SPECT/CT for Early Detection of Stress Reactions After Reverse Shoulder Arthroplasty: Potential Clinical Significance.

The altered biomechanics after reverse shoulder arthroplasty, combined with the accumulation of various stress risers, can lead to stress fractures (SFs) around the prosthesis. The incidence of stress reactions (SRs) after reverse shoulder arthroplasty, characterized by pain and tenderness without radiographic or CT evidence of fractures, is approximately 4.2%, which is comparable to the incidence of SF (6.4%). Among patients with SR, a substantial 32% eventually progress to fractures during clinical follow-up. SPECT/CT is a promising tool that combines morphologic and metabolic information for assessing mechanical bone stress. Therefore, early detection of SR through SPECT/CT can help prevent SF.