Myositis Ossificans in the Lumbar Spine: A Case Report.
A 12 year-old Japanese boy with severe low back pain was hospitalized to our hospital. He was 157 cm tall and 45 kg weight and had no history of sports activities. This low back pain had been restricting his motion more than one month. He had a history of trauma three months ago: he used one of Chinese martial arts at school and practiced nunchak (one of tools of Chinese martial arts). He hit the nunchak on his back. After that, his lower back gradually swollen up and the lower back pain developed afterwards in 2 months. On physical examination, a severe tenderness and swelling was present in the left lumbar region, at level of L4/5.
There was no erythema. The laboratory findings were normal. Neurological examination revealed no motor or sensory deficits, with normal reflexes. Both lumbar radiographs and lumbar Computed Tomography (CT) showed a ring like calcification adjacent to left facet joint of L4/5 (Figures 1 and 2). There was no evidence of bone fracture in the lumbar spine. Lumbar Magnetic Resonance Imaging (MRI) showed high signal intensity area along the left multifidus muscle on T2-weighted axial image.
Myositis ossificans is a benign, self-limiting disease. Treatment in most cases is conservative; rest, ice, and anti-inflammatory drugs to relieve pain. Typically, a regression of the symptoms is seen in the course of disease (30%). The optimum time for a surgery excision is between 9 and 12 month after the trauma.
This case is the rare localization for a myositis ossificans. It was typical findings on CT examination that heterotopic bone had matured.
Sport Exerc Med Open J. 2016; 1(6): 182-185.doi: 10.17140/SEMOJ-1-128
