Simonsen Ole Højgaard, Thomsen Hanne, Skou Søren Thorgaard, Andersen Mikkel Meyer
Orthopedics. 2013 Aug;36(8):e1077-81. doi: 10.3928/01477447-20130724-27.
Assessment of the mechanical axis is routine during the examination of patients with lower extremity pain. Long-leg radiographic examination is the gold standard for exact measurement, but it is associated with a significant radiation dose. An alternative method to examine the mechanical axis has been warranted. This article validates a newly developed computerized photograph method to calculate the mechanical axis using a digital photograph. The location of the center of the femoral head was calculated using ink marks on both superior iliac spines. Twenty-five patients (10 women and 15 men) had both legs examined using the photographic method and long-leg radiography examination. The digital photograph method was found to be highly reliable. The interobserver absolute mean difference was 0.99°±0.85°, and the intraobserver absolute mean difference (day-to-day variation) was 1.04°±0.81°. The mechanical axis determined by the 2 methods was highly correlated (R=0.943). The long-leg radiography method was within an average of ±1.88° of the photographic method, with a 95% probability. The photographic method appears to be an effective alternative to conventional long-leg radiography. The photographic method seems convenient in the routine examination of patients with leg pain and children with suspected axial deformity and for follow-up after treatment for malalignment. Calculation coefficients for children and a possible racial difference remain to be studied.
在对下肢疼痛患者进行检查时，评估机械轴是常规操作。长腿X线检查是精确测量的金标准，但它会带来显著的辐射剂量。因此，需要一种替代方法来检查机械轴。本文验证了一种新开发的计算机化摄影方法，该方法可使用数码照片计算机械轴。通过在双侧髂嵴上标记墨水来计算股骨头中心的位置。对25名患者（10名女性和15名男性）的双腿进行了摄影方法和长腿X线检查。发现数码摄影方法具有高度可靠性。观察者间绝对平均差异为0.99°±0.85°，观察者内绝对平均差异（每日变化）为1.04°±0.81°。两种方法确定的机械轴高度相关（R=0.943）。长腿X线检查方法与摄影方法的平均偏差在±1.88°以内，概率为95%。摄影方法似乎是传统长腿X线检查的有效替代方法。摄影方法在腿痛患者和疑似轴向畸形儿童的常规检查以及对线不良治疗后的随访中似乎很方便。儿童的计算系数以及可能存在的种族差异仍有待研究。
