Kitoh Hiroshi, Kitakoji Takahiko, Kurita Kazuhiro, Katoh Mitsuyasu, Takamine Yuji
Department of Orthopaedic Surgery, School of Medicine, Nagoya University, Aichi, Japan.
J Bone Joint Surg Br. 2002 Jul;84(5):680-3. doi: 10.1302/0301-620x.84b5.13107.
Lack of full extension of the elbow is a common abnormality in patients with achondroplasia. We studied 23 patients (41 elbows) clinically and radiologically. Extension of the elbow was assessed clinically and the angle of posterior bowing of the distal humerus was measured from lateral radiographs. There was limited extension of the elbow in 28 (68.3%) and the mean loss of extension was 13.1 degrees. Posterior bowing of the humerus was seen in all elbows with a mean angle of 17.0 degrees. There was a positive correlation between these two measurements. Posterior bowing greater than 20 degrees caused a loss of full elbow extension. Posterior dislocation of the radial head was seen in nine elbows (22.0%). The mean loss of extension of the elbows was 28.7 degrees which was significantly greater than that of these elbows in which the head was not dislocated (8.7 degrees), although posterior bowing was not significantly different between these two groups (19.3 degrees and 16.3 degrees). Posterior bowing of the distal humerus is a principal cause of loss of extension of the elbow. Posterior dislocation of the radial head causes further limitation of movement in the more severely affected joints.
肘关节不能完全伸直是软骨发育不全患者常见的异常表现。我们对23例患者（41个肘关节）进行了临床和放射学研究。通过临床评估肘关节的伸直情况，并从侧位X线片测量肱骨远端的后凸角度。28个（68.3%）肘关节存在伸直受限，伸直平均丧失13.1度。所有肘关节均可见肱骨后凸，平均角度为17.0度。这两项测量结果之间存在正相关。后凸角度大于20度会导致肘关节不能完全伸直。9个肘关节（22.0%）出现桡骨头后脱位。桡骨头脱位的肘关节伸直平均丧失28.7度，明显大于未脱位肘关节的伸直丧失（8.7度），尽管两组之间的后凸角度无显著差异（分别为19.3度和16.3度）。肱骨远端后凸是肘关节伸直丧失的主要原因。桡骨头后脱位会导致受影响更严重的关节活动进一步受限。
