The effect of socioeconomic status on clinical outcomes and implant survivorship after primary anatomic and reverse total shoulder arthroplasty.

Background: Low socioeconomic status has been shown to contribute to poor outcomes in patients undergoing joint replacement surgery. However, there is a paucity of studies investigating shoulder arthroplasty. The purpose of this study was to evaluate the effect of socioeconomic status on baseline and postoperative outcome scores and implant survivorship after anatomic and reverse primary total shoulder arthroplasty (TSA).

Methods: A retrospective review of a prospectively collected single-institution database was performed to identify patients who underwent primary TSA. Zip codes were collected and converted to Area Deprivation Index (ADI) scores. We performed a correlation analysis between national ADI scores and preoperative, postoperative, and preoperative to postoperative improvement in range of motion (ROM), shoulder strength, and functional outcome scores in patients with minimum 2-year follow-up. Patients were additionally grouped into groups according to their national ADI. Achievement of the minimum clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) and revision-free survivorship were compared between groups.

Results: A total of 1148 procedures including 415 anatomic and 733 reverse total shoulder arthroplasties with a mean age of 64 ± 8.2 and 69.9 ± 8.0 years, respectively, were included. The mean follow-up was 6.3 ± 3.6 years for anatomic and 4.9 ± 2.7 years for reverse total shoulder arthroplasty. We identified a weak negative correlation between national ADI and most functional outcome scores and ROM preoperatively (R range 0.07-0.16), postoperatively (R range 0.09-0.14), and preoperative to postoperative improvement (R range 0.01-0.17). Thus, greater area deprivation was weakly associated with poorer function preoperatively, poorer final outcomes, and poorer improvement in outcomes. There was no difference in the proportion of each ADI group achieving MCID, SCB, and PASS in the anatomic total shoulder arthroplasty cohort. However, in the reverse total shoulder arthroplasty cohort, the proportion of patients achieving MCID, SCB, and PASS decreased with greater deprivation. There was no difference in survivorship between ADI groups.

Conclusions: We found a negative effect of low socioeconomic status on baseline and postoperative patient outcomes and ROM; however, the correlations were relatively weak. Patients that reside in socioeconomically deprived areas have poorer functional outcomes before and after TSA and achieve less improvement from surgery. We should strive to identify modifiable factors to improve the success of TSA in socioeconomically deprived areas.