Guide to Muscular Injuries and Common Ligamentous Injuries Among Soccer Players.

With over 250 million players worldwide, soccer is the most popular sport in the world. The overall number of players at professional, amateur, and recreational levels has increased along with an increase in player diversity, including age and sex. These increases in player numbers, as well as a variety of demographics, have resulted in an increase in soccer-related injuries. Injury in the professional setting can lead to time off the field and an effect on team results and earnings. Injury at the amateur and recreational levels can lead to time off work, away from other activities, and change in activities of daily living. We provide an extensive list of common injuries sustained by soccer players, their pathophysiology, diagnosis, treatment, and general guidelines on return to play.

Meniscus Injuries in Soccer.

Soccer is considered the most popular sport in the world. The game involves frequent agile maneuvers, such as rapid accelerations/decelerations and pivoting, and carries an inherent risk of high-speed collisions, which can lead to lower extremity injury. Knee and meniscus injuries can cause significant pain and disability, precluding participation in the sport. Understanding the diagnosis and management of meniscal injuries in soccer players is essential to the care of these athletes. This paper reviews meniscal anatomy, biomechanics, and mechanisms of injury; discusses the work-up, diagnosis, and management of meniscus injuries; and reports on rehabilitation, return to sport, and outcomes after meniscal injuries in soccer players.

Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Regardless of Tibial Tubercle-Trochlear Groove Distance and Patellar Height: Minimum 5-Year Outcomes.

BACKGROUND: It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction. PURPOSE: To provide midterm results for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with recurrent patellar instability were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included history of a previous surgery for patellar instability, an off-loadable (inferior/lateral) chondral defect, anterior knee pain ≥50% of their chief complaint, and a "jumping J" sign. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic characteristics. Patient-reported outcome measures (PROMs), episodes of recurrent instability, and ability to return to sport were obtained annually. Radiographic measurements of baseline radiographs and MRI were obtained at baseline. RESULTS: A total of 138 patients underwent isolated MPFL reconstruction between March 2014 and December 2019. The mean radiographic measurements were tibial tubercle-trochlear groove, 15.1 ± 4.9 mm; Caton-Deschamps index, 1.14 ± 0.16; patellar trochlear index, 46.9% ± 15.1%; trochlear depth index, 2.5 ± 1.2 mm; tibial tubercle to lateral trochlear ridge, -8.4 ± 5.7 mm; and patellar tendon to lateral trochlear ridge, 5.7 ± 6.2 mm. Trochlear dysplasia, defined as a trochlear depth index <3 mm, was present in 79/125 (63%) patients. A total of 50 patients reached ≥5 years, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients reached ≥2 years, of whom 89 (75%) completed follow-up PROMs. Six patients (5%) reported recurrent instability with a mean time of 2.97 years after surgery. All PROMs improved over time except for the Pediatric Functional Activity Brief Scale (Pedi-FABS), which had no change. At 2 years, the mean changes from baseline for Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale (QOL), Pedi-FABS, International Knee Documentation Committee (IKDC) score, KOOS Physical Function Short Form (PS), and Kujala score were 42.1, 0.6, 35.1, -23.5, and 32.3, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .999. At 5 years, the mean changes from baseline for KOOS-QOL, Pedi-FABS, IKDC, KOOS-PS, and Kujala score were 42.6, -2.8, 32.6, -21.5, and 31.6, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .453. In total, 89% of patients returned to sport with a mean of 9.1 months. CONCLUSION: Midterm outcomes for patients who underwent isolated MPFL reconstruction were favorable and were maintained at 5 years. Outcomes for the expanded cohort of patients with a minimum 2-year follow-up support previously published results.

Greater Post-Operative Nutrition Risks Identified in Pediatric and Adolescent Patients after Anterior Cruciate Ligament Reconstruction Regardless of Age and Sex.

