Abstract
Background:
The Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) scale is widely used after anterior cruciate ligament reconstruction (ACLR), but its 3 subscale domains of emotion, risk appraisal, and confidence are rarely considered when assessing readiness to return to sport (RTS). Current guidelines for ACL-RSI scores at time of RTS are derived from adult-only studies, and there is a need for age- and sex-specific data to guide RTS decision-making.
Purpose/Hypothesis:
The purpose of this study was to investigate differences in ACL-RSI subscale scores by age and sex. It was hypothesized that males and teens would report higher scores on emotion, confidence, and risk appraisal subscales compared with females and adults.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
ACL-RSI data were obtained from a multisite clinical outcome registry. Participants were included if they were between 6 and 12 months after primary, unilateral ACLR. Sex subgroups (female, male) and age subgroups (teen: 14-18 years; adult: 19-30 years) were established and compared to identify potential sex- and age-related differences in the ACL-RSI scale (total, subscales, and item scores). Descriptive statistics were computed and multiple 2-way analyses of variance were used to determine main effects and interactions between sex and age group. The significance level (α) was set to .05.
Results:
A total of 154 participants (mean age, 20.2 ± 3.8 years; 53.9% female; mean time after ACLR, 8.7 ± 2.1 months) were included. The mean ACL-RSI total score across the cohort was 67.92 ± 24.65. A significant main effect of age group on ACL-RSI total score was found as teens exhibited significantly greater psychological readiness compared with adults (mean difference, 10.91 points). A significant main effect of age group on the confidence subscale score was found, with teens reporting significantly higher confidence in returning to sport compared with adults (mean difference, 14.05 points). The main effect of sex on ACL-RSI total score was not significant (P = .337).
Conclusion:
Teens demonstrated significantly higher total scores and confidence on the ACL-RSI scale compared with adults. Therefore, when assessing a teen athlete's psychological preparedness to RTS, target scores determined from adult data may not be appropriate. Sex was not found to influence ACL-RSI scores. Future work should strive to create age- and sex-specific ACL-RSI cutoff scores for successful RTS after ACLR in teen athletes.
Anterior cruciate ligament reconstruction (ACLR) is a significant life event for youth athletes, with only 55% able to successfully return to competitive sport. 4 Criteria used for return to sport (RTS) clearance after ACLR primarily focus on biological healing and functional recovery, with less attention paid to patient-reported function and mental preparedness. 7 Consensus guidelines for RTS decision-making recommend utilizing a biopsychosocial model to emphasize the influence that psychological perceptions have on RTS success. 2
Psychological readiness is a multidimensional construct because athletes can benefit from being confident, self-aware, and emotionally prepared before they RTS. Of those unsuccessful in RTS after ACLR, 65% report a psychological reason limiting them. 20 Fear of reinjury (77% of responses) and lack of confidence (15% of responses) are among the most commonly reported psychological limitations when unsuccessful to RTS. 20 Male and female patients report different psychological factors impacting their RTS clearance, including distress, self-efficacy, locus of control, and fear of reinjury.18,25 As discrepancies in psychological responses (eg, confidence and fear) exist between patients, using a general scale of all dimensions of psychological readiness may not be specific enough to best assess and address the limitations of adolescent athletes.
The Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) scale provides a reliable and valid assessment of psychological readiness for sport after ACLR.26,28 Psychological readiness has been shown to have a strong relationship with biological and functional outcomes after ACLR, including an increased ability to return to a previous level of sport.3,5,10,13,31 Age and sex may be associated with psychological readiness after ACLR, with adolescents and males reporting increased readiness compared with older patients and females.15,19,30 With adolescents 11 and female sex 22 commonly associated with poorer outcomes after ACLR, there is a heightened need for age- and sex-specific data on psychological readiness to guide RTS decision-making.
