The Addition of Hand-specific Skeletal Maturity Parameters Does Not Improve Skeletal Maturity Estimation Accuracy of the Modified Fels Wrist System.

BACKGROUND: The Modified Fels Wrist system is potentially the most accurate clinically accessible skeletal maturity system utilizing hand or wrist radiographs. During development, parameters distal to the metacarpals were excluded. We attempted to further optimize the Modified Fels wrist system through the inclusion of hand parameters distal to the metacarpals. METHODS: Forty-three new anteroposterior (AP) hand radiographic parameters were identified from the Fels and Greulich and Pyle (GP) skeletal maturity systems. Twelve parameters were eliminated from further evaluation for poor correlation with skeletal maturity, poor reliability, and lack of relevance in the peripubertal years. In addition to the 8 previously described Modified Fels Wrist parameters, 31 hand radiographic parameters were evaluated on serial peripubertal AP hand radiographs to identify the ones most important for accurately estimating skeletal age. This process produced a "Modified Fels hand-wrist" model; its performance was compared with (1) GP only; (2) Sanders Hand (SH) only; (3) age, sex, and GP; (4) age, sex, and SH; and (5) Modified Fels Wrist system. RESULTS: Three hundred seventy-two radiographs from 42 girls and 38 boys were included. Of the 39 radiographic parameters that underwent full evaluation, 9 remained in the combined Modified Fels Hand-Wrist system in addition to chronological age and sex. Four parameters are wrist specific, and the remaining 5 are hand specific. The Hand-Wrist system outperformed both GP and SH in estimating skeletal maturity ( P <0.001). When compared with the Modified Fels Wrist system, the Modified Fels Hand-Wrist system performed similarly regarding skeletal maturity estimation (0.36±0.32 vs. 0.34±0.26, P =0.59) but had an increased (worse) rate of outlier predictions >1 year discrepant from true skeletal maturity (4.9% vs. 1.9%, P =0.01). CONCLUSIONS: The addition of hand parameters to the existing Modified Fels Wrist system did not improve skeletal maturity estimation accuracy and worsened the rate of outlier estimations. When an AP hand-wrist radiograph is available, the existing Modified Fels wrist system is best for skeletal maturity estimation. LEVEL OF EVIDENCE: Level III.

Correlations Between Eight Comprehensive Skeletal Maturity Systems in a Modern Peripubertal Pediatric Population.

BACKGROUND: Several skeletal maturity systems allow for accurate skeletal age assessment from a wide variety of joints. However, discrepancies in estimates have been noted when applying systems concurrently. The aims of our study were to (1) compare the agreement among 8 different skeletal maturity systems in modern pediatric patients and (2) compare these discrepancy trends qbetween modern and historic children. METHODS: We performed a retrospective (January 2000 to May 2022) query of our picture archiving and communication systems and included peripubertal patients who had at least two radiographs of different anatomic regions obtained ≤3 months apart for 8 systems: (1) proximal humerus ossification system (PHOS), (2) olecranon apophysis ossification staging system (OAOSS), (3) lateral elbow system, (4) modified Fels wrist system, (5) Sanders Hand Classification, (6) optimized oxford hip system, (7) modified Fels knee system, and (8) calcaneal apophysis ossification staging system (CAOSS). Any abnormal (ie, evidence of fracture or congenital deformity) or low-quality radiographs were excluded. These were compared with a cohort from a historic longitudinal study. SEM skeletal age, representing the variance of skeletal age estimates, was calculated for each system and used to compare system precision. RESULTS: A total of 700 radiographs from 350 modern patients and 954 radiographs from 66 historic patients were evaluated. In the modern cohort, the greatest variance was seen in PHOS (SEM: 0.28 y), Sanders Hand (0.26 y), and CAOSS (0.25 y). The modified Fels knee system demonstrated the smallest variance (0.20 y). For historic children, the PHOS, OAOSS, and CAOSS were the least precise (0.20 y for all). All other systems performed similarly in historic children with lower SEMs (range: 0.18 to 0.19 y). The lateral elbow system was more precise than the OAOSS in both cohorts. CONCLUSIONS: The precision of skeletal maturity systems varies across anatomic regions. Staged, single-parameter systems (eg, PHOS, Sanders Hand, OAOSS, and CAOSS) may correlate less with other systems than those with more parameters. LEVEL OF EVIDENCE: Level III-retrospective study.

The Reliability of the Modified Fels Knee Skeletal Maturity System.