Systematic detection of risky nutrition behaviors after sports surgery may better promote healing for return-to-sport. The purpose of this study was to assess nutritional behavior differences between patients following anterior cruciate ligament reconstruction (ACLR) and following other lower-extremity orthopedic surgeries. One pediatric sports medicine center was reviewed for a custom Sports Nutrition Assessment for Consultation, which investigates nutrition-related risk factors for youth athletes at their first post-operative visit. Patients reported "Yes" or "No" to eight questions, after which they were offered a nutrition consultation for any response indicating risk. A total of 243 post-ACLR and 242 non-ACLR patients were reviewed. The post-ACLR patients more often reported a change in appetite (p = 0.021), recent weight changes (p = 0.011), a desire to better understand nutrition (p = 0.004), and recommendations to change their body composition (p = 0.032). More post-ACLR patients were identified for a nutrition consultation (p = 0.002), though an equal percentage accepted the consultation between groups. Age and sex were not determined to be significant confounders after matched sub-analysis. The post-ACLR patients more often reported nutrition risks, specifically weight-related issues, regardless of age or sex. Sports surgeons should regularly inquire about nutrition-related concerns with patients and refer to sports dietitians for recovery nutrition support as needed, particularly after ACLR.

Sex-Specific Outcomes After Anterior Cruciate Ligament Reconstruction Using an All-Soft Tissue Quadriceps Tendon Autograft in a Young Active Population.

BACKGROUND: The ideal graft for anterior cruciate ligament (ACL) reconstruction (ACLR) in young athletes has a high return-to-sport (RTS) rate and a low reinjury rate. Quadriceps tendon autografts are being used with increasing frequency for ACLR in this population, despite a paucity of evidence to support their use. PURPOSE: To report the RTS rate, ipsilateral reinjury rate, and contralateral ACL injury rate in a young athletic population undergoing primary ACLR using an all-soft tissue quadriceps tendon (ASTQT) autograft. STUDY DESIGN: Cases series; Level of evidence, 4. METHODS: Patients aged 14 to 22 years who underwent primary ACLR using an ASTQT autograft by a single surgeon between January 1, 2005, and April 30, 2020, were identified via electronic medical records and contacted ≥24 months after ACLR to complete a survey regarding subsequent ipsilateral or contralateral ACL injuries and RTS. Patients who had undergone previous ACLR (ipsilateral or contralateral) were excluded. RESULTS: A total of 656 patients (330 male, 326 female; mean age, 17.9 years) were identified, and 395 patients completed the survey (60.2%; 174 male, 221 female; mean age, 17.8 years) with a mean follow-up of 73 ± 29 months (range, 24-139 months). The RTS rate was high (male: 87.7%; female: 82.8%; P = .19). Male and female patients had similar rates of revision ACLR (male: 12.6%; female: 10.0%; P = .40) and contralateral ACL injuries (male: 13.8%; female: 11.3%; P = .46). CONCLUSION: A high RTS rate and similar rates of ipsilateral and contralateral ACL injuries were found for male and female patients in a young athletic population undergoing primary ACLR using an ASTQT autograft. These results help one to better understand the utility of ASTQT grafts to support successful ACLR in young athletic populations, for which ASTQT grafts appear to yield favorable outcomes.

Career Length After Surgically Treated ACL Plus Collateral Ligament Injury in Elite Athletes.

BACKGROUND: Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes. PURPOSE: To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level. RESULTS: A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups. CONCLUSION: Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Sport-specific Differences in Cartilage Treatment.

Articular cartilage defects in the knee are common in athletes who have a variety of loading demands across the knee. Athletes of different sports may have different baseline risk of injury. The most studied sports in terms of prevalence and treatment of cartilage injuries include soccer (football), American football, and basketball. At this time, the authors do not specifically treat patients by their sport; however, return to sports timing may be earlier in sports with fewer demands on the knee based on the rehabilitation protocol. If conservative management is unsuccessful, the authors typically perform a staging arthroscopy with chondroplasty, followed by osteochondral allograft transplantation with possible additional concomitant procedures, such as osteotomies or meniscal transplants. Athletes in a variety of sports and at high levels of competition can successfully return to sports with the appropriate considerations and treatment.

