Physeal fusion status and lesion size are more important than patient age for healing of juvenile osteochodritis dessicans lesions of the distal femur.

PURPOSE: The purpose of the study was to evaluate the effect of skeletal age and lesion size, location, and grade on the success of nonoperative treatment for juvenile osteochondritis dissecans (OCD). It is hypothesized that skeletal maturity, including a combination of maturation phenotypes, correlates with nonoperative lesion healing. METHODS: The clinical and radiographic data on 52 patients aged 7-20 years treated for OCD of the distal femur between 2010 and 2019 were retrospectively reviewed. Knee radiographs were assessed for number of lesions present and lesion location, size, and stage. Assessments of skeletal maturation were performed on all antero-posterior knee radiographs using the Roche, Wainer, and Thissen (RWT) method. Patients were categorized as healed if they demonstrated no pain on clinical examination. The relationship between skeletal maturity and nonoperative lesion healing was determined using Spearman rank correlations on available variables. RESULTS: Neither chronological nor skeletal age was associated with surgical status (Rho = 0.03, n.s., and Rho = 0.13, n.s., respectively) or the healing status of nonoperatively treated OCD lesions (Rho = 0.44, n.s., and Rho = 0.03, n.s., respectively). Epiphyseal fusion status of the distal femoral physis was moderately correlated with nonoperative healing, but was not statistically significant (lateral femoral physis: Rho = 0.43, p = 0.05; medial femoral physis: Rho = 0.43, n.s.). Lesion length correlated with surgical status (Rho = - 0.38, p = 0.009). CONCLUSION: The extent of fusion of the distal femoral physis (multi-stage grading) may be more strongly correlated with nonoperative healing than other markers of skeletal maturity or chronological age. Clinicians can use this as an additional radiographic sign when considering nonoperative treatment for juvenile OCD lesions in the distal femur. OCD lesion length and physeal fusion status appear to be more important for healing than patient age.

Occult Amyloid Deposition in Older Patients Presenting With Bilateral Carpal Tunnel Syndrome or Multiple Trigger Digits.

PURPOSE: The diagnosis of amyloidosis is important for early intervention, disease monitoring, and prevention of complications and progression. Carpal tunnel syndrome (CTS) and trigger digit (TD) are two common conditions associated with early disease. The purpose of this study was to define disease prevalence among patients with bilateral CTS and multiple TDs and assess for an increased rate of diagnosis in the presence of both. METHODS: Men older than 50 years and women older than 60 years of age diagnosed with bilateral CTS, multiple TDs, or a combination of the 2 were prospectively enrolled in our study. Tenosynovial biopsy samples taken at the time of surgery were tested for the presence of amyloid using Congo red staining. Demographic and medical covariates were also collected and analyzed for differences between amyloid-positive and -negative patients. RESULTS: Fifty-six patients were enrolled in the study, and nine patients tested positive for amyloid deposition. The demographics and medical comorbidities were similar between amyloid-positive and -negative patients. Thirty patients with bilateral CTS were enrolled, and four tested positive for amyloid. For patients with multiple TDs, a total of 17 patients were enrolled, and 4 tested positive for amyloid. Among patients with multiple TDs, only men tested positive for amyloid and were, on average, younger than those who tested negative (61 and 73 years, respectively). Patients presenting with a combination of CTS and TD did not exhibit increased amyloid discovery. CONCLUSIONS: Hand surgeons should consider tenosynovial biopsy in men older than 50 years and women older than 60 years presenting with either bilateral CTS or multiple TDs. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Relationship Between 2-Dimensional Frontal Plane Measures and the Knee Abduction Angle During the Drop Vertical Jump.

