Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Department of the Advanced Medicine for Rheumatic Diseases, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Biomed Res Int. 2017;2017:4051706. doi: 10.1155/2017/4051706. Epub 2017 Oct 23.
The purpose of this study is to investigate the compensatory correlation between knee and hindfoot in patients with rheumatoid arthritis (RA). This cross-sectional study included 218 patients (407 lower extremities). Radiographs of the hindfoot and full-length posteroanterior hip-to-calcaneus standing radiographs were evaluated. The destruction of the hindfoot was evaluated using the Larsen grading system. The coronal angular deformity of the knee and hindfoot was evaluated by the femorotibial angle (FTA) and the angle between the tibial shaft and the entire hindfoot (tibiohindfoot angle, THFA). The correlation between FTA and THFA was determined by Pearson's coefficient. For all patients, FTA correlated to THFA ( = 0.28, < 0.001). The correlation was observed as long as the talocrural joint was preserved (Larsen grade ≤ 2), even if the subtalar joint had been destroyed (Larsen grade ≥ 3). However, the correlation was not observed when the talocrural joint was destroyed (Larsen grade ≥ 3, = -0.02, = 0.94). The pain in the hindfoot did not correlate with FTA or THFA. In conclusion, a compensatory deformity of the hindfoot against the deformity of the knee was observed in RA, and the correlation was lost when talocrural joint was destroyed.
本研究旨在探讨类风湿关节炎（RA）患者膝关节与后足之间的代偿相关性。这项横断面研究纳入了 218 名患者（407 条下肢）。评估了后足和全长前后位髋关节至跟骨站立位 X 线片。采用 Larsen 分级系统评估后足破坏情况。通过股胫角（FTA）和胫骨骨干与整个后足之间的角度（胫距后足角，THFA）评估膝关节和后足的冠状面角度畸形。通过 Pearson 系数确定 FTA 和 THFA 之间的相关性。对于所有患者，FTA 与 THFA 相关（ = 0.28， < 0.001）。只要距跟关节保持完整（Larsen 分级 ≤ 2），就可以观察到这种相关性，即使距下关节已经被破坏（Larsen 分级 ≥ 3）。然而，当距跟关节被破坏（Larsen 分级 ≥ 3）时，这种相关性就不存在了（ = -0.02， = 0.94）。后足疼痛与 FTA 或 THFA 不相关。总之，在 RA 中观察到后足对膝关节畸形的代偿性变形，当距跟关节被破坏时，这种相关性就会丧失。
