Changing incidence of slipped capital femoral epiphysis

Physical Examination and Evaluation for Comorbidities in Youth with Obesity

Obesity is a complex and chronic disease that can affect the entire body. The review of systems and physical examination are important components of the evaluation. Laboratory assessment is directed toward known cardiometabolic comorbidities. Regular follow-up visits with repeated review of systems, physical examination, and laboratory testing can facilitate early detection and management of comorbidities of this chronic disease.

Walking and Running of Children with Decreased Femoral Torsion

Understanding the implications of decreased femoral torsion on gait and running in children and adolescents might help orthopedic surgeons optimize treatment decisions. To date, there is limited evidence regarding the kinematic gait deviations between children with decreased femoral torsion and typically developing children, as well as the implications of the same on the adaptation of walking to running. A three-dimensional gait analysis study was undertaken to compare gait deviations during running and walking among patients with decreased femoral torsion (n = 15) and typically developing children (n = 11). Linear mixed models were utilized to establish comparisons within and between the two groups and investigate the relationship between clinical examination, spatial parameters, and the difference in hip rotation between running and walking. Patients exhibited increased external hip rotation during walking in comparison to controls, accompanied by higher peaks for the same as well as for knee valgus and external foot progression angle. A similar kinematic gait pattern was observed during running, with significant differences noted in peak knee valgus. In terms of variations from running to walking, patients internally rotated their initially externally rotated hip by 4°, whereas controls maintained the same internal hip rotation. Patients and controls displayed comparable kinematic gait deviations during running compared to walking. The passive hip range of motion, torsions, and velocity did not notably influence the variation in mean hip rotation from running to walking. This study underlines the potential of 3D gait kinematics to elucidate the functional implications of decreased FT and, hence, may contribute to clinical decision making.

Decade-long Trends in Incidence of Slipped Capital Femoral Epiphysis in the United States: A Nationwide Database Analysis of Over 33 Million Patients

PURPOSE

Slipped capital femoral epiphysis (SCFE) is a prevalent pediatric hip disorder linked to severe complications, with childhood obesity as a crucial risk factor. Despite the rising obesity rates, contemporary data on SCFE's epidemiology remain scarce in the United States. This study examined SCFE incidence trends and demographic risk factors in the United States over a decade.

METHODS

A decade-long (2011 to 2020) retrospective cohort study was undertaken using the Healthcare Cost and Utilization Project National Inpatient Sample. Patients aged younger than 18 years were identified and further analyzed if diagnosed with SCFE through ICD-9 or ICD-10 codes. Key metrics included demographics variables, with multivariate regression assessing demographic factors tied to SCFE, and yearly incidence calculated.

RESULTS

Of 33,180,028 pediatric patients, 11,738 (0.04%) were diagnosed with SCFE. The incidence escalated from 2.46 to 5.96 per 10,000 children, from 2011 to 2020, mirroring childhood obesity trends. Lower socioeconomic status children were predominantly affected. Multivariate analysis revealed reduced SCFE risk in female patients, while Black and Hispanic ethnicities, alongside the Western geographic location, had an increased risk.

CONCLUSION

This study underscores a twofold increase in SCFE incidence over the past decade, aligning with childhood obesity upsurge. Moreover, SCFE disproportionately affects lower SES children, with male sex, Black and Hispanic ethnicities amplifying the risk. This calls for targeted interventions to mitigate SCFE's effect, especially amidst the vulnerable populations.

Incidence and Clinical Characteristics of Slipped Capital Femoral Epiphysis in Patients with Endocrinopathy: A Population-Based Cohort Study

BACKGROUND

Endocrinopathy is a risk factor for slipped capital femoral epiphysis (SCFE). We aimed to determine (1) the incidence of endocrinopathy-associated SCFE compared with that of non-endocrinopathy-associated SCFE, (2) whether the incidence of SCFE increases with the number of deficient hormones, and (3) the clinical characteristics of endocrinopathy-associated SCFE.

METHODS

We conducted a population-based cohort study using a nationwide database in South Korea. All new diagnoses of endocrinopathy or SCFE between 2002 and 2019 in children born between 2002 and 2005 were identified. The incidence of SCFE was calculated for each type of endocrinopathy. The trend of the incidence of SCFE relative to the number of deficient hormones was analyzed. The male:female ratio was compared between endocrinopathy-associated SCFE and non-endocrinopathy-associated SCFE. For endocrinopathy-associated SCFE, the time between the diagnoses of SCFE and endocrinopathy was evaluated.

RESULTS

The incidence of SCFE was higher in children with endocrinopathy than in those without endocrinopathy (37.1/100,000 versus 9.0/100,000 children) (relative risk, 4.1 [95% confidence interval, 2.8-6.1]). Among various endocrinopathies, growth hormone deficiency showed the highest incidence of SCFE (583.8/100,000 children). The Cochran-Armitage test showed a linear trend, with an increased number of deficient hormones being associated with a higher incidence of SCFE (p < 0.001). Male sex was dominant in the non-endocrinopathy-associated SCFE group (73%; 117 of 161), whereas female sex was dominant in the endocrinopathy-associated SCFE group (53%; 16 of 30) (p = 0.009). Twenty-two of the 30 cases of endocrinopathy-associated SCFE were diagnosed after the diagnosis of endocrinopathy, with a median time of 3.6 years between the diagnoses. Six (27%) of these 22 children developed SCFE >5 years after the diagnosis of endocrinopathy.

CONCLUSIONS

The incidence of SCFE was approximately 4 times higher in children with endocrinopathy than in those without endocrinopathy. The risk of SCFE increased with an increased number of deficient hormones. Long-term monitoring of SCFE occurrence in children with endocrinopathies is strongly recommended.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

The McMaster osteotomy-a novel surgical treatment to chronic slipped capital femoral epiphysis: description of surgical technique and case study

Slipped capital femoral epiphysis (SCFE) is a common adolescent hip disorder that can lead to complex proximal femur deformities and devastating consequences such as avascular necrosis, femoroacetabular impingement syndrome and early-onset osteoarthritis. Existing surgical techniques are often insufficient to fully address the constellation of multiplanar deformities in patients with severe SCFE. Therefore, the McMaster Osteotomy, a novel intertrochanteric proximal femur osteotomy, was developed to improve anatomic correction and hip mechanics in patients with chronic SCFE. The McMaster Osteotomy was implemented in two patients (A: 16-year-old male, B: 17-year-old female) with proximal femur deformities due to chronic SCFE. Surgical planning was facilitated with a 3D-printed pelvic model generated from a CT scan of a patient with the SCFE deformity. Patient B also underwent concurrent arthroscopic osteochondroplasty and labral repair. Pre- and post-operative function and radiographic measurements were recorded. Post-operatively, patient A's neck-shaft angle improved from 125° to 136°, Southwick angle from 52° to 33°, neck length from 66 mm to 80 mm and hip internal rotation from 5° to 25°. Patient B's post-operative neck-shaft angle improved from 122° to 136°, Southwick angle from 25° to 15°, neck length from 76 mm to 84 mm, hip internal rotation from 5° to 20° and alpha angle from 87.6° to 44.3°. Both patients are pain-free and have obtained full union of their osteotomies. The McMaster Osteotomy is a versatile technique that can produce a more anatomic reconstruction of hip anatomy and restoration of abductor mechanics. As an extracapsular technique, the risk of femoral head avascular necrosis is minimized.

[Evaluation of care for slipped capital femoral epiphysis (SCFE) in Germany]

INTRODUCTION

The treatment concept for slipped capital femoral epiphysis is still controversial. According to studies, there is currently no recommendation for a universal approach. Therefore, the aim of this study is to analyze the care reality of children with ECF in Germany.

METHODS

The evaluation of the study is performed based on a questionnaire sent to physicians tending to ECF in 2021. Data is compared to the literature.

RESULTS

36 of 47 questionnaires sent out were included. Overall, no significant difference in ECF care was proven in terms of annual caseload or the size of hospital.

CONCLUSION

A high variance in operative SCFE treatment is reported. According to current literature, the modified Dunn procedure is considered the best therapeutic option to date, especially for patients with severe or chronic ECF. However, compared with alternative care options, this is not feasible in every hospital due to its complicating and challenging nature. Central registration, minimum volume regulation, and expansion of continuing education measures can contribute to optimization.

