Assessment of knee joint space width by one-leg stance radiographs

摘要

Background: An arthritic knee radiographic evaluation usually includes antero-posterior or posteroanterior views with the patient standing on both feet. There is evidence that the actual stressed knee compartment narrowing in patients with osteoarthritis is underestimated by these methods of radiographic evaluation. We hypothesized that an anteroposterior view with the patient standing on one foot might provide a better estimation of the width of the loaded knee compartment, similar to the externally applied stress views. Methods: Standard anteroposterior radiographs, with patients standing on both feet and then on one foot, were obtained to evaluate osteoarthritis and varus alignment in 24 patients. The minimal medial and maximal lateral joint widths and anatomical knee axes were measured in both positions. Results: A significantly higher tendency in all the studied parameters toward varus knee alignment, i.e. narrower medial compartment and wider lateral compartment, was found on one-leg standing radiographs (P<0.01). Conclusions: We concluded that the extent of joint space narrowing is better seen on one-leg standing radiographs, which might be easily used for a routine clinical examination.