最適化された犬のセメント人工股関節全置換術：解剖体モデルにおける技術的精度と学習成果

Total hip arthroplasty effectively restores near-normal gait in most dogs with hip dysplasia unresponsive to conservative treatment. Total hip replacement (THR) requires high surgical accuracy for all surgeons, though errors and deviations are more common during the learning phase (Hayes et al. Vet Surg 40(1):1-5, 2011a). This study aimed to evaluate the technical performance and identify common intraoperative deviations in cemented THR performed by a novice surgeon using canine cadavers. Twelve adult cadavers underwent unilateral THR following a standardized protocol, with implant sizes determined through both radiographic and CT-based preoperative templating. All procedures were performed under expert supervision, with intraoperative corrections made when necessary. Postoperative radiographs were obtained not to detect missed errors but to objectively quantify final implant orientation after correction, thereby documenting technical inaccuracies, including those corrected intraoperatively. Postoperative radiographs were assessed for acetabular cup orientation, femoral stem alignment, canal fill, cement mantle quality, tip-to-cortex distance and cement quality. Overall, > 80% agreement was noted between templated and implanted components. A statistically significant association (p = 0.04) was observed between the matched acetabular cup and femoral stem. While implant positioning, including stem orientation, canal fill, and cement mantle thickness, cementation quality was within acceptable limits, increased canal fill correlated with mild varus or valgus deviations (r = 0.702, p = 0.01). These findings suggest that novice surgeons may achieve reproducible and acceptable outcomes through cadaver-based training with structured mentoring. However, optimal implant placement was not consistently achieved, indicating that further refinement is needed. Larger-scale cadaveric studies and more intensive surgical training protocols are recommended to enhance accuracy, reduce variability, and improve learning outcomes clinically in canine THR.