The incidence and management of slipped capital femoral epiphysis: a population-based study

We aimed to investigate the national trends in the incidence and management of slipped capital femoral epiphysis (SCFE) and to report the need for reoperations. We included all <19-year-old patients hospitalised for SCFE in 2004-2014 in mainland Finland (n=159). Data from the Finnish Care Register for Health Care, Statistics Finland, and Turku University Hospital patient charts were analyse for the incidence of SCFE in 2004-2012, the length of stay, and the type of surgery with respect to age, gender, study year, and season. The reoperations and rehospitalisations in 2004-2014 for SCFE were analysed for 2-10 years after surgery. In 2004 to 2012, primary surgery for SCFE was performed for 126 children. The average annual incidence of SCFE was 1.06/100 000 (95% confidence interval [CI], 0.81-1.38) in girls and 1.35/100 000 (95% CI 1.07-1.70) in boys. The median age at surgery was lower in girls than in boys (11 and 13 years, respectively, p<0.0001). During the study period, there was no significant change in the incidence of SCFE (p=0.9330), the type of primary procedures performed (p=0.9988), or the length of stay after the primary procedure (p=0.2396). However, the length of stay after percutaneous screw fixation was shorter compared with open reduction and fixation (mean 3.4 and 7.9 days, respectively, p<0.0001). There was no significant difference in the rate of reoperations according to the type of primary surgery. In conclusion, the incidence of SCFE and the proportion of different primary surgeries have recently remained stable in Finland.

Public Insurance and Single-Guardian Households Are Associated with Diagnostic Delay in Slipped Capital Femoral Epiphysis

BACKGROUND

Extensive literature documents the adverse sequelae of delayed diagnosis of slipped capital femoral epiphysis (SCFE), including worsening deformity and surgical complications. Less is known about predictors of delayed diagnosis of SCFE, particularly the effects of social determinants of health. The purpose of this study was to evaluate the impact of insurance type, family structure, and neighborhood-level socioeconomic vulnerability on the delay of SCFE diagnosis.

METHODS

We reviewed medical records of patients who underwent surgical fixation for stable SCFE at a tertiary pediatric hospital from 2002 to 2021. We abstracted data on demographic characteristics, insurance status, family structure, home address, and symptom duration. We measured diagnostic delay in weeks from the date of symptom onset to diagnosis. We then geocoded patient addresses to determine their Census tract-level U.S. Centers for Disease Control and Prevention (CDC) and Agency for Toxic Substances and Disease Registry (ATSDR) Social Vulnerability Index (SVI), using U.S. Census and American Community Survey data. We performed 3 separate logistic regression models to examine the effects of (1) insurance status, (2) family structure, and (3) SVI on a delay of ≥12 weeks (reference, <12 weeks). We adjusted for age, sex, weight status, number of siblings, and calendar year.

RESULTS

We identified 351 patients with SCFE; 37% (129) had a diagnostic delay of ≥12 weeks. In multivariable logistic regression models, patients with public insurance were more likely to have a delay of ≥12 weeks than patients with private insurance (adjusted odds ratio [OR], 1.83 [95% confidence interval (CI), 1.12 to 2.97]; p = 0.015) and patients from single-guardian households were more likely to have a delay of ≥12 weeks than patients from multiguardian households (adjusted OR, 1.95 [95% CI, 1.11 to 3.45]; p = 0.021). We did not observe a significant increase in the odds of delay among patients in the highest quartile of overall SVI compared with patients from the lower 3 quartiles, in both the U.S. comparison (adjusted OR, 1.43 [95% CI, 0.79 to 2.58]; p = 0.24) and the Massachusetts comparison (adjusted OR, 1.45 [95% CI, 0.79 to 2.66]; p = 0.23).

CONCLUSIONS

The delay in diagnosis of SCFE remains a concern, with 37% of patients with SCFE presenting with delay of ≥12 weeks. Public insurance and single-guardian households emerged as independent risk factors for diagnostic delay. Interventions to reduce delay may consider focusing on publicly insured patients and those from single-guardian households.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Surgeon Preference for Prophylactic Contralateral Fixation in Slipped Capital Femoral Epiphysis (SCFE) Patients: A Nationwide POSNA Survey Study

BACKGROUND

It is estimated that 11% to 60% of unilateral slipped capital femoral epiphysis (SCFE) patients will develop contralateral pathology, usually within 18 months after the first event. Despite this, prophylactic fixation remains controversial, and there is significant variability in surgeon preferences. Thus, this study aimed to determine which factors predict surgeon preferences for prophylactic contralateral pinning in SCFE patients.

METHODS

We designed a survey for pediatric orthopedic surgeons to collect data on (1) surgeon and hospital characteristics, (2) individual preference for contralateral SCFE pinning in three disparate hypothetical scenarios, and (3) personal risk-aversion traits. The questionnaire was distributed across the United States by the POSNA Evidence-Based Orthopaedics Committee. All POSNA members were eligible to respond. We performed analyses to evaluate the role of patient risk factors in hypothetical surgical decision-making and to determine if surgical training, hospital characteristics, and geographic region influenced prophylactic pinning in a surgeon's real-life practice.

RESULTS

A total of 126 POSNA members responded to the survey. In the last year, a median of 6.5 SCFE patients was seen per surgeon (1243 patients total). A median of 10% of those patients underwent prophylactic contralateral fixation. In multiple analyses, surgeons were influenced by body mass index, open triradiate cartilage, patient race, various endocrine abnormalities, and specific radiographic measurements when deciding to fix the contralateral side prophylactically. Moreover, in multivariate regression, more years in practice and a hospital size of 500+ beds predicted fewer prophylactic fixation procedures (all P <0.05). Surgeons practicing in the South Atlantic, New England, and Mountain regions of the United States estimated the highest rate of contralateral pinning.

CONCLUSIONS

This study's findings suggest that multiple factors influence surgeons' decisions to prophylactically fix the contralateral side in SCFE patients. Surgical training, hospital characteristics, and geographical regions played a role in decision-making.

LEVEL OF EVIDENCE

N/A.

Effects of joint loading on the development of capital femoral epiphysis morphology

INTRODUCTION

The deleterious influence of increased mechanical forces on capital femoral epiphysis development is well established; however, the growth of the physis in the absence of such forces remains unclear. The hips of non-ambulatory cerebral palsy (CP) patients provide a weight-restricted (partial weightbearing) model which can elucidate the influence of decreased mechanical forces on the development of physis morphology, including features related to development of slipped capital femoral epiphysis (SCFE). Here we used 3D image analysis to compare the physis morphology of children with non-ambulatory CP, as a model for abnormal hip loading, with age-matched native hips.

MATERIALS AND METHODS

CT images of 98 non-ambulatory CP hips (8-15 years) and 80 age-matched native control hips were used to measure height, width, and length of the tubercle, depth, width, and length of the metaphyseal fossa, and cupping height across different epiphyseal regions. The impact of age on morphology was assessed using Pearson correlations. Mixed linear model was used to compare the quantified morphological features between partial weightbearing hips and full weightbearing controls.

RESULTS

In partial weightbearing hips, tubercle height and length along with fossa depth and length significantly decreased with age, while peripheral cupping height increased with age (r > 0.2, P < 0.04). Compared to normally loaded (full weightbearing) hips and across all age groups, partially weightbearing hips' epiphyseal tubercle height and length were smaller (P < .05), metaphyseal fossa depth was larger (P < .01), and posterior, inferior, and anterior peripheral cupping heights were smaller (P < .01).

CONCLUSIONS

Smaller epiphyseal tubercle and peripheral cupping with greater metaphyseal fossa size in partial weightbearing hips suggests that the growing capital femoral epiphysis requires mechanical stimulus to adequately develop epiphyseal stabilizers. Deposit low prevalence and relevance of SCFE in CP, these findings highlight both the role of normal joint loading in proper physis development and how chronic abnormal loading may contribute to various pathomorphological changes of the proximal femur (i.e., capital femoral epiphysis).