Treatment of Hip Cartilage Defects in Athletes.

Chondral defects in the athlete's hip are a relatively common occurrence, often presenting with debilitating pain and activity limitation. Preoperative identification of cartilage defects is challenging and there are many different modalities for treatment. Nonsurgical interventions, including activity modification, physical therapy, and injections, play a vital role, especially in less severe cases and as adjuncts to surgical intervention. Treating surgeons must be familiar with the cartilage restoration procedures available, including debridement, microfracture, and various implantation and transplantation options. Safe and effective management of cartilage defects is imperative to an athlete's return to sport. It is also imperative that surgeons are aware of all these various treatment options to determine what modality is best for their patients. This review serves to outline these options, cover the published literature, and provide general guidelines for surgeons when they encounter chondral defects in the office and the operating room.

Treatment of Hand and Wrist Cartilage Defects in Athletes.

Cartilage injuries of the hand and wrist can be debilitating in the athlete. Diagnosis is difficult given the broad spectrum of presenting symptomatology. History and physical examination is crucial to achieve the correct diagnosis, and advanced imaging can offer helpful assistance to the clinician as well. TFCC injuries and ulnar impaction syndrome are among the most common conditions in athletes with hand and wrist pain. Treatment of these injuries is initially nonoperative, but elite athletes may elect to bypass nonoperative treatment in favor of earlier return to sport. Surgical treatment varies but can include open and arthroscopic methods. The clinician should tailor treatment plans to each athlete based on level of competition, type of sport, and individual preferences and goals.

Test-Retest Reliability and Visual Perturbation Performance Costs During 2 Reactive Agility Tasks.

CONTEXT: High secondary injury rates after orthopedic surgeries have motivated concern toward the construct validity of return-to-sport test batteries, as it is evident that common strength and functional assessments fail to elicit pertinent behaviors like visual search and reactive decision making. This study aimed to establish the test-retest reliability of 2 reactive agility tasks and evaluate the impact of visual perturbation on physical performance. METHODS: Fourteen physically active individuals completed 2 agility tasks with reaction time (ie, 4 corner agility), working memory, and pathfinding (ie, color recall) components. Participants completed both tasks 4 times in 2 sessions scheduled 7 days apart. Outcomes included performance metrics of reaction time, time to target, number of targets, and total time assessed with reactive training timing gates. To assess test-retest reliability, we used intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC). Stroboscopic goggles induced visual perturbation during the fourth trial of each task. To assess the effect of visual perturbation, we used paired t tests and calculated performance costs. RESULTS: The 4-corner agility task demonstrated excellent reliability with respect to reaction time (ICC3,1 = .907, SEM = 0.13, MDC = 0.35 s); time to light (ICC3,1 = .935, SEM = 0.07, MDC = 0.18 s); and number of lights (ICC3,1 = .800, SEM = 0.24, MDC = 0.66 lights). The color recall task demonstrated good-to-excellent test-retest reliability for time to lights (ICC3,1 = .818-.953, SEM = 0.07-0.27, MDC = 0.19-0.74 s); test time (ICC3,1 = .969, SEM = 5.43, MDC = 15.04 s); and errors (ICC3,1 = .882, SEM = 0.19, MDC = 0.53 errors). Visual perturbation resulted in increased time to target (P = .022-.011), number of targets (P = .039), and total test time (P = .013) representing moderate magnitude degradation of performance (d = 0.55-0.87, performance costs = 5%-12%). CONCLUSIONS: Both tasks demonstrated acceptable test-retest reliability. Performance degraded on both tasks with the presence of visual perturbation. These results suggest standardized reactive agility tasks are reliable and could be developed as components of dynamic RTS testing.

