One treatment for unilateral PFFD is surgical treatment and a prosthesis. The goal of the surgical treatment is to provide a more stable hip whenever possible and to optimize the leg as a stump for prosthetic fitting.[Westin 1969]
Foot Amputation
The first goal is to create a long, above-knee, end-bearing stump that can be easily fitted in a standard prosthesis.[Westin 1969] The previous section described the problems associated with trying to fit a prosthesis over a foot. A good end-bearing stump can be made by performing a Syme's or Boyd amputation, and fusing the ankle. (I'm still looking for a good description of the Syme's and Boyd procedure). My (Mike's) personal experience is that the amputation involves removing only the front part of the foot. The heel bone and heel pad are left in place to be a good end-bearing stump.
The ankle fusion is performed during the amputation surgery. The procedure involves pushing a thin metal rod up through the heel and into the tibia. This rod holds the ankle immobile until the fusion is complete. The patient will have to wear a mini cast or 'sleeve' to protect the incision and the metal rod that will be sticking out of the heel. The sleeve and rod will usually be removed in about 6 to 8 weeks.
The foot amputation is typically performed at about age 10-12 months. This is about the time the child will begin to walk, and many feel that it's important to get them fitted with a prosthesis as soon as possible. Of course, some prefer to fit the prosthesis over the foot and make the amputation decision at a later time - just keep in mind the fitting problems. Also, some feel the psychological problems will be less severe if the amputation is done at an earlier age.
Knee Fusion
The second goal of surgery is to try to correct the hip contracture, and create a thigh bone of approximately normal length, allowing a good lever arm to be fitted inside a prosthesis.1 Both of these goals can be accomplished by a knee arthrodesis (surgical immobilization of a joint). In other words, the fibia and tibia are fused to the femur to form one long bone that acts like a normal femur. Extension at the hip joint generated by the momentum of the long lever arm with the standard above knee prosthesis
allows for gradual stretching of the flexion contracture of the hip joint.[Aiken 1969] It was found that after knee arthrodesis in full extension, the hip-flexion contracture was spontaneously corrected.[Westin 1969]
When knee joint arthrodesis is to be performed, the time to do this surgery must be carefully selected so that the growth potentials of of the proximal tibial and distal femoral epiphyses (growth plates) are not destroyed at too early a date.[Aiken 1969] Miscalculation may produce an above-knee type of stump which is too short for satisfactory prosthetic fitting.[Aiken 1969] Knee surgery is usually performed at the age of 2 or 2 1/2 years, and one of the epiphysis around the knee is preserved to allow for some additional growth of the thigh segment.[Friscia 1989] One or both of the epiphyses at the knee can be excised (surgically removed), the goal being a long above-knee stump at maturity.
Hip Surgery
In properly selected cases, reconstructive surgical procedures about the hip joint to improve hip stability and thus facilitate maximum usage of hip musculature are desirable. As previously emphasized, only Class A and Class B PFFD cases have adequate acetabula and femoral heads. Hence, it is only in these two groups that reconstructive surgery about the hip would seem to be indicated. Aitken felt, therefore, that it was essential that the four classes be clearly differentiated and that hip surgery be carried out only in those cases where there is a femoral head and an acetabulum.[Aiken 1969]
The hip surgery is performed between the ages of 5 and 7 years, when significant portions of the proximal femur show evidence of ossifications in Aitken Class A or B cases.At the present time (1997) there is no universally accepted surgical treatment for the unstable hip of class C and D PFFD.1 (Our doctor says that current thinking is to leave the hip alone in almost all cases.)