Physeal injuries in children's and youth sports: reasons for concern?

The Immature Pediatric Appendicular Skeleton

Growth and maturation occur in a predictable pattern throughout the body and within each individual bone. In the appendicular skeleton, endochondral ossification predominates in long bones and growth plates. The ends of these long bones are sites of relative weakness in the immature skeleton and prone to injury from acute insult and overuse. We present the normal histoanatomy and physiology of the growth plate complex, highlighting the unique contribution of each component and shared similarities between primary and secondary complexes. Components of the growth plate complex include the physis proper, subjacent vascularity within the growth cartilage, and the ossification front. The second section describes imaging considerations and features of normal and abnormal growth. Finally, we review the Salter-Harris classification for acute fractures and offer examples of characteristic overuse injury patterns involving the epiphyseal (proximal humerus and distal radius), apophyseal (medial epicondyle and tibial tubercle), and secondary growth plate complexes (medial femoral condyle and capitellar osteochondritis dissecans). This article provides a foundation and basic framework to better understand and anticipate potential complications and growth disturbances and to ensure optimal follow-up and early intervention when treatment can be less invasive.

Overuse Injury of the Epiphyseal Primary Physis

Year-round participation in youth sport that involves high levels of repetitive movement fosters an environment in which overuse injuries are likely to occur. Epiphyseal primary physeal stress injuries (PSIs), unique to skeletally immature athletes, are a particular concern, given their potential for growth disturbance. Initially observed in Little League baseball players, these injuries are now known to affect the long bones around the shoulder, elbow, wrist, hand, knee, ankle, and foot of skeletally immature athletes involved in a variety of sport activities.This article offers an epidemiological and radiologic perspective on the extent and distribution of epiphyseal PSIs in youth sport. We also review a novel framework for understanding the pathophysiologic mechanisms causing these injuries. This information is essential for the early identification of epiphyseal PSIs and devising preventive measures that can reduce a delayed diagnosis and long-term morbidity. Preventing and reducing injury to the epiphyseal growth plates is essential because impairment and dysfunction can result in lifelong morbidity and a risk of premature osteoarthritis.

The Effectiveness of Treating Osgood-Schlatter Disease (OSD) with Leukocyte-Rich Platelet-Rich Plasma (LR-PRP) Depending on the Duration of the Disease

Background: Osgood-Schlatter disease (OSD) occurs mainly in physically active adolescents, causing significant physical activity restrictions. The aim of this study is to compare the effectiveness of treating OSD with leukocyte-rich platelet-rich plasma (LR-PRP) depending on the duration of the disease and to attempt to develop an alternative treatment method to the currently used conservative therapy. Methods: Treatment efficacy was evaluated using the VAS, Tegner, Lysholm, and KOOS scales. Subject satisfaction, return to sports activity, potential adverse effects, and X-ray evaluation were likewise used to assess the success of the procedure. Results: Analysis across all scales showed statistically significant treatment effectiveness with LR-PRP in both groups of patients. When comparing the two groups, significantly better treatment outcomes were achieved in the acute phase of OSD. Treatment satisfaction in the acute OSD group was 95%, compared to 64% in the chronic group. The MCID value after LR-PRP injection in acute OSD compared to chronic OSD reached 100% vs. 81% on the VAS scale, 95.5% vs. 55% on the Tegner scale, 95% vs. 47% on the Lysholm scale and 91% vs. 27% on the KOOS scale. No adverse effects were recorded in either group. Conclusions: The high efficacy of LR-PRP treatment in patients with acute OSD, in correlation with high safety, as well as rapid and lasting results, can be an effective and beneficial alternative to conservative treatment. This single procedure seems particularly justified in a group of young professional athletes, where absence from training can lead to serious consequences.

SalterHarris fractures in paediatric skiers and snowboarders

The incidence of paediatric fractures among winter sport athletes is not adequately studied. Our objective was to categorize fractures that occurred in paediatric skiers and snowboarders at a single ski resort. X-rays of 756 skiers/snowboarders aged 3-17 diagnosed with a fracture were categorized using the Salter-Harris (SH) classification. SH fractures were seen in 158 (21%) patients, with 123 (77%) being Type II. There were no significant differences between patients with a SH fracture and patients with a non-SH fracture for age, sex, snowboarding or skiing, mechanism of injury, terrain or the resort conditions on the day of injury. The most common mechanism of injury was falling onto snow while collisions resulted in more severe injuries. Compared to fractures without growth plate involvement, a higher proportion of SH fractures were seen in the humerus, radius, fibula and thumb; a lower proportion of SH fractures were observed at the tibia and clavicle.

Outcomes of physeal-sparing posterior cruciate ligament reconstruction for adolescents with an open physis

PURPOSE

The posterior cruciate ligament (PCL) rupture rarely occurs, especially in skeletally immature adolescents, and poses a dilemma in appropriately managing the open physis with its vast growth potential. However, although many epiphyseal-protecting techniques for anterior cruciate ligament (ACL) reconstruction have been reported, a similar problem in PCL reconstruction has received scant attention and needs more relevant research. So, this study aims to evaluate the short-term clinical and imaging results of the arthroscopic physeal-sparing reconstruction program.

METHOD

All the 13 patients we reviewed in this study have accepted the arthroscopic physeal-sparing PCL reconstruction from January 2019 to December 2022 in our Department of Orthopedics. Primary demographic data collected include gender (8 males and 5 females), age (11-15 years, average 13.3 years), follow-up period (15-35 months, average 25.2 months), injury mechanism (nine non-contact injuries and four contact injuries), and days following injury (1-10 days, average 5.3 days). The assessment of clinical outcomes included pre- and postoperative physical examination, knee functional scores, and imaging data.

RESULT

All patients in this study were followed up with an average 25.2-month (range 15-35 months) follow-up period. All the cases preoperatively had a positive posterior drawer test and turned negative at the final follow-up. The average ROM improved from 103.6° ± 11.4° to 132.6° ± 3.6° at the last follow-up (p < 0.05). The VAS score decreased from 5.8 ± 1.6 to 0.9 ± 0.5 (p < 0.05); the average KT-1000 healthy-side to affected-side difference decreased from 11.3 ± 1.6 to1.8 ± 0.5 mm. The comparison of all the knee functional scores (IKDC, Tegner scores, and Lysholm) at preoperative and last follow-up showed a significant difference (p < 0.05). None of the cases had operation-related complications, and all recovered to sports well.

CONCLUSION

The arthroscopic physeal-sparing posterior cruciate ligament reconstruction is a dependable and recommended treatment for posterior cruciate ligament rupture in adolescents with open physis, showing a striking improvement in knee function without growth arrest and angular deformity of the affected limb in the short-term follow-up.

Principles of musculoskeletal sport injuries for epidemiologists: a review

BACKGROUND

Musculoskeletal injuries are a common occurrence in sport. The goal of sport injury epidemiology is to study these injuries at a population level to inform their prevention and treatment.

MAIN BODY

This review provides an overview of musculoskeletal sport injuries and the musculoskeletal system from a biological and epidemiologic perspective, including injury mechanism, categorizations and types of sport injuries, healing, and subsequent injuries. It is meant to provide a concise introductory substantive background of musculoskeletal sport injuries for epidemiologists who may not have formal training in the underlying anatomy and pathophysiology.

CONCLUSION

An understanding of sport injuries is important for researchers in sport injury epidemiology when determining how to best define and assess their research questions and measures.

Adolescent athlete low back pain diagnoses, characteristics, and management: A retrospective chart review

OBJECTIVES

The aim of this study was to characterise the presentation, treatment, and management of adolescent athlete low back pain (LBP) as diagnosed in a clinical setting. The objectives were to 1) identify diagnoses associated with LBP in adolescent athletes; 2) categorise the differences in LBP diagnosis and presentation by sport, sex, BMI, and age; and 3) examine treatment and management methods of LBP in adolescent athletes.

DESIGN

Retrospective chart review.

