Tibial hemimelia is a rare congenital anomaly, occurring approximately in 1 per 1million live birth and consisting of aplastic/hypoplastic tibia with relatively intact fibula. The widely used classification was proposed by Jones and based on radiological description: type I: tibia absent, type II distal tibia not seen, type III proximal tibia not seen, type IV tibio-fibular diastases. This congenital deformity can be unilateral or bilateral and isolated, or unilateral or bilateral and associated with other malformation witch raise its genetic cause. We are reporting the cases of two monozigotic twins reflecting the “intragenotic” expression variability of the syndrome of tibial aplasia and ectrodactyly. The two monozigotic female twins are born after an unremarkable first pregnancy and delivery. Family history was positive for malformations.(syndactily, split hand, phocomelia(elbow) and hip dyspasia). Twin 1: Left leg: tibial aplasia type Ia, short femur, absent patella. Right leg: tibial aplasia type IV, clubfoot, hypoplasia of the internal ray. Left hand: split hand. Twin 2: Left leg: nornal. Right leg: tibial aplasia type II, clubfoot. Left hand: split hand. Most of the cases are unilateral and sporadic. 4 autosomal dominant tibial hemimelia syndromes are described. tibial hemimelia-foot polydactyly-triphangeal thumbs syndrome,. tibial hemimelia diplopodia syndrome,. tibial hemimelia-split-hand foot syndrome,. tibial hemimelia micromelia-oigonobrachycephaly syndrome. This is the first documennted case of monozigotic twins affected by the Tibial hemimelia-split-hand foot syndrome. Their clinical presentation demonstrates that the phenotypic manifestations are highly variable

Treatment protocols of tibial hemimelia comprised joint reconstruction and amputation or knee disarticulation and prosthetic fitting. However, amputation is not acceptable in our community. Therefore we tried to treat these cases without amputation. From 1993 till 1999, 2 cases of tibial hemimelia type IA, and 4 cases type II were referred to our center. All the cases presented late as the age of patients ranged from 3 _ years to 13 years. For type IA we applied Ilizarov External Fixator on the femur, fibula and foot to centralize the fibula between the femoral candyles and talus using gradual distraction. The second step comprised a Brown procedure. Then, the fixator was reapplied to correct the knee and foot deformities using the bloodless technique. For type II, synostosis of the tibia and fibula was performed followed by differential lengthening. Then we over lengthened the femur. Results: After follow up 2 to 5 _ years all patents were satisfied with good function. The tibial lengthening ranged from 6 to 9 cm and femoral lengthening ranged from 5 to 7.5 cm. Complications:. Pin tract infection in all cases. Cutting through of the calcanean wires in 2 cases. Flexion deformity in 4 cases. Fracture of the lengthened femur in one case. Up to our knowledge this is the first report tfor treatment of complete congenital tibial absence without amputation. Our early results are encouraging, as there are marked functional improvements in these patients