Repair Integrity and Functional Outcomes Between Knot-Tying and Knotless Suture-Bridge Arthroscopic Rotator Cuff Repair: A Prospective Randomized Clinical Trial

BACKGROUND: Knot-tying suture-bridge (SB) rotator cuff repair may compromise the vascularity of the repaired tendon, causing tendon strangulation and medial repair failure. The knotless SB repair technique has been proposed to overcome this possibility and decrease retear rates. PURPOSE: To compare clinical and structural outcomes and retear patterns between the knot-tying and knotless SB techniques. We hypothesized that the knotless technique would result in lower retear rates owing to the preservation of intratendinous vascularity. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 104 patients with full-thickness rotator cuff tears were randomly and prospectively allocated to undergo knot-tying (group 1) or knotless (group 2) SB repair. Clinical outcome measures included range of motion, the visual analog scale (VAS) for pain, and the Constant score for function. Repair integrity was evaluated on magnetic resonance imaging scans using the Sugaya classification. Retears were also classified according to their pattern as type 1 (lateral) or type 2 (medial). RESULTS: Overall, 88 patients (group 1: n = 42 [mean ± SD age, 54.3 ± 9.8 years]; group 2: n = 46 [mean ± SD age, 55.8 ± 8.2 years]) were included in the final analysis. The mean ± SD follow-up period was 25.4 ± 8.3 and 23.3 ± 7.2 months for groups 1 and 2, respectively. From preoperatively to postoperatively, the mean VAS pain score improved significantly in both groups (group 1: from 7.4 ± 1.7 to 1.0 ± 1.7; group 2: from 7.1 ± 1.9 to 1.3 ± 2.0; P < .0001 for both), as did the mean ± SD Constant score (group 1: from 51.7 ± 13.4 to 86.0 ± 11.5; group 2: from 49.4 ± 18.4 to 87.2 ± 14.8; P < .0001 for both). There was no significant difference between the groups for the postoperative VAS or Constant score. The retear rate was not significantly different between the groups (19.0% [8/42] in group 1 and 28.3% [13/46] in group 2; P > .05). There was a significant difference in the type 2 failure rate (75.0% [6/8] in group 1 and 23.1% [3/13] in group 2; P = .03). CONCLUSION: Both techniques showed excellent improvement and comparable clinical outcomes, and there was no significant difference in retear rates. Consistent with previously published data, the type 2 failure rate was significantly higher with the knot-tying technique. REGISTRATION: NCT03982108 (ClinicalTrials.gov identifier).