METHODS

This retrospective medical chart review was conducted in the Sports Medicine Division of Boston Children's Hospital (BCH), a tertiary paediatric academic hospital. Data were collected and analysed from 363 adolescent athletes who had experienced LBP between 2015 and 2020. Chi-squared tests for association were used to assess for associations between LBP diagnoses and age, sex, BMI, and sport. Statistical analysis was conducted using SAS software version 9.4 (SAS Institute, Cary NC).

RESULTS

Non-specific LBP was the most common LBP diagnosis amongst 363 adolescent athletes with LBP (34 %). This was closely followed by spondylolysis (28 %). There was a higher proportion of female athletes amongst participants diagnosed with facet-joint related pain (90 %) and SI-joint related pain (89 %) compared to the proportion of female athletes amongst participants diagnosed with spondylolysis (50 %). There was a high rate of diagnostic MRI usage in this cohort. Commonly used management techniques in this cohort were diagnostic MRI, physical therapy, relative rest, and bracing.

CONCLUSIONS

An awareness of the sex-based differences in adolescent athlete LBP diagnoses may be useful for clinicians. It may be important to refine methods of diagnosis of LBP in this group, as there was a high rate of diagnostic MRI use. Future research should be directed towards the development of management guidelines specific to LBP in adolescent athletes to assist in the optimal management of this diagnosis.

The Coronal Alignment of Lower Limbs in the Adolescent Football and Ice Hockey Players

Background

To investigate the influence of sport-specific activities on coronal axial alignment of the lower limbs in adolescent football and ice hockey players.

Methods

This cross-sectional study targeted healthy adolescent male football and ice hockey players with at least 3 years of sports participation. 90 football and 38 ice hockey players aged 12-16 years were divided into five age-matched subgroups. Coronal alignment of the lower limbs was determined by measuring the players' intercondylar or intermalleolar (ICD-IMD) distance with a custom-made calliper. In addition, their sports history was recorded. An age-matched comparison between the two sports groups was performed using the two-way model ANOVA and a multiple regression model for ICD-IMD was constructed. Results were additionally compared with age-matched data from the general population published in recent literature.

Results

A statistically significant increase in ICD-IMD values (p < 0.05) was found between 12 (football 0 mm; ice hockey - 64 mm) and 16 years (football 340 mm; ice hockey 310 mm) in both sports groups. Results of regression analysis of pooled group data showed that ICD-IMD has low positive correlation (r = 0.407; r2 = 0.168; p < 0.05) with time of participation in sport, but no association with age of athletes at the start of their sport participation (r = - 0.018; r2 = 0.000; p > 0.05). There were no statistically significant differences between the two groups at any time point. Both sports groups showed a significant increase in ICD-IMD values (mean 198 mm) after the age of 14 compared to the general population.

Conclusions

Participation in football and ice hockey is associated with a similar increase in ICD-IMD in the adolescent years in male athletes. The observed increase was higher in both groups of athletes than in their peers who do not regularly participate in sports.

Level of Evidence

Level 4 (case series).

Stress Fractures of the Distal Phalanx in Skeletally Immature Sport Climbers

Stress fractures in the distal phalanx of skeletally immature patients are rare and previously unreported clinical occurrences. We report on 2 adolescent sport climbers with such fractures of the dorsal metaphysis of the distal phalanx at the point where parts of the extensor tendon insert. A conservative treatment approach alone was sufficient in healing this fracture type in both patients after 12 wk. Clinicians should be informed of the existence of this rare clinical phenomenon and counsel patients that a conservative treatment approach may result in complete healing without the need for an invasive procedure.

[Stress injuries of bone in children and adolescents]

Stress injuries of bone in childhood and adolescence are the result of an imbalance between physical stress on the growing musculoskeletal system and its intrinsic resilience. Children who are very active in sports are particularly affected. The classical stress injuries mainly occur in the area of the lower leg, the metatarsus and the lower lumbar spine due to the disproportionate load on healthy bone; however, overuse syndromes can also occur in the area of the growth plates and possibly lead to growth plate disorders. The anamnesis usually shows stress-related pain that has existed for a long time without trauma. As part of the differential diagnosis, a stress injury must first be included in the considerations due to it being a rare entity. An X‑ray examination can show the first signs of a stress reaction. In the event of a conspicuous periosteal reaction, a malignant event must also be considered. As a rule, the MRI examination is then groundbreaking and in some rare cases biopsies have to be considered. The treatment of stress injuries is usually conservative. Recurrences should be counteracted by exercise control.

Focused extracorporeal shockwave therapy for youth sports-related apophyseal injuries: case series

BACKGROUND

Apophyseal overuse injuries are self-limited with skeletal maturity; however, they may be a source of significant pain and time lost from training. There is a lack of consensus for its management with the current available treatment, which might lag behind the ongoing development of regenerative medicine. The current retrospective case study aimed to assess the potential effectiveness and short-term safety of extracorporeal shockwave therapy (ESWT) in apophyseal injuries.

METHODS

Data from 22 growing athletes [15 patients with Osgood-Schlatter disease and seven patients with Sever's disease] who received ESWT at a sports medicine unit in a university hospital were reviewed. All patients received low energy (= 0.1 mJ/mm2) level-focused ESWT using electrohydraulic generation technology. The clinical focusing technique was used upon applying ESWT.

RESULTS

The number of sessions received to achieve full recovery ranged from 1 to 3 sessions. The time from treatment initiation to previous activity level was 2 weeks in 14 patients (63.3%), 4 weeks in seven patients (31.8%) and 11 weeks in one patient (4.5%). No adverse events were reported. No recurrence occurred up to 3 months after the last session.

CONCLUSION

ESWT is a potentially safe and effective treatment for apophyseal injuries. It may facilitate an early return to sport activities.

A posterior tibial slope angle over 12 degrees is critical to epiphyseal fracture of the proximal tibia: Three-dimensional finite element analysis

Introduction

The effects of the proximal tibial slope angle on the proximal tibial epiphysis remain unknown. To elucidate those effects, we investigated the strain distribution in proximal tibial epiphysis with different proximal tibial slope angles and proximal tibial epiphysis closure periods using finite element analysis.

Materials and methods

The finite element models of the proximal tibia were reconstructed from CT images and consisted of cancellous/cortical bone and epiphyseal plate. The variations in proximal tibial slope angle (range: 6-16°) and four closure variations in proximal tibial epiphysis (open, semi-open, semi-closed, and closed) were prepared. The loading force on the medial and lateral joint surface, and the tensile force by the patellar tendon were applied to the models, and the distal area of the tibia was fixed. The ratio of the equivalent strain in semi-open/semi-closed proximal tibial epiphysis to the strain in open proximal tibial epiphysis on different proximal tibial slope angles were calculated.

Results

The strain ratio between the semi-open/semi-closed and open proximal tibial epiphysis models indicated significant differences between 6 or 8° of proximal tibial slope angle and 12, 14, and 16° of proximal tibial slope angle models. In the increased proximal tibial slope angle model, a hoop-shaped strain in the closing proximal tibial epiphysis was found, and the maximum strain was found in the tibial tubercle.

Discussion

During epiphyseal closure, adolescents with an increased proximal tibial slope angle over 12° are significantly at risk for suffering from proximal tibial epiphyseal fractures compared with those under 10°.

Evaluating the impact of injury prevention interventions in child and adolescent sports using the RE-AIM framework and CERT: A systematic review

BACKGROUND

Participation in sport is a popular pastime for children and adolescents that improves their physical health, mental health and motor skills. Musculoskeletal injuries are a relatively common downside of sports participation and can have negative long-term consequences. Injury prevention programmes have demonstrated effectiveness in child and adolescent sports, provided compliance is adequate. However, little is known about the factors which relate to their impact on the wider community and whether the prevention programmes have been adopted and maintained in the long-term. The objective of this review was to assess the current literature on exercise-based injury prevention interventions in child and adolescent sports (aged under 19 years) against the 'Reach', 'Effectiveness', 'Adoption', 'Implementation', 'Maintenance' (RE-AIM) framework and Consensus of Exercise Reporting Template (CERT), to ascertain level of reporting for the components which relate to external validity.

