Estimation of the knee axis of rotation. On a true lateral projection of the knee, with the distal and posterior femoral condyles superimposed, the intersection of the posterior femoral cortex and the widest anteroposterior dimension of the femoral condyles gives the best estimate of knee axis of rotation. (Redrawn from van Bosse HJP, Feldman DS, Anavian J, Sala DA: Treatment of knee flexion contractures in patients with arthrogryposis, J Pediatr Orthop 27:930, 2007.) SEE TECHNIQUE 34.42.