Association Between Liner Stability Ratio and Aseptic Glenoid Loosening in Anatomic Total Shoulder Arthroplasty: A Dutch National Registry Study
Approval date: April 17th 2026
MPJ van den Bekerom, D Boulidam, AA Macken, A van Noort, P Moroder, A Shekhbihi, I Sierevelt
Research proposal abstract:
Anatomic total shoulder arthroplasty (aTSA) is widely used to treat primary glenohumeral osteoarthritis. Although overall outcomes are favorable, aseptic glenoid component loosening remains one of the most frequent causes of revision. Loosening is thought to result from eccentric loading and repetitive micromotion at the bone–implant interface, a process described as the rocking horse phenomenon. Implant geometry may influence this mechanism by modulating humeral head containment, load transfer, and resistance to translation, thereby altering the magnitude and direction of joint reaction forces acting on the glenoid component.
Recent analyses have demonstrated substantial variability in glenoid component geometry not only between implant systems but also within systems across different component sizes. The liner stability ratio (LSR), incorporating concavity depth and radius of curvature, provides a quantitative measure of biomechanical constraint and may therefore reflect susceptibility to eccentric loading consistent with the rocking horse mechanism. However, the clinical implications of this geometric variability remain unclear.
Using data from the Dutch Arthroplasty Register, this study will investigate the association between LSR and glenoid component survival following primary aTSA for osteoarthritis. Secondary outcomes include revision for instability and revision for any cause.