METHODS

Seven electronic databases; PubMed, Medline, SPORTDiscus, PsycINFO, CINAHL, Scopus and The Cochrane Library, were searched from date of inception to July 2022 using the themes of: 'Child and Adolescent', 'Sport', 'Injury' and 'Prevention'. Eligibility criteria included: Experimental trial design, exercise-based intervention programmes, primary outcome of injury incidence and participants aged under 19 years. Two reviewers assessed each trial independently against the RE-AIM model dimension items checklist (RE-AIM MDIC) and Consensus on Exercise Reporting Template (CERT) before reaching a consensus on reporting.

RESULTS

Forty-five unique trials met the eligibility criteria. Mean reporting level for all studies across the whole RE-AIM MDIC was 31% (SD ± 16.2%, Range 7-77%). The domain of 'effectiveness' was the most comprehensively reported (60%), followed by 'implementation' (48%), 'reach' (38%), 'adoption' (26%) and 'maintenance' (7%). The mean reporting score for the CERT was 50% (SD ± 20.8, range 0-81%).

CONCLUSION

Published data on injury prevention in child and adolescent sports is highly focussed on the effectiveness of the intervention, with little consideration given to how it will be adopted and maintained in the long-term. This has led to considerable gaps in knowledge regarding optimal programme implementation, with a lack of data on adoption and maintenance contributing to the gap between research and practice. Future research needs to place greater focus on external validity and consider incorporating the study of implementation and feasibility as part of effectiveness trial design. This approach should provide the data that will help narrow the considerable gap between science and practice.

TRIAL REGISTRATION

PROSPERO Registration number CRD42021272847.

Epidemiology of Physeal Fractures and Clinically Significant Growth Disturbances Affecting the Distal Tibia, Proximal Tibia, and Distal Femur: A Retrospective Cohort Study

INTRODUCTION

Childhood fractures involving the physis potentially result in premature physeal closure that can lead to growth disturbances. Growth disturbances are challenging to treat with associated complications. Current literature focusing on physeal injuries to lower extremity long bones and risk factors for growth disturbance development is limited. The purpose of this study was to provide a review of growth disturbances among proximal tibial, distal tibial, and distal femoral physeal fractures.

METHODS

Data were retrospectively collected from patients undergoing fracture treatment at a level I pediatric trauma center between 2008 and 2018. The study was limited to patients 0.5 to 18.9 years with a tibial or distal femoral physeal fracture, injury radiograph, and appropriate follow-up for determination of fracture healing. The cumulative incidence of clinically significant growth disturbance (CSGD) (a growth disturbance requiring subsequent physeal bar resection, osteotomy, and/or epiphysiodesis) was estimated, and descriptive statistics were used to summarize demographics and clinical characteristics among patients with and without CSGD.

RESULTS

A total of 1,585 patients met the inclusion criteria. The incidence of CSGD was 5.0% (95% confidence interval, 3.8% to 6.6%). All cases of growth disturbance occurred within 2 years of initial injury. The risk of CSGD peaked at 10.2 years for males and 9.1 years for females. Complex fractures that required surgical treatment, distal femoral and proximal tibial fractures, age, and initial treatment at an outside hospital were significantly associated with an increased risk of a CSGD.

DISCUSSION

All CSGDs occurred within 2 years of injury, indicating that these injuries should be followed for a period of at least 2 years. Patients with distal femoral or proximal tibial physeal fractures that undergo surgical treatment are at highest risk for developing a CSGD.

LEVEL OF EVIDENCE

Level III Retrospective Cohort Study.

Characteristics of Pressure on the Apophysis in the Course of Paediatric Heel Pain-Preliminary Report

Increased pressure on the heel apophysis is often implicated as a cause of paediatric heel pain. However, there are few reports on the causes of the increased pressure and its origin. Therefore, the aim of this study was to analyse the distribution of pressure on the feet in children with heel pain. The study included 33 paediatric patients with non-traumatic heel pain, i.e., 24 boys (73%) and 9 girls (27%), aged on average 11.2 years (±3 years). Pedobarographic diagnostics proved a decrease in the pressure on the heels in relation to the ground and the transfer of the projection of the centre of gravity to the forefoot. While standing, the average contribution of the pressure on the heel was 0.52, SD = 0.14 in children with normal and reduced weight. In overweight children, the average pressure on the heel was higher (0.60, SD = 0.08), but the small number of children with this characteristic (n = 4) did not allow conclusions to be drawn in this area. Heel underload was also demonstrated during gait. However, the assessment of this aspect requires additional observational analyses in the field of propulsion and gait phases. The reduced pressure on the heel promotes apophysis traction, causing intracanal compression. Studies have shown that the causes of apophysis traction may be postural defects (in particular, forward inclination of body posture) and overpronation of the foot, or defects in the metatarsal area.

Acute Bilateral Salter-Harris II Distal Radii Fractures in a Skeletally Immature Athlete

Distal radius fractures are a common location of physeal injuries in skeletally immature adolescents. However, reports of athletics-related acute bilateral distal radius physeal injuries are rare. Therefore, there is a need for further literature to demonstrate both the early recognition and prevention of these injuries to ensure young athletes are able to safely train and compete. We present the case of acute bilateral Salter-Harris II distal radii fractures in a 14-year-old athlete during participation in a high-energy impact sport.

Increased lower limb length ratio in patients with patellar instability

PURPOSE

Patellar height is a risk factor for patellar instability, correlated with the tibia length/femur length (T/F) ratio. This study aimed to explore the changes in the T/F ratio in patients with patella instability and the potential correlation with the morphology of the patellofemoral joint and extensor moment arm.

METHOD

A retrospective analysis was performed to assess the ratio of lower limb length morphological characteristics of the patellofemoral by full weight-bearing long-leg standing radiographs, magnetic resonance imaging, and computed tomography in 75 patients with patellar instability and 75 participants from a randomly selected control group from January 2020 to September 2021. A total of eight parts were measured, including mechanical tibia length/femur length (mT/F) ratio, anatomical tibia length/femur length (aT/F) ratio, hip-knee-ankle angle, femoral neck-shaft angle, femoral valgus cut angle, patellar height, Dejour classification, sulcus angle, trochlear angle, medial trochlear inclination, lateral trochlear inclination, patella tilt angle and patellar tendon moment arm to evaluate the difference of morphology between patient group and control groups.

RESULTS

The mT/F (0.840 ± 0.031 vs. 0.812 ± 0.026, p < 0.001) and aT/F (0.841 ± 0.033 vs. 0.808 ± 0.028, p < 0.001) ratios in the patient group were significantly greater than that in the control group. There was a significant correlation between patellar height and increased mT/F and aT/F ratios (p < 0.05).

CONCLUSION

Patients with patellar instability had a larger lower limb length ratio, and the change in lower limb length ratio was correlated with patellar height.

LEVEL OF EVIDENCE IV

[Sports injuries in children and adolescents]

CLINICAL/METHODOLOGICAL ISSUE

Due to active participation of children and adolescents in school sports as well as in club sports, sporting injuries in childhood are common. Because skeletal maturity is not yet complete, injury patterns in children differ from sporting injuries in adults. Knowledge of the pathophysiologic characteristics, as well as knowledge of typical injury sequelae, is of great relevance to radiologists. This review article therefore deals with common acute and chronic sporting injuries in children.

STANDARD RADIOLOGICAL METHODS

Basic diagnostic imaging comprises conventional X‑ray imaging in two planes. In addition, sonography, magnetic resonance imaging (MRI) and computed tomography (CT) are used.

PRACTICAL RECOMMENDATIONS

Close consultation with clinical colleagues and knowledge of childhood-specific injuries help identify sports-associated trauma sequelae.

Risk factors of lower extremity injuries in youth athletes

Objective

Lower extremity sports injuries frequently occur during an individual's growth period. The object of the current study was to analyse the risk factors for lower extremity sports injuries for youth athletes. The secondary objective was to clarify the factors related to new injuries after a lower extremity injury.

Methods

We extracted information on youth athletes (aged 10-15 years) with sports-related disorders. Background data and injury situations were collected via a specific application. During the follow-up period, new injuries were also recorded. The athletes were divided into two groups according to injury location (lower extremity or other). We performed a multiple logistic regression analysis to clarify the association between injury location and background data.

