Coronal alignment of the lower limb

Background The coronal alignment of the lower limb is important for knee reconstruction procedures. However, normal alignment is hard to define because of its wide variation among normal individuals. Our hypothesis was that the variation in the normal anatomy as assessed by radiography is greater than commonly accepted. Methods We performed anteroposterior long-leg radiographs on 100 Caucasian patients without any known knee abnormality, to determinate the femorotibial angle, coronal orientation of the distal femoral condyles, and coronal orientation of the proximal tibial condyles. All measurements were performed by the same experienced knee surgeon. Result The mean values observed were close to the values commonly described in the Caucasian population. However, only 15-20% of the cases met the mean values of Moreland et al. (1987) for the individual items, and only 2 cases had the exact normal values. There was a wide variation for all angles measured, with a standard deviation higher than the mean value. Interpretation The variation in the lower limb axes is wider than commonly believed. There is a need for individual knee reconstruction which takes the specific knee axes of the patient to be operated into account.