Treatment options for unilateral PFFD are based on 1) severity (length discrepancy, Aitken Class), and 2) presence or absence of a functional foot and ankle. A knowledge of the anticipated final leg-length discrepancy is probably the best guide to treatment options.[Hall, 1969]
By the time a child is approximately 3 yrs of age, one should be in a position to predict leg-length difference.[Hall, 1969] (Probably much sooner if the difference is great.)
In 1969 the recommendation was that if the predicted difference at maturity is 3 inches ( 7.62 cm) or less, then it can be treated with shoe lifts, limb lengthening, or leg shortening on the long leg.[Hall, 1969] In 1996 that recommendation was increased to 20 cm (7.9 inches) or less[Dahl, 1996]
Keep in mind that the 3 inch difference is at maturity. 3 inches on a newborn baby may become 10 inches at maturity.
For example, assume the femur is 50% short. 50% of a newborn femur may be only 3 inches, but 50% of an adult femur is much greater. Plus, Drs. Amstutz and Wilson observed that there is always retarded growth in the affected leg, so the difference may increase from 50% to 70% or greater.
If the predicted difference is greater than 20 cm (8 inches), then a prosthesis or prosthosis may be the only option. Prosthetic options available are 1)non-surgical - put on over foot, 2)amputate foot and fit with above knee prosthesis (knee joint in prosthesis), and 3) Van Nes rotation with below knee prosthesis (rotated ankle functions as knee joint).
When the discrepancy is likely to be between 3 and 8 inches, then one is dealing with a borderline situation, and decisions must be made based on surgical and prosthetic judgment and discussion of the problem with the parents and with the child, if he is old enough to participate.[Hall, 1969]
In summary, the current treatment options available as of 2005 are