Tunnel widening in revision anterior cruciate ligament reconstruction.

Widening of the tibial and femoral tunnels can present a substantial obstacle during revision anterior cruciate ligament reconstruction because of the associated bone loss and poor graft fixation. Delayed incorporation of soft-tissue grafts into bone and decreased graft stability are of particular concern. The degree to which mechanical (eg, graft position, fixation method) and biologic (eg, increased cytokine levels, synovial fluid propagation) factors contribute to tunnel widening remains unclear. Radiography, CT, and MRI can be used to characterize the extent of widening and aid in preoperative planning. Although many management methods exist, revision surgery remains difficult. Controversy persists regarding the clinical significance, contributing factors, prophylactic measures, and effective management of tunnel widening following anterior cruciate ligament reconstruction.