A biomechanical study of stability of the elbow to valgus stress before and after reconstruction of the medial collateral ligament.

Abstract

The purpose of this study was to assess the stability of the elbow to valgus loads after reconstruction of the anterior bundle of the medial collateral ligament (MCL). The MCL in 14 human cadaveric elbows was exposed with a muscle-splitting approach. Each sample was secured in a materials test frame,5 N-m valgus moments were applied in 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion, and baseline stability was measured. This sequence was performed after the anterior bundle was sectioned and again after ligamentous reconstruction was done with the Jobe technique. At 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion, reconstruction reproduced an average of 99%, 102%, 97%, and 89%, respectively, of the stability of the intact ligament. The only significant difference between intact and reconstructed samples was at 120 degrees of flexion (P <.05). We concluded that this procedure reliably restores stability to a ruptured MCL throughout the flexion arc in the immediate postoperative period.