Results

1575 complaints of lower extremity disorders and 328 complaints in other body parts were registered. According to the multiple regression analysis, practice time per week was significantly shorter for the lower extremity group than the other locations group (OR 0.98; 95% CI 0.963 to 0.999). Athletes whose future goal was at the recreational level had a significantly low incidence of new injuries after experiencing lower extremity disorders.

Conclusion

The practice environments and psychological factors should receive more attention to prevent lower extremity injuries.

MRI findings of growth plate fractures of the knee: are there age- and fracture-dependent differences?

OBJECTIVE

To investigate MRI findings in children with physeal fractures of the knee with respect to age, location, and articular involvement.

METHODS

Children with physeal fractures who underwent knee MRI between 2008 and 2021 were included. Two radiologists retrospectively reviewed all examinations to determine articular involvement, findings of physeal instability (perichondral disruption, periosteal entrapment), and internal derangement (cruciate ligament injury, meniscal tear, chondromalacia). Independent samples t, Mann-Whitney U, Pearson's chi-square, and Fisher's exact tests were used to compare findings.

RESULTS

Fifty-six patients (37 boys, 19 girls; mean age: 12.2 ± 2.5 years; 32 distal femur, 24 proximal tibial fractures) included 24(43%) intraarticular fractures. Fractures were more common in the tibia than the femur (67% versus 25%, p = 0.004) and intraarticular fractures were more common in older than younger children (13.1 ± 2.0 versus 11.5 ± 2.7 years, p = 0.01), to associate with chondromalacia (46% versus 12%, p = 0.02) and undergo surgery (33% versus 10%, p = 0.04) when compared to extraarticular fractures. Perichondral disruption (n = 44, 79%) and periosteal entrapment (n = 13, 23%) did not significantly differ based on location or articular involvement (p > 0.05). At a median follow-up of 17.5 months (interquartile range: 1.25-34), 3 patients (2 intraarticular, 1 extraarticular fractures) developed osteoarthritis, osteochondral lesion, and leg-length discrepancy from growth arrest, which required additional surgery.

CONCLUSION

Intraarticular physeal fractures were more common with older children, associate with chondromalacia, and underdo surgical intervention when compared to extraarticular fractures of the knee. While MRI findings of physeal instability were common, no significant differences were found between fractures based on anatomic location or fracture pattern.

Descriptive Epidemiology of Isolated Distal Radius Fractures in Children: Results From a Prospective Multicenter Registry

INTRODUCTION

More than 1 in 4 pediatric fractures involves the distal radius. Most prior epidemiologic studies are limited to retrospective, single center investigations, and often include adults. This study aims to describe the contemporary epidemiology of pediatric distal radius fractures using prospectively collected data from a multicenter Pediatric Distal Radius Fracture Registry.

METHODS

Patients aged 4 to 18 years diagnosed with a distal radius fracture from June 2018 through December 2019 at 4 tertiary care pediatric centers were screened and enrolled in this prospective longitudinal cohort study. Patients were excluded if they presented with bilateral distal radius fractures, polytrauma, or re-fracture. Demographic information, mechanism of injury, fracture characteristics, associated injuries, and procedural information were recorded. All radiographs were reviewed and measured. Descriptive statistics and bivariate analyses were performed.

RESULTS

A total of 1951 patients were included. The mean age was 9.9±3.3 years, and 61.3% of patients were male ( P <0.001). Most injuries occurred during a high-energy fall (33.5%) or sports participation (28.4%). The greatest proportion of fractures occurred during the spring months (38.5%). Torus fractures (44.0%) were more common than bicortical (31.3%) or physeal (21.0%) fractures. Of the physeal fractures, 84.3% were Salter-Harris type II. Associated ulnar fractures were observed in 51.2% of patients. The mean age at injury was higher for patients with physeal fractures (11.6±2.9 y) than patients with torus or bicortical fractures (9.4±3.1 and 9.6±3.1 y, respectively; P <0.001). Thirty-six percent of distal radius fractures underwent closed reduction and 3.3% underwent surgical fixation. Patients treated with closed reduction were more likely to be male (68.7% vs. 57.2%; P <0.001), obese (25.3% vs. 17.2%; P <0.001), and have bicortical fractures (62.2% vs. 14.5%; P <0.001).

CONCLUSIONS

Distal radius fractures in children have a male preponderance and are most likely to occur in the spring months and during high-energy falls and sports. Physeal fractures tend to occur in older children while torus and bicortical fractures tend to occur in younger children.

LEVEL OF EVIDENCE

Level I-prognostic.

Growth, maturation and injuries in high-level youth football (soccer): A mini review

Understanding the challenges football (soccer) players face during adolescence is fundamental to avoid disruptions in their development due to injury. This mini review will describe basic concepts of somatic growth and biological maturity, examine data from 53 prospective epidemiological studies on high-level youth football players and discuss how age, growth and maturity may affect the injury patterns observed. Based on the existing evidence, at least every third player sustains an injury during a football season. The thigh (median for studies of boys: 25%, median for girls: 21%), ankle (b: 18%, g: 30%), knee (b: 17%, g: 18%) and hip/groin (b: 14%, g: 10%) are the body parts injured most often, while muscle strains (b: 31%, g: 25%), sprains (b: 20%, g: 27%) and contusions (b: 17%, g: 16%) are the most common injury types. Injury trends are, however, not consistent throughout adolescence, and players' age, maturity status and position relative to peak height velocity (PHV) have shown to influence the number, type and location of injuries sustained. Despite a high volume of observational injury studies published on high-level youth players, girls (7 studies) and settings outside of Europe (included in 23% of studies) are underrepresented and should receive extra attention in the future. Based on the available epidemiological data, tailored injury reduction programmes can be considered in youth football, alongside application of general training principles such as progression, variation and individualization which may be especially important during vulnerable phases such as the adolescent growth spurt.

Comparison of pre-high school and high school football quarterback injuries

OBJECTIVE

To compare the common injuries of pre-high school American football quarterbacks (Pre-HS QBs) and high school American football quarterbacks (HS QBs) within the last 15 years.

METHODS

A retrospective chart review was performed at a sports medicine clinic at a tertiary-level pediatric medical center. Pediatric and adolescent American football quarterback patients who sustained sports-related injuries were extracted. Injury status (acute vs. overuse), injured anatomic locations, injury types, and surgical status were compared by Pre-HS QBs (<14 years old) and HS QBs (14-18 years old).

RESULTS

A total of 121 injuries were found in 118 male Pre-HS QBs (mean age: 12.4 ± 1.6), while 302 injuries were observed in 256 male HS QBs (mean age: 15.8 ± 1.4). Overall, nearly two-third (2/3) of injuries were acute (64.3%) while a little over one-third (1/3) of injuries were overuse in nature (35.7%), and there were no differences between Pre-HS and HS QBs (58.7% vs. 66.7%, p = 0.114). The top 3 injured anatomic locations for Pre-HS QBs were elbow (20.7%), shoulder (18.2%), and head/neck (14.0%). For HS QBs, the top 3 injured anatomic locations were shoulder (24.5%), knee (17.5%), and head/neck (15.2%). There were significant differences in proportion of elbow (20.7% vs. 10.6%, p = 0.006), hip/trunk/upper leg (10.7% vs. 3.3%, p = 0.002), and knee injuries (9.1% vs. 17.5%, p = 0.028) between Pre-HS and HS QBs. Pre-HS QBs had significantly more bony/cartilaginous/labral injuries than their older counterparts (60.3% vs. 46.3%, p = 0.009) while HS QBs experienced significantly more ligamentous injuries than Pre-HS QBs (14.2% vs. 5.8%, p = 0.015).

CONCLUSIONS

QB-associated injuries were distinctively different between Pre-HS and HS QBs. Future studies are warranted to investigate relatively high proportions of elbow injuries as well as bony/cartilaginous/labral injuries found in Pre-HS QBs.

