JSES - 2026-06-16 - Journal Article; Review
Inconsistencies in Terminology Used to Describe Reverse Shoulder Arthroplasty: A Systematic Review.
Werthel JD, Descamps J, Lugo E, Routman H
Topics
Key Takeaway
Among 799 rTSA studies, the center of rotation was mentioned in 72.8% but clearly defined in only 19.4%, and 53% failed to specify the anatomical origin of lateralization.
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Summary
This systematic review interrogated how rTSA implant design parameters—center of rotation position, glenoid offset, and humeral offset—are reported across peer-reviewed literature published after 2015. Glenoid and humeral lateral offsets were explicitly described in only 39.3% and 46.6% of studies, respectively, and 32.7% of studies provided no clear overall design classification. The findings expose a field-wide reporting deficit that undermines cross-study comparability of clinical and biomechanical outcomes.
Key Limitation
The binary classification of whether a parameter was 'clearly defined' was determined by the review authors without a validated rubric or reported inter-rater agreement, making the 19.4% figure for COR definition potentially unreliable.
Original Abstract
INTRODUCTION
Reverse total shoulder arthroplasty (rTSA) implant design has evolved substantially over the past decades, with numerous modifications affecting medialization, lateralization, and center of rotation (COR) geometry. Although these parameters are frequently discussed in the literature, the terminology used to describe rTSA design and configuration remains heterogeneous and inconsistently defined, limiting comparability across studies.
MATERIALS AND METHODS
A systematic review was performed to analyze how rTSA implant design and configuration are reported in the peer-reviewed literature. MEDLINE, EMBASE, and CENTRAL were searched for English- and French-language studies published after 2015. Eligible studies included clinical, biomechanical, cadaveric, computational, and review studies reporting technical data related to medialization or lateralization. Data extraction focused on implant identification, reporting of COR position, glenoid and humeral offset parameters, and overall design classification. Descriptive statistics were used to summarize reporting patterns.
RESULTS
A total of 799 studies met inclusion criteria. Although the position of the COR was mentioned in 72.8% of studies, it was clearly defined in only 19.4%. Glenoid and humeral lateral offsets were explicitly described in 39.3% and 46.6% of studies, respectively. Overall implant design was classified as lateralized in 17.6%, medialized in 15.6%, and mixed in 34.0% of studies, while 32.7% lacked a clear design classification. In more than half of studies (53%), the anatomical origin of lateralization (glenoid, humeral, or combined) was not specified.
CONCLUSION
This systematic review demonstrates substantial inconsistency in the terminology used to describe rTSA implant design and configuration. Key biomechanical parameters are frequently reported without clear, quantitative, or reproducible definitions, which may hinder interpretation and comparison of published findings. Future expert-based consensus work may help establish clearer and more reproducible descriptive terminology for reporting rTSA design and configuration.