Predicted impingement-free motion amplitudes in reverse total shoulder arthroplasty differs between supine computed tomography and standing biplanar x-ray imaging: a pilot study

Preoperative planning software is widely used to assist surgeons in selecting and positioning implant components for reverse total shoulder arthroplasty (rTSA)14. These tools rely on patient-specific bone surface models derived from preoperative supine computed tomography (CT) scans and predict postoperative impingement-free motion amplitudes by simulating uniplanar humeral movements. However, a major limitation is that the CT scans are acquired in the supine position, which fails to account for the scapula posture in a standing position, a factor critical for clinical assessments11.