Background: Anterior cruciate ligament (ACL) injury rates are affected by frequency and level of competition, sex, and sport. To date, no study has sought to quantify sport-specific yearly risk for ACL tears in the high school (HS) athlete by sex and sport played. Purpose: To establish evidence-based incidence and yearly risk of ACL tears in HS athletes by sex for sports performed at the varsity level across the majority of US high schools. Study Design: Meta-analysis. Methods: PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched to identify all articles reporting ACL tears per athletic exposure in HS athletes. ACL injury incidence rates (IRs) by sex and sport were calculated via meta-analysis. State athletic association guidelines were used to determine the number of exposures per season to calculate yearly risk of ACL tears. Results: The search recovered 3779 unique articles, of which 10 met our inclusion criteria, for a total of 700 ACL injuries in 11,239,029 exposures. The IR was 0.062 injuries per 1000 exposures (95% CI, 0.058-0.067). Although more injuries were recorded in males than females, females had a higher rate of injury per exposure (relative risk, 1.57; 95% CI, 1.35-1.82). Relative risk was highest in basketball (3.80; 95% CI, 2.53-5.85) and soccer (3.67; 95% CI, 2.61-5.27). While boys’ football had the highest number of ACL injuries at 273, girls’ soccer had the highest IR (0.148; 95% CI, 0.128-0.172). In girls, the highest injury risks per season were observed in soccer (1.11%; 95% CI, 0.96%-1.29%), basketball (0.88%; 95% CI, 0.71%-1.06%), and lacrosse (0.53%; 95% CI, 0.19%-1.15%). In comparison, the highest risks for boys were observed in football (0.80%; 95% CI, 0.71%-0.91%), lacrosse (0.44%; 95% CI, 0.18%-0.90%), and soccer (0.30%; 95% CI, 0.22%-0.41%). Conclusion: There is an approximately 1.6-fold greater rate of ACL tears per athletic exposure in HS female athletes than males. However, there is significant risk in both sexes, particularly in high-risk sports such as soccer, football, basketball, and lacrosse. Knowledge of sport-specific risk is essential for future injury reduction programs, parent-athlete decision making, and accurate physician counseling.

Background: The impact of proximal femoral and combined femoral and acetabular version on patient-reported outcomes after arthroscopic surgery for femoroacetabular impingement (FAI) remains undefined. The purpose of this study was to identify associations of proximal femoral version as well as combined version (McKibbin index) with disease-specific, validated, patient-reported outcomes following arthroscopic correction of symptomatic FAI. Methods: A prospective hip arthroscopy registry was utilized to evaluate 243 patients who underwent arthroscopic surgery to correct FAI. Femoral version and the McKibbin index were measured prospectively on preoperative computed tomography scans. Disease-specific, patient-reported outcomes included the modified Harris hip score (mHHS) and the Hip Outcome Score (HOS) ADL (Activities of Daily Living) and Sports subscales. Disease impact on quality of life was determined with use of the International Hip Outcome Tool (iHOT-33). Comparative analyses were used to evaluate the impact of femoral version on changes in patient-reported outcome scores; multiple regression was used to adjust for potential confounders. Results: The patient cohort contained 243 patients (123 female and 120 male) with a mean age of 29.2 years and a mean postoperative follow-up of twenty-one months (range, twelve to forty-two months). The cohort experienced significant improvements (p < 0.001) in all patient-reported outcome measures, with most patients improving by at least the minimal clinically important difference for all of these measures. The mean improvement was 20 points for the mHHS, 15 for the HOS ADL, 23 for the HOS Sports, and 23 for the iHOT-33. When stratified by femoral version, the postoperative improvements in patients with relative femoral retroversion (<5° anteversion) were clinically important but of significantly smaller magnitude than those in the other version groups. We did not find any associations between the McKibbin index and any patient-reported outcomes. Conclusions: Although clinically important improvements can be expected after arthroscopic FAI surgery in all femoral version groups, patients with relative femoral retroversion (<5° femoral anteversion) may experience less improvement than those with normal or increased version. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Background: Having simple and reliable validated outcome measures is vital to conducting high-quality outcomes research in the field of orthopaedic surgery. Activity level is a key prognostic variable for patients with sports injuries. There is a paucity of such activity scales for children and adolescents who are otherwise healthy and athletically active. In addition to frequency and intensity of athletic activity, level of play and coach/trainer supervision are important variables unique to children and adolescents that are not captured in available adult scoring systems. Purpose: To create and validate a concise and comprehensive activity rating scale for athletically active children and adolescents 10 to 18 years of age. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Item generation was performed with a panel of orthopaedic surgeons and adolescent athletes. Item reduction, pilot testing and scale refinement resulted in a final 8-item instrument, the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS). Existing methods were used to determine reliability and validation. The Flesch-Kincaid score was calculated at a 6.6th-grade reading level (approximately 13 years old); therefore, although all subjects provided their own answers, parents were allowed to assist children younger than 13 years with reading the questionnaire. Results: Scale reliability was excellent (test-retest reliability, intraclass correlation coefficient = 0.91; internal consistency, Cronbach alpha = .914), and there were no floor or ceiling effects. There was also robust construct validity: Convergent validity testing revealed positive correlations between the HSS Pedi-FABS and level of competition in athletic activity, number of reported hours of athletic activity per week, and existing comparable adult and pediatric scales. Discriminant validity was shown with age, body mass index, and type of sport as measured by the Daniel scale. Conclusion: The 8-item HSS Pedi-FABS can be used to reliably and accurately evaluate activity level as a prognostic variable for clinical research studies. It is a simple, reliable, and valid metric to assess activity in children and adolescents 10 to 18 years of age. This instrument will lead to better evaluation of posttreatment outcomes and patient-reported activity for child and adolescent athletes.