Slipped Capital Femoral Epiphysis Pathogenesis and Its Relation to Obesity—Where Do We Stand? A Narrative Review

Slipped capital femoral epiphysis (SCFE) is the most common adolescent hip disorder in children 9–15 years old with an incidence that ranges from 0.33:100,000 to 24.58:100,000. Idiopathic SCFE is strongly associated with obesity, while atypical SCFE is associated with endocrinopathies, metabolic and renal disease, radiation therapy, and chemotherapy. In this review, we summarized the current data regarding the pathogenesis of SCFE and its association to obesity. In the last years, there have been increasing evidence regarding the implication of obesity in the pathogenesis of SCFE, but no definitive mechanism has been proven. The etiology is probably multifactorial, with both mechanical and metabolic factors contributing to the disease, with the later gaining more ground, especially in obese patients. Understanding what causes the disease will help paediatricians and orthopaedists develop more efficient strategies for treating patients and diminishing complication rates.

Relationship between Slip Severity and BMI in Patients with Slipped Capital Femoral Epiphysis Treated with In Situ Screw Fixation

Background: Slipped capital femoral epiphysis (SCFE) is a hip disorder that occurs in adolescence before epiphyseal plate closure, causing anatomical changes in the femoral head. Obesity is known to be the single most important risk factor for idiopathic slipped capital femoral epiphysis (SCFE), which is highly related to mechanical factors. Meanwhile, as increased slip angle increases major complications in patients with SCFE, slip severity is an important factor to evaluate prognosis. In obese patients with SCFE, higher shear stress is loaded on the joint, which increases the likelihood of slip. The study aim was to assess the patients with SCFE treated with in situ screw fixation according to the degree of the obesity and to find any factors affecting the severity of slip. Methods: Overall, 68 patients (74 hips) with SCFE who were treated with in situ fixation screw fixation were included (mean age 11.38, range: 6–16) years. There were 53 males (77.9%) and 15 females (22.1%). Patients were categorized underweight, normal weight, overweight, and obese depending on BMI percentile for age. We determined slip severity of patients using the Southwick angle. The slip severity was defined as mild if the angle difference was less than 30 degrees, moderate if the angle difference was between 30 and 50 degrees, and severe if the angle difference was greater than 50 degrees. To examine the effects of several variables on slip severity, we used a univariable and multivariate regression analysis. The following data were analyzed: age at surgery, sex, BMI, symptom duration before diagnosis (acute, chronic, and acute on chronic), stability, and ability to ambulate at the time of the hospital visit. Results: The mean BMI was 25.18 (range: 14.7–33.4) kg/m2. There were more patients with overweight and obese than those with normal weight in SCFE (81.1% vs. 18.9%). We did not find significant differences between overall slip severity and degree of obesity or in any subgroup analysis. Conclusions: We did not find a relationship between slip severity and degree of obesity. A prospective study related to the mechanical factors affecting the slip severity according to the degree of obesity is needed.

Increasing incidence of slipped capital femoral epiphysis in Trinidad and Tobago: A 50-year review

Slipped Capital Femoral Epiphysis (SCFE) is a physeal disorder of the proximal femur. Misdiagnosis and late treatment are associated with poorer outcomes. The epidemiology and delays in treatment of the disease between 1968 and 2018 were investigated in North Trinidad. The number of cases presenting annually has increased over the decades and the incidence between 2008-2018 was 2.2 cases per 100 000 per year. Almost 70% of cases were above the 95^th percentile for body weight. Delay in treatment from onset of symptoms was 278 ± 258 days. Awareness of the risk factors and clinical presentation of SCFE may facilitate early diagnosis and treatment, and prevent severe hip disability in adulthood.

Do Patient Demographics and Socioeconomic Status Influence Severity and Time to Diagnosis in Children With Stable Slipped Capital Femoral Epiphysis?

BACKGROUND

The time to diagnosis in stable slipped capital femoral epiphysis (SCFE) is often several months because of nebulous history, symptoms of knee/thigh pain, and Medicaid insurance. This study examined the impact of socioeconomic status and demographics on the time to diagnosis and SCFE severity in Indiana children.

METHODS

A retrospective review of all patients at a tertiary children's hospital with SCFE from January 2010 through March 2021 was performed. Standard demographic data and type of insurance was collected. Neighborhood Atlas Mapping was used to determine the state decile of the area deprivation index (ADI), a measure of socioeconomic status using 17 variables related to income, employment, education, and housing. Statistical analyses consisted of standard univariate and bivariate analyses; logistic regression analysis was used to determine predictors of a mild SCFE. A P<0.05 was considered statistically significant.

RESULTS

There were 142 patients; 81 male and 61 female. The average age was 12.2±1.7 years, lateral epiphyseal shaft angle of 35±19 degrees, and symptom duration of 4.5±5.0 months. There was no correlation between ADI state deciles and lateral epiphyseal shaft angle (r2=0.008) or symptom duration (r2=0.019). Insurance status and race differed by ADI deciles. In the first decile (least disadvantaged), 44% had government insurance and 89% were White; in the 10th decile (most disadvantaged), 95% had government insurance and 38% were White. Predictors of a mild SCFE were female sex [odds ratio (OR): 3.2 [1.5, 7.0]; P=0.004], symptom duration <3 months [OR: 5.3 (2.4, 11.7); P=0.00004], and White race [OR: 2.4 (1.3, 6.2); P=0.01]. Insurance status and ADI were not significant.

CONCLUSIONS

Contrary to other studies, neither insurance or socioeconomic status were associated with a delay in diagnosis or SCFE severity. The symptom duration in children with SCFE does not appear to be decreasing over the last several decades. Further investigation is required as to why.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Is the modified Dunn's procedure superior to in situ fixation? A systematic review and meta-analysis of comparative studies for management of moderate and severe slipped capital femoral epiphysis

PURPOSE

The management of moderate and severe slipped capital femoral epiphysis is controversial. While in situ fixation is commonly used, the modified Dunn's procedure is increasingly popular within high-volume centers. We compared the clinical and radiological outcomes, as well as the rates of femoral head avascular necrosis or chondrolysis in patients managed with either modified Dunn's procedure or in situ fixation.

METHODS

A systematic search of the PubMed, Embase, The Cochrane Library, Science Direct, and Web of Science was performed in August 2021. Studies comparing outcomes and complications of modified Dunn's procedure versus in situ fixation in patients with moderate or severe slipped capital femoral epiphysis were included.

RESULTS

A total of four studies were included in the final analysis. Modified Dunn's procedure did not result in improved clinical outcomes. However, radiological outcomes as measured using Southwick angles and Alpha angles were significantly improved in the modified Dunn's procedure group, with a mean difference of -14.68 (p < 0.00001) and -34.26 degrees (p < 0.00001), respectively, compared to in situ fixation. There was no difference in the odds of femoral head avascular necrosis or chondrolysis, with odds ratio of 0.99 (p = 0.97).

CONCLUSION

Within the limits of our study, modified Dunn's procedure did not improve clinical outcomes. There were significantly improved radiological outcomes without higher odds of femoral head avascular necrosis or chondrolysis. Further long-term studies are required to better guide management of moderate and severe slipped capital femoral epiphysis, especially in unstable slips. In the meantime, we recommend that the modified Dunn's procedure, if done, be restricted to high-volume centers with low complication rates.

LEVEL OF EVIDENCE

Level III-Systematic review of Level III studies.

PROSPERO REGISTRATION NO

CRD42021279503.

Computer-assisted subcapital correction osteotomy in slipped capital femoral epiphysis using individualized drill templates

Background

Subcapital osteotomy by means of surgical hip dislocation is a treatment approach offered for moderate-to-severe cases of Slipped Capital Femoral Epiphysis (SCFE). This procedure is demanding, highly dependent on the surgeon’s experience, and requires considerable radiation exposure for monitoring and securing the spatial alignment of the femoral head. We propose the use of individualized drill guides as an accurate method for placing K-wires during subcapital correction osteotomies in SCFE patients.