Fracture-Separation of the Medial Humeral Epicondyle Caused by Arm Wrestling: A Systematic Review

Background:

Arm wrestling is a popular sport in which various injuries have occurred, even in children.

Purpose:

To analyze reported fracture-separation of the medial humeral epicondyle (MHE) caused by arm wrestling to determine its mechanism and provide a current overview.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed and Web of Science databases were searched using the terms “arm wrestling” and “humeral fracture” or “medial humeral epicondyle fracture”; and “sports” and “humeral fracture” or “medial humeral epicondyle fracture,” following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were English full-text articles on arm wrestling–induced MHE fracture that described patient characteristics and presented appropriate images. Studies with a lack of appropriate images or detailed description of the injury situation were excluded. The patient characteristics were evaluated, and the ratios of treatment selection and outcomes were evaluated using the chi-square test.

Results:

Included were 27 studies with a total of 68 patients, all boys with a mean age of 14.6 ± 1.24 years (based on n = 65, with 3 patients excluded from this calculation as no definitive age was provided). Boys aged 14 to 15 years accounted for 72% (49/68) of the cases. Fracture occurred suddenly during arm wrestling in 63 boys, while the other 5 boys experienced antecedent medial elbow pain. The match status at the time of injury, provided for 46 patients, was varied. In 31 boys with known match details, injury occurred when a participant suddenly added more force to change the match status. Eight patients displayed anterior and/or proximal displacement of the MHE fragment. Treatment was nonoperative in 25 patients and operative in 38 patients (n = 63, excluding 5 unknown patients). In 35 patients followed up for ≥3 months (mean, 17.6 ± 12.3 months), outcomes were not significantly different between the operative and nonoperative groups.

Conclusion:

MHE fracture-separation caused by arm wrestling occurred mostly in boys aged 14 to 15 years regardless of the match status. The likely direct cause is forceful traction of the attached flexor-pronator muscles. A relative mechanical imbalance during adolescence may be an underlying cause. A sudden change from concentric to eccentric contraction of the flexor-pronator muscles increases the likelihood of fracture occurrence.

Lower extremity physeal fractures and post-traumatic surgical deformities; National Trauma Data Bank and institutional cohorts

Background

Pediatric lower extremity physeal fractures carry a risk of developing deformities. Most epidemiological evidence is over 25 years old, single institution, and lacks follow-up, while recent studies report variable results. Understanding their epidemiology and deformity risk is important for patient counseling and follow-up.

Methods

The National Trauma Data Bank (NTDB) from 2016 was queried to describe the modern epidemiology of physeal fractures. This was contrasted with our 10-year experience of surgically treated deformities. Basic descriptive statistics, Chi-square analysis, prevalence ratios and multivariable linear regression were used to interpret results.

Results

The NTDB contained 22,048 non-physeal and 1,929 physeal fractures of the femur, tibia, and fibula. Physeal fracture prevalence rose after 8 years of age but decreased for girls 2 years sooner than boys. Salter Harris (SH) type 2 fractures predominated. Physeal fractures were more commonly associated with lower energy mechanisms of injury. Distal tibia fractures were more prevalent in the NTDB cohort, while distal femur and SH-1 fractures were more prevalent in the operative cohort. Over 10 years, only 52 (5.3%) of the deformity-correcting surgeries at our institution were for physeal fracture sequelae. Age at injury and intraarticular fractures were associated with shorter times from injury to deformity correction.

Conclusion

Lower extremity physeal fractures are uncommon. Fracture pattern prevalence differs from an operative cohort. Proximal tibia physeal fractures appear to be an underappreciated source of deformity. The risk of developing deformity requiring operative intervention appears to be low and is generally treated within 2 years of initial injury.

Inconsistencies and Imprecision in the Nomenclature Used to Describe Primary Periphyseal Stress Injuries: Towards a Better Understanding

Stress injuries involving the epiphyseal-physeal-metaphyseal complex affecting the extremities of child and adolescent athletes were first described in the early 1950s. Initially observed in Little League baseball players, these injuries are now known to affect skeletally immature athletes in a variety of sports that involve high-impact repetitive overuse activities. Collectively known as primary periphyseal stress injuries, they may affect the long bones around the shoulder, elbow, wrist, hand, hip, knee, ankle, and foot of young athletes. These injuries respond well to timely treatment and relative rest, while non-compliance with non-operative treatment can produce skeletal growth disruption and resultant limb deformity. A major concern raised from the existing literature on primary periphyseal stress injuries is the long history of inconsistent and imprecise terminology used to describe these injuries. A variety of terms have been used to describe primary periphyseal stress injuries, including those which potentially misinform regarding who may be affected by these injuries and the true nature and pathophysiologic mechanisms involved. These imprecisions and inconsistencies arise, at least in part, from a misunderstanding or incomplete understanding of the nature and mechanism of primary periphyseal stress injuries. In this article, we examine the inconsistent and imprecise nomenclature historically used to describe primary periphyseal stress injuries. We also offer a novel framework for understanding the pathophysiologic mechanisms behind these injuries, and provide suggestions for more standard use of terminology and further research moving forward.

Differences in skeletal growth pattern of yoga practising adolescent girls: A cross-sectional study

Background

Yogasana improves both mental and physical health. There is sparse systematic research on the growth of yogasana practising adolescents.

Objectives

This study aims to assess the differential skeletal growth pattern among pre-adolescent and adolescent girls as a result of yoga practice.

Methods

A cross-sectional anthropometric study was conducted on stature (height), sitting height and leg length of 757 school-going girls (4-15 years old), divided in two groups, Yoga Group (YG) (n=380) and age matched Control Group (CG) (n=377) participants participating in recreational games other than yoga. Descriptive and inferential statistical analyses were applied. Unpaired t-test was performed for assessment of level of significance and Pearson's correlation (r) test was performed to to identify the association between growth pattern of stature and leg length at specific ages.

Results

The physical growth showed an ascending trend in both Yoga group (YG)2 participants and control group (CG)3 . At the onset of adolescence (10–12 years) the mean stature and leg length of YG participants were retarded (p < 0.05). Sitting height in YG was significantly (p < 0.05) low only in 10-year-olds. The similar trends were observed in stature and leg length in YG participants at 10 years (5th and 10th percentile) and 12 years (90th and 95th percentile). There was strong positive relationship between stature and leg length of YG participants (10 years, r = 0.86, p < 0.01; 11 years, r = 0.86, p < 0.01; 12 years, r = 0.72, p < 0.01). The stunted growth in YG participants during adolescence may be related to retarded growth of leg length.

Conclusions

Intense yogasana practice with greater skeletal stress possibly hinders stature in adolescent girls from 10 to 12 years. This may compromise with the natural growth pattern, necessitating special care during yoga training among adolescents while selecting the type, intensity and duration of yogasanas practice.

Normalized Isometric Shoulder Strength as a Predictor of Ball Velocity in Youth Baseball Players

BACKGROUND

Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported.

PURPOSE

The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players.

STUDY DESIGN

Prospective cohort study (n=159).

METHODS

Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at α=0.05.

RESULTS

Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001).

CONCLUSION

Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population.

LEVEL OF EVIDENCE

Level 2b (etiology).

Part 2 of the 11+ as an effective home-based exercise programme in elite academy football (soccer) players: a one-club matched-paired randomised controlled trial

Background:Although the 11+ is known to reduce injuries and improve performance in adolescent footballers, its duration presents a notable barrier to implementation. Hence, this study investigated injury and performance outcomes when 65 elite male academy footballers either performed Part 2 3x/week at training (TG) or at home (HG).Methods:Time to stabilisation (TTS), eccentric hamstring strength (EH-S) and countermovement jump height (CMJ-H) were collected 4 times during the 2019 football season. Linear mixed models were used to evaluate main and interaction effects of group and time. Bonferroni post-hoc tests were used to account for multiple comparisons. Differences in time loss and medical attention injuries were determined using a two-tailed Z test for a comparison of rates.Results:Relative to baseline, EH-S (HG 4.3 kg, 95% CI 3 to 5.7, p < 0.001; TG 5.5 kg, 95% CI 4.3 to 6.6, p < 0.001) and CMJ-H (HG 3.5 cm, 95% CI 2.2 to 4.7, p < 0.001; TG 3.2 cm, 95% CI 2.2 to 4.3, p < 0.001) increased, with no difference between groups observed at the end of the season. All injury outcomes were similar.Conclusion: Rescheduling Part 2 did not affect performance or increased injury risks in academy footballers.