Increased posterior tibial slope is associated with increased risk of anterior cruciate ligament (ACL) injury in adults. A similar association has not been rigorously examined in children and adolescents. To determine whether alterations in posterior tibial slope are associated with ACL tears in pediatric and adolescent patients and to quantify changes in tibial slope by age. Case-control study; Level of evidence, 3. Magnetic resonance imaging (MRI) studies of the knee were reviewed by 3 raters blinded to each other in a 1:1 sample of cases and age- and sex-matched controls. A total of 76 skeletally immature ACL-injured knees were compared with 76 knees without ACL injury; the mean age of the study population was 14.8 ± 1.3 years. The posterior slope of the articular surface of the medial tibial plateau and lateral tibial plateau was measured by use of a method similar to that used in previous studies in adult populations. The current study technique differed in that the slope was measured on the cartilage surface, not the subchondral bone. Comparisons between knees were made with t tests, and Spearman correlation analysis was used to assess changes in tibial slope with advancing age. Increased slope of the lateral tibial plateau (LTS) was significantly increased in ACL-injured patients compared with controls (5.7° ± 2.4° vs 3.4° ± 1.7°; P < .001). There was no statistically significant difference in the slope of the medial tibial plateau (MTS) in the ACL-injured and control knees (5.4° ± 2.2° vs 5.1° ± 2.3°; P = .42). There was no difference in LTS between male and female patients (4.46° vs 4.58°; P = .75). Receiver operating characteristic (ROC) analysis of the LTS revealed that a posterior tibial slope cutoff of >4° resulted in a sensitivity of 76% and a specificity of 75% for predicting ACL tears in this cohort. Spearman correlation analysis revealed that MTS and LTS decreased, or flattened, by 0.31° (P = .028, correlation coefficient r = −0.18) and 0.37° (P = .009, correlation coefficient r = −0.21) per year, respectively, as adolescents age. The LTS was significantly associated with an increased risk of ACL injury in pediatric and adolescent patients. The MTS was not associated with risk of injury. Posterior slope was found to decrease, or flatten, with age. A cutoff of >4° for the posterior slope of the lateral compartment is 76% sensitive and 75% specific for predicting ACL injury in this cohort. The LTS did not influence the incidence of ACL injury differently between sexes.

Intrasubstance tears of the anterior cruciate ligament (ACL) were once considered a rare injury in skeletally immature athletes but are now observed with increasing frequency. Treatment strategies have evolved as recent studies have identified unique considerations specific to the skeletally immature patient. The current literature now supports the trend toward early operative treatment to restore knee stability and prevent progressive meniscal and/or articular cartilage damage, but the optimal approach to ACL reconstruction in this age group remains controversial. Despite the reported clinical success of transphyseal reconstruction, iatrogenic growth disturbance secondary to physeal damage remains a genuine concern. The reluctance to place drill-holes across open physes has led to the development of numerous “physeal-sparing” reconstruction techniques using anatomic femoral and tibial footprints that have adequately restored anteroposterior and rotational knee stability in biomechanical studies but have demonstrated mixed results in the clinical setting. The intent of this review is to (1) highlight the unique anatomic considerations pertaining to ACL reconstruction in the skeletally immature athlete, (2) discuss preoperative clinical and radiographic assessment of the pediatric patient with a suspected ACL injury, (3) review transphyseal and physeal-sparing reconstruction techniques and highlight surgical technical considerations, (4) present clinical outcomes according to patient and technique-specific factors, and (5) review age-specific injury prevention treatment strategies and a novel treatment algorithm based on skeletal maturity. ACL reconstruction in the skeletally immature athlete typically results in a successful clinical outcome, yet the optimal surgical technique is still controversial. This review will help guide the management of ACL injuries in the pediatric athlete.