Minimum 5-year Outcomes following Subacromial Balloon Spacer Implantation for Massive Rotator Cuff Tears

Introduction:
Massive rotator cuff tears pose a significant treatment challenge in management of pain and dysfunction due to rotator cuff pathology. Subacromial balloon spacer implantation (SBSI) has been proposed as an efficient and safe treatment modality, and clinical studies have demonstrated these in short term follow-up. However, there is paucity in clinical studies evaluating sustained improvements beyond the short-term follow-up. Therefore, the purpose of this study was to evaluate and report on minimum five-year outcomes following SBSI, in terms of clinical survivorship, pain reduction, functional outcomes, complications and reoperations.

Methods:
Data were prospectively collected and retrospectively analyzed for patients undergoing SBSI between April 1, 2012, and June 30, 2016. Patients were included if they had pre-operative and post-operative follow-up for 5 years on the following patient-reported outcomes (PROs), Constant-Murley Score (CMS), visual analog scale for pain (VAS), strength, and patient satisfaction. Reoperations as well as complications were recorded. Minimal clinical important difference was calculated based on a distribution method and the proportion of patients achieving the MCID for CMS were calculated. Statistical significance was set at P = .05. Institutional Review Board approval was granted for this study.

Results:
Between April 1, 2012 and June 30, 2016 SBSI was performed in 36 patients. Of these, four patients were lost to follow-up (89% available for follow up). Of 32 remaining patients, 3 were deceased and four underwent re-operation with a reverse total shoulder arthroplasty. For the remaining patients, mean follow-up time was 72.48 months. The mean age at the time of the operation was 72.2 ± 4.6 years, and 68% of the patients were males. Significant improvements from preoperative to last follow-up were demonstrated in CMS (36.08 vs. 64.00, p<0.001), VAS for pain Pain (6.7 vs. 1.79, p<0.001), and strength (3.8 vs. 6.04 kg, p<0.001). These improvements were demonstrated at 3 weeks, 6 months, 12 months, 24 months, and 60 months, while at the 3 month follow up a temporary decrease was demonstrated. Mean patient satisfaction at last follow up was 8.72. Minimal clinical important difference for the CMS was achieved by 88% of patients at last follow-up. Complications included one patient with balloon dislocation and one patient with a secondary infection following urinary tract infection, three months after SBSI.

Conclusion:
Pain reduction and functional improvements are sustainable at minimum five years after SBSI in patients with massive rotator cuff tears. Complications and reoperations are infrequent and patient satisfaction is high.