Koyanagi Junichiro, Sakai Takashi, Yamazaki Takaharu, Watanabe Tetsu, Akiyama Keisuke, Sugano Nobuhiko, Yoshikawa Hideki, Sugamoto Kazuomi
Department of Orthopaedic Biomaterial Science, Osaka University Graduate School of Medicine, Suita, Japan.
Clin Biomech (Bristol). 2011 Jun;26(5):477-83. doi: 10.1016/j.clinbiomech.2010.11.006. Epub 2010 Dec 4.
The in vivo kinematics of squatting after total hip arthroplasty is unclear. The purpose of the present study was to determine the range of motion of the hip joint during squatting after total hip arthroplasty.
Using fluoroscopy, we investigated 15 primary cementless total hip arthroplasties performed using a computed tomography-based navigation system. An acetabular component with concavities around the rim and a femoral component with reduced neck geometry were used. The motion of the acetabular and femoral components based on the neutral standing position was analyzed using a two-dimensional to three-dimensional registration technique.
No prosthetic impingement occurred in any hips. The mean maximum hip flexion range of motion was 86.2° (range, 55.1°-117.4°) and was not always consistent with maximum squatting. The mean maximum pelvic posterior tilting angle was 25.7° (range, 5.5°-43.5°). The pelvis began to tilt posteriorly at 50°-70° of the hip flexion range of motion. At maximum squatting, the mean ratio of the pelvic posterior tilting angle to the femoral flexion angle was 23.2% (range, 3.8%-45.7%). The mean minimum angle up to the theoretical prosthetic impingement was 26.2° (range, 11.8°-39.8°).
Although this is a preliminary study, three-dimensional assessment of dynamic squatting motion after total hip arthroplasty using the two-dimensional to three-dimensional registration technique appears to enable elucidation of the range of motion of the hip joint, the contribution of pelvic posterior tilting, and the minimum angle up to theoretical prosthetic impingement during squatting.
全髋关节置换术后蹲姿的体内运动学尚不清楚。本研究的目的是确定全髋关节置换术后蹲姿时髋关节的活动范围。
我们使用荧光透视法，对15例采用基于计算机断层扫描的导航系统进行的初次非骨水泥型全髋关节置换术进行了研究。使用了一种髋臼边缘带有凹面的髋臼组件和一种颈部几何形状减小的股骨组件。基于中立站立位，采用二维到三维配准技术分析髋臼和股骨组件的运动。
所有髋关节均未发生假体撞击。平均最大髋关节屈曲活动范围为86.2°（范围为55.1°-117.4°），且并不总是与最大蹲姿一致。平均最大骨盆后倾角度为25.7°（范围为5.5°-43.5°）。在髋关节屈曲活动范围达到50°-70°时，骨盆开始向后倾斜。在最大蹲姿时，骨盆后倾角度与股骨屈曲角度的平均比值为23.2%（范围为3.8%-45.7%）。直至理论上假体撞击的平均最小角度为26.2°（范围为11.8°-39.8°）。
尽管这是一项初步研究，但使用二维到三维配准技术对全髋关节置换术后动态蹲姿运动进行三维评估，似乎能够阐明髋关节的活动范围、骨盆后倾的作用以及蹲姿时直至理论上假体撞击的最小角度。
