Medial-Sided Ligamentous Injuries of the Athlete's Knee: Evaluation and Management

Abstract

The superficial medial collateral ligament (sMCL) is the most commonly injured ligamentous structure in the knee. The other medial knee stabilizers include the deep medial collateral ligament, the posterior oblique ligament, and the medial meniscus. Medial collateral ligament injuries frequently occur in young athletes. As a result of the good healing capacity of the sMCL, the majority of acute medial-sided knee injuries can be treated nonoperatively with good outcomes. However, missed concomitant injuries can lead to residual laxity and instability of the knee when treated conservatively. When surgical management is warranted, numerous techniques exist, including repair, augmentation, and reconstruction. Recent anatomic and biomechanical studies defining the attachment sites and functional roles of the individual medial knee structures have led to advancements in diagnosis, treatment, and rehabilitation. These studies have allowed for the development of an anatomic reconstruction technique that restores the native stability and load-sharing relationships among the medial knee structures. The purpose of this narrative review is to summarize the recent updates in the anatomy, biomechanics, evaluation, and treatment of ligamentous injuries on the medial side of the athlete's knee.

Keywords: athlete's knee; ligamentous injury; ligamentous instability; medial knee; patient-centered care; posterior oblique ligament; sports surgery; surgical reconstruction.

Figure 1. Illustration (A) and photograph of a cadaver specimen (B) showing the medial knee structures.

AMT = adductor magnus tendon; AT = adductor tubercle; GT = gastrocnemius tubercle; ME = medial epicondyle; MGT = medial gastrocnemius tendon; MPFL = medial patellofemoral ligament; POL = posterior oblique ligament; SM = semimembranosus; sMCL = superficial medial collateral ligament; VMO = vastus medialis obliquus. Panel A: Adapted with permission from LaPrade RF, Engebretsen AH, Ly TV, Johansen S, Wentorf FA, Engebretsen L. The anatomy of the medial part of the knee. J Bone Joint Surg Am. 2007;89(9):2000-2010 [7]. Panel B courtesy of LaPrade, RF.

Figure 2. Illustration of a left knee depicting the medial knee native anatomy (Panel A) and reconstruction technique (Panel B).

The sMCL and POL are reconstructed using two separate grafts and four reconstruction tunnels. The proximal tibial attachment of the sMCL is recreated by suturing the sMCL graft to the anterior arm of the semimembranosus muscle. sMCL = superficial medial collateral ligament; POL = posterior oblique ligament. Adapted with permissions from Coobs BR, Wijdicks CA, Armitage BM, Spiridonov SI, Westerhaus BD, Johansen S, Engebretsen L, LaPrade RF. An in vitro analysis of an anatomical medial knee reconstruction. Am J Sports Med. 2010;38:339-347 [16].