Dystrophic calcification and a snake in the grass

Abstract

A 45-year-old farmer presented with discharging sinii of the left leg, 5 years after snakebite at the same site. The snake had been identified as a non-poisonous wolf snake and the tissues then had developed a localised inflammatory reaction. These symptoms resolved completely within a fortnight and the patient was well for the intervening period. Six months ago, he developed fever and a painful swelling in the same leg. A general practitioner treated him with antibiotics and he recovered. Two weeks before presentation he developed discharging sinii of the left leg and was referred to us for expert orthopaedic evaluation. On examination, he was found to have a firm tender swelling over the anterolateral aspect of the left leg and two discharging sinii proximal to his lateral malleolus. He was afebrile and did no have any regional enlargement of his lymph nodes. The rest of his examination was normal.X-ray ( Fig. 1) showed diffuse new bone formation around the fibular diaphysis.Laboratory investigations revealed a total leukocyte count of 13,000/dl with a normal differential and an erythrocyte sedimentation rate (ESR at 60 min) of 46 mm. Other investigations included a peripheral blood smear for sickling, which was negative, and serum calcium level that was within acceptable limits. The chest radiograph was normal.He was clinically diagnosed to have chronic osteomyelitis of the left fibula probably secondary to the snakebite. He was scheduled to undergo curettage and debridement of the sinii.Under spinal anaesthesia and a pneumatic tourniquet, an incision was made over the anterolateral compartment of the left leg extending over most of the length. Within the anterior group of muscle, sheets of calcified tissues were found (Fig. 2). These were intermingled with the fascial planes. The tibial and fibular surfaces were free of any involucrum or new bone. There was little pus within the tissues. The cavity created by debridement was extensively curetted and irrigated before closure.The post-operative X-ray (Fig. 3) showed clearance of the diffuse opacity in the left leg. The wound healed satisfactorily and the patient was discharged on the 5th post-operative day.Histopathological examination of the excised tissue was reported as dystrophic calcification and necrosis with acute inflammatory processes. The patient has been advised regular follow-up. DiscussionThis patient suffered from snakebite on the left leg. Till he presented to us, he seemed to have recovInjury Extra (2005) 36, 537-541