K scores were significantly higher mean 4 vs 2 and pain scores lower in the amputation group allowing high impact activity compared with community ambulation with an extension prosthesis. Conclusion Childhood amputation for severe limb length inequality and foot deformity in congenital fibula absence offers excellent short-term functional outcome with prosthetic support.
The tibial kyphus does not need routine correction and facilitates prosthetic suspension. Accommodative extension prostheses offer reasonable long-term function but outcome scores are lower.
Keywords: fibula hemimelia, congenital absence of fibula, Syme amputation, extension prosthesis Introduction Congenital deficiency of the fibula is the most common long bone deficiency. In severe cases, limb deformity is portrayed by significant limb shortening, anterior tibial bowing and foot deformity including tarsal coalition, formation of a ball and socket ankle joint, absent rays and a fixed equinovalgus or rarely equinovarus foot position. Other more proximal anomalies may also be present such as femoral deformity proximal varus, valgus and retroversion, hypoplasia of the lateral femoral condyle and absent cruciate ligaments with acetabular dysplasia.
Upper limb deformities include ulna hemimelia or amelia and syndactyly. Classification systems have focused on these parameters in order to aid parental counselling and surgical decision-making. Complete absence of the fibula is often associated with a more significant limb length discrepancy and more severe foot deformities and the consensus opinion would consider amputation in these patients. However, the area between the femoral head and shaft is usually occupied by a cartilage anlage in which ossification is delayed making it undetectable on x-ray.
Serial x-rays taken over the first year or two of life will clarify the actual severity and detail the development of the deficiency. As with many congenital limb deficiencies, the degree of deficiency may vary considerably among individuals. Many systems have been proposed to classify these variations. It has been observed that only the number of cases seen limits the potential number of categories 1!
Most systems attempt to classify PFFD and related femoral deficiencies based on anatomical features of the acetabulum and proximal femur identifiable on x-ray. While no single system of classification has achieved universal acceptance, the most commonly acknowledged system is that of Ait-ken 2. Aitken identifies four classes A through D based on serial x-ray examination of the formation of the femoral head and acetabulum, with A being the least severe form of deficiency and D the most severe.
PFFD results in severe limb length inequality and hip joint instability. PFFD occurs in approximately 1 in 52, births 3. There is a high incidence of associated anomalies, with the most common being fibular hemimelia absence of a portion of the fibula 5.
Associated anomalies complicate management of the PFFD child and in some instances may con-traindicate certain surgical options. Bilateral cases are often left untreated since, if the limbs are of approximately the same length, the child can usually ambulate effectively and painlessly without intervention. Management of PFFD The biomechanics of gait in unilateral PFFD depend greatly on the type of treatment undertaken and can be almost as variable as the deficiency itself.
Where the decision is made to leave the limb surgically unrevised the issue of limb length inequality is addressed prosthetically using some form of extension prosthesis. Where the decision to revise the limb is made, there are two main options available Figure 2.
Figure 2 Traditionally, the most common revision procedure has been the Syme's ankle disarticulation with knee fusion, which results in the functional equivalent of a knee disarticulation through-knee amputation. To ensure that knee joint axes are at approximately equal heights at maturity, ankle disarticulation and knee fusion may be accompanied by epiphysiodesis halting the growth plate of the opposite knee. The other, more controversial option is to convert the limb to a functional transtibial equivalent using the Van Nes Tibial Rota-tionplasty procedure 6.
This makes it possible for the rotated ankle to voluntarily control a mechanical knee during gait. Regardless of the choice of revision surgery, it is generally accepted that when the limb is surgically revised and, provided the femur is not fused to the pelvis, the knee should be fused..
A similar approach has been used in three cases of proximal femoral focal deficiency, but in these the sockets are longer, giving ischial support, as required in Type C cases. The "Access Trap" method is not suitable when the foot is of normal size and will not enter a rigid socket unless the brim can be opened. This can be achieved in two ways. In the first, almost the entire front of the socket is made detachable. The second and, in our view, the more desirable method is to split the socket down the sides and hinge the two halves together at the toe.