BACKGROUND: The recently described Modified Fels knee skeletal maturity system (mFels) has proven utility in prediction of ultimate lower extremity length in modern pediatric patients. mFels users evaluate chronological age, sex, and 7 anteroposterior knee radiographic parameters to produce a skeletal age estimate. We developed a free mobile application to minimize the learning curve of mFels radiographic parameter evaluation. We sought to identify the reliability of mFels for new users. METHODS: Five pediatric orthopaedic surgeons, 5 orthopaedic surgery residents, 3 pediatric orthopaedic nurse practitioners, and 5 medical students completely naïve to mFels each evaluated a set of 20 pediatric anteroposterior knee radiographs with the assistance of the (What's the Skeletal Maturity?) mobile application. They were not provided any guidance beyond the instructions and examples embedded in the app. The results of their radiographic evaluations and skeletal age estimates were compared with those of the mFels app developers. RESULTS: Averaging across participant groups, inter-rater reliability for each mFels parameter ranged from 0.73 to 0.91. Inter-rater reliability of skeletal age estimates was 0.98. Regardless of group, steady proficiency was reached by the seventh radiograph measured. CONCLUSIONS: mFels is a reliable means of skeletal maturity evaluation. No special instruction is necessary for first time users at any level to utilize the (What's the Skeletal Maturity?) mobile application, and proficiency in skeletal age estimation is obtained by the seventh radiograph. LEVEL OF EVIDENCE: Level II.

Which Application Factors Are Associated With Outstanding Performance in Orthopaedic Surgery Residency?

BACKGROUND: Identifying ideal candidates for orthopaedic surgery residency is difficult. Data available for applicant selection are evolving; preclinical grades and the Alpha Omega Alpha (AOA) honors society are being phased out at some medical schools. Similarly, three-digit United States Medical Licensing Examination (USMLE) Step 1 scores have been eliminated. There is renewed interest in improving resident selection to provide a diverse, comprehensive educational opportunity that produces orthopaedic surgeons who are prepared for practice. QUESTIONS/PURPOSES: We sought to identify whether (1) academic achievements, (2) letters of recommendation, (3) research activity, and (4) miscellaneous factors available on Electronic Residency Application Service (ERAS) applications were associated with outstanding residency performance. METHODS: Ten faculty members (22% of all full-time faculty) with extensive educational involvement for at least 7 years, whose expertise covered all subspecialty departments at an urban, academic orthopaedic surgery residency program, were given an anonymous survey on the performance of the four most recent classes of residency graduates (24 residents). This survey was developed due to the lack of a validated residency outcomes tool or objective metrics for residency performance. The evaluated criteria were decided upon after discussion by a relatively large group of academic orthopaedic surgeons considering the factors most important for graduating orthopaedic residents. The faculty were selected based on their long-term knowledge of the residency, along with their diversity of specialty and backgrounds; there were no nonresponders. Faculty graded each resident on a scale from 1 to 10 (higher is better) on six criteria: surgical technical skills, research productivity, clinical knowledge, professionalism, personality, and fellowship match. The mean of the faculty ratings made by all faculty for all six criteria was calculated, producing the overall residency performance score. Factors available on each resident's ERAS application were then correlated with their overall residency performance score. Categorical ERAS factors, including AOA status, five or more honors in core clerkships, at least three exceptional letters of recommendation, collegiate athletics participation, expertise with a musical instrument, and research (6-year) track residents, were correlated with overall residency performance score via point biserial analysis. Continuous ERAS factors including USMLE Step 1 and Step 2 scores, number of publications before residency, number of research years before residency, medical school ranking, and number of volunteer experiences were correlated with overall residency performance score via Pearson correlation. USMLE Step 1 three-digit scores were evaluated despite their recent elimination because of their historic importance as a screening tool for residency interviews and for comparison to USMLE Step 2, which retains a three-digit score. Application factors with a p < 0.2 on univariate analysis (five or more honors in core clerkships, at least three exceptional letters of recommendation, research track residents) were included in a stepwise linear regression model with "overall residency performance score" as the outcome variable. All p values < 0.05 were considered significant. RESULTS: The mean overall residency performance score was 7.9 ± 1.2. Applicants with at least five honors grades in core clerkships had overall residency performance scores 1.2 points greater than those of their peers (95% confidence interval (CI) 0.3 to 2.0; p = 0.01, Cohen ƒ 2 = 0.2, representing a small effect size). ERAS applications including at least three exceptional letters of recommendation were associated with a 0.9-point increase in residency performance (95% CI 0.02 to 1.7; p = 0.046, Cohen ƒ 2 = 0.1, representing a small effect size). Participation in the residency research (6-year) track was associated with a 1-point improvement in residency performance (95% CI 0.1 to 1.9; p = 0.03, Cohen ƒ 2 = 0.2, again, representing a small effect size). Together, these three factors accounted for 53% of the variance in overall residency performance score observed in this study. CONCLUSION: Past clinical excellence, measured by core clerkship grades and exceptional letters of recommendation, is associated with slightly improved overall orthopaedic residency performance scores. Applicants meeting both criteria who also complete a research track residency may perform substantially better in residency than their counterparts, as these three factors accounted for half of all the variance observed in the current study. Although minimum requirements are necessary, traditionally used screening factors (such as USMLE scores, AOA status, medical school rank, and number of publications) may be of less utility in identifying successful future residents than previously thought. LEVEL OF EVIDENCE: Level III, therapeutic study.

