A biomechanical comparison of four reconstruction techniques for the medial collateral ligament-deficient elbow

Abstract

The initial strength of the intact medial collateral ligament (MCL) of the elbow and the strength of 4 reconstruction techniques were compared. Twenty cadaveric upper extremities were mounted in a custom jig with the elbow at 90 degrees , and a pneumatic cyclic valgus loading protocol was used. The mean peak load to failure was 142.5+/-39.4 N for the intact ligaments and 53.0+/-9.5 N for the docking reconstructions, 52.5+/-10.4 N for the EndoButton reconstructions, 41.0+/-16.0 N for the interference screw reconstructions, and 33.3+/-7.1 N for the figure-eight reconstructions. The peak load to failure of the MCL reconstructions was inferior compared with the intact ligament (P<.001). No difference in strength was found between the docking and single-strand medial collateral reconstruction with the use of an EndoButton for ulnar fixation (P>.05, beta=.14). Both of these reconstruction methods were stronger than the interference screw or figure-eight technique (P<.004). The optimal fixation method for a single-strand MCL reconstruction may require improved interference screws or a modified EndoButton procedure.