Pediatr Surg Int (1994) 9:453-454 © Springer-Verlag 1994 Complete internal duplication of the lower limb: case report and review of the literature Saleem Islam 1, Sharmeen Akraml, and M. Naeem Khan2 1 The Aga Khan University, Stadium Road, Karachi, Pakistan 2 Department of Pediatric Surgery, Children's Hospital, Pakistan Institute of Medical Sciences, Islamabad, Pakistan Accepted 28 October 1993 Abstract. There are very few reports of complete or partial duplication of the lower limb, most describing ex- ternal duplication (tripedus) [3, 5, 8] or partial internal duplication of the femur [2], tibia, or foot [1, 4]. Com- plete internal replication from the femur to the foot has not been reported previously. A case report and review of the literature are presented. Key words: Duplication of lower limb - Rare anomaly Fig. 1. External appearance of leg. Note difference in girth compared to normal left leg. Accessory foot is also visible Introduction Accessory limbs are extremely rare congenital anomalies [5], and the em- bryological etiology is not completely understood. Proposed etiologies of limb duplication vary from sponta- neous morphogenic aberrations [5] to mechanical factors. A majority of the reported cases had associated mal- formations, some involving the anor- ectal and urogenital organs [1, 9] and spine [5]. Case report An 8-year-old boy presented to the Isla- mabad Children's Hospital with a deformed right leg and delayed neurological develop- ment. He was the product of a consanguineous Correspondence to: M. Naeem Khan, Depart- ment of Surgery, Islamabad Children's Hospi- tal, RI.M.S., G-8/4, Islamabad, Pakistan marriage (first maternal cousins) with no family history of congenital malformations. There was no history of maternal diabetes, drug ingestion, or irradiation during preg- nancy. He was delivered at home after a prolonged labor. It was noted that the right leg was not moving properly and there was an accessory foot, but no medical advice was sought. Delayed neurological development became manifest as he never learned to talk or walk correctly. Clinical examination revealed an enlarged and grossly deformed right lower limb (Fig. 1). There was an accessory foot about 5 cm superior and posterior to the parent ankle with three phalanges. The girth of the right thigh was 38 cm (taken at 20 cm from the umbilicus) compared to 24 cm on the left. The fight calf was 28 cm (taken 10 cm from the tibial tuberosity) compared to 18 cm on the left. Movement at the knee joint was limited to an arc of 30 ° of flexion and extension. The parent foot was in a talipes equinovarus posi- tion, and he walked with assistance with the left leg bearing his weight. A systemic exam- ination revealed no abnormalities except for delayed motor and intellectual development. Radiographic examination of the right leg revealed complete duplication of the bony skeleton (Fig. 2). The larger femur articulated with the acetabulum of the right iliac bone while the other one formed a shallow false acetabulum on the greater trochanter of the parent femur. There were two knee joints, the accessory one medial and posterior to the larger parent joint. Distally, the accessory tibia articulated with the accessory ankle and foot, and there was only one fibula. The extra foot had normal tarsal architecture but only four metatarsals, with two metatarsals partially fused. There were three phalanges. The re- maining skeleton was normal and an ultra- sound scan on the abdomen was unremark- able. A two-stage disarticulation procedure was performed. The accessory ankle and leg were removed through a vertical incision. There were accessory gastrocnemius, solues, and peroneus muscles and the neurovascular sup- ply arose from the main popliteal vessels and nerves. The knee was disarticulated from the accessory femur and the leg removed along with the foot. Two weeks later, the thigh was explored. The muscles and fascial envelopes of the accessory femur were less developed than those around the accessory tibia. The vessels and nerves had their origin from the parent neurovascular elements. All the joints were synovial except the accessory hip joint, which was fibrous. The child recovered well postoperatively and was able to move his leg more freely. He could sit normally for the first time and was started on physiotherapy to help him walk. Discussion Duplication of limbs in humans is a rare anomaly, with only 6-8 reportOd cases of lower limb replication in the English literature [3]. There is a great deal of variation between the reported cases, from partial or complete femoral duplication to complete tripedus (three legs). We believe that this case of