Systematic review of single-bundle anterior cruciate ligament reconstruction outcomes - A baseline assessment for consideration of double-bundle techniques

Background: There is increasing interest in comparing the efficacy of single-bundle versus double-bundle anterior cruciate ligament reconstruction. Challenging this comparison, however, has been the lack of an established consensus on the success of single-bundle reconstruction. Hypothesis: The current outcomes of single-bundle reconstruction can be clarified from a large unbiased body of evidence for future comparisons with double-bundle reconstructions. Study Design: Systematic review. Methods: A systematic review of 11 randomized, controlled trials comparing patellar tendon and hamstring tendon grafting is reported. The respective outcomes of each group were combined to assist the orthopaedic surgeon in assessing the current success of single-bundle reconstruction. The primary factors assessed were tibial subluxation and side-to-side differences in laxity. Secondary outcomes included concomitant injuries and treatments, complications, graft failure, range of motion, and radiographic evidence of degenerative changes. Results: In this review of 1024 single-bundle anterior cruciate ligament reconstructions, 495 concomitant meniscal tears, 95 chondral injuries, and 2 posterior cruciate ligament tears were noted. The complication rate was 6%, and graft failure 4%. Reported pivot-shift test results were negative in 81% of cases; reported Lachman tests were negative in 59% cases; and KT 1000 arthrometer side-to-side differences were <= 5 mm in 86% of cases. Flexion and extension deficits were reported in 9 of 11 studies through mean range of motion or deficit ranges. Radiographic changes of articular surface abnormalities were observed in 7% of the knees at follow-up investigation. Conclusion: Systematic review of a significant body of unbiased outcome data on single-bundle anterior cruciate ligament reconstruction demonstrates it to be a safe, consistent surgical procedure affording reliable results. Clinical Relevance: These results may be used to assist orthopaedic surgeons in evaluating the benefit and practicality of pursuing new anterior cruciate ligament reconstruction techniques over standard single-bundle anterior cruciate ligament reconstruction.