Biomechanical evaluation of 2 arthroscopic biceps tenodeses: double-anchor versus percutaneous intra-articular transtendon (PITT) techniques.

ABSTRACT

BACKGROUND: Recently, there is increasing interest in different arthroscopic biceps tenodesis techniques. However, little data have been published about the biomechanical properties of soft tissue tenodesis. PURPOSE: This study was undertaken to evaluate the biomechanical properties of 2 different arthroscopic biceps tenodeses the percutaneous intra-articular transtendon (PITT) technique and the suture-anchor technique. STUDY DESIGN: Controlled laboratory study. METHODS: Fifteen fresh-frozen cadaveric specimens were randomly allocated to the 2 different biceps tenodesis techniques. The humerus with biceps tenodesis was mounted on a materials testing machine to perform a load to failure test. The structural properties including ultimate load (N) and stiffness (N/mm) were derived from the load-displacement curve. The mode of failure was also recorded. Ultimate load and stiffness were compared with the parametric Student t test. RESULTS: Both repairs showed typical load-displacement curves followed by a constant increase in load and displacement until failure occurred. Suture-anchor and PITT techniques had ultimate loads of 175.4 +/- 40.4 N and 142.7 +/- 30.9 N (P = .10) and stiffness of 15.9 +/- 8.4 N/mm and 13.3 +/- 3 N/mm (P = .36), respectively, with no significant differences between them. All of the surgical constructs failed in the tendon site by pulling out with the sutures through the substance of the tendon. CONCLUSION: The suture-anchor and PITT techniques exhibited satisfactory initial strength with no statistical difference between the 2 groups. These findings, along with the consistent pullout of the suture through the tendon during failure, suggest that the most important factor for initial strength is not the attachment site but the quality of the biceps tendon. CLINICAL RELEVANCE The quality of the tendon should be taken into account when deciding the surgical technique and the rehabilitation program. The PITT technique has the benefit of avoiding hardware complications and cost.