Similar outcomes in collision athletes with subcritical glenoid bone loss and on-Track Hill Sachs lesion versus off-track Hill Sachs lesion managed with open Bankart repair plus inferior capsular shift.

INTRODUCTION: Open Bankart repair plus inferior capsular shift has not yet been tested under the concept of glenoid track as a predictor of failure. The aim of this study was to compare the subjective and objective outcomes in collision athletes with subcritical glenoid bone loss and on-track Hill Sachs lesions versus those with off-track Hill Sachs lesions, all treated with open Bankart repair. METHODS: Two study groups were created: 50 patients had on-track Hill Sachs lesions, while 38 had off-track lesions. The subcritical glenoid bone loss was ≤ 10%. A minimum follow-up period of 3 years was established. Preoperative and postoperative evaluation of each group and between them was performed. The Western Ontario Shoulder Instability Index score and the American Shoulder and Elbow Surgeons scale were used to assess subjective outcomes. Recurrence rate, range of motion and return to sport were evaluated as objective outcomes. RESULTS: Significant differences were reported in the WOSI and ASES scores between preoperative and postoperative values in each group. There were no significant differences between the two groups (p-value = 0.36 and 0.71). Three dislocations (6%) in the on-track group and 3 (7.8%) in the off-track group were recorded, showing no differences between the two groups (p-value = 0.83). There were no differences in ROM between pre- and post-operatively in each group or when comparing the two groups. CONCLUSIONS: We found no differences between the outcomes of the two groups. According to the surgeon's preference, we recommend performing open Bankart repair plus inferior capsular shift as a treatment alternative in collision athletes with SGBL ≤ 10% independently of the type of Hill Sachs lesion.

Assessing readability of online patient educational material on concussion and return to play.

OBJECTIVE: Concussions are self-limited forms of mild traumatic brain injury (TBI). Gradual return to play (RTP) is crucial to minimizing the risk of second impact syndrome. Online patient educational materials (OPEM) are often used to guide decision-making. Previous literature has reported that grade-level readability of OPEM is higher than recommended by the American Medical Association and the National Institutes of Health. The authors evaluated the readability of OPEM on concussion and RTP. METHODS: An online search engine was used to identify websites providing OPEM on concussion and RTP. Text specific to concussion and RTP was extracted from each website and readability was assessed using the following six standardized indices: Flesch Reading Ease (FRE), Flesch-Kincaid Grade Level, Gunning Fog Index, Coleman-Liau Index, Simple Measure of Gobbledygook Index, and Automated Readability Index. One-way ANOVA and Tukey's post hoc test were used to compare readability across sources of information. RESULTS: There were 59 concussion and RTP articles, and readability levels exceeded the recommended 6th grade level, irrespective of the source of information. Academic institutions published OPEM at simpler readability levels (higher FRE scores). Private organizations published OPEM at more complex (higher) grade-level readability levels in comparison with academic and nonprofit institutions (p < 0.05). CONCLUSIONS: The readability of OPEM on RTP after concussions exceeds the literacy of the average American. There is a critical need to modify the concussion and RTP OPEM to improve comprehension by a broad audience.

Sport-related concussions in baseball and softball: do mechanisms of injury affect recovery?

