The medial collateral ligament (MCL) is composed of two major components:​ the deep MCL (dMCL) and superficial MCL (sMCL). Recent indications have raised questions as to the validity of previous descriptions of the MCL’s role in knee stability. Despite the relative likelihood of partial injuries to the sMCL, as opposed to complete tears, the impact of these injuries remains largely misunderstood. This thesisset out to (1) interpret the roles of the sMCL and dMCL;​ and (2) investigate the effect of partial sMCL injuries on knee stability.

A joint motion simulator was used to determine the role of the dMCL and sMCL, and the effect of partial sMCL injuries. The dMCL governed external rotation limits and transection of the sMCL led to heightened instability in valgus and external rotation. Partial sMCL injuries led to load transfer to co-stabilizing ligaments. This testing methodology will be an important tool in understanding complex knee injuries.