The posteromedial corner of the knee: medial-sided injury patterns revisited

BACKGROUND: Medial-sided knee injury patterns have been poorly defined in the available literature. The lack of definition can be attributed to the differing anatomic perspectives of physician authors and the functional significance they assigned to the posteromedial structures of the knee. HYPOTHESIS: Many so-called medial collateral ligament injuries can involve significant damage to the posteromedial corner structures that may not be appreciated. STUDY DESIGN: Retrospective cohort study. METHOD: The authors reviewed the charts of 93 patients (93 knees) with operatively treated isolated and combined medial-sided knee injuries and described the associated medial injury patterns. RESULTS: Ninety-nine percent of the knees were found to have an injury of the posterior oblique ligament. In the series, 70% of the knees also had an injury of the semimembranosus capsular attachment, and 30% were found to have complete peripheral detachment of the meniscus. Injury to the posterior oblique ligament was the common injury, but other sites of disruption capable of disabling this dynamic meniscocapsular complex were present. CONCLUSIONS: Before assigning function to the various posteromedial structures of the knee, we must better define medial-sided injury patterns, the purpose of the current work. From this review of medial-sided injuries in this series of patients, the authors have come to realize that a subgroup of these knee injuries involves injuries to the posteromedial structures that are under-appreciated.     

Management of medial-sided knee injuries, part 2: posteromedial corner

Injury to the posteromedial corner (PMC) of the knee differs anatomically and biomechanically from isolated injury to the medial collateral ligament. Newer anatomic and biomechanical studies are refining the field's understanding of the medial side of the knee, as well as its role in multiple ligament injuries. Valgus instability places additional strain on a reconstructed anterior or posterior cruciate ligament, which can contribute to late graft failure. Injuries to the PMC may not heal without surgical repair or reconstruction, particularly when part of a multiple-ligament injury. Identification of PMC injury before cruciate reconstruction is important so that appropriate repair or reconstruction of the PMC and medial collateral ligament can be undertaken at the same time. This article reviews the relevant literature on the PMC, discusses reasons for selective operative management, and illustrates reconstructive strategies for PMC injuries occurring as part of a medial-sided or multiligament injury to the knee.     

An anatomical three-dimensional study of the posteromedial corner of the knee

Purpose  

For many years, the anatomy of the medial knee corner has been reported. However, it is not exactly clear how all these structures function together. The purpose of this study is to identify and try to understand the relationship between the posteromedial corners of the knee using three-dimensional visualization techniques.     

Surgical treatment of acute medial collateral ligament and posteromedial corner injuries of the knee

The medial collateral ligament of the knee is unique in that it has shown the capacity to heal with conservative measures. As a result, nonoperative treatment is often successful in returning patients back to previous levels of activity and function. However, specific surgical indications do exist for certain isolated and many combined medial collateral ligament injuries. Strict adherence to both nonoperative and operative principles allows for optimum treatment in most instances.     

Radiology and management of multiligament injuries of the knee

Multiligament injury of the knee, which may include joint dislocation, is a severe injury that can devastate knee function. It usually results in rupture of three of the four major stabilizing ligaments of the knee, but occasionally only two of the ligaments are torn. Evaluation and management is made more complex due to associated articular and meniscal cartilage injury, bony fractures, and neurovascular injury. What is considered best treatment is often varied and controversial. This article discusses the diagnosis and management of multiligament knee injury and the role of imaging in the context of the published literature and our own experience.     

Posteromedial corner injuries of the knee

Magnetic resonance imaging (MRI) depicts in exquisite detail the supporting structures of the posteromedial corner of the knee. This musculoligamentous unit plays a central role as a dynamic stabilizer of the knee joint and the recognition of injury to the posteromedial corner carries important implications in terms of management and prognosis, most particularly in the anterior cruciate ligament-deficient knee. This article provides a resumé of the functional anatomy of the posteromedial corner of the knee as seen with MRI and follows with a review of the MRI appearances of injury to the posteromedial corner.     

膝关节后内侧结构生物力学意义及损伤的MRI表现

目的:分析膝关节后内侧结构的解剖、生物力学特点及临床意义;阐述膝关节后内侧结构的MRI正常及损伤后表现;进行后内侧结构损伤MRl分级.方法:回顾分析87例后内侧结构、以及其他相关损伤的MRI所见.结果:本组87例后内侧结构损伤,Ⅰ级损伤29例,Ⅱ级47例,Ⅲ级11例;合并交叉韧带损伤34例(39%),内侧半月板后角撕裂...     

