The impact of the underlying pathology and previous surgery on the long-term functional outcomes of reverse shoulder arthroplasty: a prospective cohort study with a minimum follow-up of 11 years.

Abstract

Background: Reverse shoulder arthroplasty (rTSA) is a successful treatment option for rotator cuff tear arthropathy (CTA). Since its introduction, the range of indications has been expanded while implant designs have been enhanced. The purpose of this study is to evaluate the long-term clinical, radiographic, and patient-reported outcomes of the Delta Xtend rTSA.

Materials and methods: In this prospective cohort study, 108 consecutive patients who underwent implantation of rTSA using the DePuy Delta Xtend in 2008 were included. Patients were divided into four indication groups: CTA (60%), revision shoulder arthroplasty (15%), fracture sequelae (19%) and post-infectious arthropathy (6%). Clinical examination and radiographic follow-up were performed after 5 years and at long-term with a minimum follow-up of 11 years.

Results: 43 patients were eligible for follow-up with a median follow-up period of 12.5 years (range: 11.5 - 12.6 years, response rate 79%). The preoperative Constant Score (CS) was 19 [9 - 24], and the CS at follow-up was 56 [41 - 64] with a significant increase between implantation and latest follow-up (p < 0.001). No significant difference of the CS at follow-up was reported between the 4 groups. Between the mid-term follow-up and the latest follow-up, a significant decrease of the CS of 10 [2 - 14] was observed (p = 0.004), however no significant difference in the age- and sex correlated CS was reported (p = 0.13). Patients who underwent previous surgery before the index arthroplasty (51 [35 - 62]) had a significantly lower CS than patients without previous surgery (63 [58 - 66], p = 0.032). Patients with revision arthroplasty had a significantly lower range of motion at long-term follow-up than patients with CTA (p = 0.013). Implant survival was 95.3% after 11 years. Patients with fracture sequelae had a significantly higher risk for revision than patients with CTA (p = 0.04). Implant survival without revision for any complication was 89.7%, the overall complication rate was 12.5%.

Conclusion: This study demonstrated favorable long-term outcomes of rTSA and a satisfactory survival rate using the Delta Xtend system. However, a significant decline of the functional outcome was observed since the mid-term follow-up. For indications other than CTA, the functional results are inferior, and the risk for revision is higher. Previous shoulder surgery prior to the index arthroplasty leads to a worse functional outcome and a higher risk of reoperation due to any complication.