Background
The conventional double-row repair is used to tie knots for the medial-row of anchor sutures. However, tying the medial row of anchor sutures can strangulate the tendon and impair vascular inflow. Recently, the knotless medial row technique has been recommended to improve vascularity.
Purpose
The purpose of this study was to compare clinical and radiological outcomes of knot-tying and knotless double-row repair of rotator cuff tears.
Methods
A systematic review was performed following the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement by searching PubMed, Embase, Scopus, and Cochrane databases. The inclusion criteria were based on the following criteria: (1) level I to III evidence of clinical studies; (2) English-language articles; (3) studies making direct comparisons between knot-tying and knotless double-row techniques of arthroscopic rotator cuff repair; (4) studies reporting postoperative patient-reported outcomes and re-tear rate; and (5) full-text availability. Of 698 studies involving double-row rotator cuff repair, 12 studies were identified which met our inclusion and exclusion criteria. The Methodology Index for Non-Randomized Studies (MINORS) criteria was used for methodological quality assessment of the included studies. The data was analyzed by RevMan analysis version 5.3. The odd ratio were calculated for dichotomous outcomes, and mean differences were calculated for continuous outcomes.
Results
Twelve clinical articles were included in this analysis, including a total of 1,411 shoulders, with the majority of tears being medium in size. One study was categorized as level of evidence I. Three studies were categorized as level of evidence II, while the other eight were categorized as level of evidence III. Eleven studies reported the overall re-tear rate of both knot-tying and knotless techniques. No statistically significant difference was found between both techniques (OR = 0.99, 95%CI: 0.67 to 1.47, p = .96). Nevertheless, the knotless technique showed a higher rate of type-I failure than the knot-tying technique. (OR = 0.42, 95%CI: 0.23 to 0.77, p = .005). On the contrary, the knot-tying technique had a higher rate of type-II failure than the knotless technique. (OR = 3.15, 95%CI: 1.70 to 5.83, p = .0003) For functional outcomes, the knot-tying technique had a higher postoperative Constant score (MD = 1.28, 95%CI: 0.03 to 2.53, p = .04). However, there was no statistically significant difference in ASES score (MD = 0.95, 95 percent CI: -0.67 to 2.57, p =.25), UCLA score (MD = 0.18, 95 percent CI: -0, p =.69), post-operative flexion (MD = -1.22, 95%CI: -4.45 to 2.00, p = .46), abduction (MD = -1.01, 95%CI: -6.48 to 4.46, p = .72), or external rotation (MD = -0.48, 95%CI: -3.62 to 2.66, p = .77).
Conclusion
There was no significant difference in overall re-tear rates between knotless and knot-tying techniques. Furthermore, both techniques demonstrated similar clinical outcomes. However, the type-II failure rate is significantly higher in knot-tying repair, and the type-I failure rate is significantly higher in knotless repair.