Abstract
Purpose: To evaluate a novel method to diagnose injury of the postero-oblique ligament (POL) complicating injury of the medial collateral ligament (MCL) of the knee and its treatment.
Methods: Five POL-injured patients with grade III MCL injury were enrolled. Injury of the POL was diagnosed by valgus stress radiography with an external rotational force applied to the leg at 30r knee flexion (VSRE) and arthroscopy.
Results: On VSRE, in the neutral position widening of the medial joint space of the knee compared to the intact side was seen in all patients. Arthroscopy also showed marked widening of the joint space at the MCL and posteriorly to it. Intraoperatively, instability on the posteromedial side of the knee remained following the repair of the MCL alone, but stability was obtained by repair of the POL. No instability of the knee was noted on VSRE even two years postoperatively, and the patients could return to their former sport activities.
Conclusions: VSRE was effective for diagnosing injury of the POL. If the POL-injury is detected using this screening test, repair of the POL as well as MCL would be considered necessary.