Context: Knee abduction angle (KAA), as measured by 3-dimensional marker-based motion capture systems during jump-landing tasks, has been correlated with an elevated risk of anterior cruciate ligament injury in females. Due to the high cost and inefficiency of KAA measurement with marker-based motion capture, surrogate 2-dimensional frontal plane measures have gained attention for injury risk screening. The knee-to-ankle separation ratio (KASR) and medial knee position (MKP) have been suggested as potential frontal plane surrogate measures to the KAA, but investigations into their relationship to the KAA during a bilateral drop vertical jump task are limited. Objective: To investigate the relationship between KASR and MKP to the KAA during initial contact of the bilateral drop vertical jump. Design: Descriptive. Setting: Biomechanics laboratory. Participants: A total of 18 healthy female participants (mean age: 24.1 [3.88] y, mass: 65.18 [10.34] kg, and height: 1.63 [0.06] m). Intervention: Participants completed 5 successful drop vertical jump trials measured by a Vicon marker-based motion capture system and 2 AMTI force plates. Main Outcome Measure: For each jump, KAA of the tibia relative to the femur was measured at initial contact along with the KASR and MKP calculated from planar joint center data. The coefficient of determination (r2) was used to examine the relationship between the KASR and MKP to KAA. Results: A strong linear relationship was observed between MKP and KAA (r2 = .71), as well as between KASR and KAA (r2 = .72). Conclusions: Two-dimensional frontal plane measures show strong relationships to the KAA during the bilateral drop vertical jump.

Epidemiology of 3825 injuries sustained in six seasons of National Collegiate Athletic Association men's and women's soccer (2009/2010-2014/2015).

AIM: To describe the epidemiology of National Collegiate Athletic Association (NCAA) men's and women's soccer injuries during the 2009/2010-2014/2015 academic years. METHODS: This descriptive epidemiology study used NCAA Injury Surveillance Program (NCAA-ISP) data during the 2009/2010-2014/2015 academic years, from 44 men's and 64 women's soccer programmes (104 and 167 team seasons of data, respectively). Non-time-loss injuries were defined as resulting in <24 h lost from sport. Injury counts, percentages and rates were calculated. Injury rate ratios (RRs) and injury proportion ratios (IPRs) with 95% CIs compared rates and distributions by sex. RESULTS: There were 1554 men's soccer and 2271 women's soccer injuries with injury rates of 8.07/1000 athlete exposures (AE) and 8.44/1000AE, respectively. Injury rates for men and women did not differ in competitions (17.53 vs 17.04/1000AE; RR=1.03; 95% CI 0.94 to 1.13) or practices (5.47 vs 5.69/1000AE; RR=0.96; 95% CI 0.88 to 1.05). In total, 47.2% (n=733) of men's soccer injuries and 47.5% (n=1079) of women's were non-time loss. Most injuries occurred to the lower extremity and were diagnosed as sprains. Women had higher concussion rates (0.59 vs 0.34/1000AE; RR=1.76; 95% CI 1.32 to 2.35) than men. CONCLUSIONS: Non-time-loss injuries accounted for nearly half of the injuries in men's and women's soccer. Sex differences were found in competition injuries, specifically for concussion. Further study into the incidence, treatment and outcome of non-time-loss injuries may identify a more accurate burden of these injuries.

Rate of skin and nerve complications as a result of cutaneous traction with modern foam boots.

INTRODUCTION: Cutaneous traction is used to temporize lower extremity fractures and relies on friction between the skin and surrounding material to apply a longitudinal force. This circumferential compressive force can lead to pressure sores, skin sloughing, or compressive neuropathies. These complications have been reported in up to 11% of patients when the cutaneous traction relies on adhesive tapes, plaster, and rubber bandages being in immediate contact with the skin. The rates of these complications are not well documented when using modern foam boots. METHODS: A retrospective chart review was performed on all orthopedic trauma patients who suffered pelvic or lower extremity injuries between March 1st, 2020 and April 30th, 2021 at a single Level-1 trauma center. We included all patients with femoral fractures, axially unstable pelvic ring and/or acetabular fractures, and unstable hip dislocations temporized with the use of cutaneous traction. All patients had intact skin and lower extremity nerve function prior to application. RESULTS: There were 138 patients identified with 141 lower extremities. The average patient age was 50.7 (6-100) years. Mean traction weight of 9.8 (5-20) pounds. Average traction duration was 20.9 (2.3-243.5) hours. At the time of traction removal, there was 1 (0.7%) new skin wound and 0 nerve palsies. The new skin wound was a stage one heel pressure sore and did not require further treatment. CONCLUSION: Cutaneous traction with a modern foam boot was found to have a skin complication rate of 0.7% and a nerve palsy complication rate of 0% for an overall complication rate of 0.7%, which has not been previously established and is lower than historically reported complication rates of 11% when utilizing adhesive and plaster directly on skin. Foam boot Cutaneous traction may be considered a safe option for traction placement.

