Skeletal changes in neuromuscular disorders mimicking juvenile rheumatoid arthritis and hemophilia

Seven patients with neuromuscular disorders were examined, including one with cerebral palsy, one with Duchenne muscular dystrophy, two with paraplegia, and three with poliomyelitis; all exhibited skeletal changes mimicking those found in juvenile rheumatoid arthritis and hemophilia. These findings included apparent overgrowth of the epiphyses, periarticular osteoporosis, and joint-space narrowing in seven subjects; accentuation of the trabecular pattern in six; gracile bones and soft-tissue wasting in five; tibiotalar slant in two; and premature epiphyseal closure in one. Changes in osseous vascular dynamics and the debilitation or immobilization found both in patients with neuromuscular disorders and those with arthritis may help explain these overlapping findings. While the clinical distinction between the neuromuscular and arthritic disorders is straightforward, the similarity in radiographic appearance has received little attention. If the clinical history is inadequate, this may result in confusion or misinterpretation by the radiologist. In the absence of more specific findings, such as articular erosions or erosions of the femoral intercondylar notch, the differential diagnosis may be mistakenly limited to juvenile rheumatoid arthritis and hemophilia. In such cases, the neuromuscular disorders should also be considered in the differential diagnosis.