The ACL-RSI scale contains 3 subscales: emotion, risk appraisal, and confidence. 28 Although the ACL-RSI total score continues to be widely used after ACLR, these subscales are rarely calculated or considered when assessing RTS readiness. In the adult population, the ACL-RSI subscale scores have been strongly related to each other, allowing the ACL-RSI total score to be utilized as a common standard of practice.16,26,28 Recently, Webster and Feller 27 further investigated psychological readiness in the adolescent population and noted differences in these 3 subscale constructs (emotion subscale, confidence subscale, and risk appraisal subscale) that were not previously seen in the adult population. Understanding these unique constructs could help clinicians develop more appropriate interventions to enhance outcomes, rather than just using a global, unidimensional construct of psychological readiness. The authors discuss benefits of further exploration into ACL-RSI subscale scores to assess the most influential psychological factors in this population. 27
Clinicians may influence the psychological recovery of athletes, and a comprehensive understanding of specific psychological limitations can help guide treatment strategies aimed at preparedness for RTS. 29 The lack of published normalized data regarding ACL-RSI scores in the teen population limits clinicians’ ability to interpret these subscales after ACLR. There is a call for increased specificity in pediatric and adolescent anterior cruciate ligament (ACL) research, specifically utilizing multicenter registry studies to obtain optimal sample sizes. 1 Therefore, the purpose of this study was to investigate differences in ACL-RSI subscale scores by age and sex at the time of RTS testing. We hypothesized that males and younger patients (teens) would report higher scores on emotion, confidence, and risk appraisal subscales compared with females and older patients (adults).
Methods
This was a multisite study from the ACL Reconstruction Rehabilitation Outcomes Workgroup (ARROW) clinical outcome registry. The purpose of ARROW is to combine data and resources from a geographically diverse consortium of researchers at affiliated universities, hospitals, and research sites to improve clinical decision-making and patient care after ACLR. Data were collected as a part of separate institutional review board (IRB)–approved research studies (University of Virginia: HSR 220225) at each site, and then a limited data set from each site was aggregated in an IRB-approved registry housed and managed by study team members at the University of Virginia (HSR 230335).
Patients
Patients were included if they were within 6 to 12 months after primary, unilateral ACLR, and between the ages of 14 and 30 years. If data were captured at multiple time points within 6 to 12 months, the latest time point was included for analysis to best align with clearance to RTS. Sex (female, male) and age group (teen: 14-18 years; adult: 19-30 years) were recorded to subsequently identify potential sex- and age-related differences in the ACL-RSI scale (total, subscales, and item scores). The teenage group of 14 to 18 years represents the range of peak ACL injury incidence. 6 Biological age was not assessed in this study; therefore, chronological age terminology was used to describe groups. The term “teen” was selected as a combination of the “early teen” and “late teen” subcategories. 8
Patient-Reported Outcome Measures
The ACL-RSI scale is a 12-item scale used to measure psychological readiness to RTS after ACLR. It is valid in both teens and adults.9,28 The ACL-RSI scale consists of 3 subscales that influence RTS: risk appraisal (2 items), confidence in performance (5 items), and negative emotional response (5 items) (Table 1). The ACL-RSI scale is scored from 0 to 100, with a higher score indicative of greater readiness to RTS. The total score is computed by averaging the 12 item scores, each captured on a 100-point scale. Similarly, subscale scores are computed by averaging the items corresponding to each subscale. The ACL-RSI scale demonstrates high validity and internal consistency (Cronbach α = 0.96). 26
ACL-RSI Items by Subscale a
ACL-RSI, Anterior Cruciate Ligament–Return to Sport after Injury.
Statistical Analysis
Means and standard deviations were computed for all continuous variables, including age, months since surgery, and ACL-RSI subscale and total scores. Given the ordinal nature of the ACL-RSI item scores, medians and interquartile ranges were computed. Specifically, interquartile ranges were computed as the difference between the 25th and 75th percentiles. The main effects of sex (female, male) and age group (teen: 14-18 years; adult: 19-30 years), as well as the interaction between sex and age group, on ACL-RSI subscale and total scores were identified using multiple 2-way analyses of variance. Similarly, for ACL-RSI item scores, an ordinal logistic regression model was performed. The significance level (α) was set to .05. If a significant interaction effect was found, post hoc analysis was performed to compare the means of one factor at each level of the second factor using a Bonferroni adjustment (α = .013). All analyses were performed using IBM SPSS Statistics for Windows (Version 224.0; IBM Corp).
