Feller, Julian A.

Background: After anterior cruciate ligament (ACL) reconstruction (ACLR), changes in the appearance of the ACL graft can be monitored using magnetic resonance imaging (MRI). Purpose: The purpose of this study was to evaluate and compare the MRI signal intensity (SI) of hamstring and quadriceps tendon grafts during the first postoperative year after ACLR. As a secondary aim, the relationship of SI to clinical and anatomic measurements was analyzed. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 78 patients who underwent ACLR with an autologous graft were reviewed; 55 received hamstring grafts and 23 received quadriceps tendon grafts. At 3 and 9 months postoperatively, 3-T MRI was performed using a dedicated knee coil, and the median SI of the intra-articular ACL graft was measured on sagittal-plane images. Postoperative lateral radiographs were analyzed to determine medial and lateral posterior tibial slope (PTS). Side-to-side difference in anterior knee laxity between injured and uninjured limbs was measured at 6 and 12 months postoperatively. Results: The median SI of quadriceps grafts was significantly greater than hamstring grafts at 3 months after ACLR ( P = .02). Between 3 and 9 months, the median SI of quadriceps grafts decreased ( P < .001), while that of hamstring grafts did not significantly change ( P = .55). The lateral PTS was significantly correlated with median SI measurements at 3 and 9 months such that greater lateral PTS values were associated with greater median SI. The side-to-side difference in anterior knee laxity decreased for the quadriceps group ( P = .04) between 6 and 12 months but did not change for the hamstring group ( P = .88). Conclusion: The median SI of quadriceps grafts significantly decreased on MRI between 3 and 9 months after ACLR, while the median SI of hamstring grafts did not significantly change. The change in MRI appearance of the quadriceps grafts was paralleled by a reduction in anterior knee laxity between 6 and 12 months after surgery. In the absence of standardized imaging techniques and imaging analysis methods, the role of MRI in determining graft maturation, and the implications for progression through rehabilitation to return to sport, remain uncertain.

Background: Many studies have investigated factors that predict a return to sport participation after anterior cruciate ligament (ACL) reconstruction, but it is unclear whether the same factors are associated with a return to preinjury level of sport performance. Purpose: To identify factors that contribute to an athlete’s return to preinjury level of performance after ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: A cohort of 222 patients (132 male, 90 female) who had ACL reconstruction surgery and completed a 12-month postoperative assessment were followed out to a mean 3 years (range, 2-4 years) to determine whether they had returned to their self-reported preinjury levels of sport performance. Rates of return to preinjury performance were calculated. Measures that had been recorded at the 12-month postoperative review—demographic (age, sex), sport activity level (Marx Activity Rating Scale, return to competition sport), knee laxity, limb symmetry (single and triple crossover hop), subjective function/symptoms (International Knee Documentation Committee subjective), and psychological readiness (Anterior Cruciate Ligament Return to Sport After Injury scale)—were compared between patients who returned to their preinjury levels of performance and those who did not. Univariate and multivariate logistic regression models were also used to prospectively determine the association between these measures and return to preinjury level of sport performance. Results: A total of 135 (61%) patients reported that they had returned to their preinjury levels of performance, with return rates similar between males (59%) and females (63%) and between those who had returned to competition at 12 months (62%) and those who had not (60%). There was no significant age difference between patients who returned to their preinjury levels of sport performance and those who did not; however, higher psychological readiness ( P < .0001), greater limb symmetry ( P < .05), higher subjective knee scores ( P = .01), and a higher activity level ( P < .04) were all associated with a return to performance. In the multivariate model, psychological readiness was the only variable that remained a significant predictor (odds ratio = 1.03; 95% CI, 1.01-1.04; P < .0001). Conclusion: A majority of athletes who returned to sport after ACL reconstruction reported that their performance was comparable with preinjury. Having a greater psychological readiness to return during rehabilitation was the most significant predictor of a subsequent return to comparable performance.

Background: Lower psychological readiness to return to sport has been reported for younger patients (≤20 years) who go on to a second anterior cruciate ligament (ACL) injury. However, changes in psychological readiness and specific psychological responses associated with second injury have not been identified. Purpose/Hypothesis: To identify changes in psychological readiness over time associated with a second ACL injury. It was hypothesized that younger patients who suffered a second injury would have smaller changes in psychological readiness to return to sport when compared with those who did not have a second injury. Study Design: Case-control study; Level of evidence, 2. Methods: Patients ≤20 years old at the time of surgery who had a primary ACL reconstruction procedure between June 2014 and June 2016 were recruited for this study. The short version of the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) scale was completed by patients before their ACL reconstruction and repeated at 12 months after surgery to assess psychological readiness to return to sport. The primary outcome of interest was the relationship between the change in psychological readiness and second ACL injuries. Results: Among 115 young patients who returned to sport after ACL reconstruction, 21 (18%) experienced a second ACL injury. Injured patients did not show improvement in their ACL-RSI score between the preoperative assessment and 12-month time point (58.5 vs 60.8 points, P = .60) and had a significantly smaller change when compared with noninjured patients (9.2 vs 24.9 points, P = .01). When compared with the noninjured group, the injured group reported they were more nervous about playing sport, less confident in playing sport without concern for the knee, more frustrated with having to consider the knee with respect to sport, and more fearful of reinjuring the knee by playing sport ( P≤ .05). Conclusion: Injured patients exhibited less improvement in psychological readiness at a group level and reported different psychological characteristics with regard to return to sport at 12 months after ACL reconstruction as monitored by the ACL-RSI scale.

Background: Psychological responses after anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) have been identified as predictors of return to sport but have not been investigated in relation to further injury. Purpose/Hypothesis: To determine whether psychological readiness to return to sport is associated with second ACL injury. It was hypothesized a priori that at both preoperative and 12-month postoperative time points, patients who sustained a second ACL injury would have lower psychological readiness than patients who did not have a second injury. Study Design: Cohort study; Level of evidence, 2. Methods: Patients who had a primary ACLR procedure between June 2014 and June 2016 completed the ACL–Return to Sport after Injury (ACL-RSI) (short version) scale before their ACLR and repeated the scale at 12 months after surgery to assess psychological readiness to return to sport. Patients were followed for a minimum of 2 years (range, 2-4 years) after surgery to determine further injury. The primary outcome was the relationship between ACL-RSI scores and the incidence of second ACL injury. Results: In 329 patients who returned to sport after ACLR, 52 (16%) sustained a second ACL injury. No difference in psychological readiness was observed at the preoperative time point, but patients who sustained a second injury trended toward lower psychological readiness at 12 months compared with noninjured patients (60.9 vs 67.2 points; P = .11). Younger (≤20 years) patients with injury had significantly lower psychological readiness to return to sport than young noninjured patients (60.8 vs 71.5 points; P = .02), but no difference was found in older patients (60.9 vs 64.6 points; P = .58). In younger patients, receiver operating characteristic curve analysis revealed a cutoff score of 76.7 points with 90% sensitivity to identify younger patients who sustained a second ACL injury. Conclusion: Younger patients with lower psychological readiness are at higher risk for a second ACL injury after return to sport.

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.