Evaluation of a Diagnostic-Therapeutic Algorithm for Finger Epiphyseal Growth Plate Stress Injuries in Adolescent Climbers

BACKGROUND

Finger epiphyseal growth plate stress injuries are the most frequent sport-specific injuries in adolescent climbers. Definitive diagnostic and therapeutic guidelines are pending.

PURPOSE

To evaluate a diagnostic-therapeutic algorithm for finger epiphyseal growth plate stress injuries in adolescent climbers.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

On the basis of previous work on diagnostics and treatment of finger epiphyseal growth plate stress injuries (EGPIs) in adolescent climbers, we developed a new algorithm for management of these injuries, which was implemented into our clinical work. During a 4-year period, we performed a prospective multicentered analysis of our patients treated according to the algorithm. Climbing-specific background was evaluated (training years, climbing level, training methods, etc); injuries were analyzed (Salter-Harris classification and UIAA MedCom score [Union Internationale des Associations d'Alpinisme]); and treatments and outcomes were recorded: union, time to return to climbing, VAS (visual analog scale), QuickDASH (shortened version of the Disabilities of the Arm, Shoulder, and Hand), and a climbing-specific outcome score.

RESULTS

Within the observation period, 27 patients with 37 independent EGPIs of the fingers were recorded (mean ± SD age, 14.7 ± 1.5 years; 19 male, 8 female; 66.7% competitive athletes). Regarding maturity at time of injury, the mean age at injury did not differ by sex. Average UIAA climbing level was 9.5 ± 0.8, with 6 ± 4.6 years of climbing or bouldering and 14 ± 9.1 hours of weekly climbing-specific training volume. Among the 37 injuries there were 7 epiphyseal strains, 2 Salter-Harris I fractures, and 28 Salter-Harris III fractures (UIAA 1, n = 7; UIAA 2, n = 30). Thirty-six injuries developed through repetitive stress, while 1 had an acute onset. Twenty-eight injuries were treated nonoperatively and 9 surgically. Osseous union was achieved in all cases, and there were no recurrences. The time between the start of treatment and the return to sport was 40.1 ± 65.2 days. The climbing-specific outcome score was excellent in 34 patients and good in 3. VAS decreased from 2.3 ± 0.6 to 0.1 ± 0.4 after treatment and QuickDASH from 48.1 ± 7.9 to 28.5 ± 3.3.

CONCLUSION

The proposed management algorithm led to osseous union in all cases. Effective treatment of EGPIs of the fingers may include nonsurgical or surgical intervention, depending on the time course and severity of the injury. Further awareness of EGPI is important to help prevent these injuries in the future.

The Effect of a Functional Strength Training Intervention on Movement Quality and Physical Fitness in Adolescents

This study compared a 12 week Functional Strength Training (FST) program on functional movement and physical performance to typical physical education (PE) classes for middle school (MS) and high school (HS) students. We randomly assigned 266 participants (M age = 14.35, SD = 0.57 years; M height = 164.82, SD = 6.13 cm; M mass = 55.09, SD = 12.19 kg; M BMI = 20.11, SD = 3.54 kg/m²) into an FST or control group. The FST group trained in flexibility and stability, functional movement patterns, and health-related functional strength. The control group continued regular physical education (PE) classes. Each group trained three-times/week in 45 minute sessions for 12 weeks. Outcome measures included the Functional Movement Screen protocol and seven physical performance tests, assessed every four weeks over a 12 week period. We employed a mixed model ANOVA with Bonferroni post-hoc tests to examine differences between and within groups. Compared to the control group, the FST group significantly (p < 0.01) improved Functional Movement Screen total scores (25.7%), curl-ups (70.4%), pull-ups (281.6%), and flexibility (83.6%). We suggest including the FST program in the MS and HS PE curriculum.

The Effects of Physical Activity on Physeal and Skeletal Development

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There is increasing evidence in the literature regarding the important health impact of and risk factors for injury in youth sport.

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Increasing pediatric and adolescent activity intensity, such as is seen in earlier single-sport focus and specialization, may be associated with morphological changes in the growing skeleton.

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Chronic subacute injury to the developing physes in the active child can lead to stress on the growth plate and surrounding tissues that induces developmental morphological changes in the joint.

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There is evidence to suggest that frequent participation in sports that place particular stress across the physes of the proximal humerus, the proximal femur, and the distal radius can be associated with an increased risk of inducing developmental and morphological changes that could lead to future joint dysfunction and premature degeneration.

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Additional research is necessary to better define the pathoetiology of activity-mediated morphological changes, as well as to create and validate parameters for safe involvement in competitive physical activities.

Shedding light on incidence and burden of physeal injuries in a youth elite football academy: A 4-season prospective study

INTRODUCTION

Physeal injuries have been overlooked in epidemiological research in youth sports. Our prospective study investigated the incidence, severity, and burden of physeal injuries in a youth elite football academy.

METHODS

In total, 551 youth male football players from under-9 to under-19 were included and observed over four consecutive seasons. Injuries involving the physis were diagnosed and recorded according to type, location, and diagnosis. Injury incidence (II), severity (days lost), and injury burden (IB) were calculated per squad per season (25 players/squad).

RESULTS

There were 307 physeal injuries: 262 apophyseal (85%), 26 physeal (9%), 2 epiphyseal (1%), and 17 other physeal injuries (5%) with 80% (n=245) causing time-loss. The overall mean incidence of time-loss physeal injuries was 6 injuries/squad-season, leading to a total of 157 days lost/squad-season. The U-16s had the highest burden with 444 days lost per squad-season [median: 20 (95% CI: 12-30) days; II: 10 (95% CI: 7.3.1-13.4)]. Apophyseal injuries of the hip-pelvis resulted in the greatest burden [median: 13 (95% CI: 10-17); II: 2.5 (95% CI: 2.1-3.0)]. Peak apophyseal injury incidence per body parts occurred in U-11 for foot-ankle (II: 2.4; 95% CI: 1.0-4.9), U-14 for knee (II: 4.5; 95% CI: 2.7-7.1), and U-17 for hip-pelvis (II: 6.4; 95% CI: 4.2-9.3).

CONCLUSION

Physeal injuries accounted for a quarter of all-time loss with the largest injury burden in U-16. Most physeal injuries involved the lower limb and affected the apophysis. Physeal and apophyseal injuries incidence, burden, and pattern vary substantially depending on age. Hip-pelvic apophyseal injuries accounted for the largest injury burden.

A longitudinal cohort study of adolescent elite footballers and controls investigating the development of cam morphology

Cam morphology describes an asphericity of the femoral head that develops during adolescence, is highly prevalent in athletes, and predisposes individuals to future osteoarthritis. However, it’s aetiology remains poorly understood. The aim of this study was to perform 3-year longitudinal follow-up of a control population and football club academy cohort to compare the change in hip and growth plate anatomy between athletes and controls. MRI and questionnaires were used to characterise change in hip and growth plate anatomy and quantify activity levels. 121 male academy footballers and 107 male and female controls participated at baseline. Footballers experienced significantly greater increases in femoral head asphericity (4.83 degrees (95% CI: 2.84 to 6.82), p < 0.001) than controls. A positive correlation existed between activity levels and change in femoral head morphology (coefficient 0.79, p  ≤  0.001). Greatest morphological change occurred in individuals aged 11–12 years at baseline, with no significant change in individuals aged 14 years and older at baseline. Cam morphology development was secondary to soft tissue hypertrophy and lateral growth plate extension. In conclusion, excessive loading of the hip joint through exercise prior to 14 years of age may result in growth plate adaptations causing cam morphology. Potential interventions may include training type and load modification in young adolescent football players.

