Tibial Deficiency-A Genetic Problem
LEON M. KRUGER, MD, RICHARD B. ABDO, MD,AND ARNOLD M. SCHWARTZ, MD*Springfield, Massachusetts
The crucial differential diagnosis for tibial deficiency is whether it is complete or partial. Complete deficiency is characterized by knee-joint instability, posterolateral displacement of the fibula, excessive limb-length discrepancy and marked foot deformity. In the patient with partial deficiency the knee joint is usually preserved but may be asymmetrical. Isolated tibial deficiency may occur. Genetic transmission is possible, with autosomal dominant inherited syndrome identified involving tibial deficiency, polydactylysyndactyly and triphalangeal thumb or absent thumb. Treatment options recommended are disarticulation for complete deficiency and below-knee amputation or ankle disarticulation for partial deficiency. When the tibial fragment is short or the knee asymmetrical, tibiofibular synostosis followed by ankle disarticulation will increase knee stability and provide length. We reviewed our experience from 1938 to 1985 with 25 patients (30 affected limbs). The case reports of two sisters are presented, for whom we propose autosomal dominant inheritance with variable expressivity.
*Shriners Hospital for Crippled Children, 516 Carew Street, Springfield, MA 01104