Long-term follow-up of perianchor cyst formation after rotator cuff repair

BACKGROUND: Perianchor cyst formation (PCF) can occur after arthroscopic rotator cuff repair with poly-L-lactic acid (PLLA) anchors; however, little is known about PCF after all-suture anchor (ASA) use. METHODS: We reviewed patients who underwent double-row arthroscopic rotator cuff repair from 2012 to 2017 with ASAs implanted in the medial row and PLLA anchors in the lateral row. We evaluated PCF (graded on magnetic resonance imaging) and compared physical examination and functional surveys between patients with PCF (WC) and without PCF (WoC) at long-term follow-up. RESULTS: Among twenty-two patients (23 shoulders), 93% of PLLA anchors (vs. 79% ASA) displayed a grade 0 PCF, P = .100. No PLLA anchors had a grade 3 or 4 PCF, compared to 11% of ASAs, P = .158. At a mean postoperative follow-up time of 113 weeks, there was no significant difference between WC and WoC cohorts with regard to range of motion, rotator cuff strength, American Shoulder and Elbow Surgeons survey scores, or retear rates. However, the WoC cohort had a significantly higher University of California at Los Angeles shoulder survey score at final follow-up (34.3 WoC vs. 30.9 WC, P = .024). CONCLUSION: No difference was found in PCF between ASAs and PLLA anchors. At long-term follow-up, WoC patients had significantly improved functional outcome scores, based on the University of California at Los Angeles survey, but equivalent range of motion and rotator cuff strength examinations compared with WC patients.