Medial Patellofemoral Ligament Reconstruction in Obese Patients Results in Low Complication Rates and Improved Subjective Outcomes.

Purpose: To compare outcomes, activity scores, and complication rates of obese and non-obese patients undergoing medial patellofemoral ligament (MPFL) reconstruction. Methods: A retrospective review identified patients undergoing MPFL reconstruction for recurrent patellofemoral instability. Patients were included if they had undergone MPFL reconstruction and had follow-up for a minimum of 6 months. Patients were excluded if they underwent surgery less than 6 months earlier, had no outcome data recorded, or underwent concomitant bony procedures. Patients were divided into 2 groups based on body mass index (BMI): BMI of 30 or greater and BMI less than 30. Presurgical and postsurgical patient-reported outcomes including Knee Injury and Osteoarthritis Outcome Score (KOOS) domains and the Tegner score were collected. Complications requiring reoperation were recorded. P < .05 was defined as a statistically significant difference. Results: A total of 55 patients (57 knees) were included. There were 26 knees with a BMI of 30 or greater and 31 knees with a BMI less than 30. There were no differences in patient demographic characteristics between the 2 groups. Preoperatively, no significant differences were found in KOOS subscores or Tegner scores (P = .21) between groups. At minimum 6-month follow-up (range, 6.1-70.5 months), patients with a BMI of 30 or greater showed statistically significant improvements in the KOOS Pain, Activities of Daily Living, Symptoms, and Sport/Recreation subscores. Patients with a BMI less than 30 showed a statistically significant improvement in the KOOS Quality of Life subscore. The group with a BMI of 30 or greater had significantly lower KOOS Quality of Life (33.34 ± 19.10 vs 54.47 ± 28.00, P = .03) and Tegner (2.56 ± 1.59 vs 4.78 ± 2.68, P = .05) scores. Complication rates were low, with 2 knees (7.69%) requiring reoperation in the cohort with a BMI of 30 or greater and 4 knees (12.90%) requiring reoperation in the cohort with a BMI less than 30, including 1 reoperation for recurrent patellofemoral instability (P = .68). Conclusions: In this study, MPFL reconstruction in obese patients was safe and effective, with low complication rates and improvements in most patient-reported outcomes. Compared with patients with a BMI less than 30, obese patients had lower quality-of-life and activity scores at final follow-up. Level of Evidence: Level III, retrospective cohort study.

Tarsal Navicular Bone Stress Injuries: A Multicenter Case Series Investigating Clinical Presentation, Diagnostic Approach, Treatment, and Return to Sport in Adolescent Athletes.

BACKGROUND: Tarsal navicular bone stress injuries (BSIs) are considered "high risk" because of prolonged healing times and higher rates of nonunion in adult populations but, to our knowledge, have not been comprehensively examined in adolescent athletes. PURPOSE: To describe the characteristics of tarsal navicular BSIs in adolescents. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective analysis of patients aged 10 to 19 years with a radiographically diagnosed tarsal navicular BSI was performed at 8 academic centers over a 9-year study period. Age, sex, body mass index (BMI), primary sport, physical examination findings, imaging, treatment, surgical technique, return-to-sport time, and complications were analyzed. RESULTS: Among 110 patients (mean age, 14.7 ± 2.7 years; 65% female), common primary sports were cross-country/track and field (29/92 [32%]) and gymnastics/dance (25/92 [27%]). Grade 4 BSIs were identified in 44% (48/110) of patients, with fracture lines present on radiography or magnetic resonance imaging. Nonoperative treatment (mean age, 14.4 ± 2.6 years), consisting of protected weightbearing and either a protective boot (69/88 [78%]) or a cast (19/88 [22%]), was trialed in all patients and was successful in 94 patients (85%). Operative treatment (mean age, 17.1 ± 1.4 years) was ultimately pursued for 16 patients (15%). Patients who required surgery had a higher BMI and a higher percentage of fracture lines present on imaging (nonoperative: 36/94 [38%]; operative: 14/16 [88%]). The median time to return to weightbearing, running, and full sport was significantly longer in duration for the operative group than the nonoperative group (P <.05). Complications associated with surgery included 1 case each of delayed union, nonunion, and painful implants, the latter of which required secondary surgery. CONCLUSION: Adolescent tarsal navicular BSIs were identified most commonly in female patients in leanness sports. Adolescents who required surgery were more likely to be older, have higher BMIs, and have grade 4 BSIs, and they returned to sport within a median of 5 months after single- or double-screw fixation with a low risk of postoperative complications. A better understanding of the presenting signs and symptoms and appropriate diagnostic imaging of navicular BSIs may lead to an earlier diagnosis and improved outcomes.

