summary Tibial Deficiency is a congenital condition characterized by a longitudinal deficiency of the tibia with varying degrees of tibial absence. Diagnosis is made radiographically with xrays of the tibia. Treatment is a variety of surgical options depending on the extent of deficiency and stability of knee joint. Etiology Genetics autosomal dominant inheritance pattern obtain genetic counseling Associated conditions musculoskeletal conditions present in 75% of patients ectrodactyly preaxial polydactyly ulnar aplasia Classification Jones classification Jones Classification Type 1a No proximal tibia visible on radiograph Extensor mech absent Hypoplastic distal femoral epiphysis Type 1b Proximal tibia eventually ossifies and extensor mechanism will function Distal femoral epiphysis appears normal Type 2 Proximal tibia present at birth but short tibia Type 3 Diaphyseal and distal tibia present but proximal tibia absent Type 4 Short tibia, fibula migrated proximal, diastasis of distal tib-fib joint Alternate system is Kalamachi and Dawe (types 1-3) Presentation Physical exam deformity shortening of the affected extremity anterolateral bowing of the tibia prominent fibular head ROM & stability the knee is usually flexed with an associated knee flexion contracture it is important to evaluate for active knee extension check stability of the knee joint in all planes treatment is based primarily on the stability of the knee joint foot deformity there is often a rigid equinovarus and supination deformity of the foot sole of foot faces perineum Imaging Radiographs recommended AP and lateral tibia/fibula findings show deficiency of the tibia early radiographs may show small and minimally ossified distal femoral epiphysis Treatment Operative knee disarticulation followed by prosthestic fitting indications complete absence of the tibia no active knee extension present (most cases) tibiofibular synostosis with modified Syme amputation indications proximal tibia present with intact extensor mechanism and minimal flexion contracture Syme/Boyd amputation indications ankle diastasis Brown Procedure (centralization of fibula under femur) no longer recommended due to high failure rate