Tarsal-carpal coalition syndrome (TCDS) is a rare disorder in which certain bones in the hands and/or feet are abnormally fused. The fusion of two adjacent bones is sometimes referred to as a synostosis. In this disorder, the abnormally fused bones may be connected by bone, cartilage, or dense fibrous tissue. Affected individuals may have fusions in the joints of the fingers, toes, wrists, and/or ankles. Individuals affected by TCDS may experience symptoms of limited mobility in the affected joint and pain from early-onset arthritis.
TCDS may be caused by a mutation in the human noggin gene (NOG). When this gene is mutated, the bones do not properly divide into separate pieces during fetal development, and instead remain connected. Bones in the hands or feet may also fuse as a result of infection, trauma, or surgical fixation. However, TCDS usually refers to fusions caused by developmental abnormalities and are present at the time of birth.
Diagnosis of TCDS may be accomplished through a physical exam and medical imaging. Treatment may include physical therapy and exercises to improve motion, as well as surgery. Recovery depends on the amount and extent of the fusions that are present. If you or your child has been diagnosed with TCDS, talk to your doctor about the most current treatment options.