Hip dysplasia associated with a hereditary sensorimotor polyneuropathy mimics a myopathic process

Some orthopedic complications have been reported in the hereditary neuropathies. However, the association of the hip dysplasia with this category of neuropathy is rarely recognized. We present a 13-year-old boy with the progressive weakness of the lower extremities, difficulty in walking, climbing stairs, and rising from floor; a wide-based, hyper-extended and waddling gait similar to a myopathic process. Hip radiography showed dysplastic acetabulae with hip subluxation, broken Shentons lines, and valgus femoral necks. In electrodiagnosis, there was a significant neuropathic process (absent all evoked sensory potentials, abnormal evoked motor responses, and neurogenic electeromyography) which eventually was found to be a hereditary mixed axonal and demyelinating sensorimotor polyneuropathy with concomitant hip dysplasia confirmed with thorough physical examination and the electrodiagnostic study. In patients with gait difficulties such as waddling gait mimicking a myopathic process, hereditary polyneuropathy complicated with hip dysplasia should be considered as well.