Primary Periphyseal Stress Injuries in Young Athletes: A Systematic Review

BACKGROUND

Overuse injuries are common in sporting children and adolescents. These injuries are a particular concern when they involve the epiphyseal-physeal-metaphyseal (EPM) complex given their potential to disturb skeletal growth. Specifically, the limits of mechanical tolerance of the EPM complex to repetitive stress may be exceeded by the intense and continuous training characteristic of many youth sports today.

OBJECTIVE

This article describes the present status of knowledge on the occurrence and outcome of primary periphyseal stress injuries (PPSIs) affecting the EPM complex in the extremities of children and adolescents involved in youth sports.

METHODS

A comprehensive review of the sports medicine literature was conducted to determine the nature and extent of PPSIs affecting the EPM complex of the extremities among youth sports participants and the potential for consequent skeletal growth disturbance and resultant limb deformity associated with these injuries.

RESULTS

Our initial search uncovered 128 original published scientific articles reporting relevant data on PPSIs. There were 101 case reports/series, 19 cross-sectional, 1 case-control, and 7 cohort studies with relevant data. The case reports/series studies reported 448 patients with PPSIs involving the extremities. Children and adolescents representing a variety of high impact repetitive youth sports activities-including baseball, badminton, climbing, cricket, dance, gymnastics, rugby, soccer, swimming, tennis, and volleyball-may sustain PPSIs involving the shoulder, elbow, hand and wrist, knee, and ankle and foot. Although incidence data from prospective cohort studies are lacking, data arising from cross-sectional studies suggest that PPSIs may be common in select groups of youth athletes-including the shoulder in baseball players (0-36.6%), wrist in gymnasts (10-83%) and platform divers (52.6%), and fingers in rock climbers (5-58%). Notably, not all stress-related skeletal changes detected on imaging were symptomatic in these studies. When diagnosed and treated with an appropriate period of rest and rehabilitation, most patients studied were able to return to their sport activities. However, our data also show that 57/448 PPSIs (12.7%) produced growth disturbance, and that 28/448 patients (6.2%) underwent surgery for their injuries. Absence of treatment, delayed presentation and diagnosis, and non-compliance with a rest regimen were common in cases that produced growth disturbance.

CONCLUSIONS

PPSIs may affect the extremities of children and adolescents engaged in a variety of youth sports, especially at advanced levels of training and competition. Most skeletally immature patients with PPSIs respond well to timely treatment; however, in extreme cases, PPSIs can progress to produce skeletal growth disruption which may necessitate surgical intervention. Clearly, establishing the early diagnosis of PPSIs and providing timely treatment of these injuries are needed to ensure the skeletal health of youth sports participants. Rigorous prospective longitudinal epidemiological and imaging studies designed to provide incidence rates of PPSIs and to determine the effect of PPSIs on long-term skeletal health are also necessary.

Physeal injury in a skeletally immature male athlete

A 12-year-old skeletally immature male athlete presented for evaluation with acute bilateral knee pain. Initial radiographs revealed subtle lucency of the medial proximal tibial physis and MRI was recommended. On MRI, broad-based intravasation of the physis into the proximal femoral and tibial physes was observed. This represented physeal widening, a phenomenon that has been observed in skeletally immature athletes presenting for acute knee pain. While such changes to the physis may be quite prominent on MRI, conventional radiographic findings may be much more subtle. As many causes of chronic knee pain in this population are managed with active rehabilitation, a high index of suspicion for this diagnosis in the presence of physeal abnormalities may warrant evaluation with MRI. The literature suggests this pathology will resolve with rest, but, if weight-bearing activities are continued, there is a risk for significant growth abnormalities.

Youth Distance Running and Lower Extremity Injury: A Systematic Review

Distance running is a popular youth sport. This systematic review identified and examined the effects of youth distance running and lower extremity musculoskeletal injury. Scientific databases were searched from database inception to May 2020. Two hundred and fifty-eight full texts were screened, with nine articles retained for data extraction. Seven of the studies were case reports or case series. Two case reports involved an apophyseal hip fracture. No correlation was found between running mileage or gender and sustaining an injury. Middle school runners reported fewer injuries than high school runners. Cross country accounted for less than 10% of injuries in youth under 15 compared to other track activities. The main finding was a paucity of research. Available literature suggests youth can participate in distance running with minimal adverse effects. One exception may be increased vulnerability to growth plate injury. Additional research is needed, especially in those under 10, as literature in this population is nonexistent.

Type 2 Salter-Harris Physeal Injury of the Proximal Phalanx of Great Toe: A Case Report and Review of Literature

Fractures involving the physes are peculiar to the pediatric age group with growing bones. These injuries, if not managed with due precaution, can lead to complications like physeal arrest and the development of deformity. Such injuries are much more common in the upper limbs as compared to the lower limbs. Physeal injuries involving the small bones of the foot are extremely rare. To date, no case of Salter-Harris type 2 physeal injury involving proximal phalanx of the great toe has been reported in the English literature. We report the first such case of a 10-year-old child who sustained a Salter-Harris type 2 physeal injury of the right great toe proximal phalanx. The fracture was managed conservatively with splintage of the great toe, and the child had good outcome at one year without any adverse sequelae.

The influence of growth and training loads on injury risk in competitive trampoline gymnasts

There is currently limited research exploring the relationship between growth, training load and injury in gymnasts. Twenty-one national level, trampoline gymnasts recorded training load and injury for 8-weeks. Percentage of predicted adult height (%PAH) was calculated using the Khamis-Roche method and used to define growth spurt status. Training load was calculated using the session rate of perceived exertion and analysed as differential loads and as a 7-day exponentially weighted moving average (EWMA7day). There was a significant non-linear association between %PAH and the probability of injury when adjusting for either training load metric (differential load, P = 0.015; EWMA7day; P = 0.008), with the highest injury risk estimated at ~90% PAH (circa growth spurt). The probability of injury significantly increased with increases in EWMA7day training load (RR: 1.88 95% CI: 1.21- 2.91, P = 0.005) but not with differential load. No significant interaction between %PAH, training load and the probability of injury were observed. Data suggest that competitive trampoline gymnasts are at an increased risk of injury during the adolescent growth spurt or with higher weekly training loads. Coaches should be educated and encouraged to identify periods of rapid growth and monitor training load, to reduce the risk of injury.

Premature Growth Plate Closure Caused by a Hedgehog Cancer Drug Is Preventable by Co-Administration of a Retinoid Antagonist in Mice

The growth plates are key engines of skeletal development and growth and contain a top reserve zone followed by maturation zones of proliferating, prehypertrophic, and hypertrophic/mineralizing chondrocytes. Trauma or drug treatment of certain disorders can derange the growth plates and cause accelerated maturation and premature closure, one example being anti-hedgehog drugs such as LDE225 (Sonidegib) used against pediatric brain malignancies. Here we tested whether such acceleration and closure in LDE225-treated mice could be prevented by co-administration of a selective retinoid antagonist, based on previous studies showing that retinoid antagonists can slow down chondrocyte maturation rates. Treatment of juvenile mice with an experimental dose of LDE225 for 2 days (100 mg/kg by gavage) initially caused a significant shortening of long bone growth plates, with concomitant decreases in chondrocyte proliferation; expression of Indian hedgehog, Sox9, and other key genes; and surprisingly, the number of reserve progenitors. Growth plate involution followed with time, leading to impaired long bone lengthening. Mechanistically, LDE225 treatment markedly decreased the expression of retinoid catabolic enzyme Cyp26b1 within growth plate, whereas it increased and broadened the expression of retinoid synthesizing enzyme Raldh3, thus subverting normal homeostatic retinoid circuitries and in turn accelerating maturation and closure. All such severe skeletal and molecular changes were prevented when LDE-treated mice were co-administered the selective retinoid antagonist CD2665 (1.5 mg/kg/d), a drug targeting retinoid acid receptor γ, which is most abundantly expressed in growth plate. When given alone, CD2665 elicited the expected maturation delay and growth plate expansion. In vitro data showed that LDE225 acted directly to dampen chondrogenic phenotypic expression, a response fully reversed by CD2665 co-treatment. In sum, our proof-of-principle data indicate that drug-induced premature growth plate closures can be prevented or delayed by targeting a separate phenotypic regulatory mechanism in chondrocytes. The translation applicability of the findings remains to be studied. © 2021 American Society for Bone and Mineral Research (ASBMR).

