A comparison of FELS and Tanner-Whitehouse II skeletal ages in male youth soccer players from the Middle East.

OBJECTIVES: To assess measurement agreement between FELS and Tanner-Whitehouse (TW) II skeletal ages in male youth soccer players from the Middle East. METHODS: We examined agreement between FELS and TW-II skeletal ages using data collected between- and within-subjects (n = 1057 observations) for 409 male, full-time, academy student-athletes recruited as part of the Qatar Football Association national soccer development programme (chronological age range, 9.8 to 18 years; annual screening range, one to seven visits). The Bland-Altman method for repeated measurements estimated the limits of agreement describing the expected range of differences for 95% of pairs of future FELS and TW-II skeletal ages determined on similar individuals from the reference population. RESULTS: The mean difference for TW-II versus FELS protocols was 0.02 years (95% confidence interval, -0.04 to 0.08 years) with lower and upper limits of agreement ranging from -1.39 years (95% confidence interval, -1.48 to -1.30 years) to 1.43 years (95% confidence interval, 1.34 to 1.52 years). CONCLUSION: Differences for 95% of pairs of future skeletal ages determined with FELS and TW-II methods in this population could be as high as ~3 years for some people that suggested protocols may not be interchangeable in youth Middle Eastern athletes. Justification of skeletal age protocol selection rests on knowledge of measurement bias and variability of expected growth estimations for rationalized application to a population of interest.

Skeletal maturation in male elite youth athletes from the Middle East.

OBJECTIVES: To examine the timing and intensity of skeletal maturation of the radius-ulna-short (RUS) bones in elite youth Arab athletes. METHODS: We compared SuperImposition by Translation And Rotation (SITAR) models with different spline degrees of freedom and transformation expressions to summarize 492 longitudinal measurements for individual RUS bones scores assessed from 99 male academy student-athletes (chronological age range, 11.4 to 18 years; annual screening range, four to seven visits). RESULTS: The SITAR model with 5 degrees of freedom and untransformed chronological age was superior to the other models. The mean growth curve increased with age and showed a mid-pubertal double-kink at a RUS score of ~600 bone score units (au). The SITAR model revealed a first peak in the skeletal maturation velocity curve of ~206 au·year-1 occurred at ~13.5 years. The mean age at the second and largest peak occurred at 15.1 years (95% confidence interval [CI], 14.9 to 15.3 years), with the respective estimated peak skeletal ossification rate of 334 au·year-1 (95% CI, 290 to 377 au·year-1 ). The mean age at peak height velocity was 13.5 years (95% CI, 13.3 to 13.7 years), with peak height velocity of 10 cm·year-1 (95% CI, 9.6 to 10.4 cm·year-1 ). CONCLUSION: Application of the SITAR method confirmed two peaks in the skeletal maturation velocity curve, with the second and largest rate of ossification occurring at a relatively later timing of ~1.5 years than the height growth spurt. Knowledge of the RUS bones timing and intensity can be important to advance strategies for athlete performance development purposes.

Association Between Magnetic Resonance Imaging Findings and Time to Return to Sport After Muscle Injuries in High-Level Youth Athletes.

OBJECTIVE: To describe the relationship between magnetic resonance imaging (MRI) findings and time to return to sport (RTS) from muscle injuries in youth athletes. DESIGN: Prospective collection of injury surveillance data over 6 seasons (2014-2015 to 2019-2020) and reanalysis of MRIs by a radiologist blinded to RTS time after the data collection period. SETTING: National sports academy and sports medicine hospital. PARTICIPANTS: Male youth (11-19 years) athletes participating in the football (soccer) or athletics (track and field) programs with a muscle injury. INDEPENDENT VARIABLES: Magnetic resonance imaging findings (eg, grade and location) in time-loss muscle injuries. MAIN OUTCOME VARIABLES: Injury incidence, distributions, and RTS time. RESULTS: In total, 353 time-loss muscle injuries were recorded for 1089 athlete-seasons, of which 85 satisfied our inclusion criteria (MRI within 14 days). Return to sport time was significantly longer for reinjuries compared with index injuries. Associations between MRI findings and RTS time were specific to the muscle group, with significant differences in RTS time observed between categories of structure, location, and grade. The largest number of injuries was to the hamstrings (n = 46), where injuries involving the tendon were more severe than those involving the myotendinous junction and muscle, proximal injuries were more severe than mid-portion and distal, and longer RTS time was observed for higher injury grade ( P < 0.05). CONCLUSIONS: Muscle injuries in youth are diverse and cannot be treated as a single injury type. Specific injury durations can be expected depending on injury characteristics such as reinjury, location, structure, and grade.

