Sesselmann Stefan, Hong Yotung, Schlemmer Frank, Hussnaetter Isabell, Mueller Lutz A, Forst Raimund, Tschunko Franz
Department of Orthopaedic Surgery, University of Erlangen-Nuremberg, Rathsberger Str. 57, 91054 Erlangen, Germany.
Department of Neuroradiology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
Biomed Tech (Berl). 2018 Nov 27;63(6):657-663. doi: 10.1515/bmt-2016-0251.
Radiostereometric analysis (RSA) is the gold standard for evaluating micromotions of orthopaedic implants. The method is applied for identifying novel design weaknesses in endoprostheses. Current research frequently assesses relatively short time periods. Short-term RSA studies have been widely used for predicting the long-term stability of many hip prosthetic designs, but only a few studies have focused on uncemented hip implants, especially for extended periods. The purpose of this study was to analyse the migration pattern of the Cerafit® femoral stem within 10 years and to verify the predictive value of short-term RSA after 2 years for this uncemented femoral hip stem. Twenty-six patients were followed for 10 years. Ten years after implantation, a mean subsidence of 0.22 mm±0.56 mm, a mean internal rotation of 0.59°±1.67° and a mean maximum total point motion (MTPM) of 1.28 mm±0.54 mm were detected. The main migration took place in the first 6 weeks after surgery (subsidence of 0.36 mm±0.73 mm; internal rotation of 0.62°±1.49°, MTPM of 1.05 mm±0.68 mm). All the migration values measured were small. No late-onset migration was observed. This study suggests that the Cerafit® implants are stable after 10 years. Thus, RSA could be the best tool to assess long-term implant behaviour.
放射性立体测量分析（RSA）是评估骨科植入物微动的金标准。该方法用于识别假体的新设计缺陷。当前的研究经常评估相对较短的时间段。短期RSA研究已被广泛用于预测许多髋关节假体设计的长期稳定性，但只有少数研究关注非骨水泥型髋关节植入物，尤其是长期的。本研究的目的是分析Cerafit®股骨柄在10年内的迁移模式，并验证2年后短期RSA对这种非骨水泥型股骨柄的预测价值。26名患者被随访了10年。植入后10年，检测到平均下沉0.22 mm±0.56 mm，平均内旋0.59°±1.67°，平均最大总点运动（MTPM）为1.28 mm±0.54 mm。主要迁移发生在术后的前6周（下沉0.36 mm±0.73 mm；内旋0.62°±1.49°，MTPM为1.05 mm±0.68 mm）。所有测量的迁移值都很小。未观察到迟发性迁移。本研究表明，Cerafit®植入物在10年后是稳定的。因此，RSA可能是评估植入物长期行为的最佳工具。
