Revision surgery for failed anterior cruciate ligament reconstruction with extension deficiency

Background: Some patients with recurrent symptomatic instability after primary anterior cruciate ligament (ACL) reconstruction have an extension deficiency (ED). This study (a) compared preoperative clinical conditions between the ED and non-ED groups undergoing revision ACL reconstruction, (b) documented clinical and arthroscopic findings in ACL-reconstructed patients with reinstability and ED, and (c) determined whether the ED could be resolved and whether the clinical results of revision surgery differed between the ED and non-ED groups. Methods: This study included 58 patients who underwent revision ACL reconstruction. Patients were divided into the ED and non-ED groups. Preoperatively, the demographics and clinical conditions of the two groups were compared. Intraoperatively, the pathological structures that related to ED were documented. After surgery, the degree of postoperative ED and functional outcomes were compared between the two groups at 2-year follow-up. Results: The International Knee Documentation Committee subjective score and SF-36 physical component summary scores were worse in the ED group than the non-ED group preoperatively (54 vs 48 [P = 0.014]; 42 vs 39 [P = 0.031], respectively). Intraoperatively, the ED group showed significantly more frequent graft malposition (50% vs 5%), anvil osteophytes (44% vs 0%), and scarring around posterior intercondylar notch (100% vs 0%). However, there was no difference in the degree of postoperative ED and functional outcome between the two groups at follow-up. Conclusions: ED in patients with recurrent instability after primary ACL reconstruction could be treated with good clinical result by addressing the pathological conditions causing ED in addition to ACL re-reconstruction.