Optimizing Fixation for Distal Biceps Tendon Repairs: A Systematic Review and Meta-regression of Cadaveric Biomechanical Testing.

Background: Various surgical techniques can be used to repair acute distal biceps tendon (DBT) tears; however, it is unknown which type of repair or implant has the greatest biomechanical strength and presents the lowest risk of type 2 failure.

Purpose: To identify associations between the type of implant or construct used and the biomechanical performance of DBT repairs in a review of human cadaveric studies.

Study Design: Systematic review and meta-regression.

Methods: We systematically searched the EMBASE and Medline (PubMed) databases for biomechanical studies that evaluated DBT repair performance in cadaveric specimens. Two independent reviewers extracted data from 14 studies that met our inclusion criteria. The pooled data set was subjected to meta-regression with adjusted failure load (AFL) as the primary outcome variable. Procedural parameters, such as number of sutures, cortices, locking stitches, and whipstitches, served as covariates. Adjusted analysis was performed to determine the differences among implant types. The alpha level was set at .05.

Results: When using no implant (bone tunnels) as the referent, no fixation type or procedural parameter was significantly better at predicting AFL. Cortical button fixation had the highest AFL (370 N; 95% CI, -2 to 221). In an implant-to-implant comparison, suture anchor alone was significantly weaker than cortical button (154 N; 95% CI, 30 to 279). Constructs using a cortical button and interference screw were not stronger (as measured by AFL) than those using a cortical button alone. The presence of a locking stitch added 113 N (95% CI, 29 to 196) to the AFL. The use of cortical button instead of interference screws or bone tunnels was associated with lower odds of type 2 failure. Avoiding locking stitches and using more sutures in the construct were also associated with lower odds of type 2 failure.

Conclusion: Cortical button fixation is associated with greater construct strength than is suture anchor repair and a lower risk of type 2 failure compared with interference screw fixation or fixation without implants. The addition of an interference screw to cortical button fixation was not associated with increased strength. The presence of a locking stitch added 113 N to the failure load but also increased the odds of type 2 failure.