Unilateral lytic changes over the weight-bearing joint causing severe destruction of ankle joint (atypical Charcot joint) in a girl with congenital insensitivity to pain without anhidrosis (hereditary sensory and autonomic neuropathy type V): Case report and literature review

Background . The presence of Charcot arthropathies, joint dislocations, infections and fractures in a child without evidence of neurological abnormality should give rise to a suspicion of congenital insensitivity to pain (hereditary sensory and autonomic neuropathy). Hereditary sensory and autonomic neuropathy (HSAN) is a rare syndrome characterized by congenital insensitivity to pain, temperature changes and by autonomic nerve formation disorders. HSAN is classified into five types: sensory radicular neuropathy (HSAN I), congenital sensory neuropathy (HSAN II), familial dysautonomia or Riley Day Syndrome (HSAN III), congenital insensitivity to pain with anhidrosis (HSAN IV) and congenital indifference to pain (HSAN V). Case presentation . A 13-year old girl first product of a non-consanguineous marriage, presented with malunion of successive fractures or Charcot’s ankle joint destruction on top of significant lytic changes/osteonecrosis. The patient had sustained many painless injuries resulting in fractures with subsequent disfiguremnt of her ankle joint. Arthropathy of the knees, ankles, tarsal bones and feet without pain associated with obvious changes in the shape of the ankle joint were present. Despite a normal sense of touch in our patient the indifference to pain made her extremely susceptible to breakdown of the skin over the ankle osseous prominences. Conclusion . Generally speaking, the orthopaedic management of such patients is extremely difficult since these patients do not restrict the movements of the involved extremity as they lack the inhibitory pain reflex. Interestingly, our attempts for surgical stabilisation of the ankle joints were succsessfull and eventually the girl became able to walk. It is important to anticipate patient and parent education in joint protection and surveillance for injury as the most important component of the treatment plan for these children. We might postulate that the degree of osteolysis of the ankle joint in our present child might be a form of secondary osteolysis.