Purpose The purpose of this study is to evaluate the effect of graft size on patient-reported outcomes and revision risk following ACL reconstruction. Methods A retrospective chart review of prospectively collected cohort data, 263 of 320 consecutive patients (82.2%) undergoing primary ACL reconstruction with hamstring autograft were evaluated. Graft size, femoral tunnel drilling technique, patient age, sex, and BMI at the time of ACL reconstruction, pre-operative and 2-year post-operative KOOS and IKDC scores, and whether each patient underwent revision ACL reconstruction during the 2 year follow-up period were recorded. Revision was used as a marker for graft failure. The relationship between graft size and patient-reported outcomes was determined by multiple linear regression. The relationship between graft size and risk of revision was determined by dichotomizing graft size at 8mm and stratifying by age. Results After controlling for age, sex, operative side, surgeon, BMI, graft choice, and femoral tunnel drilling technique, a 1 mm increased in graft size was noted to correlate with 3.3-point increase in the KOOS-pain subscale (p = 0.003), a 2.0-point increased in the KOOS activities of daily living subscale (p = 0.034), a 5.2-point increase in the KOOS-sport/recreation function subscale (p = 0.004), and a 3.4-point increase in the subjective IKDC score (p = 0.026). Revision was required in 0 of 64 patients (0.0%) with grafts greater than 8mm in diameter and 14 of 199 patients (7.0%) with 8 mm or smaller grafts (p = 0.037). Among patients age 18 and under, revision was required in 0 of 14 patients (0.0%) with grafts greater than 8mm in diameter and 13 of 71 patients (18.3 %) with 8 mm or smaller grafts. Conclusions Smaller hamstring autograft size is a predictor of poorer KOOS Sport and Recreation function 2 years following primary ACL reconstruction. Larger sample size is required to confirm the relationship between graft size and risk of revision ACL reconstruction. Level of Evidence Level 3

Different surgical methods of graft fixation in ACL reconstruction were examined to determine the effects on mechanical properties of the reconstructed ACL. Ten human cadavers were used in this study. Six different types of grafts were studied. The tendon grafts were removed from each cadaver and fixed to femurs and tibias as ACL substitutes with different surgical fixation methods, leaving femur-reconstructed graft-tibia preparations. The surgical techniques used were staple fixation, tying sutures over buttons, and screw fixation. In the latter, the screws were introduced through femoral and tibial drill holes from the outside in order to achieve interference fit as described by Lambert. Tensile testing demonstrated that the original ACL is significantly stronger than the graft used for reconstruction in linear load, stiffness, and maximum tensile strength. All of the failures of the reconstructed ACL grafts occurred at the fixation site, indicating that the mechanically weak link of the reconstructed graft is located at the fixation site. Among the different methods of fixation, one-third of the patellar tendon secured with a cancellous screw, especially with a custom designed large diameter screw, showed significantly higher values. Although many other factors affect the success of ACL reconstruction, our study indicates that the method of surgical fixation is the major factor influencing the graft's mechanical properties in the immediate postoperative period.

Background There is limited information on outcomes and return to play (RTP) after ACL reconstruction (ACLR) in soccer athletes. Hypothesis The purpose of this study was to (i) test the hypotheses that player sex, side of injury and graft choice do not influence RTP, and (ii) define the risk for future ACL injury in soccer players after ACLR. Study design Retrospective cohort study, Level II. Methods Soccer players in a prospective cohort were contacted to determine RTP following ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant) and incidence of subsequent ACL surgery was recorded. Results Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACL reconstruction returned to soccer. At average follow up of 7.0 years, 36% were still playing, a significant decrease compared to initial RTP (p<0.0001). Based on multivariate analysis, older athletes (p=0.006) and females (p=0.037) were less likely to return to play. Twelve soccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% v. 5.5%, p=0.03). Soccer athletes who underwent ACLR on their non-dominant limb had a higher future rate of contra-lateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (p=0.03). Conclusion Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer following ACLR declines over time.

The contralateral normal knee anterior cruciate ligament is at a similar risk of anterior cruciate ligament tear (3.0%) as the anterior cruciate ligament graft after primary anterior cruciate ligament reconstruction (3.0%).

Background The predictors of ACL reconstruction outcome at six years as measured by validated patient based outcomes instruments are unknown. Hypothesis We hypothesize that certain variables evaluated at the time of ACL reconstruction will predict return to sports function (as measured by the IKDC and KOOS Sports and Recreation subscale), knee-related quality of life (as measured by the KOOS Knee Related Quality of Life subscale), and activity level (as measured by the Marx scale). Potential predictor variables include demographics, surgical technique and graft choice for ACL reconstruction, and intra-articular injuries and treatment. Study Design Prospective cohort, Level 1 Methods All unilateral ACL reconstructions from 2002 currently enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) cohort were evaluated. Patients preoperatively completed a series of validated outcome instruments, including the IKDC, KOOS, and Marx activity level. Physicians documented intra-articular pathology, treatment, and surgical techniques utilized at the time of surgery. At 2 and 6 years postoperatively, patients completed the same validated outcome instruments. Results Follow-up was obtained on 395/448 (88%) at 2 years and 378/448 (84%) at 6 years. The cohort was 57% male with median age of 23 at the time of enrollment. The ability to perform sports function was maintained at six years (IKDC T2 = 75, T6 = 77; KOOSsports/rec T2 = 85, T6 = 90). The Marx activity level continued to decline from baseline (T0 = 12, T2 = 9, T6 = 7). Revision ACL reconstruction and use of allograft predicted worse outcomes on the IKDC and both KOOS subscales. Lateral meniscus treatment, smoking status, and BMI at T0 were each predictors on two of three scales. The predictors of lower activity level were revision ACL reconstruction and female sex. Conclusions Six years after ACL reconstruction, patients are able to perform sports-related functions and maintain a high knee-related quality of life similar to their two year level, although their physical activity level (Marx) drops over time. Choosing autograft rather than allograft, not smoking, and having normal BMI are advised to improve long-term outcomes.