[Revision of failed anterior cruciate ligament reconstruction].

Failures of ACL reconstruction still occur despite improved arthroscopic methods and new technical instruments. The reasons for failures, which are mostly related to technical surgical errors, must be recognized, analyzed, and considered for the planning and execution of revision ACL surgery. This review article describes the reasons for failed ACL reconstructions, indications, preoperative evaluation, planning, and performance of the operative procedure as well as the issue of rehabilitation. The strategies are evaluated for graft selection, staging of the revision, and the steps of the operative procedure including hardware removal, tunnel placement, graft fixation, or additional operations. Special attention is given to the dilemma of arthrofibrosis and its management in ACL revision cases. Since the results are worse after revision than following primary ACL surgery, the operative procedure has to be tailored to the needs of the patient, planned carefully, and performed by an experienced knee surgeon.