Results
A total of 154 patients (mean age, 20.2 ± 3.8 years; mean time from after, 8.7 ± 2.1 months) were included for analysis. The cohort consisted of 53.9% female patients, and 45.5% of patients were included in the teen subgroup. The teen subgroup had a mean age of 16.91 ± 1.14 years, while the adult subgroup had a mean age of 22.85 ± 3.07 years. Subgroup breakdowns are presented in Table 2. Overall, the mean ACL-RSI total score across the cohort was 67.92 ± 24.65, and the mean emotion, confidence, and risk appraisal subscale scores were 63.05 ± 28.07, 72.74 ± 26.04, and 67.44 ± 28.40, respectively.
ACL-RSI Item, Subscale, and Total Scores by Age Group and Sex a
Item scores are presented as median [IQR], and subscale scores are presented as mean ± SD for each age group within each sex. Significant age group differences are noted in bold. No significant sex differences were found, and no interaction effects between sex and age group were identified. Thus, neither is noted in the table. ACL-RSI, Anterior Cruciate Ligament–Return to Sport after Injury; Q, question.
A significant main effect of age group on ACL-RSI total score was identified (F[1, 150] = 7.406; P = .007; η p 2 = 0.047) (Figure 1). Specifically, teens exhibited significantly greater psychological readiness compared with adults (mean difference, 10.91 points). However, the main effect of sex was not significant (P = .337), and no significant interaction effect between sex and age group on ACL-RSI total score was found (P = .996). Similarly, a significant main effect of age group on the confidence subscale score was observed (F[1, 152] = 11.552; P < .001; η p 2 = 0.071), with teens reporting significantly higher confidence in returning to sport compared with adults (mean difference, 14.05 points). The main effect of sex (P = .103) and the interaction effect (P = .621) on the confidence subscale score were not significant. Additionally, no differences by sex, age group, or the interaction between sex and age group were found for the emotion or risk appraisal subscales.
Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) subscale, total, and item scores by age group. Significant age group differences are noted with an asterisk.
Contributing to the age-specific difference in confidence subscale score, teens reported greater confidence in their knee not giving way by playing their sport (X2[1, 156] = 5.708; P = .017), their knee holding up under pressure (X2[1, 156] = 6.283; P = .012), and their ability to perform well at their sport (X2[1, 156] = 3.990; P = .046). No significant differences by sex or the interaction between sex and age group were found for the any of the confidence subscale items. Lastly, a significant main effect of age group on 1 item in the emotion subscale score was found. Specifically, teens reported feeling more relaxed about playing their sport (X2[1, 156] = 6.609; P = .010). The main effect of sex (P = .119) and the interaction effect between sex and age group (P = .385) were not significant. Furthermore, no significant differences by sex, age group, or the interaction between sex and age group were found for the remaining emotion subscale items or the 2 risk appraisal subscale items.
Discussion
The purpose of this study was to investigate differences in ACL-RSI subscale scores by age and sex. Both male and female teens reported significantly greater confidence in performance compared with adults. Male teens reported the highest total ACL-RSI scores of all groups, but the main effect of sex was not statistically significant for ACL-RSI total or subscale scores. Overall, these results indicate a stark difference in psychological readiness between teens and adults after ACLR that should be considered at the time of RTS.
Our results are comparable to previous studies reporting ACL-RSI total scores in teens 6 to 12 months postoperatively,15,19 supporting the notion that younger age positively affects ACL-RSI scores. 30 Milewski et al 19 reported significantly higher ACL-RSI mean total scores in adolescents (61.5 ± 20.4) versus adults (52.5 ± 19.8), although their total scores trended 15% to 20% lower than those in our study. This is likely because of their earlier time point of collection (6 months postoperatively) versus our mean time point of 8.7 ± 2.1 months postoperatively, as ACL-RSI scores improve throughout the first year of postoperative ACLR rehabilitation. 24 As current practice patterns have shifted away from clearing teen athletes for RTS before 9 months postoperatively, having ACL-RSI total scores and subscale scores near the time of RTS decision-making may be most beneficial for clinicians. 14
There are many factors that can influence reported psychological readiness for sport in teens versus adults. Current target scores for the ACL-RSI scale are from adult-based studies, with a total score >56 at 4 months postoperatively 5 and a total score >72 at 12 months postoperatively 17 predictive of successful RTS. Social factors may influence an adult's perspective of their psychological readiness for RTS after ACLR. Fones et al 13 identified that those athletes transitioning to adulthood who did not RTS reported life changes, such as changes in training or starting work/college, as one of the primary barriers for RTS. Teens have access to organized competitive and recreational sports through school leagues, and commitment to sport may look very different in adults when compared with teens. 13 We postulate that our findings on the ACL-RSI scale may also be due to adults viewing RTS more negatively because of decreased access to competitive sport, as well as the financial and time burdens of ACLR and subsequent rehabilitation. Filbay et al 12 identified that adults after ACLR modify their activity preferences and alter their lifestyles to accommodate for knee impairments and improve quality of life. With these differences in mind, clinicians may need to hold higher expectations for ACL-RSI total scores in teens and consider subscale scores, instead of relying on previously utilized target scores derived from adult populations.