Pediatric Musculoskeletal Trauma: Upper Limb

Pediatric upper extremity injuries, acute and chronic due to overuse, are commonly encountered in the clinical setting. However, interpretation of imaging studies is often challenging in pediatric patients because of changing postnatal skeletal development and the broad spectrum of pathology that can potentially occur. This article discusses normal skeletal development and the pathomechanics of skeletal injuries in pediatric patients. It also outlines a framework for imaging as it pertains to the pediatric upper extremity, with specific emphasis on acute and chronic injuries to the shoulder, elbow, forearm, and wrist.

Risk Factors, Diagnosis and Management of Bone Stress Injuries in Adolescent Athletes: A Narrative Review

Physical activity is known to be beneficial for bone; however, some athletes who train intensely are at risk of bone stress injury (BSI). Incidence in adolescent athlete populations is between 3.9 and 19% with recurrence rates as high as 21%. Participation in physical training can be highly skeletally demanding, particularly during periods of rapid growth in adolescence, and when competition and training demands are heaviest. Sports involving running and jumping are associated with a higher incidence of BSI and some athletes appear to be more susceptible than others. Maintaining a very lean physique in aesthetic sports (gymnastics, figure skating and ballet) or a prolonged negative energy balance in extreme endurance events (long distance running and triathlon) may compound the risk of BSI with repetitive mechanical loading of bone, due to the additional negative effects of hormonal disturbances. The following review presents a summary of the epidemiology of BSI in the adolescent athlete, risk factors for BSI (physical and behavioural characteristics, energy balance and hormone disruption, growth velocity, sport-specific risk, training load, etc.), prevention and management strategies.

Enhanced BMP signalling causes growth plate cartilage dysrepair in rats

Growth plate cartilage injuries often result in bony repair at the injury site and premature mineralisation at the uninjured region causing bone growth defects, for which underlying mechanisms are unclear. With the prior microarray study showing upregulated bone morphogenetic protein (BMP) signalling during the injury site bony repair and with the known roles of BMP signalling in bone healing and growth plate endochondral ossification, this study used a rat tibial growth plate drill-hole injury model with or without systemic infusion of BMP antagonist noggin to investigate roles of BMP signalling in injury repair responses within the injury site and in the adjacent "uninjured" cartilage. At days 8, 14 and 35 post-injury, increased expression of BMP members and receptors and enhanced BMP signalling (increased levels of phosphorylated (p)-Smad1/5/8) were found during injury site bony repair. After noggin treatment, injury site bony repair at days 8 and 14 was reduced as shown by micro-CT and histological analyses and lower mRNA expression of osteogenesis-related genes Runx2 and osteocalcin (by RT-PCR). At the adjacent uninjured cartilage, the injury caused increases in the hypertrophic zone/proliferative zone height ratio and in mRNA expression of hypertrophy marker collagen-10, but a decrease in chondrogenesis marker Sox9 at days 14 and/or 35, which were accompanied by increased BMP signalling (increased levels of pSmad1/5/8 protein and BMP7, BMPR1a and target gene Dlx5 mRNA). Noggin treatment reduced the hypertrophic zone/proliferative zone height ratio and collagen-10 mRNA expression, but increased collagen-2 mRNA levels at the adjacent growth plate. This study has identified critical roles of BMP signalling in the injury site bony repair and in the hypertrophic degeneration of the adjacent growth plate in a growth plate drill-hole repair model. Moreover, suppressing BMP signalling can potentially attenuate the undesirable bony repair at injury site and suppress the premature hypertrophy but potentially rescue chondrogenesis at the adjacent growth plate.

Association of Skeletal Maturity and Injury Risk in Elite Youth Soccer Players: A 4-Season Prospective Study With Survival Analysis

BACKGROUND

The association between injury risk and skeletal maturity in youth soccer has received little attention.

PURPOSE

To prospectively investigate injury patterns and incidence in relation to skeletal maturity in elite youth academy soccer players and to determine the injury risks associated with the skeletal maturity status, both overall and to the lower limb apophysis.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All injuries that required medical attention and led to time loss were recorded prospectively during 4 consecutive seasons in 283 unique soccer players from U-13 (12 years of age) to U-19 (18 years). The skeletal age (SA) was assessed in 454 player-seasons using the Fels method, and skeletal maturity status (SA minus chronological age) was classified as follows: late, SA >1 year behind chronological age; normal, SA ±1 year of chronological age; early, SA >1 year ahead of chronological age; and mature, SA = 18 years. An adjusted Cox regression model was used to analyze the injury risk.

RESULTS

A total of 1565 injuries were recorded; 60% were time-loss injuries, resulting in 17,772 days lost. Adjusted injury-free survival analysis showed a significantly greater hazard ratio (HR) for different status of skeletal maturity: early vs normal (HR = 1.26 [95% CI, 1.11-1.42]; P < .001) and early vs mature (HR = 1.35 [95% CI, 1.17-1.56]; P < .001). Players who were skeletally mature at the wrist had a substantially decreased risk of lower extremity apophyseal injuries (by 45%-61%) compared with late (P < .05), normal (P < .05), and early (P < .001) maturers.

CONCLUSION

Musculoskeletal injury patterns and injury risks varied depending on the players' skeletal maturity status. Early maturers had the greatest overall adjusted injury risk. Players who were already skeletally mature at the wrist had the lowest risk of lower extremity apophyseal injuries but were still vulnerable for hip and pelvis apophyseal injuries.

[Apophyseal injuries in sports]

The number of adolescents and children in elite and high-intensity mass sports is increasing, with respect to industrial nations. High-intensity training can cause overload due to the increased traction effect, particularly on tendon and muscle insertion sites. Apophyses are the center for ossification in tendon and muscle insertions and are therefore particularly vulnerable in youths to overload-related pathologies. Core measures in the prevention are a systematic planning of training and the avoidance of mechanical overstraining in the growth period. An exact imaging enables the diagnosis of apophyseal structural damage at an early stage, which in this phase can be healed by a pause in training and conservative measures.

Relationship between humeral retroversion and baseball positions during elementary and junior-high school

BACKGROUND

Humeral retroversion is greater in the dominant shoulder than in the nondominant shoulder in baseball players. However, the effect of different baseball positions during childhood on humeral retroversion remains unknown. The purpose of this study was to investigate the following: (1) the relationship between humeral retroversion and baseball positions played during elementary and junior-high schools; (2) the association between humeral retroversion and the prevalence of pain during the medical checkup and self-reported history of injuries in the dominant shoulder or elbow.

METHODS

We enrolled 149 male high-school baseball players who started playing baseball in elementary school. The subjects were classified into 3 groups according to their baseball positions in elementary and junior-high schools. All participants completed questionnaires regarding their current and past positions, current incidence and history of injuries in their shoulder or elbow joints, and the age they started playing baseball. Shoulder range of motion, humeral retroversion on ultrasonographic-assisted measurement, and the association between humeral retroversion and shoulder and elbow pain were evaluated.

RESULTS

Humeral retroversion was significantly greater in the dominant shoulder than in the nondominant shoulder in all groups (P < .001). In addition, humeral retroversion in the dominant shoulder was significantly greater in players who were pitchers in both elementary and junior-high schools than in those who were fielders during both periods (96.2° and 89.4°, respectively; P = .02). Humeral retroversion in the dominant shoulder was positively correlated (P = .005, r = 0.23) with the length of career as a pitcher during elementary and junior-high schools. Humeral retroversion was not correlated with the prevalence of pain during the medical checkup or self-reported history of injuries in the dominant shoulder or elbow (P values ranging from 0.09-0.99).

CONCLUSION

These results suggest that playing baseball as a pitcher during elementary school and junior-high school affects the increase in humeral retroversion in the dominant shoulder. Increased humeral retroversion in the dominant shoulder by repetitive throwing motion is an adaptive change, rather than a pathologic change.