Ectopic calcification following tibial fracture: property analysis

We present a patient whose ectopic calcification following deep posterior c ompartment syndrome was studied by electron microscopy, chemical analyses, and X-ray diffraction. The patient complained of a toe flexion deformity fo llowing a tibial fracture which he sustained 18 years earlier. Damage to th e peroneal artery was demonstrated by magnetic resonance angiography, sugge sting that the patient had had deep posterior compartment syndrome in the p ast. A large radiopaque mass, identified in the flexor hallucis longus musc le by radiographs and computed tomography, was resected, resulting in a dra matic improvement of the toe deformity. The resected material was analyzed in detail. It included no osseous tissue, and was not birefringent under a polarizing microscope, being compatible with ectopic calcification rather t han ossification. On electron microscopy the material was found to be an as sembly of tiny rods. Chemical and X-ray diffraction analyses suggested a ca rbonate-containing apatite as the most probable substance.