Outcome and Risk Factors After Anterior Cruciate Ligament Reconstruction: A Follow-up Study of 948 Patients

Purpose: The aim of the study was to assess the outcome and risk factors after anterior cruciate ligament (ACL) reconstruction in a large group of patients. Type of Study: Case series. Methods: Included in this retrospective study were 948 patients (323 female, 625 male) with a symptomatic unilateral ACL rupture, who underwent arthroscopic reconstruction using patellar tendon autograft and interference screw fixation at 3 Swedish hospitals. The median age of the patients at the time of the index operation was 26 years (range, 14 to 53 years). The patients underwent surgery at a median of 12 months (range, 0.5 to 360 months) after their injury. Independent physiotherapists performed the follow-up examinations at a median of 32 months (range, 21 to 117 months) postoperatively. Results: Of the 948 patients, 550 (58%) underwent meniscal surgery before, during, or after the ACL reconstruction. The median Tegner activity level was 8 (range, 2-10) before injury, 3 (range, 0-9) preoperatively, and 6 (range, 1-10) at follow-up (P < .0001 preoperative v follow-up). At follow-up, the median Lysholm score was 90 points (range, 14-100), the median KT-1000 anterior side-to-side laxity difference was 1.5 mm (range, −6 to 13 mm), and the median 1-leg hop test quotient was 95% (0% to 167%) compared with the contralateral normal side. At follow-up, 69.3% of the patients were classified as normal or nearly normal according to the International Knee Documentation Committee evaluation system. However, 36% of the patients were unable to or had severe problems performing the knee-walking test. Inferior results correlated with increased time period between the index injury and reconstruction and concomitant joint damage found at the index operation. Conclusions: Overall, the results were good after ACL reconstruction using patellar tendon autograft and interference screw fixation. Concomitant joint damage and a long time period between the injury and reconstruction are major risk factors for inferior outcome after ACL reconstruction. Level of Evidence: Level IV, case series.