Comparison of the Suture Anchor and Transosseous Techniques for Patellar Tendon Repair: A Biomechanical Study.

Abstract

Minimizing gap formation and maximizing the strength of patellar tendon repairs are 2 critical factors for successful healing of these injuries. The purpose of this study was to compare transosseous and screw-in anchor repair techniques to determine if there is a difference in gap formation and load to failure of the 2 constructs. The research hypotheses were that the anchor construct would have significantly less gap formation and would also have significantly greater load-to-failure strength. Controlled laboratory study. A total of 24 porcine specimens were randomly assigned into transosseous and 4.75-mm polyetheretherketone (PEEK) screw-in anchor repair groups. The repairs were then completed using 2 No. 2 FiberWire sutures, and each specimen was cyclically loaded on a tensile test machine to 250 N for a total of 1000 cycles. Gap formation was measured at 1, 10, 250, 500, and 1000 cycles. Each specimen was loaded to failure after 1000 cycles. Independent t tests were conducted. Statistically significant gap formation and load-to-failure differences were found between the 2 repair techniques. The mean gap in the anchor group (2.16 ± 1.81 mm) was significantly less than that seen in the transosseous group (5.71 ± 1.58 mm) (P < .001). The mean load to failure of the anchor group (669.9 ± 91.8 N) was significantly higher than that of the transosseous group (582.8 ± 92.6 N) (P = .03). The results support the 2 study hypotheses. These findings suggest that the 4.75-mm PEEK screw-in anchor construct may be superior to the transosseous technique for minimizing gap formation and improving load-to-failure strength after surgical repair of the patellar tendon. The use of the suture anchor technique in patellar tendon repair may support early load-bearing rehabilitation.