Duplication of the Lower Extremities
Congenital duplications of the lower extremities has an extremely rare occurrence. There are less than 200 cases have reported in the literature. I am presenting a case that presented to me while I was a chief resident in Orthopedics and Traumatology in Haiti, in 1977. A young attending who recently returned to the country of Haiti after his training at a hospital .in The United States, was with me on the case. His name is Raymond Bernardin MD with whom I kept a long friendship. For years, I wanted to write about the case but we were unable to have any study performed on the baby once we discovered him at the State University Hospital of Port au Prince.
A young baby male was born from an apparent healthy mother who did not have much complications from the pregnancy and at the birth of her baby. She delivered at home with the help of a” sage-femme” with no apparent complication. A hormonal workup was submitted with the mean of our capabilities at the State University Hospital and radiographic studies were performed. In the lab of the radiological department at the HUEH, multiple attempts at obtaining an arteriogram of the lower extremities to visualize the vasculature were done. No pulses were appreciated although the right lower extremity was deformed but well vascularized. We wanted to perform a cut-down but the mother refused to give us the authorization and decided to leave with the baby. This was the first case of tri-plication we have ever heard about and the mother never returned to the institution.
The deformation involved the right lower extremity which grossly was kept in a flexed position at the knee level. Clinically visible, two right femoral bones and two distinct right knee joints were present and held tightly together by what appear to be a connective tissue or an amniotic band. There was no motion at the knee joints, none as well as the hip joint but it was difficult to appreciate any right ankle joints. Both knees were fused in almost 90 degrees with prominent patellae. The patellae were well demarcated and a quadriceps musculature was adequately covering the entire femurs except that proximally, the femur was enlarged with a redundant but deformed femoral head and neck. Distally, the right thigh was exposing two distinct femoral bones. Three tibias appeared to be present following the anatomical structure and difficult to evaluate some vestigial fibulae. The distal aspect of the long bones of the leg appeared to be representing two or three tibiae or maybe a fibula but no distinct ankle joints.
The presence of at least two partially formed feet or perhaps a third one incompletely developed toes and nubbins were visible. The ankles were inexistent and the feet were held together by connective tissue as well as metatarsal bones and connective tissue. I wish now to have been able to retrieve the radiological studies for a better presentation and description of the deformed right lower extremity. We were unable to see the baby back in the clinic. To my knowledge no such case has ever been presented in the orthopedic pediatric literature. No apparent spinal deformity was apparent, no spina bifida and he had an anus present. The left lower extremity was in the normal limits.
The term “Caudal duplication syndrome” was first used in 1993. Other have used in recent debates the term “Caudal Split syndrome” due to the split seen in spite of a duplication. Caudal duplication syndrome is a rare congenital disorder in which various structures of the caudal region (embryonic cloaca and neural tube) exhibit a spectrum of abnormalities. The exact causes of the condition are not known but there are several theories implicating abnormal embryological development. Diagnosis is often made during the prenatal development during the second trimester because of abnormal scans. Conservative management to resection of the caudal segment to restore function and appearance can be offered. This is a rare congenital disorder with a prevalence of 1/100,000. As already discussed, less than two hundred cases reported around the world.
The condition may come with a spectrum of Gastro-intestinal (GI), Urogenital (GU), Spinal and Limb anomalies. Anorectal malformations and duplication of the external genitalia, incomplete duplication of the lower spine and the spinal cord (diastematomyelia) or a partial fusion or duplication of the uterus, vagina, colon and bladder. Malformation of the spine may come with varying levels of neurological impairment especially when spinal duplications are present with severe or mild neurological symptoms. Other patients may present with an absent segment of the pelvis and a variety of symptoms like a duplication of colon, rectum, anus, urinary bladder, urethra, vagina and external genitalia. Patient with such syndrome can still be found asymptomatic. Many of these patients may not be cosmetically or physiologically detrimental to the individual.
Such spinal malformations can be diagnosed during a prenatal examination via a Scan during the second trimester. If the anomaly is detected early on, psychological and surgical preparation for a C-section may prevent an obstructed labor. Some babies can be asymptomatic but may develop the complications during the adulthood. It is as well extremely rare but can be diagnosed through imaging modalities like CT-Scan.