation

BACKGROUND: We report the outcomes of patients treated with a new arthroscopic treatment modality for knee dislocation after high-velocity trauma. METHODS: Twenty-three patients (12 men, 11 women; 25 knees) with traumatic knee dislocation were treated with this technique. Under arthroscopy with gravity inflow irrigation, the ruptured posterior cruciate ligament was reconstructed with a patellar bone-tendon-bone graft, and the anterior cruciate ligament was debrided subacutely. The collateral ligament, meniscus, and capsules were repaired through additional incisions. RESULTS: The average interval between injury and surgery was 11.1+/-5 days (range, 5 to 25 days). After a mean follow-up period of 27.2+/-7.86 months, the mean extension was 1+/-2 degrees and the average flexion was 129.6+/-4.91 degrees. The mean Lysholm score was 84. There were no major complications. CONCLUSION: Arthroscopic posterior cruciate ligament reconstruction seems to be an effective treatment for traumatic knee dislocation.     

髌腱复合体重建创伤性前后交叉韧带

目的：为了评价髌腱复合体(带骨块的髌韧带，即骨—髌膜—骨)对前后交叉韧带断裂后重建的手术疗效。方法：1995—2001年，收治32例前后交叉韧带损伤的患者给予髌腱复合体重建术。结果：所有病人患膝关节稳定性明显增强，术后抽屉试验全部阴性。结论：带骨块的髌韧带具有强抗牵拉力，固定可靠，等长重建，功能改善明显等优点。髌膜复合体是理想的前后交叉韧带替代材料。     

Irreducible open posterolateral knee dislocation due to medial meniscus interposition

Posterolateral knee dislocations are generally irreducible due to the interposition of the medial capsule and retinaculum. These injuries have a 'dimple sign' which shows the invagination of the tissues in the medial joint line. We present an unusual case of an open posterolateral traumatic knee dislocation (KD-4 [ACL/PCL/MCL/LCL-PLC torn] open knee dislocation) without a 'dimple sign'. Closed reduction attempts were unsuccessful. In surgery, it was found that the medial meniscus was detached from the meniscocapsular junction and entrapped in the joint. The medial meniscus was extracted from the joint, and the joint was reduced. The medial meniscus was sutured to the meniscocapsular junction with anchors. This is the first study reporting medial meniscus interposition in an open posterolateral knee dislocation. Moreover, the presented case is peculiar because although it was a posterolateral knee dislocation, the posterolateral ligament complex was also torn.