Effects of Injury Pattern and Treatment on Case Length and Disposition for Hand Injuries Treated Under a Workers' Compensation Claim.

BACKGROUND: In treating occupational hand injuries under workers' compensation, the 2 most important goals are to maximize patient function, ideally to preinjury levels, and permit a timely return to work (RTW). The purpose of this study was to determine factors affecting total case length, that is, the total time from injury until primary closure of a patient's claim, and disposition among patients with hand injuries treated under workers' compensation. METHODS: All cases treated under workers' compensation by a single fellowship-trained hand surgeon within a single year were retrospectively reviewed. A case is defined as the entire management and treatment of a single patient related to a single occupational injury incident. Independent variables included age, sex, body mass index, comorbidity, occupation, injury pattern, and treatment modality. Dependent variables included treatment duration from injury to case closure and final case disposition (RTW, functional capacity evaluation [FCE], or loss to follow-up [LTFU]). Comparison between groups was accomplished with analysis of variance. Multivariate linear and logistic regression analysis was performed to predict case length and disposition. RESULTS: In all, 447 cases involving a workers' compensation claim were reviewed. Among these, 75 (16.8%) were LTFU, 24 (5.4%) required an FCE, and 346 (77.4%) an RTW. The RTW cases averaged 138.5 days, whereas those requiring FCE averaged 331.5 days. Compared with average case length, crush injuries (76.8 days. P < .001) and fractures (111.8 days, P = .0224) had significantly shorter time to closure. In a multivariate linear model, cases of soft tissue and nerve injury were associated with longer case lengths, remaining open for an additional 56.8 and 347.1 days, respectively (P < .001). Each treatment modality studied, therapy, injections, and surgery, was associated with an increase in case length. CONCLUSIONS: Cases requiring FCE were open significantly longer than those resulting in RTW. In addition, injury pattern and treatment modality were associated with significant variations in total case length. These results imply that a specific subset of patients, namely those with soft tissue and nerve injuries, may experience delayed resolution among patients treated under a workers' compensation claim.

Decreased Upward Vertical Movement for Fastballs After Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers.

Purpose: To analyze the velocity and movement of the 4-seam fastball, curve, and slider thrown before and after ulnar collateral ligament reconstruction (UCLR) in Major League Baseball pitchers using PITCHf/x data. Methods: Velocity and movement data of the 4-seam fastball, curve, and slider were collected for 3 time frames (12-24 months before the date of UCLR as an uninjured baseline, 12-24 months after the date of UCLR, and 24-36 months after the date of UCLR). Pitchers were separated into 3 age groups (<26, 26 to 31, and >31 years). A paired t-test for means was used to assess mean differences between 2 time periods and a generalized linear model, with time-dependent covariance structure and age group as a covariate, was used to determine differences across time. All analyses were performed using SAS, version 9.4. Results: Vertical movement of the 4-seam fastball decreased in the 24 to 36 months' postoperative time frame, compared with 12 to 24 months' preoperatively (9.46 to 9.14 inches, P = .032). Movement decreases in the 4-seam fastball were not age-related. Velocity did not significantly change for any pitch and movement did not change for the slider or curve pitches. Conclusions: Following UCLR, Major League Baseball pitchers experienced no changes in horizontal or vertical movement or velocity of the curve or slider in either time frame. Decreased upward vertical movement of the fastball occurred after UCLR at final follow-up, but no change was observed in velocity. Similar trends in pitch movement and velocity effects were observed regardless of age. Level of Evidence: IV, case series.

No Difference in Complication Rates or Patient-Reported Outcomes Between Bone-Patella Tendon-Bone and Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction.

