Rejection reaction to stabilizing bolts after ACL reconstruction: a case report.

A case of an adverse reaction to the stabilizing bolts after an ACL reconstruction is presented. A 21-year-old patient had an ACL reconstruction using the Mark II system. Six months post op, he presented to clinic having formed a pretibial swelling with serous discharge. There was mild tenderness over the femoral scar. Successive cultures of the tibial cyst effluent showed no microorganism growth and laboratory tests were normal. One year post op, symptoms and swelling persisted. X-rays showed periosteal reaction around the femoral bolt and resorption with widening of the distal tibial tunnel. An adverse reaction to the bolts was suggested as the possible cause. Surgical exploration was then performed. During the operation, free fluid evacuated from the femoral site and the tibial cyst was completely excised. All specimens were sent for culture, which were proven negative. Tibial and femoral bolts were both removed and no communication of the osseous tunnels to the joint was found. An arthroscopy was performed at the same time which showed degeneration of the ACL autograft, but an otherwise normal joint. Eighteen months later, the patient was symptom free and all inflammation indices still within the normal range.