Biologics, Stem Cells, Growth Factors, Platelet-Rich Plasma, Hemarthrosis, and Scaffolds May Enhance Anterior Cruciate Ligament Surgical Treatment.

Biologics including mesenchymal stem cells (MSCs), growth factors, and platelet-rich plasma may enhance anterior cruciate ligament (ACL) reconstruction and even ACL primary repair. In addition, hemarthrosis after acute ACL injury represents a source of biologic factors. MSCs can differentiate into both fibroblasts and osteoblasts, potentially providing a transition between the ligament or graft and bone. MSCs also produce cytokines and growth factors necessary for cartilage, bone, ligament, and tendon regeneration. MSC sources including bone marrow, synovium, adipose tissue, ACL-remnant, patellar tendon, and umbilical cord. Also, scaffolds may represent a tool for ACL tissue engineering. A scaffold should be porous, which allows cell growth and flow of nutrients and waste, should be biocompatible, and might have mechanical properties that match the native ACL. Scaffolds have the potential to deliver bioactive molecules or stem cells. Synthetic and biologically derived scaffolds are widely available. ACL reconstruction with improved outcome, ACL repair, and ACL tissue engineering are promising goals. LEVEL OF EVIDENCE: Level V, expert opinion.

Applicability of Shoulder, Olecranon, and Wrist-based Skeletal Maturity Estimation Systems to the Modern Pediatric Population.

BACKGROUND: The proximal humerus ossification system (PHOS), olecranon apophyseal ossification system (OAOS), and modified Fels wrist skeletal maturity system (mFWS) were recently developed or updated using a historical, mostly White, pediatric population. These upper extremity skeletal maturity systems have demonstrated skeletal age estimation performance superior or equivalent to Greulich and Pyle in historical patients. Their applicability to modern pediatric populations has not yet been evaluated. METHODS: We reviewed anteroposterior shoulder, lateral elbow, and anteroposterior hand and wrist x-rays of 4 pediatric cohorts: White males, Black males, White females, and Black females. Peripubertal x-rays were evaluated: males 9 to17 years and females 7 to 15 years. Five nonpathologic radiographs for each age and joint were randomly selected from each group. Skeletal age estimates made by each of the 3 skeletal maturity systems were plotted against the chronological age associated with each radiograph and compared between cohorts, and with the historical patients. RESULTS: Five hundred forty modern radiographs were evaluated (180 shoulders, 180 elbows, and 180 wrists). All radiographic parameters had inter- and intra-rater reliability coefficients at or above 0.79, indicating very good reliability. For PHOS, White males had delayed skeletal age compared with Black males (Δ-0.12 y, P =0.02) and historical males (Δ-0.17 y, P <0.001). Black females were skeletally advanced compared with historical females (Δ0.11 y, P =0.01). For OAOS, White males (Δ-0.31 y, P <0.001) and Black males (Δ-0.24 y, P <0.001) had delayed skeletal age compared with historical males. For mFWS, White males (Δ0.29 y, P =0.024), Black males (Δ0.58 y, P <0.001), and Black females (Δ0.44 y, P <0.001) had advanced skeletal age compared with historical counterparts of the same sex. All other comparisons were not significant ( P >0.05). CONCLUSIONS: The PHOS, OAOS, and mFWS have mild discrepancies in skeletal age estimates when applied to modern pediatric populations depending on the race and sex of the patient. LEVEL OF EVIDENCE: Level III - retrospective chart review.

Applicability of the Modified Fels and Optimized Oxford Skeletal Maturity Estimation Systems to the Modern Pediatric Population.

BACKGROUND: The recently developed modified Fels knee and optimized Oxford hip skeletal maturity systems (SMS) have demonstrated impressive performance compared with the Greulich and Pyle skeletal age atlas when applied to the same historical, mostly white, pediatric population. We sought to determine whether these 2 systems require modification before being used in modern children. METHODS: We collected knee and hip radiographs between January 2015 and September 2020 from our electronic medical record from 4 groups of children: (1) white males, (2) black males, (3) white females, and (4) black females. Males between 9 and 17 years and females between 7 and 15 years were included. After reliability analyses, 5 nonpathologic radiographs for each age and joint were randomly selected from each group and evaluated with the appropriate SMS. The mean discrepancy between each group's chronological age at the time of radiograph and estimated skeletal age was compared between our modern cohort and the historical Bolton-Brush children. After normality testing, paired t tests or Wilcoxon signed-rank tests were performed, as appropriate. A Bonferroni correction was applied to address multiple testing. RESULTS: Three hundred sixty modern radiographs were evaluated (180 knees and 180 hips). All 7 modified Fels knee parameters and all 5 optimized Oxford hip parameters had inter and intrarater reliability coefficients ≥0.7, indicating good to very good reliability. For the modified Fels knee SMS, white males (Δ0.74 y, P <0.001), black males (Δ0.69 y, P <0.001), and black females (Δ0.4 y, P =0.04) had advanced skeletal age compared with their historical counterparts of the same sex. No differences were found between historical and modern patients for the optimized Oxford hip SMS. No differences were found for either SMS comparing modern patients along racial lines ( P >0.05 for all). CONCLUSIONS: Discrepancies in skeletal age estimates made by the modified Fels knee SMS exist between modern pediatric white males, black males, and black females and their historic counterparts. No differences were found when using optimized Oxford hip SMS. Future studies should evaluate how these translate to clinical decision-making. LEVEL OF EVIDENCE: Level III; retrospective chart review.

