Bone metabolism in complex regional pain syndrome : PAIN Reports
nclear. Objectives: This study aimed to evaluate bone metabolism in CRPS using TPBS and bone serum markers. Methods: A deep learning model for automated segmentation quantified tracer enhancement in TPBS images. Serum markers analysed included alkaline phosphatase (AP), 25-OH vitamin D, osteoprotegerin, procollagen type I N-terminal propeptide (PINP), and β-C-terminal telopeptide, compared to 48 healthy controls (HC). The study included 114 patients with CRPS, 41 of whom underwent TPBS. Results: Of the 41 patients with CRPS with TPBS, 39 (95.1%) displayed radiotracer enhancement in the bone phase across CRPS subtypes. Serum markers of 114 patients did not significantly differ between patients and HC, nor did they correlate with TPBS enhancement, except in warm CRPS. In these patients, TPBS accumulation in the metacarpophalangeal region correlated with PINP (Spearman ρ = 0.63, P = 0.038), and AP levels were elevated at 78 U/L (interquartile range 64–88) compared to cold CRPS at 66 U/L (