Methods

Five CT scans of the hip joint from otherwise healthy patients with moderate-to-severe SCFE were selected (ages 11–14). Three dimensional models of each patient’s femur were reconstructed by manual segmentation and physically replicated using additive manufacturing techniques. Five orthopaedic surgeons virtually identified the optimal entry point and direction of the two threaded wires for each case. 3D printed drill guides were designed specific to each surgical plan, with one side shaped to fit the patient’s bone and the other side containing holes to guide the surgical drill. Each surgeon performed three guided (using the drill guides) and three conventional (freehand) simulated procedures on each case. Each femur model was laser scanned and digitally matched to the preoperative model for evaluation of entry points and wire angulations. We compared wire entry point, wire angulation, procedure time and number of x-rays between guided and freehand simulated surgeries.

Results

The guided group (1.4 ± 0.9 mm; 2.5° ± 1.4°) was significantly more accurate than the freehand group (5.8 ± 3.2 mm; 5.3° ± 4.4°) for wire entry location and angulation (p < 0.001). Guided surgeries required significantly less drilling time and intraoperative x-rays (90.5 ± 42.2 s, 3 ± 1 scans) compared to the conventional surgeries (246.8 ± 122.1 s, 14 ± 5 scans) (p < 0.001).

Conclusions

We conclude that CT-based preoperative planning and intraoperative navigation using individualized drill guides allow for improved accuracy of wires, reduced operative time and less radiation exposure in simulated hips.

Clinical relevance

This preliminary study shows promising results, suggesting potential direct benefits to SCFE patients by necessitating less time under anesthesia and less intra-operative radiation exposure to patients, and increasing surgical accuracy.

A protocol for a nationwide multicentre, prospective surveillance cohort and nested-consented cohort to determine the incidence and clinical outcomes of slipped capital femoral epiphysis

Aims

Slipped capital femoral epiphysis (SCFE) is one of the most common hip diseases of adolescence that can cause marked disability, yet there is little robust evidence to guide treatment. Fundamental aspects of the disease, such as frequency, are unknown and consequently the desire of clinicians to undertake robust intervention studies is somewhat prohibited by a lack of fundamental knowledge.

Methods

The study is an anonymized nationwide comprehensive cohort study with nested consented within the mechanism of the British Orthopaedic Surgery Surveillance (BOSS) Study. All relevant hospitals treating SCFE in England, Scotland, and Wales will contribute anonymized case details. Potential missing cases will be cross-checked against two independent external sources of data (the national administrative data and independent trainee data). Patients will be invited to enrich the data collected by supplementing anonymized case data with patient-reported outcome measures. In line with recommendations of the IDEAL Collaboration, the study will primarily seek to determine incidence, describe case mix and variations in surgical interventions, and explore the relationships between baseline factors (patients and types of interventions) and two-year outcomes.

Discussion

This is the first disease to be investigated using the BOSS Study infrastructure. It provides a robust method to determine the disease frequency, and a large unbiased sample of cases from which treatment strategies can be investigated. It may form the basis for definitive robust intervention studies or, where these are demonstrated not to be feasible, this may be the most robust cohort study.

The Universal Entry Point with oblique screw is superior to fixation perpendicular to the physis in moderate slipped capital femoral epiphysis

PURPOSE

Stable slipped capital femoral epiphysis (SCFE) is often treated with in situ pinning, with the current gold standard being stabilization with a screw perpendicular to the physis. However, this can lead to impingement and a potentially unstable construct. In this study we model the biomechanical effect of two screw positions used for SCFE fixation. We hypothesize that single screw fixation into the centre of the femoral head from the anterior intertrochanteric line (the Universal Entry Point or UEP) provides a more stable construct than single screw fixation perpendicular to the physis with an anterior starting point.

METHODS

Sawbone models of moderate SCFE were used to mechanically test the two screw constructs and an unfixed control group. Models were loaded to failure with a shear load applied through the physis in an Instron mechanical tester. The primary outcomes were maximum load, stiffness and energy to failure.

RESULTS

Screw fixation into the centre of the femoral head from the UEP resulted in a greater load to failure (+19%), stiffness (+13%) and energy to failure (+45%) than screw fixation perpendicular to the physis.

CONCLUSIONS

In this sawbone construct, screw fixation into the centre of the femoral head from the UEP provides greater biomechanical stability than screw fixation perpendicular to the physis. This approach may also benefit by avoiding an intracapsular entry point in soft metaphyseal bone and subsequent risk of impingement and loss of position.

Normative Values for Capital Femoral Epiphyseal Extension of the Developing Hip Based on Age, Sex, and Oxford Bone Age

BACKGROUND

Recent evidence suggests that increasing capital femoral epiphyseal extension may be an adaptive response that underlies the development of most cam morphology, whereas slipped capital femoral epiphysis is associated with its deficiency. However, there is an absence of rigorous data on the normal development of epiphyseal extension in the hip joint in modern adolescents. The aim of this study was to establish normative values for anterior and superior epiphyseal extension in a normal adolescent control population.

METHODS

A total of 210 pediatric subjects (420 hips) between the ages of 8 and 17 years old at the time of presentation who received pelvic radiographs were retrospectively reviewed. Basic demographic data were collected. All subjects with underlying hip pathology were excluded. Epiphyseal extension ratio (EER) was measured, defined as the ratio of extension of the capital femoral epiphysis down the femoral neck relative to the diameter of the femoral head. Superior EER was measured on the anterioposterior view and anterior EER on the frog-leg lateral view bilaterally. Skeletal maturity was graded based on Oxford bone age (OBA) at the proximal femur.

RESULTS

The superior EER increased from 0.63±0.05 at age 8 to 0.80±0.05 at age 17. The anterior EER similarly increased from 0.56±0.06 at age 8 to 0.74±0.05 at age 17. The superior and anterior EERs increased with age in a linear fashion for males (r=0.80 and 0.75, respectively) and females (r=0.67 and 0.65) through physeal closure. When subjects were standardized by the OBA stage of the femoral head, females and males showed no statistical difference at OBA stages 6, 7 or 8.

CONCLUSIONS

Superior and anterior EER increased throughout adolescent development until physeal closure. When controlling for skeletal maturity, there were no significant differences between sexes. This normative data may help guide future management and research of slipped capital femoral epiphysis and cam morphology.

LEVEL OF EVIDENCE

Level II, Diagnostic.

[Slipped Capital Femoral Epiphysis]

Slipped capital femoral epiphysis is the most common hip disease during infancy and adolescence. The incidence of this disease increases continuously. The reason is the likewise increasing body mass index of these age groups. Early diagnostic and treatment are necessary to avoid complications and consequential damages. Primary aims of the treatment are to avoid a further slip of the epiphysis and to reduce the resulting cam-deformity by reposition or osteotomy. After the end of physiological remodelling the rest of cam-deformity should be treated before an early osteoarthritis after slipped capital femoral epiphysis can be developed. There are open as well as arthroscopic surgical procedures for recontouring the femoral neck. The question at hand is to find out which surgical procedure will lead to an improvement of the long term results of slipped capital femoral epiphysis.

Fate of patients with slipped capital femoral epiphysis (SCFE) in later life: risk of obesity, hypothyroidism, and death in 2,564 patients with SCFE compared with 25,638 controls

Background and purpose - Associations between obesity and slipped capital femoral epiphysis (SCFE) during adolescence are described; however, few studies report on the lifetime risk of obesity in patients with SCFE. In addition, with the obesity epidemic in children and adolescents, an increasing incidence of SCFE might be expected. An association of SCFE with hypothyroidism seems ambiguous, and the association between SCFE and depression and all-cause mortality has not yet been evaluated. This study investigates the associations of SCFE with obesity, hypothyroidism, depression, and mortality, and putative changes in the yearly incidence of SCFE.Patients and methods - 2,564 patients diagnosed with SCFE at age 5-16 diagnosed between 1964 and 2011 were identified in the Swedish Patient Register. These were matched for age, sex, and residency with unexposed control individuals. Cox regression models were fitted to estimate the risk of obesity, hypothyroidism, depression, and death, in exposed compared with unexposed individuals.Results - The risk of obesity (HR 9, 95% CI 7-11) and hypothyroidism (HR 3, CI 2-4) was higher in SCFE patients compared with controls. There was no increase in the risk of developing depression (HR 1, CI 1-1.3) in SCFE patients. In contrast, all-cause mortality was higher in SCFE patients than in controls (HR 2, CI 1-2). The incidence of SCFE did not increase over the past decades.Interpretation - Patients with SCFE have a higher lifetime risk of obesity and hypothyroidism and a higher risk of all-cause mortality compared with individuals without SCFE. These findings highlight the lifetime comorbidity burden of patients who develop SCFE in childhood, and increased surveillance of patients with a history of SCFE may be warranted. The incidence of SCFE did not increase over the last decades despite increasing obesity rates.