OBJECTIVE: Baseball and softball pose unique risks for sport-related concussion (SRC). Although these are not collision sports, concussions in baseball and softball can nonetheless involve high-speed impacts. In a regional, single-institution cohort of baseball and softball athletes who sustained an SRC, the current study sought to 1) describe the mechanisms of injury that led to SRC, and 2) compare initial symptom burden and recovery metrics across mechanisms, including time to return to learn (RTL), time to symptom resolution, and time to return to play (RTP) by mechanism of injury. METHODS: A retrospective cohort study was performed of baseball and softball athletes 12 to 23 years old who sustained an SRC between November 2017 and April 2022. Mechanisms of injury were divided into two categories: 1) contact mechanism (i.e., what initiated contact with the injured player, such as head-to-ball), and 2) player mechanism (i.e., the action the injured player was performing at the time of injury, such as fielding). The recovery outcomes of time to RTL, symptom resolution, and RTP were compared between mechanisms using bivariate analysis and multivariable regression analysis, controlling for sex, age, time to present to concussion clinic, and initial total symptom score. RESULTS: The sample included 58 baseball and softball players (60.3% female, mean age 16.0 ± 1.9 years). Most SRCs (62.1%) occurred during competition. Head-to-ball (50.0%) was the most common contact mechanism, followed by head-to-head/body (31.0%) and head-to-wall/ground/equipment (17.2%). Fielding (63.8%) was the most common player mechanism, followed by drills (20.7%) and running (13.8%). SRCs sustained in practice had significantly longer RTL (median 10.0 [interquartile range (IQR) 3.3-16.3] vs 4.0 [IQR 2.0-8.0] days; U = 421.5, p = 0.031) and symptom resolution (37.0 [IQR 18.0-90.0] vs 14.0 [IQR 7.0-41.0] days; U = 406.5, p = 0.025) compared with SRCs sustained in competition. Multivariable regression analysis revealed that head-to-wall/ground/equipment contact mechanism was associated with longer RTL (ß = 0.30, 95% CI 0.07-0.54, p = 0.013). CONCLUSIONS: The current study found that SRCs in baseball and softball occurred more often in competition than in practice. Head-to-ball and fielding were the most common contact and player mechanisms, respectively. SRCs sustained in practice were associated with longer time to RTL and symptom resolution, and head-to-wall/ground/equipment was associated with longer RTL in multivariable regression analysis. These results provide empirical data to improve concussion safety in baseball/softball.

The association between continuing to play, clinical domains, and recovery outcomes in collegiate athletes following concussion.

OBJECTIVE: Continued play following concussion can lead to worse outcomes and longer recoveries compared with athletes who immediately report. This has been well documented in youth athletes, while less attention has been paid to collegiate athletes despite differences in healthcare access, recovery trajectories, and additional pressures to play. Therefore, the purpose of this study was to determine if continuing to play immediately following a concussion influenced clinical outcomes and recovery time in collegiate athletes. METHODS: A prospective, repeated-measures design was used to compare clinical outcomes and recovery time between collegiate athletes who continued playing (n = 37) and those immediately removed (n = 56) after a concussion. Assessments were conducted within 5 days of the concussion and at full medical clearance (FMC; ± 3 days) using the Sport Concussion Assessment Tool-5th edition (SCAT5), Vestibular/Ocular Motor Screening assessment, and High-Level Mobility Assessment Tool. Mann-Whitney U-tests determined differences in clinical outcomes between groups. Cox proportional hazards regression models examined the relationship between factors associated with days to symptom resolution and days to FMC, and covariates were selected a priori based on previous literature. Hazard ratios with 95% CIs were reported for each predictor variable. RESULTS: Significant differences were found in SCAT5 concentration composite scores (p = 0.010) and SCAT5 delayed recall composite scores (p = 0.045) at the acute visit and near point of convergence average distance (cm; p = 0.005) at the FMC visit between the group who continued to play and those who were immediately removed. There were no differences between groups in days to symptom resolution (10 vs 7 days, p = 0.05) and days to clearance (13 vs 11.50 days, p = 0.13). The association between groups and days to symptom resolution (χ2[4] = 5.052, p = 0.282), and days to clearance (χ2[4] = 3.624, p = 0.459) were not significant when adjusting for covariates. CONCLUSIONS: Collegiate athletes who continued to play following concussion did not exhibit worse clinical outcomes or recovery times compared with athletes who were immediately removed. While the lack of differences found in this study could be supported by prior literature, including improved education, awareness, reporting attitudes, and concussion management at the collegiate level in recent years, the authors believe discrepancies are more likely due to study-specific differences (e.g., sample size, care setting, and timing). Therefore, these findings should not diminish the dangers of continued play and the importance of timely removal after concussion.

