The Resches, however, sought a less radical solution, andlearned about the "The Leg Up Project," a Purdue mechanicalengineering senior design project in 2009 to create a prosthesis for an Indianaboy with PFFD. During an Internet search, Ned Resch came across a YouTube videoabout that project.
Proximal focal femoral deficiency (PFFD) is a rare congenital deformity of unknown aetiology with hypoplasia or absence of the proximal femur, with an incidence of one in 50 000. Patients with PFFD often have associated instability of the hip and rotational malalignment, poor hip musculature, contractures involving the hip and leg length discrepancy., There are many surgical and prosthetic options for patients with these complex problems. In 1950, Van Nes described a patient with congenital defects of the femur who had undergone a rotationplasty using the ankle and foot as a knee joint within a below-knee prosthesis. This procedure theoretically produces a functional joint at the level of the knee in order to allow a more normal gait pattern (). The procedure was later modified to include fusion of any residual knee joint, but it remains controversial because of the perceived poor cosmetic appearance with the foot facing backwards, associated difficulties in achieving a comfortable prosthesis and the possible need for subsequent rotational osteotomies as the limb might alter its rotatory alignment during growth.
The PFFD group's knee kinematics data support the proposition that rotationplasty provides a functional joint at the knee allowing single limb support and foot clearance during swing, even though an initial loading response was not always seen. The dramatic increase in anterior pelvic tilt in the PFFD group is interesting and may be a result of limited ROM and musculature of the hip. This compensatory strategy may assist in controlling the centre of mass, thus improving balance over the prosthetic limb.
Despite the cosmetic defect of having a shortened limb facing backwards, all the patients in this study who had undergone Van Nes rotationplasty for congenital PFFD used their prosthesis all the time and maintained high levels of function, were well-adjusted emotionally and socially, and comfortable with their appearance and prosthetic design. Unexpectedly, there were no differences between the PFFD and control groups for any health related QoL subscales on the SF-36. These findings did not support the hypothesis that the PFFD group would have decreased QoL despite having notable deficits in ROM, strength, gait parameters and postural control.