Shoji Takeshi, Inoue Tadashi, Kato Yuichi, Fujiwara Yusuke, Sumii Junnichi, Shozen Hideki, Adachi Nobuo
Department of Artificial Joints and Biomaterials, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
Clin Biomech (Bristol). 2022 Dec;100:105770. doi: 10.1016/j.clinbiomech.2022.105770. Epub 2022 Sep 27.
Femoral offset and anteversion have been reported to affect the incidence of dislocation following bipolar hemiarthroplasty, although the magnitudes of contributions of the femoral offset and stem anteversion on dislocation, both singly and in combination is not fully understood.
Using the CT data of 61 patients (61 hips), including 30 male and 31 female who underwent bipolar hemiarthroplasty, three-dimensional dynamic motion analysis was performed using a modular implant that enabled adjustment of femoral offset and stem anteversion independently. The pattern of impingement and relationship between femoral offset/stem anteversion and range of motion were evaluated using the software.
We found that a higher femoral offset and stem anteversion correlate with a greater range of motion of flexion and internal rotation. Furthermore, an increased femoral offset has a great effect on increasing range of motion of flexion than stem anteversion, and increased both femoral offset and stem anteversion have fewer effect on the flexion, whereas increasing stem anteversion has a great impact on internal rotation than offset, especially in the case with lower femoral anteversion. However, a higher stem anteversion decrease the range of motion of external rotation, whereas a higher femoral offset leads to an increased range of motion of external rotation.
We demonstrated that both a higher femoral offset and stem anteversion substantially affected the range of motion in flexion, internal rotation and external rotation. However, these are not independent, but rather mutually confounding, the surgeons should consider retaining femoral/anterior offset in bipolar hemiarthroplasty.
据报道，股骨偏心距和前倾角会影响双极半髋关节置换术后脱位的发生率，尽管股骨偏心距和假体柄前倾角对脱位的单独及联合影响程度尚未完全明确。
利用61例（61髋）接受双极半髋关节置换术患者的CT数据，其中男性30例，女性31例，使用一种能够独立调节股骨偏心距和假体柄前倾角的模块化假体进行三维动态运动分析。使用软件评估撞击模式以及股骨偏心距/假体柄前倾角与活动范围之间的关系。
我们发现，较高的股骨偏心距和假体柄前倾角与更大的屈曲和内旋活动范围相关。此外，增加股骨偏心距对增加屈曲活动范围的影响大于假体柄前倾角，同时增加股骨偏心距和假体柄前倾角对屈曲的影响较小，而增加假体柄前倾角对内旋的影响大于偏心距，尤其是在股骨前倾角较低的情况下。然而，较高的假体柄前倾角会减小外旋活动范围，而较高的股骨偏心距会导致外旋活动范围增加。
我们证明，较高的股骨偏心距和假体柄前倾角均会显著影响屈曲、内旋和外旋的活动范围。然而，这些因素并非相互独立，而是相互干扰，外科医生在双极半髋关节置换术中应考虑保留股骨/前方偏心距。
