BACKGROUND Preoperative planning is a fundamental step for successful total hip arthroplasty (THA). Studies have highlighted the accuracy of preoperative digital templating for estimating acetabular cup and stem size. Stem design such as single-wedge metadiaphyseal (Type 1 stem) versus mid-short stem (microplasty) and surgical approach (anterior, direct lateral or posterior) have not been well investigated as predictors of THA templating accuracy. METHODS 204 patients (220 hips) who had undergone elective THA between November 2016 and December 2019 and presented a saved preoperative template were retrospectively reviewed. Templates from 5 different surgeons were involved in the analysis. 3 different approaches were used: direct lateral (DL), posterior (PA), direct anterior (DAA). 2 different stem designs were used: single-wedge metadiaphyseal and single-wedge mid-short (Biomet Taperloc Microplasty), while the acetabular component remained the same. Bivariate and multivariate regression analyses were performed to determine predictors of accuracy. RESULTS Femoral component size templating accuracy was significantly improved when using the single-wedge mid-short stem (Taperloc Microplasty) design when performing bivariate analysis. Although accuracy of cup sizing was not affected by approach, precision was significantly better in the PA group (p < 0.05). Accuracy of templating was found to be independent of BMI and gender but dependent on presence of calibration marker and stem design (p < 0.05). CONCLUSIONS When striving for improved templating accuracy, acetabular and femoral component accuracy were best achieved using a calibration marker and a metaphyseal short femoral stem design.

中文翻译：

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非骨水泥初次全髋关节置换术中数字模板的准确性：哪些因素与术前计划的准确性相关？

背景技术术前计划是成功进行全髋关节置换术（THA）的基本步骤。研究强调了术前数字模板用于估计髋臼杯和柄尺寸的准确性。诸如单楔形干骨干（1 型柄）与中短柄（微成形术）和手术入路（前路、直接侧向或后路）等柄设计作为 THA 模板准确性的预测因素尚未得到充分研究。方法 对 2016 年 11 月至 2019 年 12 月期间接受择期 THA 并提供保存的术前模板的 204 例患者（220 髋）进行回顾性分析。分析涉及来自 5 名不同外科医生的模板。使用了 3 种不同的入路：直接外侧入路 (DL)、后入路 (PA)、直接前入路 (DAA)。使用了 2 种不同的柄设计：单楔形干干骺端和单楔形中短形（Biomet Taperloc Microplasty），而髋臼组件保持不变。进行双变量和多变量回归分析以确定准确性的预测因子。结果 在执行双变量分析时，使用单楔形中短柄 (Taperloc Microplasty) 设计时，股骨组件尺寸模板的准确性显着提高。尽管罩杯尺寸的准确性不受方法的影响，但 PA 组的精确度明显更高 (p < 0.05)。发现模板的准确性与 BMI 和性别无关，但取决于校准标记和茎设计的存在 (p < 0.05)。结论 当努力提高模板精度时，使用校准标记和干骺端短股骨柄设计可以最好地实现髋臼和股骨假体的精度。