Lower average cortical bone thickness predicts cemented fixation in short-stem reverse shoulder arthroplasty.

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Short-stem reverse shoulder arthroplasty (RSA) involves choosing between cemented and cementless humeral fixation.
• Predictors for this intraoperative decision in patients ≤80 years are not fully established.

Purpose of the Study:

• To identify radiographic and demographic factors influencing the choice between cemented and cementless humeral fixation in patients ≤80 years undergoing short-stem RSA.

Main Methods:

• Retrospective analysis of 267 RSA cases (02/2019-10/2024) in patients ≤80 years.
• Patients were grouped based on intraoperative fixation: cementless (n=209) or cemented (n=58).
• Preoperative variables included age, sex, BMI, ASA score, diagnosis, and radiographic parameters (CBTg, CBTavg, AHD, Hamada, Walch). Multivariate logistic regression was performed.

Main Results:

• Cemented fixation group was older (74 vs. 70 years) and more often female (81% vs. 61%).
• Lower average cortical thickness (CBTavg: 5.15 mm vs. 6.42 mm) was observed in the cemented group.
• Independent predictors for cemented fixation were increasing age (OR 1.1), female sex (OR 2.8), and reduced CBTavg (OR 0.6).

Conclusions:

• Lower average cortical thickness (CBTavg) is the strongest independent predictor for cemented humeral fixation in short-stem RSA.
• Integrating CBTavg into preoperative planning can enhance surgical decision-making and fixation strategy consistency.