Posteromedial corner of the knee: MR imaging with gross anatomic correlation

Objective. The objective of this study was to illustrate the magnetic resonance (MR) image appearance of the structures of the posteromedial ”corner” of the knee with particular emphasis on the anatomy and differentiation between the medial collateral ligament and the posterior oblique ligament. Design. Six cadaveric knee specimens underwent MR imaging, before and following instillation of intra-articular contrast material. The knees were sectioned in the axial, coronal, and coronal oblique planes and the gross morphology of the posteromedial corner and surrounding structures was studied and correlated with the MR images. Patients. The human cadaveric specimens were from two female and four male patients (age at death, 72–86 years; average, 78 years). Results and conclusions. The contrast-enhanced sequences and the coronal oblique images allowed for improved visualization of the structures. Received: 26 October 1998 Revision requested: 11 December 1998 Revision received: 21 January 1999 Accepted: 26 January 1999     

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.     

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.     

Injury patterns to the posteromedial corner of the knee in high-grade multiligament knee injuries: a MRI study

Injury patterns to the posteromedial corner of the knee have not been previously studied in the context of multiligament knee injuries. We performed a retrospective magnetic resonance imaging and clinical review of a consecutive series of 27 dislocatable knees presenting to a single level-one trauma center from 2005 to 2008. Post-injury magnetic resonance imaging studies were reviewed by two fellowship-trained musculoskeletal radiologists to assess injury patterns to the posteromedial corner. In our series, injury to at least one structure within the posteromedial corner was observed in 81% (22/27) of cases while injury to the superficial medial collateral ligament alone was seen in 63% (17/27) of cases. Furthermore, injuries to the posterior horn of the medial meniscus were associated with a tear of the meniscotibial ligaments in all cases and with a tear of the posterior oblique ligament in 67% of cases. All patients with grade III laxity (>10 mm medial opening) under an examination under anesthesia had a complete tear of the posterior oblique ligament and meniscotibial ligament in addition to a medial collateral ligament injury. Injury to the semimembranosus attachment alone was not associated with clinically significant laxity under an examination under anesthesia. Our findings demonstrate that injuries to the posteromedial corner are common in the setting of traumatic knee dislocations. Interestingly, high-grade medial instability during an examination under anesthesia and injury to the posterior horn of the medial meniscus may be important indicators for further posteromedial corner injury.     

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.     

The posterolateral corner of the knee

OBJECTIVE: The purpose of this article is to review the clinical importance and MRI appearances of injuries to the posterolateral corner of the knee. CONCLUSION: Injuries to the posterolateral corner structures of the knee can cause significant disability due to instability, cartilage degeneration, and cruciate graft failure. Becoming familiar with the anatomy of this region can improve one's ability to detect subtle abnormalities and can perhaps lead to improvements in diagnosing and understanding injuries to this area.     

Imaging of the posterolateral corner of the knee

The structures of the posterolateral corner of the knee are increasingly recognized as fulfilling an important role in maintaining knee stability. The posterolateral aspect of the knee is stabilized by a complex anatomy of osseous, myotendinous and ligamentous structures. Unrecognized injuries to this part of the knee are a cause of failure of cruciate ligament reconstruction. This review focuses on the anatomy and common injury patterns involving the posterolateral corner of the knee, with emphasis on magnetic resonance imaging.     

Acute knee injuries

Skeletally immature athletes do get major knee injuries. Hemarthrosis is associated with peripheral meniscal tears, anterior cruciate ligament ruptures, tibial tubercle avulsion injuries, and patellar/femoral osteochondral fractures and cannot be ignored. The primary diagnostic tool for patients with a knee injury is a clinical examination by a physician well trained in knee evaluation. MR imaging has significant limitations in this age group. The algorithm for anterior cruciate ligament injury treatment must take into account the patient's physiologic maturity, not chronological age.     

