肘部管症候群除圧術後の短期的な症状悪化：後向きコホート研究からの臨床的特徴とメカニズムの洞察

While surgical decompression for cubital tunnel syndrome (CuTS) generally leads to favorable outcomes, some patients experience early postoperative worsening marked by transient symptom flare-ups. The underlying mechanisms remain poorly understood. We retrospectively analyzed 127 patients who underwent anterior ulnar nerve transposition without corticosteroids. Clinical scores (VAS, PRUNE, two-point discrimination) and electrophysiological parameters (CMAP, SNCV, MNCV) were assessed preoperatively, at 2 weeks, and at 6 months. Early worsening was defined as deterioration in any clinical indicator at 2 weeks. At 6 months, most patients improved significantly. However, 26.8% showed early worsening at 2 weeks, with elevated PRUNE scores, reduced sensory discrimination, and declines in CMAP, SNCV, and MNCV (all p < 0.001). These changes resolved spontaneously without surgical failure. Likely contributors include inflammatory edema, mechanical stress, transient ischemia, and central sensitization. Early postoperative worsening affects over one-quarter of CuTS patients but is typically self-limiting. Awareness of this pattern can prevent misdiagnosis, reduce unnecessary interventions, and improve patient counseling. Future research should identify predictive markers and develop mitigation strategies.