Our data show both male and female teens reporting significantly higher scores on confidence items in comparison with adults. Although high confidence is a key component in returning to competitive sport, it is not protective from reinjury. 23 Paterno et al 23 included females with high self-reported confidence as a predictive variable in an algorithm that attempts to identify young athletes at high risk for secondary ACL injury. Using the confidence subscale score in addition to other physical performance metrics (eg, knee strength and functional performance) may be useful to assess patients’ readiness to progress in rehabilitation. Disproportionate physical and mental recovery may lead to poor outcomes, and, as a degree of caution, low confidence could be beneficial if the patient is physically not ready to advance in activity. Clinicians should be aware of the increased confidence scores common in teens, as greater confidence could inflate ACL-RSI total scores and overshadow suboptimal emotion responses if only the total ACL-RSI score is being evaluated.
We hypothesized that males would have higher scores on the ACL-RSI scale compared with females. In our sample, the mean total score for teen males (75.96 ± 20.31) trended higher than the mean total score for teen females (72.08 ± 25.00), and the mean total score for adult males (65.04 ± 22.54) trended higher than the mean total score for adult females (62.81 ± 25.98), but no significant main effect of sex for the ACL-RSI total score or subscale scores was found. Previous studies reporting sex-specific ACL-RSI scores have shown higher scores in males versus females,15,19 although a recent meta-analysis of 2618 patients 21 after ACLR indicated only a mean difference of approximately 5 points on the ACL-RSI scale between sexes.
This paper provides the first available data on ACL-RSI individual item responses by teens after ACLR. By isolating the individual questions, or items, of the ACL-RSI scale and reporting mean subscale scores, our results can help clinicians more accurately assess how different components of their patients’ psychological readiness compare with age- and sex-specific data. Using the individual item scores is important to make patient-specific recommendations and deliver effective interventions before RTS. In our study, the emotion subscale scored the lowest across both sex and age groups. Fear of reinjury and stress have been reported as major impediments in returning to sport. 13 Being able to identify abnormally low scores on specific emotion items can guide the health care team toward targeted cognitive interventions to increase the likelihood of successful RTS.
Limitations
There were a few limitations in this study. Because of the variances between sites, ACL-RSI data were collected at different time points between 6 and 12 months postoperatively (8.7 ± 2.1 months), and it was not guaranteed that patients successfully returned to sport at this assessment time point. Additionally, there were insufficient data from the youngest age group (12-14 years), requiring those patients to be excluded. Early teens may present differently than late teens with regard to psychological readiness and should be considered a priority in future large, multicenter studies. The level of competition and type of sport for patients included in this study were not recorded. Knowing that the ACL-RSI scale was developed specifically for athletes planning to RTS after ACLR, 28 the sport-specific items included in the ACL-RSI scale may not be applicable for those who participate in general, unorganized recreational forms of sport as opposed to competitive, organized sport. Adults may have less access to organized competitive sport 13 and therefore a lower level of activity compared with the teen group.
Conclusion
Teens demonstrate significantly higher total scores on the ACL-RSI scale in comparison with adults. When assessing a teen athlete's psychological preparedness to RTS, target scores determined from adult data may not be appropriate. Both male and female teens show increased confidence subscale scores when compared with adults, which may inflate ACL-RSI total scores, and disguise limited emotional readiness. Clinicians should utilize ACL-RSI subscale or individual item scores to make patient-specific recommendations and provide appropriate interventions. Future work should strive to create age- and sex-specific ACL-RSI cutoff scores for successful RTS after ACLR in teen athletes.
