The Effect of Ulnar Collateral Ligament Repair With Internal Brace Augmentation on Articular Contact Mechanics: A Cadaveric Study

BACKGROUND: There has been renewed interest in ulnar collateral ligament (UCL) repair in throwing athletes because of a greater understanding of UCL injuries, improvement in ligament repair technology, and potentially expedited rehabilitation time and return to play relative to UCL reconstruction. PURPOSE: To evaluate elbow articular contact and overall joint torque after UCL reconstruction and repair augmented with a collagen-coated fiber tape, InternalBrace. STUDY DESIGN: Controlled laboratory study. METHODS: Ten matched pairs of cadaveric arms (mean age, 41 ± 11 years) were dissected to expose the UCL. Each specimen was secured into a custom test fixture at 90°, and 1 specimen from each pair underwent either a modified Jobe UCL reconstruction or UCL repair with InternalBrace. Each specimen underwent 10 cycles of elbow valgus angular displacement between 0° and 5° at a rate of 1 deg/s in the intact state, after UCL avulsion, and then after UCL reconstruction or repair. Articular contact mechanics and overall joint torque and stiffness were recorded. RESULTS: Contact mechanics of reconstructed and repaired specimens were not significantly different. Both reconstruction and repair procedures returned the overall resistance of the joint to valgus torsion to near-intact levels. UCL repair tended to restore joint torque more closely to the intact state than did reconstruction, given that reconstruction showed a nonsignificant trend toward lower torque than the intact state (P = .07). CONCLUSION: Neither UCL reconstruction nor UCL repair with InternalBrace overconstrained the elbow joint, as both groups had similar contact pressures compared with the native joint. Both procedures also restored elbow joint torque and stiffness to levels not statistically different from the intact state. CLINICAL RELEVANCE: Given the sound biomechanical properties of UCL repair with InternalBrace, it may have a significant role as treatment for UCL injuries.