Anterior and superior plate positions in diaphyseal clavicle fractures produce similar patient outcomes.

PURPOSE: While diaphyseal clavicle fractures can be treated with plate fixation on either the superior or anteroinferior aspect of the clavicle, the optimal plate position remains controversial. The purpose of this study was to determine if anteroinferior vs. superior plating for clavicle fracture fixation leads to better patient outcomes. METHODS: A retrospective review of patients who sustained clavicle fractures (OTA/AO 15.2) treated with superior or anteroinferior plating at a tertiary Level I trauma center from 2015 to 2021 was performed. The clinical outcomes of clavicle fractures were compared between groups treated with an anterior versus a superior approach via Mann-Whitney U and Chi-squared tests as appropriate to evaluate for differences in outcomes between the two plate positions. RESULTS: A total of 315 diaphyseal clavicle fractures were identified. One hundred and forty patients were excluded due to inadequate follow-up. Of the remaining 175 patients, 25 were treated with an anteroinferior approach (14%) and 150 were treated with a superior approach (86%). There were no differences in age, BMI, tobacco use, or substance use between the two groups (p > 0.05 for all). On univariate analysis, there was no difference in rate of union (p = 0.60), nerve injury (p = 0.60), infection (p = 1.0), implant-related irritation (p = 0.42), implant removal (p = 0.26), or revision (p = 1.0) based on approach. Contoured plates had an association with risk of nerve injury (p = 0.04). CONCLUSION: There are no differences in union, nerve injury, infection, symptomatic implant, or revision rate between anteroinferior and superior clavicle approaches. Plate positioning during diaphyseal clavicle fracture fixation can reasonably be dictated based on surgeon preference and ideal reduction quality.

Estimating Skeletal Maturity Using Wrist Radiographs During Preadolescence: The Epiphyseal:Metaphyseal Ratio.

BACKGROUND: Although skeletal maturity is most relevant during adolescence, it has utility in treatment of younger patients in some circumstances, such as scoliosis, limb length discrepancy, or endocrinopathies. Currently, a quick, accurate, and reproducible method of estimating skeletal maturity in preadolescents using wrist radiographs is lacking. METHODS: Serial anteroposterior wrist radiographs taken at historical growth study visits leading up to the chronological age (CA) associated with 90% of the final height (an enhanced skeletal maturity standard as compared with peak height velocity) were analyzed in 102 children. Epiphyseal and metaphyseal widths of 5 physes were evaluated: distal radius, distal ulna, first metacarpal, third metacarpal, and fifth metacarpal. Ulnar styloid height and radial styloid height were also measured, for a total of 7 epiphyseal:metaphyseal radiographic parameters. Greulich and Pyle (GP) bone age was also measured. A combination of stepwise linear regression and generalized estimating equation analyses was used to produce a skeletal maturity estimation model incorporating demographics (CA and sex) and the epiphyseal:metaphyseal ratios significantly correlated with skeletal maturity. RESULTS: A total of 273 left anteroposterior hand-wrist radiographs from 56 girls (163 radiographs, range 4 to 13 y) and 46 boys (112 radiographs, range 3.8 to 15 y) were included. The demographics+ratios model had better prediction accuracy than GP only and GP with demographics (0.44, 0.87, and 0.47 y mean discrepancy from actual skeletal age, P <0.05 for both comparisons). There was no significant difference in the rate of outlier skeletal age estimates, defined as an estimate >1 year off from the true skeletal age, between the demographics+ratios model and the demographics+GP model (5.9% vs. 8.4%, P =0.12). CONCLUSIONS: When combined with CA and sex data, measurement of the epiphyseal:metaphyseal ratios of the left first and third metacarpals allows for improved skeletal maturity estimation compared with the GP technique. CLINICAL RELEVANCE: Our modified wrist skeletal maturity system offers a relatively quick and reproducible method for estimating skeletal maturity extending into the juvenile age range. This study is a level III retrospective study of longitudinal human growth data obtained from the Bolton Brush Collection in Cleveland, Ohio.

Estimating Skeletal Maturity by Segmented Linear Modeling of Key AP Knee Radiographic Parameters.