Lateral ligament injuries of the knee

Between 1982 and 1994 28 patients were treated for acute lateral knee ligament injuries; 25 patients, with a median age of 25.5 (range 16–75) years at injury, appeared for follow-up. Seven patients had isolated injury of the lateral collateral ligament/capsular structures, the remaining 19 patients had concomitant ligament injuries in the knee. Eight patients were treated conservatively, 1 with plaster immobilization and 7 with early mobilization. Eighteen patients underwent surgery, 17 of these within 3 weeks of injury. Repair/reconstruction of the cruciate ligaments was done at the same time as the lateral collateral ligament repair in 10 patients. At follow-up after a median of 7.5 years (range 6 months to 13 years), 11 had no varus instability, 7 had 1+, 5 had 2+, and 2 patients had 3+ varus instability. All patients with a final result of 2+ or 3+ had combined ligament injuries. The surgically treated lateral collateral ligament injuries all had a primary instability of 2+ or more. These patients showed an improvement in varus instability from a mean of 2.83+ preoperatively to a mean of 1.17+ postoperatively. Two-thirds of the surgically treated patients were stable or had a 1+ instability at follow-up. One conservatively treated patient with a 2+varus instability and 1 with 1+ showed no improvement. Five conservatively treated patients with initial varus instability of 1+ were stable at follow-up. One patient with a 1+ varus instability had anterior cruciate ligament (ACL) rupture. He had a primary ACL reconstruction without lateral repair. He had no varus instability at follow-up. Our study supports the notion that operation performed at an early stage in fresh injuries with a varus instability of 2+ or more gives improved stability as a final result. Conservative treatment may not be expected to give an improved stability, but is sufficient in mild varus instability (1+) without additional cruciate ligament injuries. Received: 22 January 1997 Accepted: 20 June 1997     

异体跟腱骨移植对后交叉韧带及后外侧结构损伤的联合重建

目的介绍后交叉韧带(PCL)断裂伴有后外侧角(PLC)损伤单根异体跟腱骨移植同时进行重建的手术技术及经验。方法对12例PCL并PLC 3度以上慢性损伤不稳的膝关节,行关节镜下PCL全关节内重建,同期重建PLC。单束重建PCL的移植物在胫骨骨道和股骨内髁均以可吸收螺钉固定,采用改良Larson方法重建腓侧副韧带和胭腓韧带等结构。重建的韧带只需1根完整的异体跟腱骨做供体。平均手术时间130min,其中PCL重建90min,PLC重建40 min。支具固定6周以后可渐进负重行走。结果术后随访5～24个月,平均12个月,体检提示83% (10/12)膝关节恢复胫骨台阶；后抽屉试验0～1~+75%(9/12)。Dial sign测试外旋角正常为75% (8/12),30°内翻应力试验正常83%(10/12)。Lysholm,Tegner和HSS膝关节评分分别为90．7,5．1和86．4(P＜0．01),优于术前。结论采用单根异体跟腱骨同期重建PCL和PLC可以获得满意的临床效果,减少了供体耗费,缩短了手术时间。     

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.     

The posterolateral corner of the knee: repair versus reconstruction

BACKGROUND: Injuries to the posterolateral corner of the knee are disabling. Despite improved understanding of this group of tendons and ligaments, the best surgical treatment of an unstable corner is not clear. HYPOTHESIS: Surgical repair of acute tears of the posterolateral corner has outcomes that are as good as those from reconstruction combined with an early motion rehabilitation protocol. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Sixty-three patients with 64 posterolateral corner tears were included in this study, with 39 posterolateral corner repairs and 25 reconstructions using the modified 2-tailed technique. Patients were evaluated with clinical and KT-2000 arthrometer examinations, as well as with Lysholm, International Knee Documentation Committee, and Short Form-36 scores. RESULTS: Fifty-six patients with 57 corner tears had minimum clinical follow-up of 24 months (range, 24-59 months). Acute primary repairs were performed on 35 patients, with 22 successful outcomes and 13 (37%) failures. Primary reconstructions were performed on 22 patients, with 20 successful outcomes and 2 (9%) failures. The difference in stability on clinical examination between repairs and reconstructions was significant (P < .05). Fourteen of 15 patients with failures of the primary posterolateral corner repair or reconstruction underwent successful revision reconstruction. The final patient with failure of the primary repair elected not to have a revision reconstruction. The final mean Lysholm knee score for both repair and reconstruction patients was 88.7 (range, 53-100). Final International Knee Documentation Committee objective scores yielded 14 (26%) normal, 28 (52%) near-normal, 9 (17%) abnormal, and 3 (6%) severely abnormal knees; the mean score was 60 at the most recent clinical evaluation. CONCLUSION: Results with repair followed by early motion rehabilitation have been significantly inferior when compared with results from reconstruction using the modified 2-tailed technique. The authors now use reconstruction rather than repair in the majority of patients who sustain posterolateral corner tears after high-energy injuries.