"Hockey wrist:" dorsal ulnotriquetral ligament injury.

Background Ulnar-sided wrist pain at the dorsal proximal triquetrum, especially during wrist pronation, flexion and radial deviation, is common in athletes, particularly ice hockey players. The purpose of this study was to evaluate in which position the dorsal ulnotriquetral ligament (DUTL) is placed under the greatest strain, the torque to failure and the injury pattern. We hypothesized that the DUTL is maximally strained with wrist flexion, pronation and radial deviation, and that, at failure, the ligament tears off the triquetrum. Methods We performed a biomechanical study on 7 fresh frozen cadaveric upper extremities, with testing done on a wrist-movement stimulator to identify the position (45 degrees of wrist flexion, 45 degrees of wrist extension or neutral) that generated the highest and earliest strain increases in the DUTL. We performed load-to-failure testing, characterized the ligament's pattern of failure, and repaired and retested the DUTL using the same load-to-failure protocol. Results The DUTL reached 3 Nm the earliest in 45 degrees of wrist flexion (p = 0.02). The native DUTL failed at 0.35 Nm (standard deviation [SD] 0.13 Nm) per degree of angular stiffness, 12.93 Nm of yield strength and with angular deformation of 57.73 degrees (SD 20.62 degrees). There was no significant difference in these variables between the native and repaired DUTL. Tearing occurred at a mean of 10 mm (SD 2 mm) proximal from the triquetrum's insertion in a transverse midsubstance pattern. Conclusion This study showed a reproducible pattern of injury to the DUTL in a cadaveric model. Additional work is needed to further characterize the pathoanatomy of hockey wrist.