BACKGROUND: The recently described Modified Fels knee system allows for accurate skeletal maturity estimation using a single anteroposterior knee radiograph but requires evaluation of 7 parameters. A faster method may have clinical utility in the outpatient setting. METHODS: Seven anteroposterior knee radiographic parameters associated with 90% of the final height (an enhanced skeletal maturity standard compared with peak height velocity) were analyzed in 78 children. Segmented linear regression and generalized estimating equation analyses were used to identify the subsets of parameters most important for accurate skeletal maturity estimation for different patient demographics and parameter scores. This process produced abbreviated skeletal maturity systems, which include fewer parameters and are quicker to use. The accuracy of the resulting abbreviated skeletal maturity systems was evaluated and compared with the full 7-parameter Modified Fels knee system and with the Greulich and Pyle (GP) left-hand bone age. RESULTS: A total of 326 left knee radiographs from 41 girls (range, 7 to 15 y) and 37 boys (range, 9 to 17 y) were included. Models generated by segmented regression and generalized estimating equation analysis required fewer parameters (range, 1 to 5 parameters) than the full Modified Fels knee system (7 parameters). Skeletal age estimates produced by segmented regression models were more accurate than GP (P<0.05) and not significantly different from the full Modified Fels system (P>0.05). The percentage of outlier estimations (estimations >1 y off from actual skeletal age) made by segmented regression models was not significantly different from GP (P>0.05) or the Modified Fels knee system (P>0.05). CONCLUSION: An abbreviated version of the Modified Fels knee system estimates skeletal maturity more accurately than the GP system with just 2 to 3 radiographic knee parameters. CLINICAL RELEVANCE: The abbreviated Modified Fels knee system may allow for rapid skeletal age estimation (~30 s) appropriate for routine outpatient practice.

Using Skeletal Maturity in Pediatric Orthopaedics: A Primer.

This article provides researchers with the background and guidance necessary to practically incorporate skeletal maturity estimation into any study of adolescents with imaging of the shoulder, elbow, hand, hip, knee, or foot. It also provides clinicians with a comprehensive, concise synopsis of systems that can be used to estimate skeletal maturity in clinical practice. In the article, we provide a relatively brief overview of each currently available skeletal maturity system that has been validated on a longitudinal dataset. The supplementary files include 2 PowerPoint files for each skeletal maturity system. The first PowerPoint file offers examples and instructions for using each radiographic system. The second PowerPoint file includes 20 graded radiographs that can be used for reliability analyses in the research setting. We have also developed a free mobile application available on the iOS and Android platforms named "What's the Skeletal Maturity?" that allows clinicians to rapidly estimate skeletal maturity on any patient using any commonly obtained orthopaedic radiograph.

The Optimized Oxford Hip Skeletal Maturity System Proves Resilient to Rotational Variation.

BACKGROUND: The recently described optimized Oxford skeletal maturity system utilizes anteroposterior (AP) hip radiographs to accurately, rapidly, and reliably estimate skeletal maturity. However, in the real-world setting, significant positional variation in AP hip radiographs may influence the accuracy of optimized Oxford skeletal age estimates. We sought to evaluate the consistency of skeletal age estimations using the optimized Oxford system between differently rotated radiographs. METHODS: Thirty normal computerized tomography scans of males (15 children, 9 to 15 y) and females (15 children, 8 to 14 y) were obtained retrospectively, converted into 3D reconstructions, and then used to produce simulated hip radiographs in five different rotational positions. The optimized Oxford system was applied to the 150 simulated AP hip radiographs (5 differently rotated views of 30 hips) to produce a skeletal age estimate for each. RESULTS: Rotational position did not have a statistically significant effect on the skeletal age (P=0.84) using 1-way repeated measures analysis of variance. Of the 5 radiographic parameters in the optimized Oxford system, only greater trochanter height showed significant rotational variation after Greenhouse-Geisser correction (F2.58, 74.68=5.98, P<0.001). However, post hoc analyses showed that the greater trochanter height obtained at the most centered position was not different from the other 4 rotational positions (P>0.05 for all). CONCLUSION: The optimized Oxford skeletal maturity system is resilient to rotational variation. Mildly to moderately rotated radiographs obtained in the modern clinical setting can be used for skeletal age estimation by this method, broadening the clinical usage of this system. LEVEL OF EVIDENCE: Level III-diagnostic study.

The Utility of the Modified Fels Knee Skeletal Maturity System in Limb Length Prediction.

