Department of Biomedical and Neurimotor Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy.
Ist Orthopedic Department, IRCCS - Istituto Ortopedico Rizzoli, Bologna, Italy.
Int Orthop. 2023 Jun;47(6):1441-1447. doi: 10.1007/s00264-023-05762-5. Epub 2023 Mar 14.
The purpose of this study is to estimate the effect of unilateral hip osteoarthritis (OA) on hip muscle volume and fatty infiltration and to evaluate changes of muscles after total hip arthroplasty (THA) surgery.
A retrospective analysis was conducted on patients with unilateral hip OA subjected to THA with perioperative pelvic girdle 1.5 T magnetic resonance imaging (MRI). Thirty-five patients were included. Ten of these have also postoperative MRIs. Medius gluteus (MG) and iliopsoas (IP) muscles were manually segmented on the MRI scans, the corresponding 3D muscle geometries were reconstructed, and the volumes extracted. Muscle quality was assessed using the Goutallier classification on coronal MRI images. Volume and muscle quality differences were calculated between healthy and affected side.
Pre-operatively, MG and IP on the affected side presented a mean muscle volume 17.5 ± 18% (p < 0.001) and 14.4 ± 15.8% (p < 0.001) smaller than the healthy counterpart, respectively. Muscles on the affected side showed a significant higher grade of fatty infiltration compared to the healthy side (p < 0.05 for MG; p < 0.001 for IP). At an average follow-up of 13 ± 5.3 months after THA, MG, and IP muscles of the affected hip showed an average 22.8% (p < 0.001) and 28.2% (p < 0.001) volume increase after THA. Also, the healthy side showed a significant increase of muscle volume for IP (17.1% p < 0.001). No significant change for MG muscle was observed.
The study demonstrated preoperative reduced muscle volume and higher fatty infiltration at the muscles of the OA hip compared to the contralateral healthy one. A significant positive effect of THA on hip muscle volume was observed. These findings give an interesting insight on muscle deconditioning and recovery in patients undergoing THA.
本研究旨在评估单侧髋关节炎（OA）对髋部肌肉体积和脂肪浸润的影响，并评估全髋关节置换术（THA）后肌肉的变化。
对接受单侧髋 OA 行 THA 术并进行骨盆带 1.5T MRI 检查的患者进行回顾性分析。共纳入 35 例患者，其中 10 例患者有术后 MRI。在 MRI 扫描上手动分割臀中肌（MG）和髂腰肌（IP），重建相应的 3D 肌肉几何形状，并提取体积。使用冠状位 MRI 图像上的 Goutallier 分级评估肌肉质量。计算健康侧和患侧之间的体积和肌肉质量差异。
术前，患侧 MG 和 IP 的肌肉体积分别为健康侧的 17.5±18%（p<0.001）和 14.4±15.8%（p<0.001）。患侧肌肉的脂肪浸润程度明显高于健康侧（MG：p<0.05；IP：p<0.001）。在 THA 后平均 13±5.3 个月的随访中，患侧髋关节的 MG 和 IP 肌肉体积分别平均增加了 22.8%（p<0.001）和 28.2%（p<0.001）。此外，健康侧的 IP 肌肉体积也显著增加（17.1%，p<0.001）。MG 肌肉体积无明显变化。
本研究表明，与对侧健康侧相比，OA 髋部肌肉的术前肌肉体积减小，脂肪浸润程度更高。THA 对髋关节肌肉体积有显著的积极影响。这些发现为接受 THA 的患者的肌肉失代偿和恢复提供了有趣的见解。
