Kalra S, Smith T O, Berko B, Walton N P
Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, UK.
J Bone Joint Surg Br. 2011 Jun;93(6):777-81. doi: 10.1302/0301-620X.93B6.26062.
The Oxford unicompartmental knee replacement gives good results in patients with symptomatic osteoarthritis of the medial compartment. Previous studies have suggested that the presence of radiolucent lines (RLLs) does not reflect a poor outcome in such patients. However, the reliability and validity of this assessment have not been determined. Our aim was to assess the intra- and interobserver reliability and the sensitivity and specificity of the assessment of RLLs around both tibial and femoral components using standard radiographs. Two reviewers assessed the radiographs of 45 patients who had loosening of the tibial or femoral component confirmed at revision surgery and compared them with those of a series of 45 asymptomatic patients matched for age and gender. The results suggested that, using standard radiographs, tibial RLLs were 63.6% sensitive and 94.4% specific and femoral RLLs 63.9% sensitive and 72.7% specific for loosening. Overall intra- and interobserver reliability was highly variable, but zonal analysis showed that lucency at the tip of the femoral peg was significantly associated with loosening of the femoral component. Fluoroscopically guided radiographs may improve the zonal reliability of the assessment of RLLs, but further independent and comparative studies are required. In the meantime, the innocence of the physiological RLLs detected by standard radiographs should be viewed with caution.
牛津单髁膝关节置换术在治疗内侧间室有症状性骨关节炎的患者中取得了良好效果。先前的研究表明，透光线（RLLs）的存在并不反映此类患者预后不佳。然而，这种评估的可靠性和有效性尚未确定。我们的目的是使用标准X线片评估观察者内和观察者间对胫骨和股骨假体周围RLLs评估的可靠性以及其敏感性和特异性。两位评估者对45例在翻修手术中证实胫骨或股骨假体松动的患者的X线片进行了评估，并将其与45例年龄和性别匹配的无症状患者的X线片进行比较。结果表明，使用标准X线片时，胫骨RLLs对松动的敏感性为63.6%，特异性为94.4%；股骨RLLs对松动的敏感性为63.9%，特异性为72.7%。总体观察者内和观察者间的可靠性差异很大，但分区分析表明，股骨柄尖端的透亮与股骨假体松动显著相关。透视引导下的X线片可能会提高RLLs评估的分区可靠性，但还需要进一步的独立对比研究。与此同时，对于标准X线片检测到的生理性RLLs是否无害应谨慎看待。
