Biomechanical Evaluation of Two Arthroscopic Biceps Tenodesis Techniques: Proximal Interference Screw and Modified Percutaneous Intra-Articular Transtendon.

: The percutaneous intra-articular transtendon (PITT) technique has recently been shown to have results comparable to those of more accepted techniques. Its mode of failure was secondary to the suture pulling through the tendon substance. A modification was made whereby the tendon is locked within the suture configuration in an attempt to avoid pullout. We compared this new technique with a well-accepted technique of all-arthroscopic interference screw. In each of 8 pairs of cadaveric shoulders (mean age, 55 years; range, 51-59 years), one shoulder was randomized to be treated with either modified PITT or interference screw (Biceptor; Smith & Nephew) biceps tenodesis, and the other shoulder was treated with the other technique. The tendons were preloaded at 10 N and then cycled at 0 to 50 N for 100 cycles at 1 Hz. Load to failure was calculated at a rate of 1.0 mm per second until peak load was observed. Mean (SD) ultimate load to failure was 157 (41) N for the modified PITT technique and 107 (29) N for the interference screw technique (P = .003). In 7 of 8 specimens, the interference screw technique failed at the junction of the tendon, the screw, and the bone interface. In 7 of 8 specimens, the PITT technique failed by the tendon slipping through the suture or pulling through transverse ligament/rotator interval tissue. Study results showed the modified PITT technique was a biomechanically superior construct.