Background: Younger age is being increasingly recognized as a risk factor for anterior cruciate ligament (ACL) graft rupture and contralateral ACL injury after ACL reconstruction. Recent reports estimate second ACL injury rates to be in the range of 20% to 40%, which is a significant concern and requires further exploration. Purpose: The primary purpose was to determine the rates of graft rupture and injury to the contralateral native ACL in younger athletes. We also sought to explore the influence of sex and age groupings (<18 years vs 18-19 years at the time of surgery) on the risk of subsequent ACL injury. Study Design: Cohort study; Level of evidence, 3. Methods: The study cohort consisted of 354 consecutive patients who were younger than 20 years when they underwent their first primary hamstring tendon autograft ACL reconstruction. The number of subsequent ACL injuries (graft rupture or a contralateral injury to the native ACL) was determined at a mean follow-up of 5 years (range, 3-10 years). Subgroup analysis included sex and age (<18 years vs 18-19 years at the time of surgery) comparisons. Descriptive statistics were calculated for the timing of ACL graft rupture and contralateral ACL injury. Results: The overall follow-up rate was 89% (316/354). Graft ruptures occurred in 57 patients (18%) at an average time of 1.8 years after surgery. Almost half (47%) occurred within the first postoperative year, and 74% occurred within the first 2 years. The highest graft rupture rate of 28.3% was in the youngest males (<18 years), and this was significantly higher than in females of the same age (12.9%), as well as in male patients older than 18 years (13.8%). Contralateral ACL injuries occurred in 56 patients (17.7%) at an average time of 3.7 years after surgery. There were no significant age- or sex-based differences for contralateral ACL injuries. The total number of patients who had at least 1 further ACL injury subsequent to the primary surgery was 110 (35%). Conclusion: The high rate of subsequent ACL injury in younger patients was confirmed. Early graft ruptures were more prevalent in patients who underwent surgery when they were younger than 18 years versus those in the 18- to 19-year age group. Males had higher rates of graft rupture than did females, with the youngest males (<18 years) at the highest risk in the investigated cohort.

Background: Graft rupture of the same knee or injury to the anterior cruciate ligament (ACL) in the contralateral knee is a devastating outcome after ACL reconstruction surgery. While a number of factors have been identified as potentially increasing the risk of subsequent ACL injury, the literature is far from definitive. Purpose: To determine the rates of graft rupture and contralateral ACL injury in a large cohort and to investigate patient characteristics that may be associated with these. Study Design: Case-control study; Level of evidence, 3. Methods: A consecutive cohort of 750 patients who had undergone primary ACL reconstruction surgery with a minimum 3-year follow-up were questioned about the incidence of ACL graft rupture, contralateral ACL injury, family history of ACL injury, and current activity level. Patient databases provided details for age, sex, original injury mechanism, meniscus or articular surface injury, and graft diameter. Results: Responses were received from 561 patients (75%) at a mean ± SD follow-up time of 4.8 ± 1.1 years. Anterior cruciate ligament graft ruptures occurred in 25 patients (4.5%), and contralateral ACL injuries occurred in 42 patients (7.5%). The highest incidence of further ACL injury occurred in patients younger than 20 years at the time of surgery. In this group, 29% sustained a subsequent ACL injury to either knee. The odds for sustaining an ACL graft rupture or contralateral injury increased 6- and 3-fold, respectively, for patients younger than 20 years. Returning to cutting/pivoting sports increased the odds of graft rupture by a factor of 3.9 and contralateral rupture by a factor of 5. A positive family history doubled the odds for both graft rupture and contralateral ACL injury. Conclusion: Patients younger than 20 years who undergo ACL reconstruction are at significantly increased risk for both graft rupture and contralateral ACL injury. Whether age per se is a risk factor or age represents a proxy for other factors remains to be determined.

Background: Anterior cruciate ligament (ACL) injury has a significant psychological effect, and a negative psychological state is a commonly cited reason for a reduction or cessation of sports participation after ACL reconstruction (ACLR) surgery. Purpose: To identify factors that contribute to an athlete’s psychological readiness to return to sport (RTS) after ACLR. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A cohort of 635 athletes (389 male, 246 female) who underwent ACLR and had been cleared to RTS completed the Anterior Cruciate Ligament–Return to Sport After Injury (ACL-RSI) scale at an average 12 months (range, 11-24 months) after surgery. Demographics (age, sex), sporting outcomes (preinjury frequency), surgical timing (injury to surgery interval), clinical factors (laxity), functional measures (single-limb hop symmetry), and symptoms of pain and function (International Knee Documentation Committee subjective) were also taken, and univariate and multiple regression models were used to determine the association between these and the psychological readiness of the athlete to RTS (ACL-RSI scores). Data for the entire cohort were initially analyzed; then, patients were grouped according to whether they had returned to competitive sport, and the analysis repeated for each group (return/nonreturn). Results: Univariate analysis for the entire group showed that all of the following had a positive effect on psychological readiness: male sex (β = 5.8; 95% CI, 2-10), younger age (β = −0.2; 95% CI, –0.4 to 0.01), a shorter interval between injury and surgery (β = −0.1; 95% CI, −0.1 to −0.02), a higher frequency of preinjury sport participation (β = 5.4; 95% CI, 2-9), greater limb symmetry (β = 0.5; 95% CI, 0.3-0.6), and higher subjective knee scores (β = 1.3; 95% CI, 1.1-1.4). In the multivariate model, subjective knee scores and age significantly accounted for 37% of the variance in psychological readiness ( r ² = 0.37, P < .0001). The only difference between the groups who had and had not returned to sport was that female sex was a significant contributor for the nonreturn group. Conclusion: Self-reported symptoms and function were most associated with psychological readiness to RTS after ACLR surgery. Male patients who participated frequently in sport before ACL injury had higher psychological readiness. Conversely, female patients had a more negative outlook and may therefore benefit more from interventions designed to facilitate a smooth transition back to sport.