Concussions in ice hockey: mixed methods study including assessment of concussions on games missed and cap hit among National Hockey League players, systematic review, and concussion protocol analysis.

OBJECTIVE: Concussions can occur at any level of ice hockey. Incidence estimates of concussions in ice hockey vary, and optimal prevention strategies and return-to-play (RTP) considerations have remained in evolution. The authors performed a mixed-methods study with the aim of elucidating the landscape of concussion in ice hockey and catalyzing initiatives to standardize preventative mechanisms and RTP considerations. METHODS: The authors performed a five-part mixed-methods study that includes: 1) an analysis of the impact of concussions on games missed and income for National Hockey League (NHL) players using a publicly available database, 2) a systematic review of the incidence of concussion in ice hockey, 3) a systematic review of preventative strategies, 4) a systematic review of RTP, and 5) a policy review of documents from major governing bodies related to concussions in sports with a focus on ice hockey. The PubMed, Embase, and Scopus databases were used for the systematic reviews and focused on any level of hockey. RESULTS: In the NHL, 689 players had 1054 concussions from the 2000-2001 to 2022-2023 seasons. A concussion led to a mean of 13.77 ± 19.23 (range 1-82) games missed during the same season. After cap hit per game data became available in 2008-2009, players missed 10,024 games due to 668 concussions (mean 15.13 ± 3.81 per concussion, range 8.81-22.60 per concussion), with a cap hit per game missed of $35,880.85 ± $25,010.48 (range $5792.68-$134,146.30). The total cap hit of all missed games was $385,960,790.00, equating to $577,635.91 per concussion and $25,724,052.70 per NHL season. On systematic review, the incidence of concussions was 0.54-1.18 per 1000 athlete-exposures. Prevention mechanisms involved education, behavioral and cognitive interventions, protective equipment, biomechanical studies, and policy/rule changes. Rules prohibiting body checking in youth players were most effective. Determination of RTP was variable. Concussion protocols from both North American governing bodies and two leagues mandated that a player suspected of having a concussion be removed from play and undergo a six-step RTP strategy. The 6th International Conference on Concussion in Sport recommended the use of mouthguards for children and adolescents and disallowing body checking for all children and most levels of adolescents. CONCLUSIONS: Concussions in ice hockey lead to substantial missed time from play. The authors strongly encourage all hockey leagues to adopt and adhere to age-appropriate rules to limit hits to the head, increase compliance in wearing protective equipment, and utilize high-quality concussion protocols.

Examining for gender differences in return to learn following sport-related concussion in high school student athletes.

OBJECTIVE: Prior studies have investigated associations between gender, symptom resolution, and time to return to play following sport-related concussion (SRC). However, there is a notable gap in research regarding the association between gender and return to learn (RTL) in adolescents. Therefore, this study 1) compared the patterns of RTL between boys and girls who are high school student athletes, and 2) evaluated the possible association between gender and time to RTL after adjusting for covariates. METHODS: A retrospective cohort study of a prospective surveillance program that monitored concussion recovery of athletes in high schools throughout the state of Maine between February 2015 and January 2023 was performed. The primary independent variable was gender, dichotomized as boys and girls. The primary outcome was time to RTL, defined by the number of days for an athlete to return to school without accommodations. Mann-Whitney U-tests were used to compare RTL between the boys and girls. Each athlete's RTL status was dichotomized (i.e., returned vs had not returned) at several time points following injury (i.e., 1, 2, 3, and 4 weeks), and chi-square tests were performed to compare the proportions who achieved RTL between groups. Multivariable linear regression analyses were performed to evaluate the predictive value of gender on RTL. Covariates included age, number of previous concussions, history of learning disability or attention-deficit disorder or attention-deficit/hyperactivity disorder, history of a psychological condition, history of headaches or migraines, initial Sport Concussion Assessment Tool (SCAT3/SCAT5) score, and days to evaluation. RESULTS: Of 895 high school athletes, 488 (54.5%) were boys and 407 (45.5%) were girls. There was no statistically significant difference in median [IQR] days to RTL between genders (6.0 [3.0-11.0] vs 6.0 [3.0-12.0] days; U = 84,365.00, p < 0.375). A greater proportion of boys successfully returned to learn without accommodations by 3 weeks following concussion (93.5% vs 89.4%; χ2 = 4.68, p = 0.030), but no differences were found at 1, 2, or 4 weeks. A multivariable model predicting days to RTL showed that gender was not a significant predictor of RTL (p > 0.05). Longer days to evaluation (ß = 0.10, p = 0.021) and higher initial SCAT3/SCAT5 scores (ß = 0.15, p < 0.001) predicted longer RTL. CONCLUSIONS: In a cohort of high school athletes, RTL did not differ between boys and girls following SRC. Gender was not a significant predictor of RTL. Longer days to evaluation and higher initial symptom scores were associated with longer RTL.

