The Journal of Bone and Joint Surgery

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Pain in the Lateral Malleolus Fifty-two Months Following Open Reduction and Internal Fixation of an Ankle Fracture¹

A twenty-eight-year-old woman sustained a closed, displaced bimalleolar fracture of the left ankle when she slipped on ice (Fig. 1). She had insulin-dependent diabetes mellitus but was otherwise healthy at the time of injury. On the day of admission, the fracture fragments were anatomically reduced and fixed with bioabsorbable poly-L-lactic acid screws (Bioscience, Tampere, Finland). Complete recovery of ankle motion and function was recorded at ten weeks.

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Fig. 1: Anteroposterior radiograph of the left ankle, showing a displaced bimalleolar fracture.

Fig. 2: Anteroposterior radiograph of the left ankle, made fifty-two months postoperatively.

Fifty-two months after the procedure, the patient had local pain on the lateral side of the ankle (Fig. 2). Within a week, a tender, poorly demarcated erythematous papule, 1.5 cm in diameter, developed at the lateral malleolus, over the entrance point of the screw. The erythrocyte sedimentation rate and the serum concentration of C-reactive protein were each measured three times. The highest erythrocyte sedimentation rate measured was 25 mm/hr (normal,<11 mm/hr). The serum concentration of C-reactive protein was normal (<10 mg/L) each time it was measured.

Plain radiographs and computed tomographic scans showed a poorly defined, multilobular osteolytic lesion corresponding to the course of the screw track in the lateral malleolus. Needle aspiration of the papule yielded no fluid for bacterial culture. During the next four months, the local symptoms and findings remained unchanged. No sinus tract to the skin developed. The patient was able to bear full weight on the leg, and the range of motion of the ankle joint was normal. No symptoms or signs were present on the medial side of the ankle. The patient requested removal of the persistent, painful papule.

What is the diagnosis?