The Percentage of Mature Height as a Morphometric Index of Somatic Growth: A Formal Scrutiny of Conventional Simple Ratio Scaling Assumptions.

PURPOSE: To assess conventional assumptions that underpin the percentage of mature height index as the simple ratio of screening height (numerator) divided by actual or predicted adult height (denominator). METHODS: We examined cross-sectional data from 99 academy youth soccer players (chronological age range, 11.5 to 17.7 y) skeletally immature at the screening time and with adult height measurements available at follow-up. RESULTS: The y-intercept value of -60 cm (95% confidence interval, -115 to -6 cm) from linear regression between screening height and adult height indicated the failure to meet the zero y-intercept assumption. The correlation coefficient between present height and adult height of .64 (95% confidence interval, .50 to .74) was not equal to the ratio of coefficient of variations between these variables (CVx/CVy = 0.46) suggesting Tanner's special circumstance was violated. The non-zero correlation between the ratio and the denominator of .21 (95% confidence interval, .01 to .39) indicated that the percentage of mature height was biased low for players with generally shorter adult height, and vice versa. CONCLUSION: For the first time, we have demonstrated that the percentage of mature height is an inconsistent statistic for determining the extent of completed growth, leading to potentially biased inferences for research and applied purposes.

Relative Skeletal Maturity and Performance Test Outcomes in Elite Youth Middle Eastern Soccer Players.

PURPOSE: This study aimed to explore the influence of differences in relative skeletal maturity on performance test outcomes in elite youth soccer players from the Middle East. METHODS: We integrated skeletal age and performance assessments using mixed-longitudinal data available for 199 outfield players (chronological age range, 11.7 to 17.8 yr) enrolled as academy student-athletes (annual screening range, 1 to 5 visits). Skeletal age was determined as per the Tanner-Whitehouse II protocol. Relative maturity was calculated as the difference (∆) between Tanner-Whitehouse II skeletal age minus chronological age. Performance test outcomes of interest were 10-m sprinting, 40-m sprinting, countermovement jump height, and maximal aerobic speed. Separate random-effects generalized additive models quantified differences in performance test outcomes by relative skeletal maturity. Estimated differences were deemed practically relevant based on the location of the confidence interval (95% CI) against minimal detectable change values for each performance test outcome. RESULTS: For 40-m sprinting, differences of +0.51 s (95% CI, +0.35 to +0.67 s) and +0.62 s (95% CI, +0.45 to +0.78 s) were practically relevant for relative maturity status of ∆ = -1.5 yr versus ∆ = +0.5 and ∆ = +1 yr, respectively. For countermovement jump height, a difference of -8 cm (95% CI, -10 to -5 cm) was practically relevant for ∆ = -1.5 yr versus ∆ = +1 yr relative maturity status comparison. Effects for 10-m sprinting and maximal aerobic speed were unclear. CONCLUSIONS: Integration of skeletal age and performance assessments indicated that conventional maturity status classification criteria were inconsistent to inform player development processes in our sample. Between-player differences in test performance may depend on a substantial delay in skeletal maturation (∆ ≤ -1.5 yr) and the performance outcome measure.

Apophysitis Among Male Youth Soccer Players at an Elite Soccer Academy Over 7 Seasons.

BACKGROUND: Apophyseal injuries are common in children and adolescent athletes. These injuries are believed to be caused by repetitive overloading, which can create inflammatory and degenerative conditions in growing bone prominences. However, their prevalence, diagnosis, and treatment in young soccer players have been understudied. PURPOSE: To evaluate characteristics of apophyseal injuries in adolescent athletes at an elite soccer academy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All apophyseal injuries between July 2008 and June 2015 were evaluated. For each injury, the authors recorded the type and location, age of the player, injury date, imaging modalities, and time absent from training/competition. RESULTS: Over the 7 seasons of this study, 210 apophyseal injuries were documented, including 172 simple apophyseal injuries and 38 apophyseal avulsion fractures. The rate of apophyseal injuries was 0.35 per 1000 hours of training exposure. A total of 196 (93.3%) cases were primary injuries, and the rest (6.7%) were reinjuries. Ultrasonography was the most commonly used imaging modality for diagnosis (172 cases; 81.9%). The most common location of apophyseal injuries was the anterior inferior iliac spine (AIIS). Return to sport was faster in athletes with apophyseal injury at the ischiopubic ramus, those with simple apophyseal injuries, and younger athletes. CONCLUSION: The most common location for apophyseal injury among soccer players was the AIIS. Return to training and competition differed according to injury location, type of apophyseal injury, and age.

