The pathoanatomy of medial ligamentous disruption in the dislocated and multiple ligament injured knee.

PURPOSE: To describe the medial-sided pathoanatomy and ligament injuries in acute MLKIs with medial-sided involvement andlook forassociated injury patterns based upon location of ligamentous injury.

METHODS

Patients who underwent treatment for MLKI at two level-1 trauma centers were identified between January 2001 and May 2023. Only cases involvingcomplete disruption of the superficial medial collateral ligament (sMCL) were included. Zone of injury to the sMCL, the posterior oblique ligament (POL), the medial patellofemoral ligament (MPFL), the vastus medialis oblique (VMO) was recorded, as well as demographics,injury details, neurovascular status, and mechanism of injury.Data was summarized usingdescriptive statistics.

RESULTS

A total of 92 patientswere included, with a mean age of 37.8 ± 12.7 years. Forty-four (47.8%) patients had a high velocity injury. Within sMCL tears, 39% were proximal avulsions, 29% were midsubstance tears, and 32% were distal avulsions. The medial-sided injury patterns were: 31 (33.7%) isolated sMCL tears, 24 (27.3%) combined sMCL, POL, and MPFL tears, 23 (25%) combined sMCL and MPFL tears, and 11 (12%) combined sMCL and POL tears. Most common location of sMCL injury varied based upon the number of associated medial knee ligaments injured: isolated sMCL (even distribution), sMCL & POL (distal), sMCL-MPFL (proximal), sMCL-POL-MPFL (proximal).

CONCLUSION

Medial-sided ligament injuries seen MLKIs were found to occur in four injury patterns ranging from isolated sMCL or combined injury patterns of the adjacent medial structures. Additionally, location of sMCL injury varied based upon the number of medial-sided ligaments injured.