Medial Ulnar Collateral Ligament Repair With Augmentation: A Systematic Review and Meta-analysis of Preclinical Studies.

BACKGROUND: Reconstruction is the gold standard treatment for medial ulnar collateral ligament (MUCL) injuries. However, recent studies show a successful and renewed interest in direct suture repair, particularly in young athletes. Repair augmentation with a suture tape may provide greater stability, enabling healing of the MUCL while protecting the repair at higher valgus loads.

PURPOSE: To perform a systematic review and meta-analysis on whether MUCL repair with augmentation provides a similar biomechanical profile to the traditional MUCL reconstruction.

STUDY DESIGN: Systematic review.

METHODS: The Cochrane Controlled Register of Trials, PubMed, Medline, and Embase were used to perform a systematic review and meta-analysis using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following search terms: ("ulnar collateral ligament" OR "medial ulnar collateral ligament") AND ("internal brace" OR "augmentation" OR "suture tape"). Data pertaining to certain biomechanical properties (gap formation, failure to torque [ultimate load to failure], stiffness, degree of valgus opening, and modes of failure) were extracted. The pooled outcome data were analyzed by random- and fixed-effects models. A total of 203 abstracts were identified through the aforementioned databases.

RESULTS: After abstract and full-text screening, 6 biomechanical studies were included. All were on cadaveric elbows, with 53 repairs with augmentation and 53 reconstructions compared. There were no differences between the 2 in regard to ultimate load to failure (standard mean difference [SMD], -0.34 N·m; 95% CI, -1.36 to 0.68; P = .51) and rotational stiffness (SMD, 0.26; 95% CI, -1.14 to 1.66; P = .72). Despite a trend in resistance to gapping with augmented repair, this was not significant (SMD, -0.53; 95% CI, -1.08 to 0.01; P = .06). Augmented repairs were more likely to fail by pullout or at the suture-tendon/anchor-suture interface (odds ratio [OR], 12.19; 95% CI, 4.17 to 35.62; P < .00001), while failure by fracture was more common with reconstruction (OR, 5.75; 95% CI, 2.07 to 15.99; P = .0008).

CONCLUSION: MUCL augmented repair establishes the required time-zero structural properties without the need for a tendon graft. However, future clinical studies are necessary to determine its true effectiveness as well as its success at higher levels of professional sport.