Background: Medial-sided knee injuries can lead to symptomatic valgus laxity or anteromedial rotatory instability and may require surgery, particularly in the setting of cruciate tears and tibial-sided medial collateral ligament (MCL) avulsions. The LaPrade (LP) technique utilizes 2 free grafts to reconstruct the superficial MCL (sMCL) and the posterior oblique ligament (POL). An alternative MCL reconstruction devised by the senior author comprises an anatomic single-bundle reconstruction using a free graft to reconstruct the sMCL with advancement and imbrication of the posteromedial capsule/POL (MCL anatomic reconstruction with capsular imbrication [MARCI] technique). These techniques have not been biomechanically compared with one another.
Purpose: To identify if one of these reconstruction techniques better restores valgus and rotational medial knee stability throughout the range of motion.
Study design: Controlled laboratory study.
Methods: A total of 20 fresh-frozen, male (mean age, 43.7 years [range, 20-63 years]), midfemur-to-toe-matched cadaveric knees were utilized. All reconstructions were performed by a single fellowship-trained sports medicine surgeon. Left and right specimens within matched pairs were randomized to 1 of the 2 treatment groups: LP or MARCI. Each specimen was tested in 3 phases: (1) intact knee, (2) destabilized (MCL and POL completely severed), and (3) reconstructed (post-LP or post-MARCI reconstruction). We quantified valgus angulation defined by medial joint line opening, as well as internal and external tibial rotation at 0°, 20°, 30°, 60°, and 90° of knee flexion under applied external moments/torques at each phase.
Results: There were significant differences between the MARCI and LP reconstruction groups in valgus stability compared with the intact state (P = .021), with the MARCI reconstruction more closely approximating the intact knee. There was no overall difference between the MARCI and LP reconstruction techniques for internal rotation (P = .163), with both closely resembling the intact state. For external rotation, the effect of the reconstruction technique was dependent on the knee flexion angle (P < .001). At the highest angles, there were no differences between reconstructions; however, for lower knee flexion angles, the MARCI technique more closely resembled the intact state.
Conclusion: Although both techniques improved knee stability compared with destabilized conditions, the MARCI technique better approximated intact stability during valgus at knee flexion angles from 0° to 90° and external rotation loads at knee flexion angles ≤30° in a cadaveric model.
Clinical relevance: The MARCI technique provides an alternative option to improve valgus stability throughout the range of motion. It utilizes a POL advancement without the potential limitations seen in the LP technique, such as multiple tunnel complexity and collision, particularly in the multiple ligament-injured knee.
Keywords: knee reconstruction; medial collateral ligament; multiligament injury; posterior oblique ligament; posteromedial corner.