Capital Femoral Epiphyseal Cupping and Extension May Be Protective in Slipped Capital Femoral Epiphysis: A Dual-center Matching Cohort Study

BACKGROUND

Peripheral cupping of the capital femoral epiphysis over the metaphysis has been reported as a precursor of cam morphology, but may also confer stability of the epiphysis protecting it from slipped capital femoral epiphysis (SCFE). The purpose of this study was to investigate the relationship between a novel morphologic parameter of inherent physeal stability, epiphyseal cupping, and the development of SCFE in a dual-center matched-control cohort study.

METHODS

We performed a dual-center age-matched and sex-matched cohort study comparing 279 subjects with unilateral SCFE and 279 radiographically normal controls from 2 tertiary children's hospitals. All SCFE patients had at least 18 months of radiographic follow-up for contralateral slip surveillance. Anteroposterior and frog lateral pelvis radiographs were utilized to measure the epiphyseal cupping ratio and the current standard measure of inherent physeal stability, the epiphyseal extension ratio.

RESULTS

Control hips were found to have greater epiphyseal cupping than the contralateral uninvolved hip of SCFE subjects both superiorly (0.28±0.08 vs. 0.24±0.06; P<0.001) and anteriorly (0.22±0.07 vs. 0.19±0.06; P<0.001). The 58/279 (21%) subjects who went on to develop contralateral slip had decreased epiphyseal cupping superiorly (0.25±0.07 vs. 0.23±0.05; P=0.03) and anteriorly (0.20±0.06 vs. 0.17±0.04; P<0.001). When we compared controls with hips that did not progress to contralateral slip and hips that further developed a contralateral SCFE, 1-way ANOVA demonstrated a stepwise decrease in epiphyseal cupping and epiphyseal extension ratio in the anterior and superior planes from control hips to contralateral hips without subsequent slip to contralateral hips that developed a SCFE (P<0.01 for each).

CONCLUSIONS

This study provides further evidence that epiphyseal cupping around the metaphysis is associated with decreased likelihood of SCFE and may reflect increased inherent physeal stability. Epiphyseal cupping may represent an adaptive mechanism to stabilize the epiphysis during adolescence at the long-term cost of the eventual development of associated cam-femoroacetabular impingement deformity.

LEVELS OF EVIDENCE

Level III-prognostic Study.

Increased body mass index percentile is associated with decreased epiphyseal tubercle size in asymptomatic children and adolescents with healthy hips

PURPOSE

To investigate whether body mass index (BMI) percentile impacts the morphology of the capital femoral epiphysis in children and adolescents without hip disorders.

METHODS

We assessed 68 subjects with healthy hips who underwent a pelvic CT for evaluation of appendicitis. There were 32 male patients (47%) and the mean age was 11.6 years (sd 2.3). The BMI (k/m²) was calculated for sex- and age-related percentiles according to the Centers for Disease Control and Prevention growth charts. CT images were segmented, and the epiphysis and metaphysis were reformatted using 3D software. We measured the epiphyseal tubercle (height, width and length), the metaphyseal fossa (depth, width and length) and the peripheral cupping of the epiphysis. All measurements were normalized to the diameter of the epiphysis. Pearson's correlation analysis was used to assess the correlations between the variables measured and BMI percentile adjusted for age.

RESULTS

Following adjustment to age, increased BMI correlated to decreased tubercle height (r =-0.34; 95% confidence interval (CI) -0.53 to -0.11; p = 0.005), decreased tubercle length (r = -0.32; 95%CI -0.52 to -0.09; p = 0.008) and decreased tubercle width (r = -0.3; 95% CI -0.5 to -0.07; p = 0.01). There was no correlation between BMI and metaphyseal fossa and epiphyseal cupping measurements.

CONCLUSION

The association between increased BMI percentile and decreased epiphyseal tubercle size, without changes of the metaphyseal fossa and peripheral cupping suggests another morphological change of the femur that may be associated with decreased growth plate resistance to shear stress. Further study is necessary to investigate whether the epiphyseal tubercle size plays a role in the pathogenesis of slipped capital femoral epiphysis in obese children and adolescents.

LEVEL OF EVIDENCE

Level IV.

Evaluation of the Three-Dimensional Translational and Angular Deformity in Slipped Capital Femoral Epiphysis

The purpose of this study was to quantify three-dimensional translational and angular deformity (defined as theta) present at the proximal femoral physis in slipped capital femoral epiphysis (SCFE), and to use theta to differentiate between SCFE hips, contralateral unaffected hips, and normal hips by comparing to the current gold standard measure of the Southwick slip angle (SSA). 3DCT reconstructions of the pelvis and femur in SCFE patients and normal adolescents were obtained and pelvic position was standardized. The center point and direction vector of the femoral epiphysis was determined. The femoral neck axis was defined. The angle between the femoral neck axis and epiphysis vector defined the 3D angle of deformity (theta). The 3D translation of the femoral epiphysis, measured as a percentage of femoral neck diameter, was measured in three planes. The average theta angle was significantly greater in SCFE hips (46.5 ± 24.3°) compared with control (13.7 ± 6.4°) or normal (11.7 ± 3.7°) hips (p < 0.001). There was no significant difference in theta angle between control and normal hips (p = 0.468). Theta angle correlated strongly with SSA (r_s  = 0.737, p < 0.001). Statement of clinical significance: The proximal femoral deformity in patients with slipped capital femoral epiphysis can be defined by measuring displacement of the epiphysis in all three dimensions in relation to the femoral neck axis. This information can be used in epiphyseal reorientation surgery to ensure anatomic reduction. The similarity between control and normal hips may argue against the thought that there is pre-existing deformity in a pre-slip condition of unaffected contralateral hips in SCFE patients. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1081-1088, 2020.

The Atypical Patient With Slipped Capital Femoral Epiphyses May Be at Increased Risk for a Missed Contralateral Slip

Slipped capital femoral epiphysis (SCFE) is a commonly encountered hip disorder. The goal of this study was to describe the incidence of missed contra-lateral SCFE as well as to identify risk factors. The authors hypothesized that contralateral slips are more often missed in patients with severe involvement of the treated side. After institutional review board approval was obtained, a retrospective chart review was performed of all pediatric patients who were treated for sequential and bilateral SCFE at a single institution during an 18-year period. Medical records were reviewed for demographic features and attending surgeon. Radiographs were reviewed for skeletal maturity, Klein's line, and severity of the treated slip. All radiographs were reviewed by 3 pediatric orthopedists. Contralateral SCFE was deemed present when consensus was achieved. Comparisons were made with Fisher's exact test, and P<.05 was considered significant. Of the records that were reviewed, 56 patients met the study criteria. Of these, 19 patients had bilateral involvement and 5 missed slips were identified (8.9%). The patients with missed disease tended to be younger (mean age, 10.8 vs 11.4 years), with a lower body mass index. Fellowship-trained pediatric surgeons were more likely to identify bilateral disease compared with orthopedists without pediatric training (P=.0065). A contralateral slip was more likely to be present in patients who had a positive finding for Klein's line (P<.0001). Severity of the treated slip did not increase the likelihood of missing a contralateral slip. Although Klein's line is a useful tool in the diagnosis of SCFE, a false-negative rate of 40% was observed. The authors recommend increased vigilance when an "atypical" patient with SCFE presents with unilateral disease. [Orthopedics. 2020;43(2):e114-e118.].

