Value comparison of humeral component press-fit and cemented techniques in reverse shoulder arthroplasty

Abstract

Background: Press-fit humeral fixation for reverse shoulder arthroplasty (RSA) has been shown to have loosening rates and outcomes similar to a cemented technique; however, increased value has not been reported. The purpose of this study was to determine whether the press-fit technique could improve the value of RSA using the procedure value index (PVI).

Methods: Primary RSA patients with complete hospitalization cost data, preoperative and minimum 2-year postoperative Simple Shoulder Test (SST) scores, and postoperative satisfaction were included. The PVI was calculated as improvement in the SST score (in units of minimal clinically important difference) divided by total cost and normalized. Itemized cost data were obtained from hospital financial records and categorized. Radiographic complications, infections, and revisions were noted. Comparisons were made between the press-fit and cemented RSA cohorts.

Results: A total of 176 primary RSA patients (83 cemented and 93 press fit) met the inclusion criteria (mean follow-up period, 44.6 months). Surgical indications (except failed rotator cuff repair), baseline SST scores, and demographic characteristics were similar. The calculated minimal clinically important difference for the SST score was 3.98. The average PVI was significantly greater in the press-fit cohort (1.51 vs 1.03, P < .001), representing a 47% difference. SST score improvement was not significantly different (P = .23). However, total hospitalization costs were significantly lower for the press-fit cohort ($10,048.89 vs $13,601.14; P < .001).

Conclusion: Use of a press-fit technique led to a 47% increase in value over a cemented technique. This appeared to be a function of decreased total costs rather than increased outcome scores.

Keywords: Reverse shoulder arthroplasty (RSA); SST; cemented; cost; press fit; procedure value index (PVI); radiographic outcomes; value.

Figure 1

Cemented humeral stem. (A) Anteroposterior radiograph of a right shoulder showing an example of a cemented modular humeral stem. (B) Anteroposterior radiograph of a left shoulder showing an example of a cemented Monoblock humeral stem.

Figure 2

Press-fit humeral stem. (A) Anteroposterior radiograph of a right shoulder showing an example of a metaphyseal press-fit inset humeral stem. (B) Anteroposterior radiograph of a left shoulder showing an example of a diaphyseal press-fit humeral stem.

Figure 3

Mean cost categories per patient shown as a percentage of total costs. RSA, reverse shoulder arthroplasty.

Figure 4

Procedure value index (PVI), Simple Shoulder Test (SST) score improvement, and costs in US dollars plotted over time according to date of surgery. Black lines depict moving averages. Red lines indicate the approximate date of press-fit stem introduction at our institution.