Primary inlay reverse shoulder arthroplasty has a higher rate of revision than onlay reverse shoulder arthroplasty: Analysis from the Australian Orthopaedic Association National Joint Replacement Registry

David Rj Gill; Stephen D Gill; Sophia Corfield; Carl Holder; Richard S Page; Investigation performed at AOANJRR

doi:10.1177/17585732221122275

Primary inlay reverse shoulder arthroplasty has a higher rate of revision than onlay reverse shoulder arthroplasty: Analysis from the Australian Orthopaedic Association National Joint Replacement Registry

Shoulder Elbow. 2023 Nov;15(3 Suppl):75-81. doi: 10.1177/17585732221122275. Epub 2022 Aug 24.

Authors

David Rj Gill¹, Stephen D Gill², Sophia Corfield³, Carl Holder⁴, Richard S Page^{2

3}; Investigation performed at AOANJRR

Affiliations

¹ Orthopaedics Central, Nedlands, Western Australia.
² Barwon Centre for Orthopaedic Research and Education (B-CORE), St John of God Hospital and Deakin University, Geelong, Australia.
³ Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), Adelaide, Australia.
⁴ South Australia Health and Medical Research Institute (SAHMRI), Adelaide, Australia.

PMID: 37974643
PMCID: PMC10649502 (available on 2024-11-01)
DOI: 10.1177/17585732221122275

Abstract

Background: Two classes of primary reverse total shoulder arthroplasty (rTSA), inlay (in-rTSA), and onlay (on-rTSA) were compared to determine differences in rates of revision.

Methods: Between 1 January 2012 and 31 December 2020, all primary in-rTSA or on-rTSA procedures were compared from a large national arthroplasty registry by cumulative percentage revision (CPR). Kaplan-Meier estimates of survivorship and hazard ratios from Cox proportional hazard models adjusted for age, gender, glenosphere size, and humeral fixation determined any associations to the risk of revision.

Results: Of the 14,807 in-rTSA and 6590 on-rTSA procedures, the CPR at seven years was 4.9%. There was an increased risk of revision for in-rTSA vs on-rTSA (p = 0.039) when adjusted for age, gender, glenosphere size, and humeral fixation. Glenosphere size <38 mm adjusted for age and gender (p = 0.016) increased the revision risk. Revision for instability/dislocation occurred more often for in-rTSA vs on-rTSA (p < 0.001) in the first three months. Males had a higher rate of revision than females for in-rTSA (3months+, p = 0.001) and for on-rTSA (p < 0.001).

Discussion: Care should be taken when considering in-rTSA particularly in males, and if preoperative planning suggests a small (<38 mm) glenosphere.

Level of evidence: Level III, therapeutic study. Original article.

Keywords: inlay reverse shoulder arthroplasty; onlay reverse shoulder arthroplasty; primary shoulder arthroplasty; reverse shoulder arthroplasty.