Pediatric Hip and Pelvis

The most common pediatric orthopedic conditions of the hip and pelvis involve abnormal architecture of the joint leading to pain and dysfunction. Developmental dysplasia of the hip and femoroacetabular impingement are 2 common and distinct forms of structural pathology in the pediatric hip. The authors also discuss 2 of the more common, and often questioned, pediatric hip disorders-slipped capital femoral epiphysis and Legg-Calvé-Perthes disease. Future investigations are aimed at identifying risk factors to provide pediatric orthopedists tools to risk stratify their patients and understand when conservative approaches such as close observation versus surgical interventions are more appropriate.

Predicting epiphyseal stability of slipped capital femoral epiphysis with preoperative CT imaging

BACKGROUND

We analyzed preoperative CT scans of hips with slipped capital femoral epiphysis (SCFE) for characteristics that could be predictive of intraoperative epiphyseal stability and developed a set of imaging criteria for stable and unstable SCFE. We then compared this grading system with the Loder classification.

METHODS

We reviewed preoperative CT imaging to develop a SCFE stability classification system. Three orthopaedic surgeons used the classification system to grade stability on a series of SCFE hips. Kappa was used to evaluate intra- and interobserver reliability among the observers. A series of SCFE hips treated with open procedures in which intraoperative stability was determined under direct visualization was evaluated. Intraoperative stability was compared with stability ratings as determined by the CT classification system and the Loder classification system.

RESULTS

Interobserver reliability among our three observers was κ = 0.823 (95% confidence interval (CI) 0.414 to 1.0; p < 0.001). Intraobserver reliability was κ = 0.901 (95% CI 0.492 to 1.31; p < 0.001). In all, 27 hips were used in the comparison of intraoperative stability with the Loder and CT classification systems. CT-predicted stability exhibited 78% concordance with intraoperative stability. The sensitivity and specificity of CT-predicted stability was 75% and 82%, respectively, versus Loder sensitivity of 69% and specificity of 91%.

CONCLUSION

The CT evaluation method provided is easy to use and can help to improve the accuracy in determining preoperative epiphyseal stability, which may lead to improved treatment outcomes for this population.

LEVEL OF EVIDENCE

III.

The role of PPARγ in childhood obesity-induced fractures

Globally, obesity is on the rise with ~ 30% of the world’s population now obese, and childhood obesity is following similar trends. Childhood obesity has been associated with numerous chronic conditions, including musculoskeletal disorders. This review highlights the effects of childhood adiposity on bone density by way of analyzing clinical studies and further describing two severe skeletal conditions, slipped capital femoral epiphysis and Blount’s disease. The latter half of this review discusses bone remodeling and cell types that mediate bone growth and strength, including key growth factors and transcription factors that help orchestrate this complex pathology. In particular, the transcriptional factor peroxisome proliferator-activated receptor gamma (PPARγ) is examined as it is a master regulator of adipocyte differentiation in mesenchymal stem cells (MSCs) that can also influence osteoblast populations. Obese individuals are known to have higher levels of PPARγ expression which contributes to their increased adipocyte numbers and decreased bone density. Modulating PPAR*gamma* signaling can have significant effects on adipogenesis, thereby directing MSCs down the osteoblastogenesis pathway and in turn increasing bone mineral density. Lastly, we explore the potential of PPARγ as a druggable target to decrease adiposity, increase bone density, and be a treatment for children with obesity-induced bone fractures.

Risk Factors for Readmission After Surgical Treatment of Slipped Capital Femoral Epiphysis

Slipped capital femoral epiphysis (SCFE) is a common, surgically treated adolescent hip condition. This study sought to evaluate postoperative complications and factors associated with hospital readmission using a nationally representative database. The 2013 Healthcare Cost and Utilization Project's Nationwide Readmissions Database was queried to analyze the incidence of acute readmission and complications for all patients with SCFE. Patients were separated based on 3 different operative approaches (open procedures, closed procedures, or both) and were compared based on choice of procedure, clinical characteristics, patient demographics, comorbidities, and complications. Univariate and multivariate techniques were used to predict readmission and complications. A total of 1082 patients with SCFE were identified; 58 (5.9%) were readmitted within 90 days of the index surgery, and 47 (73.4%) underwent a "closed" surgery, including 18 bilateral (27.4%). Increasing age and shorter primary length of stay were protective against readmission. Patients with the comorbidity of hypothyroidism were 47.4 times more likely to be readmitted. Obesity, sex, and median household income were not predictive of readmission. Patients readmitted were more likely to have undergone an index procedure of closed reduction or both an open and closed reduction procedure. This study is the first to report national SCFE readmission and complication rates and allows pediatric orthopedic surgeons to have a better understanding of associated risk factors. [Orthopedics. 2019; 42(6):e507-e513.].

Temporal changes in slipped upper femoral epiphysis at a regional level: a declining incidence and literature review

PURPOSE

Slipped upper femoral epiphysis (SUFE) is one of the most common adolescent hip pathologies in children with potential for life-long morbidity secondary to avascular necrosis (AVN). The primary aim is to determine an up-to-date demographic of SUFE, as well as current trends in presentation and radiological characteristics. Secondary aims are to quantify prophylactic fixation and subsequent contralateral SUFE.

METHODS

Between 01 January 2013 and 31 December 2015, all cases of SUFE were identified in Northern Ireland. Patient demographics, slip characteristics and outcomes are presented and the incidence rates were calculated using census data. Temporal changes in incidence, compared with a previous cohort, are demonstrated.

RESULTS

A total of 56 patients (80 hips) were identified. Based on census data, SUFE incidence has declined from 7.14 to 4.69/100,000 population aged < 16 years. Male cases predominated by > 2:1 ratio, and tended to be older than female cases. Approximately 75% of patients were above the 75th centile for age-sex adjusted body weight. Knee pain as a presenting symptom led to a delay in diagnosis. Prophylactic fixation was performed in 25.9%, with contralateral slips occurring in 27.5%. AVN occurred in 7.4% and remained static.

CONCLUSION

The incidence of SUFE has declined ~34% in our region. When SUFE occurs, knee pain often results in a delay in definitive diagnosis, and commands clinical vigilance to avoid delays in diagnosis. Patients in our region should be aware of a 1-in-4 contralateral slip rate. Overall, AVN rates remain static and are acceptable, despite the declining incidence of SUFE.

LEVEL OF EVIDENCE

Level III - Retrospective Cohort Study.

[Slipped capital femoral epiphysis-etiology and pathogenesis]

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is the most significant hip disease in adolescence. Because of its typical occurrence at the time of the pubertal growth spurt and some particular clinical symptoms, it has been a topic of special interest in orthopedic research for a long time. A large number of etiological factors have been described, however their meaning in detail is still controversial.

OBJECTIVES

After a short summary of the structure and function of the epiphysis, an overview of concepts in the pathogenesis of SCFE is given.

MATERIALS AND METHODS

A selective review of literature was performed.

RESULTS

Etiology of SCFE includes genetic, endocrinologic, histochemical and biomechanical factors. During puberty, obesity together with reduced femoral antetorsion are the main risk factors for the disease. The rarer atypical SCFE is closely related to metabolic disorders or other chronical diseases. The pathogenesis is characterized by the disproportion between the load-bearing capacity of the epiphysis and the acting forces on the proximal femur.

CONCLUSIONS

The concept of the multifactorial etiology of SCFE is convincing. The susceptibility of the femoral epiphysis is explained considering the remarkable biomechanic local forces. The initial damage can be shown on the histological and the histochemical level. Important new aspects refer to the leptin-metabolism. However, in the majority of cases, biomechanical factors seem to be more significant than endocrinological phenomena. A complete understanding has not succeeded to date.

Comparison of Surgical Outcomes Between a Triplane Proximal Femoral Osteotomy and the Modified Dunn Procedure for Stable, Moderate to Severe Slipped Capital Femoral Epiphysis

BACKGROUND

Recent studies have demonstrated the intra-articular cartilage and labral damage that can occur from the proximal femoral cam-like deformity of a moderate to severe slipped capital femoral epiphysis (SCFE). The approach to treating this deformity in a symptomatic Loder stable hip is controversial. The purpose of this study was to compare radiographic outcomes, complication rates, and revision rates between Imhauser type triplane proximal femoral osteotomy (TPFO) and the modified Dunn procedure (MDP).