MRI of the posterolateral corner of the knee: normal appearance and patterns of injury

The posterolateral corner (PLC) of the knee is a complex area, previously poorly understood by radiologists. Numerous structures make up the PLC, whose evaluation is difficult because of the variable presence of the individual components, their intimate and commonly overlapping insertions, and their oblique course on traditional imaging planes. The clinical relevance of PLC injuries, especially the infrequently repaired "minor" components, adds to the confusion. Our purpose is to review the anatomy, imaging, clinical evaluation, and treatment options for PLC injuries.     

Outcomes of operative and nonoperative treatment of multiligament knee injuries: an evidence-based review

Knee dislocation is an uncommon orthopedic diagnosis with a high rate of neurovascular complications. The goal of definitive management is to provide a pain free and functional knee through restoration of ligamentous stability and range of motion. Operative management has been suggested to be superior to nonoperative management for knee dislocations largely in part owing to a meta-analysis on the topic published a decade ago. The purpose of this study was to summarize the results of operative and nonoperative treatment of knee dislocations over the past 10 year period. There were a total of 855 patients from 31 studies managed operatively and 61 patients from 4 studies managed nonoperatively. The overall methodological quality of the studies was poor as measured by the Newstead-Ottawa scale. Data regarding functional outcome, instability, contracture, and return to activity were all in favor of operative management. Significant differences were found for return to employment (P<0.001) and return to sport (P=0.001). The results of this study provide further evidence for the superiority of operative management, compared with nonoperative management, for knee dislocations across several clinical and functional domains. There is a need for higher level studies to assist the treating surgeon in the management of these challenging injuries.     

Evaluation of arthrography and arthroscopy for lesions of the posteromedial corner of the knee

Injuries of the posteromedial corner of the knee joint were evaluated using the results of clinical, arthrographic, and arthroscopic examinations in 137 surgically treated patients (137 knees) with injuries of the ACL (acute in 61, chronic in 76). The accuracy of each diagnosis was confirmed by determining the site of the injury during the arthrotomy. A tear of the posteromedial corner of the medial meniscus was present in 40 patients, and an accurate diagnosis was made in 29 patients by clinical examination, in all 40 patients by arthrography, and in 38 patients by arthroscopy. Injury of the posterior oblique ligament was noted in 37 patients, and an accurate diagnosis was made in 15 patients by clinical examination, in 35 patients by arthrography, and in 8 patients by arthroscopy. Lesions of the posterior oblique ligament which were not detected in the arthroscopic examination alone were either rupture at the attachment to the femur or longitudinal tears in the meniscofemoral or meniscotibial portion. The results revealed that arthrography is an important means of evaluation in the diagnosis of injuries of the posteromedial corner of the knee joint.     

分析比较急性髌骨外侧脱位与膝关节多发韧带损伤后内侧髌股韧带损伤的特点

 目的 分析比较急性髌骨外侧脱位(lateral patellar dislocation,LPD)与膝关节多发韧带损伤(multiligament knee injuries,MLKIs)后内侧髌股韧带(medial patellofemoral ligament,MPFL)损伤的特点。方法 回顾性分析急性LPD 92例和MLKIs 83例患者的MRI资料,根据患者年龄分为青少年组(年龄≤18岁)84例和成人组(年龄＞18岁)91例,对LPD和MLKIs伴发MPFL损伤程度、部位进行统计学分析。结果 青少年LPD组50例中,MPFL部分撕裂20例,完全撕裂25例,未损伤5例;青少年MLKIs组34例患者中,MPFL部分撕裂9例,完全撕裂6例,未损伤19例;两组比较,差异有统计学意义(χ²=21.725,P<0.05)。青少年LPD组MPFL髌骨侧损伤19例,股骨侧14例,体部2例,多部位损伤10例;青少年MLKIs组MPFL髌骨侧损伤3例,股骨侧7例,多部位损伤5例;青少年LPD组和MLKIs组间MPFL髌骨侧、股骨侧、多部位损伤发生率差异均具有统计学意义(χ²=19.753,9.644,8.193,P值均小于0.01)。成人LPD组42例中,MPFL部分撕裂17例,完全撕裂19例,未损伤6例;成人MLKIs组49例中,MPFL部分撕裂13例,完全撕裂7例,未损伤29例;两组比较,差异有统计学意义(χ²=20.771,P<0.05)。成人LPD组MPFL髌骨侧损伤11例,股骨侧15例,体部2例,多部位损伤8例;成人MLKIs组MPFL髌骨侧损伤4例,股骨侧9例,多部位损伤7例;LPD组和MLKIs组间MPFL髌骨侧、股骨侧、多部位损伤发生率差异均具有统计学意义(χ²=14.773,12.777,6.822,P均<0.01)。结论 急性LPD比MLKIs更易导致MPFL损伤,MPFL髌骨侧损伤、股骨侧损伤和多部位损伤LPD也较MLKIs更常见。     

