Mechanical axis of the lower extremity determined by a new digital photographic method

Ole Højgaard Simonsen, Hanne Thomsen, Søren Thorgaard Skou, Mikkel Meyer Andersen

    Publikation: Bidrag til tidsskriftArtikelForskningpeer review


    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.

    Sider (fra-til)e1077-e1081
    Udgave nummer8
    StatusUdgivet - 1 aug. 2013

    Fingeraftryk Udforsk hvilke forskningsemner 'Mechanical axis of the lower extremity determined by a new digital photographic method' indeholder.