Tanner-Whitehouse and Modified Bayley-Pinneau Adult Height Predictions in Elite Youth Soccer Players from the Middle East.

PURPOSE: To provide the first scrutiny of adult height prediction protocols based on automated Greulich-Pyle and Tanner-Whitehouse (TW) skeletal ages applied to elite youth soccer players from the Middle East. METHODS: We examined the application of modified Bayley-Pinneau (BoneXpert®), TW-II, and TW-III protocols using mixed-longitudinal data available for 103 subjects (chronological age range, 19.4 to 27.9 yr) previously enrolled as academy student-athletes (annual screening range, one to six visits). Random-effects generalized additive models quantified the presence of systematic mean differences between actual versus predicted adult height. Effects were deemed practically equivalent based on the location of the confidence interval (95% CI) against a realistic difference value of Δ = ± 1 cm. Each model pooled residual standard deviation described the actual precision of height predictions and was used to calculate a 95% prediction interval. RESULTS: The BoneXpert® method overpredicted adult height systematically at chronological ages in the range of approximately 13.5 to 14.5 yr (95% CI range, -1.9 to -1 cm) and Greulich-Pyle skeletal ages between 13.5 and 15 yr (95% CI range, -3.1 to -1 cm). Effects based on TW-II were practically equivalent across the chronological and skeletal age measurement ranges, with this protocol yielding adult height predictions with a precision (standard deviation) of approximately ±2.6 cm. The mean TW-III effects indicated systematic adult height overpredictions until the attainment of 14.5 and 15 yr of chronological age (95% CI range, -3.8 to -1.1 cm) and TW-III skeletal age (95% CI range: -5.2 to -2.3 cm), respectively. CONCLUSIONS: Tanner-Whitehouse-II adult height prediction method provided more consistent estimates and can be considered the method of choice for talent development purposes in youth soccer players from the Middle East.

Injury incidence and injury patterns by category, player position, and maturation in elite male handball elite players.

The aim of this cohort study is to estimate the influence of position, category, and maturity status on the incidence and pattern of injury in handball players, across two seasons. Injury registration from 164 players-season (12-27 years) was conducted, and players were categorized into youth (133) and adults (31), and per position: 27 goalkeepers, 67 backs, 70 wings and pivots. Maturity status in youth players was also measured by testicular volume on clinical examination (32 immature, 101 mature). 190 injuries occurred during 34 221 hours of exposure. Injury incidence in youth was 6.0 per 1000 total hours [CI 95%, 4.8-7.2] (14.9 match [9.7-20.1] and 3.7 training hours [2.7-4.6]; n= 142 injuries), and in adults 6.5 per 1000 total hours [4.4-8.6] (22.2 match [8.8-35.6] and 3.0 training hours [1.3-4.6]; n=48 injuries). There were significant differences in knee (P=0.01) and cartilage injury (P=0.05) according to playing position. There were significant differences according to age category in ankle (P=0.03), head (P=0.01), thigh (P=0.05) and muscular injury (P= 0.02), and apophysitis (P=0.04) for biological maturity state. Adult handball players had more ankle and muscle injuries than youths. Pivot and wings (2nd line) had more knee and cartilage problems. A higher incidence of apophysitis was found in immature youth players.

Hamstring and other thigh injuries in children and young athletes.

BACKGROUND: In adults, hamstring injuries may lead to long periods of rehabilitation and carry a definite risk of recurrence. However, no studies detail how these injuries affect young athletes. OBJECTIVE: To describe and analyze injuries in the hamstring area in young athletes. To identify risk factors for injuries to the hamstring area in this age group, which will make it possible to design and optimize prevention plans. METHODS: The study population consisted of 1157 young athletes with an average age of 13.56 years, all members of the Barcelona Football Club. Injuries to the hamstring area over three consecutive seasons (from July 2007 to June 2010) were analyzed. RESULTS: The 50 injuries in the hamstring muscle complex included 14 injuries to the biceps femoris, 17 to the semitendinosus-semimembranosus complex, 10 cases of delayed onset muscle soreness (DOMS), and nine avulsion of the ischial tuberosity. Hamstring injuries were first identified in young athletes starting from age nine, with an age-related increased rate up to the age of 15, and a lower incidence at age 14, 16, and 18. The average time lost following an hamstring injury was 21 days and 43.4 days following avulsion from the ischium. The highest incidence of injuries occurred in football players. CONCLUSIONS: Hamstring injuries in this group of young athletes are less prevalent than in adults.