Physical examination and imaging of the medial collateral ligament and posteromedial corner of the knee

The medial side is one of the most commonly injured areas of the knee. The anatomy, diagnosis, and treatment of medial collateral ligament and posteromedial corner (PMC) injuries can be challenging. Understanding the mechanism of injury and performing a thorough physical examination and radiographic evaluation is essential. Frequently, there are concomitant meniscal and other ligament injuries associated with medial-side injuries. Correct identification of all injured structures is important, as missed diagnoses can lead to significant disability. Unrecognized PMC injuries have been implicated in anteromedial rotary instability and failed anterior cruciate ligament reconstructions. Valgus stress testing is the cornerstone for the identification of medial-side knee injuries. Coronal sequences from magnetic resonance imaging are the most useful tool to view the medial collateral ligament and posteromedial structures. Stress x-rays and ultrasound may also be helpful. Thorough physical examination and imaging of injuries to the PMC should dictate the appropriate treatment for optimal results.     

膝关节韧带损伤的MRI诊断

目的:探讨膝关节韧带损伤的MRI表现及诊断价值。方法:36例临床怀疑膝关节损伤的患者于关节镜及手术前行MRI检查,以关节镜结果作为金标准,前瞻性分析膝关节韧带损伤的MRI表现及诊断价值。结果:关节镜证实前交叉韧带损伤21例,其中完全撕裂15例,部分撕裂6例,后交叉韧带损伤12例,正常患者15例。MRI诊断前交叉韧带损伤的敏感度为95.2%,特异度为80%,准确度为88.9%;诊断后交叉韧带损伤的敏感度为100%,特异度为95.8%,准确度为97.2%。结论:MR1是诊断膝关节韧带损伤的理想检查方法,具有较高的临床应用价值。     

膝关节损伤MRI表现与关节镜检查对照研究

目的分析研究膝关节半月板及韧带损伤的MRI表现，并与关节镜诊断结果相对照，评价MRI的临床应用价值。方法48例膝关节外伤患者均经MRI和关节镜检查。半月板损伤的分级标准采用Kaplan的三级分类方法。韧带损伤参照Ruiz进行分级。膝关节MRI检查采用常规序列：T1WI／SE，T2WI／TSE，STIR和GRE。关节镜检查由一名主任医师和一名主治医师共同完成。MRI检查后患者均于1～2周内行关节镜检查或手术。结果与关节镜检查结果比较，MRI诊断半月板损伤的准确率为85．4％，敏感性为92．1％，特异性为81．0％，阳性预测值为76．1％，阴性预测值为94．0％。MRI诊断韧带损伤的准确率为93．1％。然而，MRI对滑膜皱襞综合征、剥脱性骨软骨炎及创伤性滑膜炎诊断价值较低。结论MRI对膝关节半月板及韧带损伤诊断具有明显的临床应用价值，同时可作为关节镜术前的筛选工具，指导关节镜在临床中的合理运用。     

Posterolateral corner injuries of the knee: anatomy, diagnosis, and treatment

Injuries to the posterolateral corner of the knee continue to be a complex problem for orthopedic surgeons. Early recognition and treatment are important factors in the patient's long-term outcome. To properly treat these patients, the surgeon must have a clear understanding of the anatomic relationships amongst the structures in the posterolateral knee. This knowledge combined with a thorough physical examination and imaging studies, allows the surgeon to make the correct diagnosis and devise an appropriate treatment plan. This article will discuss the anatomy, diagnosis, and treatment options to improve the surgeon's understanding of posterolateral knee injuries. The senior author's technique for anatomic reconstruction of the posterolateral corner of the knee and the rehabilitation protocol are described.