The posterior half which includes the plantar surface of the socket is mounted on the foot. The socket is opened to allow the foot to gain access and a strap or elastic is used to hold the socket closed round the leg Fig.
This technique was also used for a girl of 12 years who had an amputation of the forefoot and shortening of the leg due to multiple tibial fractures. When wearing a surgical boot, her function was excellent but the appearance ungainly.
The circumference of the hind foot was considerably larger than that of the leg below the knee. A socket was made incorporating a hinge distally and cut down the sides. This was mounted at the correct height on a foot from which an inferior wedge was removed Fig. The socket opened for insertion of the leg and the wedge was then replaced under the foot and a normal shoe was worn.
Conventional prosthetics do not give Lucas the ability to run and ride a bicycle or play like his friends do, said his parents, Ned and Melissa Resch of Providence, RI. He is active, and his parents have been searching for ways to allow him to retain that level of activity as he grows. Zakrajsek developed an assistive technology senior design project as part of her work through the Bilsland Strategic Initiatives Fellowship. Dosenbach, Kramer and Vandewalle are mechanical engineering seniors, and the other students are biomedical engineering seniors.
Barring a new type of prosthetic leg, the family was told that the child's best hope was to undergo a surgical procedure in which the foot is rotated degrees so that the ankle of the shorter leg could act as a knee joint.
When wearing a surgical boot, her function was excellent but the appearance ungainly. Cosmetic appearance naturally becomes an increasing concern for both boys and girls.
The child is so lightweight and the gait pattern so primitive that commercial feet are optional. This can be achieved in two ways. From an electronic patient database, active case records were listed as having congenital limb deficiency.
A socket was made incorporating a hinge distally and cut down the sides. Instead, the proximal part of the socket is enlarged sufficiently to allow passage of the foot in conjunction with a posterior access trap lower down Fig. The Purdue students will create a mold of Lucas's shin to make for a better fit, and the child's family will return later this year to receive the form-fitted leg. In most cases the very young child has no awareness of being different from his peers. Where the decision to revise the limb is made, there are two main options available Figure 2.
For those with concomitant upper-limb involvement, the socket brim may be utilized as a control cable anchor point. Bach, Professor H. A Symposium. A similar technique has been used in a Type C case of a boy with a congenital absence of the forefoot, ten inches mm of shortening, and the knee ankylosed in 40 degrees of flexion. We believe that pelvic and hip kinematics are consistent within the PFFD population despite variability in the degree of severity and treatment 8,9,
Quality of life was assessed using the PedsQL inventory questionnaire; pain by a verbal severity score. Tablada C: A technique for fitting converted proximal femoral focal deficiencies. Dynamic-response feet have been well received by adults, and some types are beginning to appear in pediatric sizes. Many systems have been proposed to classify these variations. Table 1. Validated outcome measures were used to look at comfort, function and prosthetic use.
Knee criteria have been previously discussed; a free knee is unnecessary for the very young child.
Four Syme and one trans-tibial amputation in four patients took place in older children mean age 6. Almost all pediatric designs use nonarticulated feet; the high-level or bilateral case is the possible exception. Transparent test sockets are invaluable in evaluating the above factors. In some cases, parents opt for no surgical intervention, preferring to rely on an extension prosthesis to maintain limb length equality. Similarly, absence of the fibula can be associated with limb shortening that is suitable for reconstruction and present with feet that are clinically normal.
Joints and corsets are rarely seen, being reserved primarily for the child with marked ligamentous damage to the knee.
Figure 2 Traditionally, the most common revision procedure has been the Syme's ankle disarticulation with knee fusion, which results in the functional equivalent of a knee disarticulation through-knee amputation. This type of prosthesis has been fitted to five children, all of whom have been wearing it for more than three years. Another approach is to provide a flexible laminated rubber "boot" for both function and better cosmetic appearance. Presumably this is due to his small stature short lever arms and high energy level. This does not necessarily mean that he is limited; he will be as functional as society and circumstances allow. Abstract Purpose Complete fibula absence often presents with significant lower-limb deformity.