METHODS

Twenty-six subjects with minimum 1-year follow-up were included (12 treated with a TPFO, and 14 treated with the MDP). A chart review was performed to capture data related to complications, revision procedures, surgical time, and body mass index. Radiographs were measured preoperatively and at final follow-up to evaluate epiphyseal-slip angle, neck-shaft angle, articular surface to trochanter distance, and medial proximal femoral angle.

RESULTS

Surgical time was shorter for the TPFO group (150.0±57.4 min) compared with the MDP group (203.8±30 min) (P=0.005). All preoperative and postoperative radiographic measures were similar between the 2 groups except postoperative neck-shaft angle, which was significantly less in the TPFO group (129.7±8.6 vs. 140.9±9.4 degrees) (P=0.005). There were no cases of femoral head avascular necrosis (AVN) in the TPFO group. The modified Dunn group had a 29% AVN rate (P=0.1). The overall complication rate was similar between the TPFO (33%) and modified Dunn (36%) groups (P=1.0) and the reoperation rate was slightly greater in the TPFO group (33%) as compared with the modified Dunn group (21%) (P=0.67).

CONCLUSIONS

The complex 3-dimensional proximal femoral deformity of a moderate to severe SCFE can be difficult to treat with relatively high complication/reoperation rates observed in both TPFO and MDP groups. All 4 instances of AVN in this study of stable slips, however, were in the MDP group. As this can be a devastating complication leading to early total hip arthroplasty, we advise against the MDP in stable SCFE patients.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Obesity in Childhood and Adolescence, Genetic Factors

Obesity and excess weight are a pandemic phenomenon in the modern world. Childhood and adolescent obesity often ends up in obesity in adults. The costs of obesity and its consequences are staggering for any society, crippling for countries in development. Childhood obesity is also widespread in Macedonia. Metabolic syndrome, dyslipidemia and carbohydrate intolerance are found in significant numbers. Parents and grandparents are often obese. Some of the children are either dysmorphic, or slightly retarded. We have already described patients with Prader-Willi syndrome, Bardet-Biedl syndrome or WAGR syndrome. A genetic screening for mutations in monogenic obesity in children with early, rapid-onset or severe obesity, severe hyperphagia, hypogonadism, intestinal dysfunction, hypopigmentation of hair and skin, postprandial hypoglycaemia, diabetes insipidus, abnormal leptin level and coexistence of lean and obese siblings in the family discovers many genetic forms of obesity. There are about 30 monogenic forms of obesity. In addition, obesity is different in ethnic groups, and the types of monogenic obesity differ. In brief, an increasing number of genes and genetic mechanisms in children continue to be discovered. This sheds new light on the molecular mechanisms of obesity and potentially gives a target for new forms of treatment.

Natural History of Slipped Capital Femoral Epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) occurs at a rate of 1 in 10,000 to 20,000 children.

METHODS

A PubMed search was undertaken to evaluate recent SCFE literature. A convenience sample of articles were selected and summarized.

RESULTS

Most slips appear well tolerated long-term with ∼5% resulting in total hip arthroplasty (THA) at 20-year follow-up. Classic data reveals poor outcomes following closed reduction for treatment of SCFE. Improvements in intraoperative fluoroscopy and avoidance of pin penetration have reduced the rates of chondrolysis. Unfortunately, avascular necrosis remains a known risk in patients, occurring in 15% to 50% of patients following acute, unstable slips. This is the most common cause of THA in patients with SCFE. Rate of THA due to degenerative arthritis secondary to SCFE is more difficult to determine and occurs at a later age. Although realignment procedures to address anatomic abnormalities from SCFE have increased in popularity, it is unclear if this prevents degenerative arthritis and subsequently reduces the rate of THA. SCFE patients face an increased risk of disability and death due to their underlying medical comorbidities. Interventions for weight loss, blood pressure management, and lifestyle adjustments should be considered at the time of SCFE diagnosis.

CONCLUSIONS

SCFE remains a challenging and common condition for pediatric orthopedists. Although innovative techniques have been proposed, long-term outcome data still supports in situ pinning for stable slips, and in situ pinning with capsular decompression for unstable slips to minimize the risk of avascular necrosis.

Capital Femoral Epiphyseal Extension May Confer Physeal Stability in Slipped Capital Femoral Epiphysis

BACKGROUND

Factors including obesity and morphologic parameters around the hip that increase physeal stress are associated with an increased risk of slipped capital femoral epiphysis (SCFE). Recent evidence suggests that superior epiphyseal extension may confer stability to the physis and help protect against SCFE. The purpose of this study is to investigate the relationship between epiphyseal extension and SCFE using an age-matched and sex-matched cohort study.

METHODS

We generated 2 separate cohorts for comparison: 89 patients with unilateral SCFE and 89 healthy subjects with no evidence of hip disease or deformity. We utilized the anterior-posterior and lateral films of the hip to measure the Southwick angle and the epiphyseal extension ratio (EER), defined as the ratio of extension of the capital femoral epiphysis down the femoral neck relative to the diameter of the femoral head. We then compared these measurements between cohorts and in subgroup analysis based on slip stability and whether subjects progressed to a contralateral slip.

RESULTS

The SCFE cohort demonstrated a decreased superior epiphyseal extension ratio compared with control (superior EER 0.71 vs. 0.68, P=0.002). There was also a significant downward trend in superior EER from the control subjects (0.71±0.07) to the stable slips (0.69±0.06) to the unstable slips (0.65±0.04) with an overall difference between the groups (P=0.001). Eighteen of 44 (41%) subjects with unilateral stable slips and at least 6 months of follow-up went on to develop SCFE of the contralateral limb. The subjects who developed contralateral slips were younger (11.6±1.2 vs. 12.7±1.4 y, P=0.008); however, there was no difference in superior or anterior epiphyseal extension (P=0.75 and 0.23, respectively). There was no significant linear correlation between Southwick angle and superior or anterior EER (r=0.13 and 0.17, respectively, P>0.05 for both).

CONCLUSIONS

Increasing capital femoral epiphyseal extension may confer physeal stability in the setting of SCFE. We propose that this epiphyseal extension reflects an adaptive response to limit physeal stress and reduce the risk for progression to SCFE.

LEVEL OF EVIDENCE

Level III-prognostic study.

Childhood Obesity and Slipped Capital Femoral Epiphysis

: media-1vid110.1542/5828355774001PEDS-VA_2018-1067Video Abstract BACKGROUND: Slipped capital femoral epiphysis (SCFE) is believed to be associated with childhood obesity, although the strength of the association is unknown.

METHODS

We performed a cohort study using routine data from health screening examinations at primary school entry (5-6 years old) in Scotland, linked to a nationwide hospital admissions database. A subgroup had a further screening examination at primary school exit (11-12 years old).

RESULTS

BMI was available for 597 017 children at 5 to 6 years old in school and 39 468 at 11 to 12 years old. There were 4.26 million child-years at risk for SCFE. Among children with obesity at 5 to 6 years old, 75% remained obese at 11 to 12 years old. There was a strong biological gradient between childhood BMI at 5 to 6 years old and SCFE, with the risk of disease increasing by a factor of 1.7 (95% confidence interval [CI] 1.5-1.9) for each integer increase in BMI z score. The risk of SCFE was almost negligible among children with the lowest BMI. Those with severe obesity at 5 to 6 years old had 5.9 times greater risk of SCFE (95% CI 3.9-9.0) compared with those with a normal BMI; those with severe obesity at 11 to 12 years had 17.0 times the risk of SCFE (95% CI 5.9-49.0).

CONCLUSIONS

High childhood BMI is strongly associated with SCFE. The magnitude of the association, temporal relationship, and dose response added to the plausible mechanism offer the strongest evidence available to support a causal association.

Trends in slipped capital femoral epiphysis: is the rate declining?

PURPOSE

Slipped capital femoral epiphysis (SCFE) is an adolescent hip condition with a high risk of complication. The purpose of this study was to evaluate trends in treatment using a prospectively collected paediatric nationally representative database.

METHODS

A total of 9034 patients undergoing treatment for idiopathic SCFE were selected by querying the Healthcare Cost and Utilization Project's Kids' Inpatient Database for the years 1997, 2000, 2003, 2006, 2009 and 2012. The selected patients were separated based on operative approach and these cohorts were analyzed based on temporal and categorical differences in operative approach, patient demographics and clinical characteristics. Univariate and multivariate analyses were used when appropriate and the Mantel-Haenszel test for trend was used in temporal analysis.

