Inconsistencies in reporting risk factors for ulnar collateral ligament reconstruction failure: a systematic review

Background: When return to sport (RTS) at a competitive level is desired, treatment of injury to the ulnar collateral ligament (UCL) frequently involves surgical reconstruction. Although RTS rates between 66% and 98% have been reported, there remains a paucity of comparative clinical studies, with far fewer reporting statistically significant risk factors for reconstruction failure. The goal of this study was to perform a systematic review of the literature to demonstrate the variety and inconsistency with which risk factors associated with reconstruction failure are reported. Materials and Methods: A systematic review of the PubMed Central and MEDLINE databases was performed to identify clinical outcome studies reporting ≥1 statistically significant risk factor associated with failure of UCL reconstruction. Failure was defined as (1) reinjury, recurrent instability, or need for revision surgery; (2) failure show improvement in postoperative patient-reported outcomes (PROs); or (3) failure to RTS at the preinjury level (RSL). Results: A total of 349 unique studies were initially identified, of which 12 were deemed eligible for inclusion in our study. Of these 12 studies, 4 defined outcomes based on recurrent instability, reinjury, or revision surgery; 2 defined outcomes based on PROs; and 6 defined outcomes based on RSL. In the group with instability, reinjury, or revision failure, 11 significant risk factors were identified across all studies: age, height, body mass index, professional experience, injury to the nondominant arm, history of competitive throwing, mechanism of injury, history of a psychiatric diagnosis, presence of preoperative instability or stiffness, postoperative workload, and time to RTS. In the PRO failure group, 12 risk factors were identified across all studies: age, status as a military cadet, injury to the nondominant arm, graft type, baseball position, current injury to the ipsilateral arm, current level of competition attributed to reconstruction surgery, shoulder surgery after reconstruction, no competitive throwing history, non-throwing mechanism of injury, history of a psychiatric diagnosis, and preoperative instability or stiffness. In the RSL failure group, 4 risk factors were identified across all studies: age, ulnar neuritis, level of professional play, and amount of time spent at the professional level. Conclusions: Age, level of professional play prior to surgery, postoperative workload, and time at the professional level are the most commonly reported risk factors associated with UCL reconstruction failure. There remains a paucity of data associating risk factors with patient-specific outcomes and marked levels of inconsistency and conflict among the studies that report such data.