Purpose: To compare subjective outcomes and complications of anterior cruciate ligament reconstruction (ACLR) using either bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft. Methods: A retrospective analysis of prospectively collected data identified consecutive cohorts of patients undergoing ACLR with either BPTB or QT autograft. Patients with less than 12-month follow-up and those undergoing concomitant osteotomies, cartilage restoration, and/or other ligament reconstruction procedures were excluded. Pre- and postsurgical patient-reported outcomes including International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, Patient-Reported Outcomes Measurement Information System (PROMIS), Single Assessment Numeric Evaluation, Tegner, and Marx were compared between groups. Complications requiring reoperation were recorded. Results: One hundred nineteen patients met inclusion criteria, including 39 QT autografts and 80 BPTB autografts. Demographic information was comparable between groups. Mean follow-up was comparable between groups (QT 22.4 ± 10.6 months vs BPTB 28.5 ± 18.5 months, P = .06). At minimum 12-month follow-up (range 12.0-100.8 months), patients in both groups demonstrated statistically significant improvements in International Knee Documentation Committee (QT 60.0%, P < .0001; BPTB 57.7%, P < .0001), all Knee Injury and Osteoarthritis Outcome Score domains, PROMIS Mobility T-Score (QT 27.2%, P = .0001; BPTB 23.2%, P < .0001), PROMIS Global Physical Health (QT 14.4%, P = .002; BPTB 13.4%, P = .001), PROMIS Physical Function (QT 29.6%, P < .0001; BPTB 37.1%, P < .0001), PROMIS Pain Interference (QT -16.5%, P < .0001; BPTB -20.8%, P < .0001), Single Assessment Numeric Evaluation, (QT 76.9%, P < .0001; BPTB 73.3%, P < .0001), Tegner (QT 92.9%, P = .0002; BPTB 101.4%, P < .0001), and Marx (QT -26.6%, P = .02; BPTB -32.0%, P = .0002) with no statistically significant differences between the 2 groups. Overall postoperative reoperation rate did not differ between groups (QT 12.8% vs BPTB 23.8%, P = .2). Revision ACL reconstruction rate did not differ between groups (QT 5.1% vs BPTB 7.5%, P = .6). Conclusions: Patients undergoing autograft ACLR with either BPTB or QT demonstrated significant subjective improvements in patient-reported outcomes from preoperative values and no statistically significant differences in outcomes between the groups. Complication and revision ACLR rates were similar between the 2 groups. Level of Evidence: III, retrospective cohort study.

A Community-based Boxing Program is Associated with Improved Balance in Individuals with Parkinson's Disease.

In alignment with efforts to mitigate the negative health consequences of Parkinson's Disease (PD), the purpose of this investigation was to examine if participation in a community-based boxing program (CBP) was associated with improvements in balance and fall risk reduction among individuals with PD. In this retrospective cross-sectional study, de-identified data from 12 individuals with PD participating in a CBP was examined. Participants included those with a Hoehn and Yahr stage between 1 and 3, averaging 2.8 ± 0.8 CBP sessions per week for 6.1 ± 0.8 months between testing. Baseline and re-evaluation testing included the Fullerton Advanced Balance (FAB) Scale and Timed Up and Go (TUG) to quantify balance and fall risk. Sessions were 90-minutes in length involving a warm-up, boxing drills, strength and endurance exercises, and cool down. Sessions included multiple bouts of 30-60 second high-intensity exercise intervals (RPE between 15/20 to 17/20). Paired t-tests were used to determine if differences existed between the FAB and TUG from baseline to re-evaluation, with statistical significance accepted at p < 0.05 and > 0.8 interpreted as a large effect using Cohen's d. Results indicated a statistically significant increase and large effect in FAB performance, with a mean increase in score above previously reported minimal detectable change (MDC). While participation in CBP was associated with a statistically significant improvement and medium effect in the TUG, this did not demonstrate a population specific MDC. This study found that participation in a CBP was associated with improved balance among clients with PD.

Hip Impingement after Anterior Inferior Iliac Spine Avulsion Fractures: A Case Report with Review of the Literature.