Authors
Dylan P. Roman, DPT (Connecticut Children's, Hartford, Connecticut, USA); Sophia Ulman, PhD (Scottish Rite for Children, Dallas, Texas, USA); Lauren Butler, DPT (Florida International University and Nicklaus Children's Hospital, Miami, Florida, USA); Cody Walker, DAT, ATC, CSCS (Arkansas Children's Hospital, Little Rock, Arkansas, USA); Taylor Douthit, DPT (Children’s Health Andrews Institute, Gulf Breeze, Florida, USA); Christopher M. Kuenze, PhD, ATC (University of Virginia, Charlottesville, Virginia, USA); Victor V. Prati, DPT, Brant Sachleben, MD (Arkansas Children's Hospital, Little Rock, Arkansas, USA); Lucy Phan, MS, CSCS, Stephen LaPlante, MS, PT, ATC, Lee Pace, MD, Dhalston Cage, PT, DPT, MS, John Roaten, MD, John Abt, PhD, Dustin Loveland, MD, MBA (Children’s Health Andrews Institute, Gulf Breeze, Florida, USA); Elliot Greenberg, DPT, PhD, Meredith Link, PT, DPT, ATC, CSCS, Theodore Ganley, MD (Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA); Adam Weaver, PT, DPT, Nicholas Giampetruzzi, PT, MS, (Connecticut Children's, Hartford, Connecticut, USA); Brooke Farmer, MS, ATC, Terry L. Grindstaff, PhD, PT, ATC (Creighton University, Omaha, Nebraska, USA); Edward Chang, MD, Rachel Cherelstein, BS (Inova Health System, Falls Church, Virginia, USA); Corey D. Grozier, MS, Matthew Harkey, PhD, ATC, Arjun Parmar, BA, Jessica Tolzman, MS (Michigan State University, East Lansing, Michigan, USA); Alexa Martinez, DPT (Nicklaus Children's Hospital, Miami, Florida, USA); Jacob Landers, DPT (Scottish Rite for Children, Dallas, Texas, USA); Kylee Rucinski, PhD, MHA, Chelsea Harrison, PTA, Steven DeFroda, MD, Richard Ma, MD (University of Missouri, Columbia, Missouri, USA); Natalie Kupperman, PhD, ATC, Xavier Thompson, MS, ATC, Michelle Walaszek, PT, DPT, MS, Kevin Cross, PhD, ATC, PT (University of Virginia, Charlottesville, Virginia, USA); Elaine Reiche, ATC, CSCS, Caitlin Brinkman, MS, LAT, ATC, Tom Birchmeier, PhD, ATC, CSCS, Joseph M. Hart, PhD, ATC, Shelby Baez, PhD, ATC (University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA).
Footnotes
Final revision submitted February 21, 2024; accepted March 28, 2025.
One or more of the authors has declared the following potential conflict of interest or source of funding: E.C. is a consultant for Avanos Medical and has received research support from Arthrex. L.P. is a consultant for Arthrex and JRF Ortho and a paid speaker for Arthrex; has received research support from Arthrex; is a committee member of the American Orthopaedic Society for Sports Medicine and PRiSM; and owns stock in OutcomeMD. R.M. is a consultant for Johnson & Johnson; has received research support from Novocart, Moximed, and Cartiheal; is a committee member of the American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and American College of Sports Medicine; and serves on the Associate Editor Panel for Journal of Bone and Joint Surgery American and as a board member of the Rugby Research & Injury Prevention Group. T.G. has received research support from AlloSource and Vericel, educational support from Arthrex and Paladin Technology Solutions, and hospitality payments from Arthrex; is an associate editor of The American Journal of Sports Medicine; serves as a committee member of POSNA and PRiSM; serves as a board or committee member of IPOS and AAOS; and serves as a board member of the AAP Section on Orthopedics. S.D. has been a speaker for AO North America; is a consultant for Stryker; and has received research support from Stryker, Arthrex, OREF, and AANA. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
Ethical approval for this study was obtained the University of Virginia (HSR 230335).