Return to Sport After Ulnar Collateral Ligament Tears Treated with Platelet Rich Plasma Injections Is influenced by Length of Rehabilitation and Leukocyte Content of Injections: A Systematic Review

Abstract

To analyze the current literature assessing return to sport (RTS) outcomes after platelet-rich plasma (PRP) injections for the nonoperative treatment of ulnar collateral ligament (UCL) injuries. A systematic review of PubMed, Embase, and Web of Science databases was conducted in June 2023 to identify studies assessing RTS after PRP injections for UCL injuries. Tear severity, leukocyte content of PRP, rehabilitation protocol, and RTS outcomes were collected. Heterogeneity was assessed through proportional random-effects models for RTS and return to preinjury level of play (RTLP) with subgroup analysis by rehabilitation length, leukocyte content of PRP, and tear severity. Eight studies with 278 partial-thickness and 44 full-thickness tears were identified. The mean age of patients ranged from 17.3 to 26 years. The mean RTS time after injection ranged from 5.2 to 25.4 weeks. High heterogeneity was observed among studies, with RTS rates ranging from 46% to 100% (I2= 83%) and RTLP rates ranging from 34% to 100% (I2= 83%). Studies with the longest rehabilitation programs (12-14 weeks) had RTS rates of 87% to 100% (I2= 0%). RTS rates among athletes treated with leukocyte-poor and leukocyte-rich PRP ranged from 73% to 100% (I2= 30%) and 52% to 88% (I2= 84%), respectively. Subanalysis of RTS by tear severity demonstrated high variability, with partial-thickness rates ranging from 59% to 100% (I2= 55%) and full-thickness rates ranging from 27% to 100% (I2= 63.2%). Studies assessing RTS after PRP injections are highly heterogeneous; however, current data suggest nonoperative RTS and RTLP rates ranging from 46% to 100% and 34% to 100%, respectively. Studies with at least 12 weeks of rehabilitation and studies using leukocyte-poor PRP demonstrated low heterogeneity and greater RTS rates. Alternatively, high heterogeneity was observed among both partial- and full-thickness tears. Level IV, systematic review of Level III-IV studies.