Avulsion fractures of the anterior inferior iliac spine (AIIS) are rare injuries in adolescent athletes. We present a case of a 15-year-old male who sustained an avulsion injury to his right AIIS when kicking a soccer ball. The patient had chronic pain and extra-articular subspinal impingement leading to decreased hip flexion and rotation. The injury occurred 1.5 years prior to symptom onset, and we were the first health care providers to manage the injury. We attempted six months of nonoperative management including activity modifications and nonsteroidal anti-inflammatory (NSAID) therapy without improvement. Although this injury can often be managed nonoperatively, his symptoms required excision of the AIIS and associated heterotopic ossification. He had an excellent outcome with return to soccer and no pain at his final follow-up visit two years after surgery. Due to the limited literature guiding the surgeon's management of AIIS avulsion injuries with associated heterotopic ossification, we provide a review of the literature detailing pre- and postoperative ranges of motion, surgical approach, fixation or excision of the avulsion fragment, and return to sport in this patient population.

Force-Time Waveform Shape Reveals Countermovement Jump Strategies of Collegiate Athletes.

The purpose of this study was to relate the shape of countermovement jump (CMJ) vertical ground reaction force waveforms to discrete parameters and determine if waveform shape could enhance CMJ analysis. Vertical ground reaction forces during CMJs were collected for 394 male and female collegiate athletes competing at the National Collegiate Athletic Association (NCAA) Division 1 and National Association of Intercollegiate Athletics (NAIA) levels. Jump parameters were calculated for each athlete and principal component analysis (PCA) was performed on normalized force-time waveforms consisting of the eccentric braking and concentric phases. A K-means clustering of PCA scores placed athletes into three groups based on their waveform shape. The overall average waveforms of all athletes in each cluster produced three distinct vertical ground reaction force waveform patterns. There were significant differences across clusters for all calculated jump parameters. Athletes with a rounded single hump shape jumped highest and quickest. Athletes with a plateau at the transition between the eccentric braking and concentric phase (amortization) followed by a peak in force near the end of the concentric phase had the lowest jump height and slowest jump time. Analysis of force-time waveform shape can identify differences in CMJ strategies in collegiate athletes.

The effect of silicone ankle sleeves and lace-up ankle braces on neuromuscular control, joint torque, and cutting agility.

OBJECTIVE: To evaluate the effects of silicone ankle sleeves (SASs) and lace-up ankle braces (LABs) on neuromuscular control, net joint torques, and cutting agility in healthy, active individuals. DESIGN: Markerless motion-capture technology tracked subjects fitted with SASs, LABs, or no brace while they performed the movements: Y-excursion, left cutting, right cutting, single-leg drop vertical jump (SLDVJ), 45-degree bound, and single-leg squat (SLS). SETTING: University Laboratory. PARTICIPANTS: Ten healthy, active individuals (5 males and 5 females, mean ± SD 23.60 ± 1.43 years of age). MAIN OUTCOME MEASURES: Degrees of joint range of motion (ROM), Newton-meters of joint torque, time to perform a cutting maneuver. RESULTS: SASs and LABs resulted in significantly different knee and ankle ROM and hip internal rotation in the SLDVJ, SLS, Y-excursion, cutting maneuver, and 45-degree bound when compared to control (p < .05). Both ankle and knee torque were significantly reduced in the 45-degree bound and cutting movements with both types of PABs (p < .05). There were minimal differences between the SASs and LABs for all conditions. There were no statistically significant differences in cutting times for any of the 3 conditions. CONCLUSION: Both SAS and LAB positively impacted neuromuscular control, reduced net joint torque, and neither impaired cutting agility when compared to control.

Early Single Sport Specialization in a High-Achieving US Athlete Population: Comparing National Collegiate Athletic Association Student-Athletes and Undergraduate Students.

