Prosthetic Management of a Bilateral Tibial Hemimelia Patient
P. LEUNG, MD,* M. MOREAU, MD*,B. FAULKNER, CP,** AND G. FAULKNER, RPT**Edmonton, Alberta
Tibial hemimelia is a rare disorder presenting prosthetic management problems in early life1-3. Many children require knee disarticulations. Subsequent fitting with hinged prostheses is apt to be unsatisfactory, for commercial units are too large for young children.
The prosthetic management of a child with bilateral tibial hemimelia with knee disarticulations illustrates an acceptable alternative. R.R. is a 4-year-old boy, born after a normal pregnancy and delivery. He presented bilateral lobster-claw hands with a bifid left thumb. The distal femurs were markedly enlarged and the legs were very short, atrophic and laterally positioned with a single digit foot. Radiographs demonstrated bilateral complete tibial hemimelias and questionable distal bifid femurs.
R.R.'s parents were of Mediterranean origin. His father had three normal children from a previous marriage. His 29-year-old mother has bilateral lobster claw hands, of lesser involvement than R.R.'s. On her right hand she has two functional digits on each side of a deep central cleft. On her left hand a normal thumb, index and fifth finger are present. She also has a bifid second toe on the left foot. Interestingly, Mrs. R. had a history of two spontaneous abortions, each during the first trimester of pregnancy, prior to having R.R.
R. R. underwent bilateral knee disarticulations at 6 months of age. He managed to bear weight well on the amputation limbs. At 13 months he was fitted with bilateral "stubbies" and learned to walk by circumduction, using a wide-based gait. At 15 months (Fig. 1 ) he walked independently.
When R.R. was 22 months of age he was fitted with bilateral prostheses, using parapodium joints as knee joints (Fig. 2 ). His femoral condyles were quite enlarged and rotated; hence, a hinge was incorporated into the socket for donning and doffing. The hinge was made with silicone incorporated into the lay-up material of the socket and fastened with Velcro straps (Fig. 3 ). The parapodium joints were secured to a flat plate for proximal socket attachment. Elastic extension assists were added. Distally, the joints were attached onto the base plate and tubing. A SACH foot-ankle assembly was bolted to the base plate. He was able to crawl with the prostheses which had wide hollowed bases extended distally from the sockets enclosed at the knee and reduced posteriorly to allow for flexion. A foam cover provided good appearance.
Gait training was initiated. When allowed to walk independently, R.R. would keep the knees in extension. In contrast, when given assistance, R.R. was able to walk by flexing the knees and hips during swing phase. One advantage of the hinge joint was that it allowed him to climb stairs with one-hand support. When R.R. outgrew his prostheses at 4 years of age, new single-axis knee joints were especially machined for his new prostheses (Fig. 4 ).
A rare case of bilateral complete tibial hemimelia, associated with lobster-claw hands, demonstrates the hereditary component. The case illustrates the use of modified parapodium hinge joints in knee-disarticulation prostheses for a young child. Although the child continues to walk with his knees locked, he has the cognitive and physical capacity to walk more physiologically, thus probably making future gait training easier. Also, the parapodium joints enable the boy to crawl and climb stairs. A hinged joint, such as the one described, is an improvement over "stubbies" for such a young child.
A child with bilateral knee disarticulations had a pair of "customized" knee joints constructed. He benefits more from early ambulation using prostheses with the special knee joints.
*Associes Moreau and O'Brien Associates, 10118 - 111 Street, Edmonton, Alberta, T5K 1K6 Canada
**Glenrose School Hospital, 10230 111th Avenue, Edmonton, Alberta T5G 0B7, Canada
- Aitken, G.T.: Amputation as a Treatment for Certain Lower Extremity Congenital Abnormalities. J Bone Joint Surg 41-A:1267-1285, 1959.
- Jones, D., J. Barnes, and G. Lloyd-Roberts: Congenital Aplasia and Dysplasia of the Tibia with Intact Fibula - Classification and Management. J Bone Joint Surg 60-B:31-39, 1978.
- Wolfgang, G.: Complex Congenital Anomalies of the Lower Extremities: Femoral Bifurcation, Tibial Hemimelia, and Diastasis of the Ankle - Case Report and Review of the Literature. J Bone Joint Surg 66-A:453-457, 1984.