A Change-Point Method to Detect Meaningful Change in Return-to-Sport Progression in Athletes.

PURPOSE: To explore how the change-point method can be used to analyze complex longitudinal data and detect when meaningful changes (change points) have occurred during rehabilitation. METHOD: This design is a prospective single-case observational study of a football player in a professional club who sustained an acute lower-limb muscle injury during high-speed running in training. The rehabilitation program was entirely completed in the football club under the supervision of the club's medical team. Four wellness metrics and 5 running-performance metrics were collected before the injury and until the player returned to play. RESULTS: Data were collected over 130 days. In the univariate analysis, the change points for stress, sleep, mood, and soreness were located on days 30, 47, 50, and 50, respectively. The change points for total distance, acceleration, maximum speed, deceleration, and high-speed running were located on days 32, 34, 37, 41, and 41, respectively. The multivariate analysis resulted in a single change point for the wellness metrics and running-performance metrics, on days 50 and 67, respectively. CONCLUSIONS: The univariate approach provided information regarding the sequence and time point of the change points. The multivariate approach provided a common change point for multiple metrics, information that would benefit clinicians to have a broad overview of the changes in the rehabilitation process. Clinicians may consider the change-point method to integrate and visualize data from multiple sources to evaluate athletes' progression along the return-to-sport continuum.

Relationships between quantitative magnetic resonance imaging measures at the time of return to sport and clinical outcomes following acute hamstring strain injury.

Hamstring strain injuries (HSI) are a common occurrence in athletics and complicated by high rates of reinjury. Evidence of remaining injury observed on magnetic resonance imaging (MRI) at the time of return to sport (RTS) may be associated with strength deficits and prognostic for reinjury, however, conventional imaging has failed to establish a relationship. Quantitative measure of muscle microstructure using diffusion tensor imaging (DTI) may hold potential for assessing a possible association between injury-related structural changes and clinical outcomes. The purpose of this study was to determine the association of RTS MRI-based quantitative measures, such as edema volume, muscle volume, and DTI metrics, with clinical outcomes (i.e., strength and reinjury) following HSI. Spearman's correlations and Firth logistic regressions were used to determine relationships in between-limb imaging measures and between-limb eccentric strength and reinjury status, respectively. Twenty injuries were observed, with four reinjuries. At the time of RTS, between-limb differences in eccentric hamstring strength were significantly associated with principal effective diffusivity eigenvalue λ1 (r = -0.64, p = 0.003) and marginally associated with mean diffusivity (r = -0.46, p = 0.056). Significant relationships between other MRI-based measures of morphology and eccentric strength were not detected, as well as between any MRI-based measure and reinjury status. In conclusion, this preliminary evidence indicates DTI may track differences in hamstring muscle microstructure, not captured by conventional imaging at the whole muscle level, that relate to eccentric strength.