Radiographic Assessment of Lower Limb Deformities

Abstract

Radiographs of the lower limbs are obtained in orthogonal reference planes: frontal plane, AP view; sagittal plane, LAT view. The true AP view of the knee is obtained in the knee forward position (patella centered on the femoral condyles). The knee forward plane corresponds to the frontal plane. For standing radiographs, the radiography technologists are usually taught to position the patient with the feet together in the “stand at attention” posture. If the patient has external or internal tibial torsion, such positioning will result in the kneecap’s pointing inward or outward, respectively (► Figs. 3-1 and 3-2). The correct method is to orient the patella forward, irrespective of the foot position. To orient the patella forward, feel the patella with the index finger and thumb of one hand and rotate the foot until the patella is pointing forward (►Fig. 3-2). The radiograph confirms the correct position, showing the patella centered between the femoral condyles (► Fig. 3-lb).