Comparison of clinical outcomes between knotted and knotless double-row arthroscopic rotator cuff repairs: a meta-analysis

BACKGROUND: The ideal rotator cuff repair technique should allow for a quick and simple arthroscopic application which provides both adequate biomechanical stability and an appropriate biological state with the intention of promoting eventual healing of tendon to bone. While the biomechanical superiority of double-row repairs including higher repair strength, reduced gap formation, and wider footprint restoration have been proven, controversy remains regarding the clinical benefits of knotless compared with knot tying techniques. Our study aims to review the available evidence in the literature comparing the clinical outcomes between knotted and knotless transosseous double-row rotator cuff repair techniques. METHODS: A systematic literature search via PubMed, Embase, and Scopus was conducted by 2 independent reviewers. Studies reporting clinical outcomes of arthroscopic rotator cuff repair using the double-row knotted and knotless surgical techniques were identified. Data were analyzed with Review Manager 5.3, using Mantel-Haenszel statistics with both fixed and random effect models. RESULTS: A total of 1144 studies were identified from our initial search. Based on our inclusion and exclusion criteria, 8 studies were eventually selected for our review. The selected studies were published between 2012 and 2018. Of the 8 studies, 3 reported level 2 evidence and 5 reported level 3 evidence. There were a total of 589 subjects. Our meta-analysis revealed that there were no significant differences in functional outcomes postoperatively when comparing Constant score (mean difference = −1.85, 95% confidence interval: −4.42 to 0.73), University of California at Los Angeles score (mean differences = −0.14, 95% confidence interval: −0.90 to 0.62), and American Shoulder and Elbow Surgeons score (mean differences = −2.19, 95% confidence interval: −5.55 to 1.17) between patients who underwent knotted and knotless rotator cuff repairs. DISCUSSIONS AND CONCLUSION: Our review revealed no statistically significant difference in functional outcomes between knotted and knotless transosseous double-row techniques for arthroscopic rotator cuff repairs. To our knowledge, this is the first meta-analysis related to this topic. However, no level 1 studies were available for this review. Further studies related to this topic should focus on reporting level 1 evidence comparing the clinical outcomes of knotless and knotted techniques for double-row repairs.