BACKGROUND: Predicting ultimate lower extremity length is important in the treatment of lower limb length discrepancy (LLD), congenital limb deficiency, and other etiologies. Utilizing skeletal age over chronological age improves the prediction of ultimate lower extremity length. The recently described modified Fels knee skeletal maturity system allows for skeletal age estimation via imaging always available in LLD patients. We sought to compare the accuracy of the modified Fels knee skeletal maturity system versus chronological age in ultimate limb length prediction of a modern adolescent clinical population. METHODS: The medical records of all patients treated at our institution over a 20-year period with unilateral lower extremity pathology and available lower extremity imaging before and after reaching skeletal maturity were reviewed. Skeletal maturity was defined radiographically by closed distal femoral, proximal tibial, and proximal fibular physes. The femoral, tibial, and lower extremity length was measured in all radiographs. The modified Fels knee skeletal maturity system was applied to all radiographs obtained before maturity to estimate skeletal age. The accuracy of 3 widely utilized lower extremity length prediction systems was compared when utilizing estimated Fels skeletal age versus chronological age inputs. RESULTS: A total of 245 radiographs (109 before maturity) from 43 patients were eligible for inclusion. On cross-sectional analysis, linear modeling using Fels skeletal ages was uniformly associated with higher (improved) R2 values than chronological age-based models. On longitudinal analysis, skeletal age mixed-effects models had significantly lower (improved) Akaike information criterion and Bayesian information criterion values than chronological age models in all cases. Cohen d values were also significantly different (P<0.05) for the skeletal age models compared with chronological age models in all cases. CONCLUSIONS: In the treatment of LLD, the modified Fels knee skeletal maturity system can be readily applied to available imaging to improve the prediction of ultimate femoral, tibial, and lower extremity length. This skeletal maturity system may have significant utility in the estimation of ultimate LLD and determination of appropriate timing of epiphysiodesis. LEVEL OF EVIDENCE: Level III.

Estimating Skeletal Maturity Using Knee Radiographs During Preadolescence: The Epiphyseal:Metaphyseal Ratio.

BACKGROUND: Though skeletal maturity is most relevant during adolescence, it has utility in treatment of younger patients in some circumstances. Accurate estimation of skeletal maturity using knee radiographs would be useful when treating limb length discrepancy and other general medical conditions in preadolescent patients. Currently, a quick, accurate, and reproducible method of estimating skeletal maturity in preadolescents is lacking. METHODS: Serial anteroposterior knee radiographs taken at historical growth study visits leading up to the chronological age associated with 90% of final height (an enhanced skeletal maturity standard as compared with peak height velocity) were analyzed in 75 children. Epiphyseal and metaphyseal widths of the distal femur, proximal tibia, and proximal fibula were measured and the epiphyseal:metaphyseal ratio was calculated. Greulich and Pyle (GP) bone ages were also assigned by an experienced pediatric endocrinologist using left hand radiographs. Stepwise linear regression and generalized estimating equation analyses were used to make a skeletal maturity model incorporating demographics (age+sex) and knee epiphyseal:metaphyseal ratios. RESULTS: A total of 258 left knee radiographs from 39 girls (mean age 8.6 y, range: 2.9 to 13 y) and 36 boys (mean age 10.6 y, range: 3.8 to 15 y) were included. The demographics+ratios model had similar prediction accuracy (0.49 vs. 0.48 y, P=0.84) and rate of outliers (11% vs. 9%, P=0.11) as the demographics+GP model. The demographics+ratios model outperformed all other models evaluated, including a demographics-only model (P<0.001 for all). CONCLUSIONS: When combined with chronological age and sex, epiphyseal:metaphyseal ratio measurement in the knee allows for skeletal maturity estimation comparable to using the GP technique. CLINICAL RELEVANCE: We have defined a knee skeletal maturity system that could be applied in treatment of orthopaedic conditions in preadolescents where a knee radiograph is already obtained, avoiding the need for an additional hand radiograph.

Systematic Isolation of Key Parameters for Estimating Skeletal Maturity on AP Hip Radiographs.

BACKGROUND: The ability to estimate skeletal maturity using a hip radiograph does not yet exist, but may have utility in the treatment of scoliosis, slipped capital femoral epiphysis, and lower limb deformity. We sought to develop a fast, accurate, and reproducible method. METHODS: Fourteen hip radiologic parameters were evaluated on serial anteroposterior hip radiographs from 3 years before to 2 years after the skeletal age associated with 90% of final height, a validated skeletal maturity definition which correlates with the timing of peak height velocity. The Greulich and Pyle (GP) left hand bone age was obtained for comparison. Stepwise linear regression and generalized estimating equation analyses were used to isolate key hip and demographic parameters, creating the "optimized Oxford" skeletal maturity system. The accuracy of the optimized Oxford system in predicting years from 90% of final height was evaluated and compared with systems of demographics only, the modified Oxford, demographics+modified Oxford, and demographics+GP. RESULTS: A total of 284 hip radiographs from 41 girls (range: 7 to 15 y) and 38 boys (range: 9 to 17 y) were included. Following multivariate analyses, 5 of the original 14 hip radiographic parameters remained significant. The predictions made by the optimized Oxford model had greater accuracy and fewer outlier predictions (predictions >1 y off from actual years from 90% of final height) than the demographics only and modified Oxford only models (P<0.05 for all). The optimized Oxford model had greater prediction accuracy than the demographics+modified Oxford model, but similar rates of outlier predictions (P=0.903). No differences in mean prediction accuracy or rate of outlier predictions were observed between the optimized Oxford and the demographics+GP model (P>0.05). CONCLUSION: High precision in skeletal maturity estimation can be achieved by using chronological age, sex, and 5 hip radiographic parameters. CLINICAL RELEVANCE: We have developed a skeletal maturity system that utilizes anteroposterior hip radiographs and performs as accurately as GP.

