BIOMECHANICAL EVALUATION OF THE MEDIAL COLLATERAL LIGAMENT OF THE ELBOW

Citation
Gh. Callaway et al., BIOMECHANICAL EVALUATION OF THE MEDIAL COLLATERAL LIGAMENT OF THE ELBOW, Journal of bone and joint surgery. American volume, 79A(8), 1997, pp. 1223-1231
Citations number
31
Categorie Soggetti
Orthopedics,Surgery
ISSN journal
00219355
Volume
79A
Issue
8
Year of publication
1997
Pages
1223 - 1231
Database
ISI
SICI code
0021-9355(1997)79A:8<1223:BEOTMC>2.0.ZU;2-Z
Abstract
Anatomical dissection and biomechanical testing were used to study twe nty-eight cadaveric elbows in order to determine the role of the media l collateral ligament under valgus loading, The medial collateral liga ment was composed of anterior, posterior, and occasionally transverse bundles, The anterior bundle was, in turn, composed of anterior and po sterior bands that tightened in reciprocal fashion as the elbow was fl exed and extended. Sequential cutting of the ligament was performed wh ile rotation caused by valgus torque was measured, The anterior band o f the anterior bundle was the primary restraint to valgus rotation at 30, 60, and 90 degrees of flexion and was a co-primary restraint at 12 0 degrees of flexion, The posterior band of the anterior bundle was a co-primary restraint at 120 degrees of flexion and a secondary restrai nt at 30 and 90 degrees of flexion, The posterior bundle was a seconda ry restraint at 30 degrees only. The reciprocal anterior and posterior bands have distinct biomechanical roles and theoretically may be inju red separately, The anterior band was more vulnerable to valgus overlo ad when the elbow was extended, whereas the posterior band was more vu lnerable when the elbow was flexed, The posterior bundle was not vulne rable to valgus overload unless the anterior bundle was completely dis rupted. The intact elbows rotated a mean of 3.6 degrees between the ne utral position and the two-newton-meter valgus torque position, Cuttin g of the entire anterior bundle caused an additional 3.2 degrees of ro tation at 90 degrees of flexion, where the effect was greatest. CLINIC AL RELEVANCE: Physical findings in a patient who has an injury of the anterior bundle may be subtle, and an examination should be performed with the elbow in 90 degrees of flexion for greatest sensitivity, As t he anterior bundle is the major restraint to valgus rotation, reconstr uctive procedures should focus on anatomical reproduction of that stru cture, Parallel limbs of tendon graft placed from the inferior aspect of the medial epicondyle to the area of the sublimis tubercle will sim ulate the reciprocal bands of the anterior bundle, Temporary immobiliz ation with the elbow in flexion may relax the critically important ant erior band of the reconstruction during healing.