ACL femoral cortical button failure with subsequent abscess formation case report

Anterior cruciate ligament (ACL) tears are a common athletic injury, and account for a large proportion of knee injuries. ACL reconstruction is a common procedure with typically excellent results. This procedure is not without risk of complication, which can be devastating to the patient/athlete. Common complications include graft tunnel mismatch, malposition of bone tunnel, posterior blowout of the femoral wall, graft failure, arthrofibrosis and infection, including septic arthritis. Infection is rare in ACL reconstruction procedures and is typically superficial in nature. There is limited literature reporting on failure of the femoral cortical button, as it is a rather rare complication. We present a case of femoral cortical button failure with a concomitant abscess formation in a 59-year-old female, who was subsequently treated with operative debridement, removal of the femoral cortical button, and intravenous antibiotics with complete resolution of her symptoms. There are a small number of cases in the literature of femoral cortical button failure, these cases identify tunnel malposition as the most likely reason for failure and their observed findings. In these cases there was no finding of an infectious process or abscess related to the suture button migration. There are several proposed mechanisms for suture button failure in this case including implant contamination, ACL failure, and tunnel malposition. In this reported case it is unclear which occurred first, the displacement of the suture button fixation device providing a nidus for infection, or the infectious process leading to disruption of the suspensory fixation device, ultimately leading to migration.