Xu Dongmin, Koyama Hiroshi, Furuhashi Hiroki, Nishikino Shoichi, Hoshino Hironobu, Matsuyama Yukihiro
Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
J Orthop Sci. 2017 Nov;22(6):1102-1106. doi: 10.1016/j.jos.2017.08.015. Epub 2017 Sep 8.
In total hip arthroplasty (THA) surgery, hip muscle preservation is important in strengthening the stability of the hip and improving the activities of the patient. However, whether the type of femoral stem affects the recovery of the hip muscles remains unknown. The aim of this study was to compare the postoperative hip muscle recovery among femoral stem varieties after THA.
The computed tomography (CT) images of 44 patients (44 hips) who underwent THA using an anterolateral approach were reviewed. Twenty-two patients received a fit-and-fill (FF) stem and 22 received the tapered-wedge (TW) stem. The volumes of the gluteus maximus (GMA), gluteus medius (GME), and obturator internus (OI) were measured on three-dimensional models reconstructed using preoperative and 6-month postoperative CT images. Relationships between muscle volume changes and factors including the femoral stem length were evaluated.
The GMA and GME volumes increased postoperatively by 8.2% and 8.3%, respectively, in the FF stem group and 7% and 6%, respectively, in the TW stem group, with no group differences. In contrast, the OI volume decreased postoperatively by 17.8% in the FF group and was preserved in TW group (p < 0.001). Moreover, OI volume was decreased in 19 patients (86%) in the FF group and in 11 patients (50%) in the TW group (p = 0.01). The normalized stem length was significantly associated with the postoperative change in OI volume (r = -0.45, p = 0.002).
The TW stem showed a significant advantage over the FF stem in terms of OI preservation. Surgeons should pay close attention during surgery to avoid OI injury when using different femoral stem types. We suggest that a short and reduced lateral shoulder femoral stem is a better choice for the preservation of external rotation muscles.
在全髋关节置换术（THA）中，保留髋部肌肉对于增强髋关节稳定性和改善患者活动能力至关重要。然而，股骨柄类型是否会影响髋部肌肉的恢复仍不清楚。本研究的目的是比较THA术后不同股骨柄类型之间髋部肌肉的恢复情况。
回顾了44例采用前外侧入路行THA的患者（44髋）的计算机断层扫描（CT）图像。22例患者接受了紧压配合（FF）柄，22例接受了锥形锲入（TW）柄。使用术前和术后6个月的CT图像重建三维模型，测量臀大肌（GMA）、臀中肌（GME）和闭孔内肌（OI）的体积。评估肌肉体积变化与包括股骨柄长度在内的因素之间的关系。
FF柄组术后GMA和GME体积分别增加了8.2%和8.3%，TW柄组分别增加了7%和6%，两组之间无差异。相比之下，FF组术后OI体积减少了17.8%，而TW组则得以保留（p<0.001）。此外，FF组19例患者（86%）的OI体积减少，TW组11例患者（50%）的OI体积减少（p=0.01）。标准化柄长度与术后OI体积变化显著相关（r=-0.45，p=0.002）。
在保留OI方面，TW柄比FF柄具有显著优势。手术医生在使用不同类型股骨柄时，术中应密切注意避免OI损伤。我们建议，短的且外侧肩部缩小的股骨柄是保留外旋肌肉的更好选择。