Subtle Slipped Capital Femoral Epiphysis Is not Associated With Idiopathic Cam Morphology.

BACKGROUND: The etiology of idiopathic cam morphology remains unclear. One theory suggests that subtle slipped capital femoral epiphysis (SCFE) leads to proximal femoral changes resulting in cam morphology. The purpose of this study was to evaluate the association between subtle SCFE and cam morphology in a large osteological collection. METHODS: We examined 962 cadaveric hips to measure 2 markers of cam morphology, alpha angle and anterior femoral head-neck offset (AHNO), and a validated, objective marker of subtle SCFE deformity (calcar ridge line offset). When the femur is viewed medially, the calcar ridge line extends from the lesser trochanter proximally along the postero-inferior femoral neck and points toward the fovea. In SCFE-like deformity, the fovea deviates posteriorly from this projected line. Pearson correlations were performed to evaluate for possible association of calcar ridge line offset with alpha angle and AHNO. In addition, a multiple regression analysis was performed to determine the influence of age, alpha angle, and AHNO on calcar ridge line offset. RESULTS: There was no clinically relevant association between the calcar ridge line offset and alpha angle (r=-0.02, P=0.58) or AHNO (r=0.08, P=0.012). Furthermore, specimens whose calcar ridge line deviated 1 SD above the mean (more SCFE-like deformity) had a smaller alpha angle (46.6±9.1 vs. 48.3±10.6, P=0.046) and greater AHNO (0.83±0.19 vs. 0.77±0.16, P<0.001), both reflecting less cam-like morphology. On regression analysis, increasing age and increasing AHNO (decreased cam morphology) predicted increased calcar ridge line offset, though the model accounted for only 1.2% of the variance. CONCLUSIONS: Subtle SCFE-like deformity, as objectively measured from the calcar ridge line, was not predictive of more cam-like morphology, and in fact mild opposite associations were found. Further study is needed to identify other potential etiologies of idiopathic cam morphology. CLINICAL RELEVANCE: We present evidence from a large, well-documented osteological collection indicating that subtle SCFE is not associated with idiopathic cam morphology.

The More the Merrier: Integrating Multiple Models of Skeletal Maturity Improves the Accuracy of Growth Prediction.

BACKGROUND: Multiple systems using radiographic skeletal markers to measure development have been described, including the Greulich and Pyle Atlas (GP), the Fels Method (Fels), and the Sanders Hand Classification (Sanders). The purpose of this study was to quantitatively assess whether the integration of skeletal maturity assessment methods and demographic variables improves the accuracy of pediatric growth predictions over the use of skeletal markers or chronologic age alone. METHODS: The Brush Inquiry contains prospectively collected longitudinal data on children who lived in Cleveland, Ohio between 1926 and 1942. A total of 16 boys and 29 girls were selected for study. All had age, height, and an anteroposterior radiograph of the hand at each of 3 visits. Those visits occurred at 85%, 90%, and 95% of final height. We determined the growth completed at each visit by dividing the height observed by the final height at skeletal maturity. Boys and girls were analyzed separately using chronologic age, height, GP, Fels, and Sanders. The residual difference between the height predicted and actual height, as well as the SD of the prediction error of the cohort at each time point was calculated. To account for multiple visits from each subject, all linear models were produced using the generalized estimating equations (GEEs) procedure. RESULTS: For boys, age, GP, and Fels performed similarly in predicting growth remaining at all 3 time points. For girls, age, GP, and Fels performed similarly in predicting growth remaining at the 85% and 95% time points; however, the Fels Method demonstrated improved performance at the 90% time point compared with chronologic age (P = 0.0076) and GP alone (P = 0.0155). For both boys and girls, the most accurate multivariate GEE model with the lowest SD of prediction error integrated Fels, age, GP, Sanders, and height. CONCLUSIONS: The most accurate multivariate GEE model of growth prediction for both boys and girls integrated Fels, age, GP, Sanders, and height. When calculating the amount of growth remaining, it is prudent to integrate multiple systems for greater predictive accuracy. LEVEL OF EVIDENCE: Level III.

Fractures in Patients With Diabetes Mellitus: Findings From a 20-year Registry at a Single Level 1 Trauma Center.

