The Medial and Posteromedial Ligamentous and Capsular Structures of the Knee: Review of Anatomy and Relevant Imaging Findings

Abstract

The medial and posteromedial regions of the knee are important for knee stability but also frequently injured. Medial ligaments and capsule are primary and secondary stabilizers of valgus, rotation, and anterior and posterior translation. In the setting of rupture of the cruciate ligaments, it is important to identify injuries in this region because it can possibly alter the treatment strategy and even delay or prevent successful reconstruction of the cruciate ligaments. Injuries may occur to the superficial and deep medial collateral ligament, the posterior oblique ligament, the posteromedial capsule, and the semimembranosus tendon and its attachments. Meniscocapsular separation is associated with these injuries, and if normal movement of the meniscus and tension of the capsule and ligaments is altered, instability and eventually osteoarthritis may occur. Injuries to the posteromedial corner may be underdiagnosed. This article reviews the anatomy and imaging findings in the medial and posteromedial regions of the knee.

Ramp Lesions

“…The contemporary literature describes these injuries as tears at the posterior meniscocapsular junction and/or tears of the posterior meniscotibial ligament. [5][6][7][8] The expression "hidden lesion," also has been recently used to describe this injury, and the term refers to the difficulty in identifying ramp lesions from standard anterior arthroscopic portals, 6,9 and also with preoperative MRI, which has low sensititvity. [10][11][12] Ramp lesions are hypothesized to occur through a number of possible mechanisms.…”

Diz Eklemi: Meniskus ve Baglar

“…Diz ekleminin medyal kesimi patellanın medyal tarafından başlayarak arkada AÇB hizasına dek uzanan kesimdeki yapıları kapsar [8]. Bu yapılar içinde i) patellar retinakulum, ii) medyal kollateral ligamanın (MKL) yüzeyel (y) ve derin (d) kısımları, iii) posterior oblik ligaman, iv) pes anserin ve semimembranozus tendonları ve v) kapsül yer alır.…”

Multiligamentous Injury of the Knee: MRI Diagnosis and Injury Patterns

“…The anatomy of these corner structures has been elucidated in full detail elsewhere in the literature. [9][10][11][12][13][14][15] Therefore, our discussion focuses on the ligamentous structures of greatest surgical importance, as well as those structures that may be reliably identified on nearly every normal MRI of the knee.…”

“…When describing injuries to the PTMC, it is important to include the extent of the tear (partial versus full thickness), location of the tear (intra-versus extra-articular), degree of tendon retraction, and the presence of an avulsed bone fragment attached to the tendon. [10][11][12]39 Avulsion fractures about the knee may indicate underlying PLC, cruciate, and lateral collateral ligamentous complex pathology. Small osseous avulsions are notoriously difficult to visualize on MRI, and comparison radiographs of the knee should be reviewed at the time of MRI interpretation.…”

“…When injured they may be thickened, disrupted, or associated with osseous avulsion injuries. 11,12,51,52 An osseous avulsion injury of the meniscotibial ligament is referred to as a "reverse Segond" fracture and often associated with PCL rupture. 63 Meniscocapsular separation is best identified on sagittal imaging with increased T2 signal and thickening of the capsule with surrounding edema.…”