Department of Orthopaedic Surgery and Traumatology, "Maggiore" Hospital of Chieri, Turin, Italy.
Department of Orthopaedic Surgery and Traumatology, "Edoardo Agnelli" Hospital, ASL TO3, Pinerolo, Italy.
Musculoskelet Surg. 2023 Sep;107(3):305-311. doi: 10.1007/s12306-022-00758-7. Epub 2022 Aug 19.
To evaluate the influence of short versus long stems implanted through a Direct Anterior Approach (DAA) on clinical and radiological outcomes in THA at medium-term follow-up (average follow-up of 44.8 months).
167 consecutive total hip arthroplasties treating patients affected by primary hip osteoarthritis were retrospectively evaluated. A standard-length stem (H-MAXs) was used in 70 patients, while a short metaphyseal-fitting femoral stem (MINIMA) was used in 97 patients. The Harris Hip Score (HHS) and Forgotten Joint Score-12 (FJS) were used as outcomes measurements. Post-operatively, Engh's score and Brooker classification were analyzed at 6 months, 1 year and every 2 years until the final FU. The correct size of the implant was evaluated determining the canal fill index (CFI), and all undersized stems were classified according to Magra classification.
The average HHS was 83 ± 13.4 in the standard stems group and 87 ± 14.1 for short stems group (p = 0.148). The average FJS was 87.9 ± 15.2 for patients in the standard stems group and 84.5 ± 17.7 with no significant differences (p = 0.327). None of the stems showed radiographic signs of instability (standard stems mean Engh's score: 19.25 versus short stems mean Engh's score: 19.50-p = 0.41). According to Brooker classification, no significant difference in severity was found using different stems (p = 0.715). A high rate of undersized stems was found (standard stems 24%-short stems 25%) but without statistical difference between groups (p = 0.078), while a different trend in malposition following the recent classification proposed by Magra et al. was observed evaluating all undersized stems (p = 0.0387).
Both groups achieved good and comparable patient-reported outcome measurements (PROMs) and radiographic stability with fixation observed by bone ingrowth. A high rate of undersized stems was found with a correlation between femoral stem length and specific pattern of malposition. Malalignment in Varus was frequent in shorter stems in contact proximally with medial calcar and distally with lateral cortex, while a uniform undersizing was observed for longer ones with a continuous margin around the stem. However, the stems never presented progressive radiolucent lines over the whole surface of the stem.
评估通过直接前入路（DAA）植入的短柄和长柄对 THA 中期随访（平均随访 44.8 个月）临床和影像学结果的影响。
回顾性评估了 167 例连续接受初次全髋关节置换术治疗的原发性髋关节骨关节炎患者。70 例患者使用标准长度柄（H-MAXs），97 例患者使用短型髓腔匹配股骨柄（MINIMA）。采用 Harris 髋关节评分（HHS）和遗忘关节评分-12（FJS）作为疗效评估指标。术后 6 个月、1 年及以后每 2 年随访至最终随访时，采用 Engh 评分和 Brooker 分级进行分析。通过测量 canal fill index（CFI）评估假体的正确尺寸，根据 Magra 分类对所有小于标准尺寸的假体进行分类。
标准柄组的平均 HHS 为 83±13.4，短柄组为 87±14.1（p=0.148）。标准柄组的平均 FJS 为 87.9±15.2，短柄组为 84.5±17.7，差异无统计学意义（p=0.327）。两组均未出现影像学不稳定征象（标准柄组平均 Engh 评分：19.25 与短柄组平均 Engh 评分：19.50-p=0.41）。根据 Brooker 分级，使用不同的柄并未发现严重程度有差异（p=0.715）。研究发现大量假体尺寸小于标准（标准柄组 24%-短柄组 25%），但两组间无统计学差异（p=0.078），而按照 Magra 等最近提出的分类对所有小于标准尺寸的假体进行评估时，观察到假体位置存在不同的趋势（p=0.0387）。
两组患者的患者报告结局测量（PROM）和影像学稳定性均良好且相当，均观察到骨长入固定。研究发现大量假体尺寸小于标准，且股骨柄长度与特定的假体位置模式之间存在相关性。在与内侧小粗隆近端和外侧皮质远端接触的较短柄中，常发生内翻畸形，而对于较长柄，观察到的是均匀的小于标准尺寸，且在柄周围有连续的边界。然而，假体在整个柄表面均未出现进行性透亮线。
