The effect of forearm rotation on laxity and stability of the elbow

Objective. The purpose of this study was to quantify the relationship between forearm rotation and valgus/varus laxity of the elbow joint over the range of elbow flexion. Background. There is little known about the influence of forearm rotation on the laxity and stability of the elbow joint. The general opinion exists that forearm rotation does not significantly influence the laxity and stability of the elbow joint. Methods. Nine fresh-frozen cadaver elbows were used. Passive elbow flexion with the forearm in neutral rotation and in 40° and 80° of pronation and supination was performed under valgus/varus loads: (1) in intact elbows; (2) after a lateral surgical approach (lateral epicondylar osteotomy of the distal humerus); (3) after release of the anterior bundle of the medial collateral ligament; and (4) after release of the anterior bundle of the medial collateral ligament plus radial head resection. Valgus/varus elbow laxity was quantified using an electromagnetic tracking device. Results. There was a statistically significant effect (P