Stabilizing effect of an elbow orthosis with an adjustable hinge axis after lateral collateral ligament injury: A biomechanical study

Abstract

Background Current commercial elbow braces have a straight hinge that does not account for the native carrying angle of the elbow. The objective of this study was to determine the effectiveness of a custom-designed hinged elbow orthosis (HEO) with variable valgus angulations in stabilizing a lateral collateral ligament (LCL) deficient elbow. Methods Eight cadaveric upper extremities were mounted in an elbow motion simulator in the abducted varus gravity-loaded position. The specimens were examined before and after simulated LCL injury and then with the addition of the custom-designed HEO with 0°, 10°, and 20° of valgus angulation. Kinematic data were recorded using an electromagnetic tracking system. Results The LCL injured state with or without the brace resulted in significant increases in varus angulation of the elbow compared to the intact state in both pronation and supination ( P < 0.05). There were no significant differences in varus-valgus angulation or ulnohumeral rotation between any of the brace angles and the LCL injured state with the forearm pronated and supinated. Discussion The custom-designed HEO did not provide any additional stability to the LCL injured elbow. The varus arm position should be avoided during the rehabilitation of an LCL injured elbow even when an HEO is used.