INTRODUCTION: Diabetes mellitus (DM) is a risk factor of infection. Although DM has been associated with worse functional outcomes after acetabular fracture, literature regarding the effect of DM on surgical site infection and other early complications is lacking. METHODS: A 20-year registry from a level 1 trauma center was queried to identify 134 patients with DM and 345 nondiabetic patients with acetabular fractures. RESULTS: The diabetic patient population was older (57.2 versus 43.2; P < 0.001) and had higher average body mass index (33.6 versus 29.5; P < 0.001). Eighty-three patients with DM and 270 nondiabetics were treated surgically (62% versus 78%; P < 0.001). Diabetic patients who were younger (54.6 versus 61.4; P = 0.01) with fewer comorbidities (1.7 versus 2.2; P = 0.04) were more frequently managed surgically. On univariate analysis, patients with DM more commonly developed any early infection (28.4% versus 21%; P = 0.049) but were no more likely to develop surgical site infection, or other postoperative complications. Older patient age, length of stay, baseline pulmonary disease, and concurrent abdominal injury were independent predictors of postoperative infection other than surgical site infection. Diabetics that developed infection had more comorbidities (2.4 versus 1.5; P < 0.001) and higher Injury Severity Score (24.1 versus 15.8; P = 0.003), and were more frequently insulin-dependent (72.7% versus 41%; P = 0.01). DISCUSSION: Independent of management strategy, diabetic patients were more likely to develop an infection after acetabular fracture. Insulin dependence was associated with postoperative infection on univariate analysis. Optimal selection of surgical candidates among patients with DM may limit postoperative infections.

The Modified Fels and Abbreviated Modified Fels Knee Skeletal-Maturity Systems in the Prediction of Leg-Length Discrepancy.

BACKGROUND: The Modified Fels (mFels) and Abbreviated Modified Fels (abFels) knee systems have been recently developed as options for grading skeletal maturity without the need for a separate hand radiograph. We sought to determine the interobserver reliability of these systems and to compare their prediction accuracy with that of the Greulich and Pyle (G-P) atlas in a cohort managed with epiphysiodesis for leg-length discrepancy (LLD). METHODS: Three reviewers scored 20 knee radiographs using the mFels system, which includes 5 qualitative and 2 quantitative measures as well as a quantitative output. Short leg length (SL), long leg length (LL), and LLD prediction errors at maturity using the White-Menelaus (W-M) method and G-P, mFels, or abFels skeletal age were compared in a cohort of 60 patients managed with epiphysiodesis for LLD. RESULTS: Intraclass correlation coefficients for the 2 quantitative variables and the quantitative output of the mFels system using 20 knee radiographs ranged from 0.55 to 0.98, and kappa coefficients for the 5 qualitative variables ranged from 0.56 to 1, indicating a reliability range from moderate to excellent. In the epiphysiodesis cohort, G-P skeletal age was on average 0.25 year older than mFels and abFels skeletal ages, most notably in females. The majority of average prediction errors between G-P, mFels, and abFels were <0.5 cm, with the greatest error being for the SL prediction in females, which approached 1 cm. Skeletal-age estimates with the mFels and abFels systems were statistically comparable. CONCLUSIONS: The mFels skeletal-age system is a reproducible method of determining skeletal age. Prediction errors in mFels and abFels skeletal ages were clinically comparable with those in G-P skeletal ages in this epiphysiodesis cohort. Further work is warranted to optimize and validate the accuracy of mFels and abFels skeletal ages to predict LLD and the impact of epiphysiodesis, particularly in females. Both the mFels and abFels systems are promising means of estimating skeletal age, avoiding additional radiation and health-care expenditure. LEVEL OF EVIDENCE: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Optimizing calibration of modern skeletal maturity systems.

Purpose: Greulich and Pyle is the most used system to estimate skeletal maturity but has significant drawbacks, prompting the development of newer skeletal maturity systems, such as the modified Fels skeletal maturity systems based on knee radiographs. To create a new skeletal maturity system, an outcome variable, termed a "skeletal maturity standard," must be selected for calibration of the system. Peak height velocity and 90% of final height are both considered reasonable skeletal maturity standards for skeletal maturity system development. We sought to answer two questions: (1) Does a skeletal maturity system developed using 90% of final height estimate skeletal age as well as it would if it was instead developed using peak height velocity? (2) Does a skeletal maturity system developed using 90% of final height perform as well in lower extremity length prediction as it would if it was instead developed using peak height velocity? Methods: The modified Fels knee skeletal maturity system was recalibrated based on 90% of final height and peak height velocity skeletal maturity standards. These models were applied to 133 serially obtained, peripubertal antero-posterior knee radiographs collected from 38 subjects. Each model was used to estimate the skeletal age of each radiograph. Skeletal age estimates were also used to predict each patient's ultimate femoral and tibial length using the White-Menelaus method. Results: The skeletal maturity system calibrated with 90% of final height produced more accurate skeletal age estimates than the same skeletal maturity system calibrated with peak height velocity (p < 0.05). The 90% of final height and peak height velocity models made similar femoral and tibial length predictions (p > 0.05). Conclusion: Using the 90% of final height skeletal maturity standard allows for simpler skeletal maturity system development than peak height velocity with potentially more accuracy.