Bilateral Tibial Hemimelia: A Case Report

James E. Sweigart, C P.O. I. Leaman, R.P.T. William T. Morris, M.D.


The orthopaedic treatment of complete paraxial tibial hemimelia is not well defined. Brown1 has described an operative procedure for centralization of the proximal fibula in which he reported early success. The problem is complicated by the fact that muscle anomalies usually coexist with the bony deficit, and deforming forces may jeopardize the results of what initially appears to be a satisfactory operative procedure. The case report presented here, we feel, was adversely affected by lack of active knee extension and subsequent flexion deformity.

M.R. was noted at birth to have severe congenital deformities of both lower limbs. These anomalies consisted of bilateral terminal longitudinal paraxial tibial hemimelias (Fig. 1 and Fig. 2 ). He had severe varus deformities of both ankles and fixed flexion contractures of 40 deg. in both knees. Early treatment consisted of casting in an attempt to correct the knee deformities. This method of management was unsuccessful and at the age of 15 months the boy's left fibula was centralized in the intercondylar notch. The same procedure was carried out on the right limb at the age of 17 months. Bilateral Syme's-type amputations were performed when the child was 23 months of age2. He was fitted with bilateral below-knee prostheses which consisted of patellar-tendon-bearing sockets attached to a full pelvic band. The full band was necessary in order to control external rotation. The child progressed to an independent gait, but his knee-flexion contractures recurred. His problem was complicated by lack of any active knee extension. He also developed bilateral hip-flexion and external-rotation deformities. He complained of severe pain in his lower limbs and refused to wear his prostheses. He was readmitted to the hospital at the age of three years and five months for bilateral knee disarticulations (Fig. 3 ). His postoperative x-rays are shown in Fig. 4 . Postoperatively he regained full range of motion in his hips. He was fitted initially with adjustable prostheses and is presently ambulating with crutches. He has bilateral quadrilateral sockets attached to split pelvic bands to control external rotation. His present status is shown in Fig. 5 .

The patient's physical therapy program consisted of routine preprosthetic exercises including strengthening of the hip adductors, extensors and internal rotators, stump conditioning, and mat activities for upper-limb strengthening. After prosthetic fitting he progressed from ambulation in the parallel bars to ambulation with axillary crutches. He is presently learning to apply his prostheses and ambulates with Canadian crutches. We hope eventually that he will ambulate with a single cane.

Conclusions

Tibial hemimelia presents a difficult problem for surgical reconstruction. This difficulty is caused primarily by the absence of a normal knee joint. Even though centralization procedures may appear to give satisfactory positioning, deforming muscle forces may jeopardize the late success of the procedure. It is felt that the lack of active knee extension was a major contributing factor in the case presented in this report.

Stale Hospital for Crippled Children Etizabethtown, Pennsylvania

References:
1. Brown, Frederic W., Reconstruction of a knee joint in congenital total absence of the tibia (paraxial hemimelia tibia). J. Bone and Joint Surg., 47A:4:695-704, June 1965.
2. Harris, R. I., Syme's amputation-The technique essential to secure a satisfactory end-bearing stump. Part II. Can. J Surg., 7:1, January 1964.