CONTEXT: Early single-sport specialization and the relative age effect are often cited as improving the chances of sport success. Both concepts suggest that genetics and the environment have little influence on sport success. OBJECTIVE: To compare National Collegiate Athletic Association Division I student-athletes (SAs) with their undergraduate nonathlete peers (NAs) in terms of birth month, age of sport initiation, and age of single-sport specialization. A family history of sport participation was examined as a potential marker for genetic and social influences. DESIGN: Cross-sectional survey. SETTING: Large urban university. PATIENTS OR OTHER PARTICIPANTS: A total of 273 Division I SAs (138 women, 135 men) and 155 NAs (78 women, 77 men) participated. The NAs had been involved in competitive youth sports before entering the university. MAIN OUTCOME MEASURE(S): Participants were asked to complete a questionnaire that addressed the age of sport initiation, birth month, age of single-sport specialization, and parental and sibling sport achievement. MAIN RESULTS: Neither birth month nor the age of sport initiation differed between groups (age of sport initiation = 7.16 ± 2.6 years for the SAs versus 7.71 ± 3.5 for the NAs; P = .176). A larger proportion of SAs began participating before 10 years of age (80% versus 63%; P = .02). The parents of SAs were more likely to have participated in collegiate (32.4% versus 8.4%; P < .0001) and professional (10.9% versus 1.3%; P = .0005) sports. The SAs specialized in a single sport at an older age (15.38 ± 2.7 years versus 14.30 ± 2.6 years; P = .002). Both groups participated in multiple sports in childhood (SAs = 3.9 ± 1.8 sports, NAs = 3.2 ± 1.8 sports; P = .366). CONCLUSIONS: The Division I SAs did not specialize in a single sport at a younger age than the NAs. No evidence of a relative age effect was present. Importantly, higher levels of sport achievement among the parents and siblings of SAs suggest that genetic endowment and family or other environmental dynamics play a large role in athletic performance. Overall, the results are not consistent with deliberate practice theory and point toward an alternative model that includes not only sport-specific skill development but also genetic and social factors as key elements of long-term sport achievement.

Do neoprene sleeves and prophylactic knee braces affect neuromuscular control and cutting agility?

OBJECTIVES: To evaluate the effects of neoprene sleeves (NSs) and prophylactic knee braces (PKBs) on neuromuscular control and cutting agility. DESIGN: Markerless motion-capture technology tracked subjects (1) without a brace as a control (2) with NSs and (3) with PKBs during single-leg drop vertical jump (SLDVJ), single-leg squat (SLS), Y-excursion, and cutting movements. Movements were recorded five times per bracing condition in three different sessions. SETTING: University laboratory. PARTICIPANTS: Ten healthy, active subjects (5 male, 5 female; age range, 22-26 years). MAIN OUTCOME MEASURES: Degrees of motion and time to completion. RESULTS: Use of NSs and PKBs reduced subjects' hip internal rotation in the loading phase of SLDVJ (p = 0.026, 0.02) and SLS (p = 0.005, <0.001), reduced knee flexion in the loading phase of SLDVJ (p = 0.038, <0.001), and reduced knee frontal plane abduction (FPA) with SLS (p = 0.015, 0.024) and Y-excursion (p = 0.002, 0.005) compared to control. Use of PKBs decreased subjects' hip internal rotation in the Y-excursion (p = 0.024) and reduced knee FPA in the SLDVJ loading phase (p = 0.014) compared to control. There was no difference in cutting agility for either group (p = 0.145, 0.347). CONCLUSION: Both NSs and PKBs positively impacted neuromuscular control without impacting cutting agility.

Youth Baseball Pitching Mechanics: A Systematic Review.

CONTEXT: Pitching injuries in youth baseball are increasing in incidence. Poor pitching mechanics in young throwers have not been sufficiently evaluated due to the lack of a basic biomechanical understanding of the "normal" youth pitching motion. OBJECTIVE: To provide a greater understanding of the kinetics and kinematics of the youth baseball pitching motion. DATA SOURCES: PubMed, MEDLINE, and SPORTDiscus databases were searched from database inception through February 2017. STUDY SELECTION: A total of 10 biomechanical studies describing youth pitching mechanics were included. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Manual extraction and compilation of demographic, methodology, kinetic, and kinematic variables from the included studies were completed. RESULTS: In studies of healthy youth baseball pitchers, progressive external rotation of the shoulder occurs throughout the start of the pitching motion, reaching a maximum of 166° to 178.2°, before internally rotating throughout the remainder of the cycle, reaching a minimum of 13.2° to 17°. Elbow valgus torque reaches the highest level (18 ± 4 N·m) just prior to maximum shoulder external rotation and decreases throughout the remainder of the pitch cycle. Stride length is 66% to 85% of pitcher height. In comparison with a fastball, a curveball demonstrates less elbow varus torque (31.6 ± 15.3 vs 34.8 ± 15.4 N·m). CONCLUSION: Multiple studies show that maximum elbow valgus torque occurs just prior to maximum shoulder external rotation. Forces on the elbow and shoulder are greater for the fastball than the curveball.

