Failure Rates of Suture Anchor Fixation Versus Transosseous Tunnel Technique for Patellar Tendon Repair: A Systematic Review and Meta-analysis of Biomechanical Studies

Background: Transosseous tunnel (TO) repair is considered the gold standard for patellar tendon rupture; however, suture anchor (SA) repair has emerged as a viable alternative in recent years. Although both these techniques are used widely in clinical practice, the most biomechanically optimal construct for patellar tendon repair remains unknown. Purpose: To examine published studies on the biomechanical properties of TO and SA fixation for patellar tendon repair in terms of ultimate load to failure and cyclic gap formation. The null hypothesis was that there would be no significant difference in either outcome measure between the groups. Study Design: Systematic review. Methods: A systematic review using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed by searching PubMed, the Cochrane Library, and Embase to identify studies that analyzed the biomechanical properties of SA and TO techniques for repair of a ruptured patellar tendon. The search phrase implemented was "patellar tendon repair." Meta-analysis was performed to provide a quantitative comparison of the 2 techniques with regard to ultimate load to failure and cyclic gap displacement. Weighted averages were calculated for all quantitative outcomes, and outcomes were summarized in a forest plot. A random-effects model was used to account for the heterogeneity among the included studies in the final statistical analysis. Results: Of 875 studies initially screened, the inclusion criteria were met by 7 studies, including 128 cadaveric specimens (66 SA, 62 TO). The pooled analysis from 6 studies reporting on gap displacement revealed a statistically significant difference in favor of SA versus TO fixation (P < .001). Pooled analysis from 7 studies reporting on ultimate load to failure did not reveal a statistically significant difference between the use of SA and TO for tendon repair (P = .465). Conclusion: Our systematic review revealed that the use of SA fixation for patellar tendon repair was associated with lower cyclic gap displacement when compared with TO fixation. There was no significant difference in ultimate load to failure between the repair techniques.