Improved functional outcome and tuberosity healing in patients treated with fracture stems than nonfracture stems during shoulder arthroplasty for proximal humeral fracture: a meta-analysis and systematic review

Abstract

Background: Proximal humeral fractures are difficult injuries to treat and obtain satisfactory outcomes. For those treated with arthroplasty, humeral fracture stems have been popular due to better ability for reduction and fixation of tuberosities. This study aims to investigate the outcomes of fracture stems in shoulder arthroplasty for proximal humeral fracture and the comparison of outcomes between fracture vs. nonfracture stems.

Methods: A meta-analysis was conducted with a multidatabase search (PubMed, OVID, EMBASE, Medline) according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines on May 19, 2020. Data from all published literature meeting inclusion criteria were extracted and analyzed.

Findings: Eleven studies were included for analysis, including 383 hemiarthroplasties (HA) (294 fracture stems, 89 nonfracture stems) and 358 reverse total shoulder arthroplasties (RTSA) (309 fracture stems, 49 nonfracture stems). At the final follow-up, meta-analysis shows favorable overall ASES score in all fracture stem prosthesis (mean = 74.0, 95% confidence interval [CI]: 69.3-78.7), Constant-Murley score (mean = 67.2, 95% CI: 61.6-72.8), external rotation (mean difference [MD] = 7°, 95% CI: 3°-10°, P < .001), and forward flexion (MD = 17°, 95% CI: 10°-25°, P < .001). Pooled proportion (PP) of greater tuberosity healing (PP = 0.786, 95% CI: 0.686-0.886) was high, whereas all-cause revisions (PP = 0.034, 95% CI: 0.018-0.061) remained low. With the exception of RTSA scapular notching (PP = 0.109, 95% CI: 0.020-0.343), other complication metrics had PP of ≤0.023. In the 4 studies comparing fracture (138 HA, 54 RTSA) vs. nonfracture stems (89 HA, 49 RTSA), fracture stems had statistically significant better American Shoulder and Elbow Surgeons scores (MD = 14.29, 95% CI: 8.18-20.41, P < .001), external rotation (MD = 6°, 95% CI: 2°-9°, P = .003), forward flexion (MD = 16°, 95% CI: 7°-24°, P < .001), and greater tuberosity healing (odds ratio = 2.20, 95% CI: 1.28-3.77, P = .004). There was no statistically significant difference in complications.

Conclusion: Fracture stems showed promising overall clinical outcomes with low complication rates in treating proximal humeral fractures. The use of fracture stems is also associated with greater chance of tuberosity healing compared with nonfracture stems. There is increasing evidence to suggest the superiority of fracture stems over nonfracture stems in clinical outcomes, while maintaining similar complication rates.

Keywords: Shoulder arthroplasty; fracture stems; proximal humeral fractures; reverse total shoulder arthroplasty; shoulder hemiarthroplasty.