Bone channeling in arthroscopic rotator cuff repair: A systematic review and meta-analysis of level I studies

There is ongoing controversy regarding the effect of bone channeling in arthroscopic rotator cuff repair. Since the most recent systematic reviews in 2019, several large high-level trials have been completed. This study assesses all available level I randomized controlled trials that compare arthroscopic rotator cuff repair with and without bone marrow channeling. A systematic search of Ovid MEDLINE, Embase and Cochrane Library databases was conducted through to mid-January of 2023. Two reviewers screened for studies meeting eligibility criteria: English-language randomized controlled trials in patients ≥ 18 years old comparing arthroscopic rotator cuff repair of full-thickness tears with and without bone marrow channeling (channeling and control, respectively). Functional scores, pain, healing rates, and reoperations were reviewed using pooled analysis where appropriate. The methodologic quality of included studies was assessed using the Cochrane risk of bias tool and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A total of six randomized studies (N=593) met inclusion criteria. Pooled analysis of all six studies showed no significant mean difference in function (1.32, 95% CI -0.63, 3.26), as measured by the Constant-Murley score. Retear rates were also not statistically different between groups (risk ratio 0.99, 95% CI 0.57, 1.71) with pooled retear rates of 19.6% (48 of 245) with channeling and 19.8% (51 of 257) without. Only a subset of studies had the other outcomes of interest available for analysis. There were no standardized mean differences in pain (0.09, 95% CI -0.18, 0.36) and there were similar reoperation rates (risk ratio 1.19, 95% CI 0.43, 3.34) in the channeling and control groups. For the included studies, overall quality of evidence by outcome was judged to be moderate (function, pain, reoperations) or low (retear rates), mainly due to risk of bias (all outcomes) and inconsistency (retear rate). The results of this study refute prior systematic reviews which found that channeling reduces the retear rate when combined with arthroscopic rotator cuff repair. This meta-analysis of level I evidence, including recent larger RCTs, demonstrates that bone marrow stimulation in the setting of primary arthroscopic rotator cuff repair has no significant effect on functional outcomes, healing, pain or reoperation rates.