Overuse of Magnetic Resonance Imaging in the Diagnosis and Treatment of Moderate to Severe Osteoarthritis.

Background: MRI in the evaluation of end-stage knee joint osteoarthritis (OA) is usually unnecessary when radiographic and clinical evidence of gonarthrosis is clear. The purpose of this study was to assess the prevalence of MRI scans ordered in patients with radiographically obvious gonarthrosis and to examine the characteristics of health care providers who ordered these imaging studies. Methods: We retrospectively identified 164 patients diagnosed with moderate to severe OA who were referred for total knee replacement (TKA) over a one-year period. The percentage of patients who had an MRI scan with or without X-ray, within the preceding 3 months prior to referral, were calculated. Subgroups were analyzed to identify characteristics that may influence the decision to order an MRI, including K-L grade, provider type, level of training, and practice location. Results: Of 145 patients, 19 (13.1%) presented with an MRI scan. Between the number of MRI scans ordered, there was a significant difference when comparing physicians versus non-physicians, with physicians ordering less MRI scans (p=0.018). There was a significant difference when comparing non-academic versus academic, with academic providers ordering less MRI scans (p=0.044). There was no significant difference with fellowship training or provider proximity to our academic institution. Conclusions: In this study, 13.1% of patients with radiographically obvious knee OA obtained an MRI prior to referral for TKA. Non-physicians and non-academic physicians were more likely to order MRI scans. Improved education for referring providers may be necessary to decrease overuse of MRI in the diagnosis of moderate to severe arthritis. Level of Evidence: Level II.

The Epidemiology of Severe Injuries Sustained by National Collegiate Athletic Association Student-Athletes, 2009-2010 Through 2014-2015.

CONTEXT: Few researchers have described the incidence of the most severe injuries sustained by student-athletes at the collegiate level. OBJECTIVE: To describe the epidemiology of severe injuries within 25 National Collegiate Athletic Association (NCAA) sports in the 2009-2010 through 2014-2015 academic years. DESIGN: Descriptive epidemiology study. SETTING: Aggregate injury and exposure data from 25 NCAA sports. PATIENTS OR OTHER PARTICIPANTS: Collegiate student-athletes in the 2009-2010 through 2014-2015 academic years. MAIN OUTCOME MEASURE(S): Injury data from the NCAA Injury Surveillance Program were analyzed. A severe injury (1) occurred during a sanctioned competition or practice, (2) required medical attention by an athletic trainer or physician, and (3) resulted in at least 21 days lost from sport activity or a premature end to the sport season. Injury counts, proportions, rates per 1000 athlete-exposures (AEs), rate ratios (RRs), and injury proportion ratios were reported with 95% confidence intervals (CIs). RESULTS: A total of 3183 severe injuries were reported, for an injury rate of 0.66/1000 AEs. Wrestling had the highest severe injury rate (1.73/1000 AEs), followed by women's gymnastics (1.40/1000 AEs) and football (0.97/1000 AEs). Overall, the severe injury rate was higher in competition than in practice (RR = 4.25, 95% CI = 3.97, 4.56). Most severe injuries were reported during the regular season (69.3%, n = 2206); however, severe injury rates did not differ between the preseason and regular season (RR = 0.98, 95% CI = 0.91, 1.06). Common severely injured body parts were the knee (32.9%, n = 1047), lower leg/ankle/foot (22.5%, n = 715), and head/face/neck (11.2%, n = 358). Common severe injury diagnoses were sprains (32.9%, n = 1048), strains (16.9%, n = 538), and fractures (14.4%, n = 458). Common severe injury mechanisms were player contact (39.3%, n = 1251), noncontact (25.1%, n = 800), and surface contact (12.0%, n = 383). CONCLUSIONS: Severe injuries occurred across many sports and by numerous mechanisms. By identifying these sport-specific patterns, clinicians' efforts can be tailored toward improving injury-prevention strategies and health outcomes.