Purpose: The aim of this study was to biomechanically assess patellar tendon repair techniques with additional cable wire or polydioxanone suture (PDS) cord augmentation in comparison with a suture-anchor repair technique.
Methods: Patellar tendon repair was performed in 60 specimens using a porcine bone model. Yield load, maximum load, stiffness and elongation of patellar tendon reconstructions with (1) cable wire augmentation, (2) PDS cord augmentation or (3) suture anchor repair were evaluated using a cyclic loading and load-to-failure test setup.
Results: In comparison with suture anchor repair, augmentation of the reconstruction with either cable wires or PDS cords provides significantly higher maximum loads (527 and 460 N vs. 301 N; p < 0.01 and p = 0,012, respectively) under load-to-failure testing and less elongation (8.81 mm ± 1.55 mm and 10.56 mm ± 3.1 mm vs. 18.38 mm ± 7.51 mm; p = 0.037 and p = 0.033, respectively) under cyclic loading conditions.
Conclusion: Augmentation of a patellar tendon repair with either a cable wire or a PDS cord provides higher primary stability than suture anchor repair in patellar tendon ruptures. The study supports the use of additional augmentation of a tendon repair in the clinical setting in order to prevent loss of reduction and allow for early post-operative mobilisation.
Keywords: Knee-extensor mechanism; McLaughlin cerclage; Patellar tendon rupture; Suture anchor.