Hasler Julian, Hoch Armando, Fürnstahl Philipp, Ackermann Jakob, Zingg Patrick O, Vlachopoulos Lazaros
Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, CH-8008, Zurich, Switzerland.
Research in Orthopaedics Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
BMC Musculoskelet Disord. 2021 Mar 11;22(1):268. doi: 10.1186/s12891-021-04131-w.
Preoperative templating in total hip arthroplasty (THA) is mandatory to achieve appropriate offset and leg length equality. However, templating methods using the contralateral hip might be susceptible to errors resulting from side-differences in the femoral morphology. The distance of the lesser trochanter to the femoral head center (LTFHD) is a frequently used reference parameter for preoperative planning and intraoperative validation during THA. However, currently no three-dimensional (3D) analysis of side differences of the LTFHD exists.
Using Computer tomography (CT)-based surface models from 100 paired femora (50 cadavers), side-to-side asymmetry of the LTFHD, femoral length, femoral head diameter (FHD) and femoral antetorsion were analyzed. Univariate linear regression models were established to evaluate potential associations between sides regarding LTFHD and FHD as well as a correlation of these parameters with each other.
Statistically significant side-differences were found for the LTFHD (p = 0.02) and FHD (p = 0.03) with a mean absolute side-difference of 1.6 ± 1.4mm (range 0.1-5.5mm) and 0.4mm ± 0.6mm (range 0-3mm), respectively. The ratio between the LTFHD and FHD was consistent with an average value of 1.16 ± 0.08 and reliable between sides with a correlation coefficient (r) of 0.72 (p < 0.01).
The LTFHD is a reliable reference parameter for preoperative templating and intraoperative validation during THA with a high correlation between sides (r = 0.93, p < 0.01). However, 8 % of the investigated specimens revealed a LTFHD of more than 4mm, which should be anticipated during THA to avoid unsatisfiable results.
全髋关节置换术（THA）术前模板测量对于实现合适的偏心距和双下肢长度相等至关重要。然而，使用对侧髋关节的模板测量方法可能容易受到股骨形态侧方差异导致的误差影响。小转子到股骨头中心的距离（LTFHD）是THA术前规划和术中验证常用的参考参数。然而，目前尚无对LTFHD侧方差异的三维（3D）分析。
使用来自100对股骨（50具尸体）基于计算机断层扫描（CT）的表面模型，分析LTFHD、股骨长度、股骨头直径（FHD）和股骨前倾角的左右不对称性。建立单变量线性回归模型以评估LTFHD和FHD两侧之间的潜在关联以及这些参数之间的相关性。
发现LTFHD（p = 0.02）和FHD（p = 0.03）存在统计学上显著的侧方差异，平均绝对侧方差异分别为1.6±1.4mm（范围0.1 - 5.5mm）和0.4mm±0.6mm（范围0 - 3mm）。LTFHD与FHD的比值平均为1.16±0.08，两侧之间可靠，相关系数（r）为0.72（p < 0.01）。
LTFHD是THA术前模板测量和术中验证的可靠参考参数，两侧之间具有高度相关性（r = 0.93，p < 0.01）。然而，8%的研究标本显示LTFHD超过4mm，THA期间应予以考虑以避免出现不满意的结果。
