Age, Graft Size, and Tegner Activity Level as Predictors of Failure in Anterior Cruciate Ligament Reconstruction With Hamstring Autograft

Background: Patient age, Tegner activity level, and graft size could be factors that influence the outcome of anterior cruciate ligament reconstruction (ACLR) with hamstring autografts. Hypothesis: Decreased graft size, higher Tegner activity score, and younger age are associated with an increased failure rate of ACLR, represented by continued knee laxity and revision surgery. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 98 patients who had undergone ACLR with hamstring tendon autografts between 2000 and 2007 were identified from a computerized relational database. Inclusion criteria consisted of a minimum of 2 years of follow-up, all age groups, and all activity levels. Exclusion criteria consisted of treatment with other grafts or previous ligament surgery, previous ACL repairs, bilateral ACL injuries, and associated ligament tears. Failure was defined as a 2+ Lachman result, positive pivot shift, and 5-mm difference or more on KT-1000 arthrometer measurement. Results: Fifteen of the 98 ACLRs (15.3%) were defined as failures. Of the failures, 12 of 48 (25%) occurred in patients aged 25 years and younger, whereas 3 of 50 (6%) occurred in patients older than 25 years. There was a statistically significant association when comparing failure rate and age groups ( P = .009); however, a significant association was not found between graft size and failure rate in the entire study population ( P = .135) or within the different age groups (age ≤25 years vs >25 years) based on failure rate ( P = .390 and P = .165, respectively). No statistical significance was found when Tegner activity level and failure rate were compared in the overall study population ( P = .463) or within age groups (≤25 years, P = .707; >25 years, P = .174). Conclusion: In this study population, younger patients (≤25 years) demonstrated a higher failure rate compared with the over-25 age group. A statistically significant difference was not found in terms of graft size and activity level correlating with failure rate in ACL reconstruction with hamstring autograft.