Pretibial linear vertical creases or indentations (shin dimples) associated with arthrogryposis

Among 2,500 cases of arthrogryposis, 14 families and 17 individuals were identified that had a linear vertical crease (indentation/dimple) along the anterior tibia, usually bilaterally. Approximately half had developmental delay/intellectual disability and the others had normal intellectual development. There are generalized flexion contractures with the legs more severely affected than the arms. The ankles are flexed at birth suggesting a relationship of contraction of the anterior tibial compartment to the in utero development of the anterior tibial crease. Dislocated hips are seen in 60%. Hands open with physical therapy and become quite functional. Those with normal intelligence are ambulatory, often with a crouching stance. Three families had recurrence suggesting a recessive pattern of inheritance. All parents were normal. No affected individuals have had offspring. Several have had CGH arrays, which were normal. The presence of this crease in cases of arthrogryposis appears to be a helpful clinical observation and may even be pathognomonic.