Matching-adjusted indirect treatment comparison of ribociclib and palbociclib in HR+, HER2- advanced breast cancer.

BACKGROUND: Ribociclib (RIBO) and palbociclib (PALBO), combined with letrozole (LET), have been evaluated as treatments for hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in separate Phase III randomized controlled trials (RCTs), but not head-to-head. Population differences can lead to biased results by classical indirect treatment comparison (ITC). Matching-adjusted indirect comparison (MAIC) aims to correct these differences. We compared RIBO and PALBO in hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer using MAIC. METHODS: Patient-level data were available for RIBO (MONALEESA-2), while only published summary data were available for PALBO (PALOMA-2). Weights were assigned to MONALEESA-2 patient data such that mean baseline characteristics matched those reported for PALOMA-2; the resulting matched cohort was used in comparisons. Limited by the results reported in PALOMA-2, progression-free survival (PFS) was the primary comparison. Cox regression models were used to calculate adjusted hazard ratios (HRs) for PFS, before indirect treatment comparison (ITC) was performed with 95% confidence intervals. An exploratory analysis was performed similarly for overall survival using earlier PALBO data (PALOMA-1). Grade 3/4 adverse events were also compared. RESULTS: Racial characteristics, prior chemotherapy setting, and the extent of metastasis were the most imbalanced baseline characteristics. The unadjusted PFS HRs were 0.556 (0.429, 0.721) for RIBO+LET versus LET alone and 0.580 (0.460, 0.720) for PALBO+LET versus LET alone. MAIC adjustment resulted in an HR of 0.524 (0.406, 0.676) for RIBO+LET versus LET. PFS ITC using unadjusted trial data produced an HR of 0.959 (0.681, 1.350) for RIBO versus PALBO, or 0.904 (0.644, 1.268) with MAIC. Unadjusted overall survival HR of RIBO versus PALBO was 0.918 (0.492, 1.710); while exploratory MAIC was 0.839 (0.440, 1.598). ITC of grade 3/4 adverse events yielded a risk ratio of 0.806 (0.604, 1.076). CONCLUSION: MAIC was performed for RIBO and PALBO in the absence of a head-to-head trial: though not statistically significant, the results favored RIBO.

Health-related quality of life of postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer treated with ribociclib + letrozole: results from MONALEESA-2.

PURPOSE: Evaluate patient-reported outcomes (PROs) for postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer treated with first-line ribociclib plus letrozole. METHODS: In the phase III MONALEESA-2 study (NCT01958021), 668 patients were randomized 1:1 to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole. PROs were assessed using the European Organisation for Research and Treatment of Cancer core quality-of-life (EORTC QLQ-C30) and breast cancer-specific (EORTC QLQ-BR23) questionnaires. Changes from baseline and time to deterioration in health-related quality of life (HRQoL) were analyzed using linear mixed-effect and stratified Cox regression models, respectively. Exploratory analysis of area-under-the-curve for change from baseline in pain score (AUC-pain) was performed. RESULTS: On-treatment HRQoL scores were consistently maintained from baseline and were similar between arms. A clinically meaningful (> 5 points) reduction in pain score was observed as early as Week 8 and was maintained up to Cycle 15 in the ribociclib arm. A statistically significant increase in mean AUC-pain was also observed in the ribociclib arm. Scores for all other EORTC QLQ-C30 and EORTC QLQ-BR23 domains were maintained from baseline and were similar between arms. CONCLUSIONS: HRQoL was consistently maintained from baseline in postmenopausal women with HR+, HER2- advanced breast cancer receiving ribociclib plus letrozole and was similar to that observed in the placebo plus letrozole arm. Together with the improved clinical efficacy and manageable safety profile, these PRO results provide additional support for the benefit of ribociclib plus letrozole in this patient population.