Outcomes of total shoulder arthroplasty in patients with prior anterior shoulder instability: minimum 5-year follow-up

Abstract

Patients with a history of anterior shoulder instability (ASI) commonly progress to glenohumeral arthritis or even "dislocation arthropathy" and often require total shoulder arthroplasty (TSA). The purposes of this study were to 1) report patient reported outcomes (PROs) after TSA in patients with a history of ASI, 2) compare TSA outcomes of those whose ASI was managed operatively versus those managed nonoperatively, and 3) report PROs of TSA in patients who previously underwent arthroscopic versus open ASI management. Patients were included if they had a history of ASI and were at least 5 years out from TSA performed by a single surgeon between 10/2005 and 01/2017. Exclusion criteria included prior rotator cuff repair, hemi-arthroplasty, or glenohumeral joint infection prior to index TSA. Patients were separated into two groups, those with previous operatively managed ASI and those whose ASI was treated nonoperatively. Prospectively collected demographic, surgical, and subjective data were retrospectively reviewed. PROs utilized were the ASES score, SANE, QuickDASH, SF-12 PCS. Failure was defined as revision TSA surgery, conversion to reverse TSA, or prosthetic joint infection. Kaplan-Meier survivorship analysis was performed. 36 patients (27 male, 9 female) with a mean age of 56.4 years (range, 18.8-72.2) were included. Patients in the operative ASI group were younger than those in the nonoperative ASI group (50.6 vs 64.0 years, p<.001). Operative ASI patients underwent 10 open and 11 arthroscopic anterior stabilization surgeries prior to their TSA (mean, 2; range, 1-4). 6 of 21 (28.6%) TSAs failed in patients with operative ASI while there were no failures in the nonoperative ASI group (p=0.03). Follow-up was obtained in 28 of 30 (93%) eligible patients at an average of 7.45 years (range, 5.0-13.6). In the collective cohort, ASES, SANE, QuickDASH, and SF-12 PCS scores significantly improved with no differences in the postoperative PROs between the two groups. No significant differences were found when comparing PROs between prior open and prior arthroscopic ASI procedures or when comparing the number of prior ASI procedures. Kaplan-Meier analysis demonstrated 79% 5-year survivorship in patients with prior ASI surgery and 100% survivorship in nonoperatively managed ASI patients (p=.030). At mid-term follow-up, patients with a history of prior ASI undergoing TSA can expect continued improvement in function compared to preoperative values. However, TSA survivorship is decreased in patients with a history of ASI surgery compared to those without prior surgery.