Causes of Failure of Anterior Cruciate Ligament Reconstruction and Revision Surgical Strategies

PURPOSE: Long-term outcomes of anterior cruciate ligament (ACL) reconstruction are good or excellent; however, 0.7%–20% of patients suffer from recurrent instability due to graft failure. The purpose of this paper was to analyse failure aetiology and the possibilities of revision surgical strategies, with a description of our experience. We obtained optimal and good results in most of our patients. MATERIALS AND METHODS: We retrospectively reviewed 42 patients who underwent revision surgery (43 revisions) due to relapsing instability after ACL reconstruction between 2006 and 2015. We used allografts in 39 cases and autografts in 4 cases. RESULTS: The 85.7% of the patients obtained optimal results (normal knee; group A) and the 7.2% obtained good results (nearly normal knee; group B) according to the International Knee Documentation Committee score. The most frequent failure causes were traumatic events, non-anatomic tunnel placement, and lack of graft incorporation. CONCLUSIONS: A correct revision surgery requires accurate patient evaluation and knee imaging. Preoperative planning starts with the identification of the cause of failure of the primary reconstruction. Then, the most suitable procedure should be determined for each case. It is also important to accurately inform the patient of all the complexity of an ACL revision surgery even if it is a procedure with high rates of excellent and good outcomes.