RESULTS

Overall SCFE procedures have decreased 27.5% (p < 0.001). Closed procedures have decreased 28.5% (p < 0.001), while open procedures have decreased 44.8% (p < 0.001). Bilateral closed procedures have increased 7.2% (p < 0.001). The ratio of open to closed procedures decreased in patients aged nine to 12 years and increased in patients aged 13 to 16 years (p < 0.001).

CONCLUSION

Here we report age stratified trends in treatment for idiopathic SCFE using nationally representative data and show an overall decrease in admissions and procedures over time.

LEVEL OF EVIDENCE

Level III, retrospective comparison study.

Slipped Capital Femoral Epiphysis: A Review for Pediatricians

Slipped capital femoral epiphysis (SCFE) is one of the most common hip pathologies that occurs during adolescence, and its incidence has been increasing over the past decades. For this reason, pediatricians should be aware of this entity to ensure an early diagnosis and intervene in a timely manner. The typical patient with SCFE is an adolescent who is obese presenting with hip pain, but it can also occur in children who are not obese; therefore, SCFE should be part of the differential diagnosis in any skeletally immature patient presenting with hip or knee pain. This article provides an overview for the clinician of relevant aspects of this disease that can lead to serious long-term consequences if not diagnosed and treated appropriately. [Pediatr Ann. 2018;47(9):e377-e380.].

Slipped Capital Femoral Epiphysis: The European Perspective

Treatment of slipped capital femoral epiphysis remains a contentious and debated issue. The opinion for the correct method of treatment can differ not only between different continents and nations, but also between units and surgeons within individual units. We aim to review the European perspective on the treatment of slipped capital femoral epiphysis and consider the trends for treatment among the European orthopaedic surgical community.

Obesity-related metabolic and endocrine disorders diagnosed during postoperative follow-up of slipped capital femoral epiphysis

Background and purpose - Patients with slipped capital femoral epiphysis (SCFE) are phenotypically overweight or obese and may therefore require clinical follow-up of obesity-related disorders. We evaluated obesity-related disorders such as dyslipidemia, type 2 diabetes mellitus (DM), and vitamin-D deficiency during the postoperative period in patients with SCFE. Patients and methods - 51 patients who were operated and followed-up for SCFE and 62 healthy adolescents without SCFE (control group) were included in this retrospective study. Patients' BMI, serum lipid profile (total cholesterol, LDL-C, HDL-C, triglyceride), fasting blood glucose, HbA1c, and serum vitamin D levels were evaluated. Results - At the time of surgery, 45 patients in the SCFE group were overweight or obese (BMI >25). At the latest follow-up, 42 patients in the SCFE group and 53 patients in the control group were overweight/obese. Abnormal serum lipid profile and ratio of total dyslipidemia were similar between the groups. 8 patients had abnormal HbA1c levels in the SCFE group and mean HbA1c levels were significantly higher in the SCFE group (p = 0.03). All patients and controls had low levels of vitamin D. Interpretation - Although serum lipid profile and vitamin D levels were detected as similar in SCFE and control groups, the potential risk of type 2 DM identified via abnormal HbA1c levels was significantly higher in patients with SCFE. We recommend that patients diagnosed with SCFE should be considered as potential candidates for type 2 DM; thus follow-up after surgical treatment should include not only orthopedic outcomes but also evaluation of future risk for DM.

Morphologic Features of the Contralateral Femur in Patients With Unilateral Slipped Capital Femoral Epiphysis Resembles Mild Slip Deformity: A Matched Cohort Study

BACKGROUND

Hip osteoarthritis has been reported in the contralateral hip in patients who had been treated for unilateral slipped capital femoral epiphysis (SCFE) during adolescence. Although this might be related to the presence of a mild deformity, the morphologic features of the contralateral hip in unilateral SCFE remains poorly characterized.

QUESTIONS/PURPOSES

Do measurements of (1) femoral head-neck concavity (α angle and femoral head-neck offset), (2) epiphyseal extension into the metaphysis (epiphyseal extension ratio and epiphyseal angle), and (3) posterior tilt of the epiphysis (epiphyseal tilt angle) differ between the contralateral asymptomatic hips of patients treated for unilateral SCFE and hips of an age- and sex-matched control population without a history of hip disease?

METHODS

From January 2005 to May 2015, 442 patients underwent surgical treatment for SCFE at our institution. Patients were included in this study if they had a pelvic CT scan and unilateral SCFE defined by pain or a limp in one hip without symptoms or obligatory external rotation with flexion in the contralateral hip and no evidence of SCFE findings on available radiographs. Seventy-two (16%) patients had a pelvic CT scan; however, 32 patients with bilateral involvement and one patient with CT imaging of inadequate quality for multiplanar reformatting were excluded. Thirty-nine control subjects were identified from a preexisting database of patients who underwent pelvic CT between January 2008 and January 2014 for assessment of abdominal pain in the setting of suspected appendicitis. Patients in the contralateral asymptomatic hip group then were matched to control subjects using a modified nearest-neighbor approach based on sex and age. Patients in the contralateral asymptomatic hip group were separated in males and females and control subjects were assigned to an appropriate sex category. Then subjects closest in age were matched with each patient. If more than one subject was available as a match for a given patient, the control subject with the closest BMI was selected. The contralateral asymptomatic hip and matched groups had 19 (49%) male patients and 20 (51%) female patients, with mean ages (± SD) of 16 (± 3) years and 16 (± 3) years, respectively (p = 0.16). Matched subjects had a mean BMI of 25 ± 4 kg/m and the mean BMI difference among groups was 5 ± 5 kg/m (p < 0.001). According to the Southwick radiographic criteria nine patients (23%) had a mild slip, 10 (26%) had a moderate slip, and 19 (49%) had severe SCFE. The α angle and femoral head-neck offset, epiphyseal extension ratio and epiphyseal angle, and epiphyseal tilt were assessed in the anterior, anterosuperior, and superior femoral planes on radially reformatted CT by one observer not involved in clinical care of the patients. Inter- and intrarater reliability were determined on 10 randomly selected hips assessed by the same observer and another observer and it was found to be excellent for all femoral measurements (intraclass correlation coefficients > 0.85). Paired t-tests were used to compare the contralateral asymptomatic hip of patients with SCFE and control hips.

RESULTS

The head-neck junction showed decreased concavity in the contralateral femur of patients with unilateral SCFE compared with control subjects as assessed by slightly higher mean α angle in the anterosuperior plane (51° ± 6° versus 48° ± 7°; mean difference, 2°, 95% CI, 0°-5°; p = 0.04) and slightly higher median α angle in the superior plane (45° [range 37°-72°] versus 42° [range, 36°-50°], median shift, 4° [range, 2°-5°], p < 0.001), and slightly lower head-neck offset (anterosuperior: 5 mm ± 2 mm versus 6 mm ± 2 mm, mean difference, -1mm [range, -1 mm to 0 mm], p = 0.009; superior: median, 6 mm [range, 1 mm-8 mm] versus 7 mm [range, 5 mm-9 mm]; median shift, -1 mm [range, -1 mm to 0 mm], p < 0.001). There was less epiphyseal extension in the anterosuperior plane as evidenced by lower epiphyseal extension ratio (72% ± 6% versus 75% ± 6%; p = 0.005) and higher epiphyseal angle (64° ± 7° versus 60° ± 7°; p = 0.003). The epiphysis was slightly more posteriorly tilted (anterior plane tilt: 8° ± 6° versus 5° ± 4°; p = 0.03) and more vertically oriented (superior plane tilt 11° ± 5° versus 14° ± 4°; p = 0.006) in the contralateral asymptomatic hip of patients with SCFE.

CONCLUSIONS

The contralateral femur in patients treated for unilateral SCFE shows decreased concavity of the head-neck junction assessed by a higher α angle and reduced head-neck offset compared with age- and sex-matched control subjects. Because we noted lower epiphyseal extension but a more posteriorly tilted epiphysis, the reduced concavity resembles a mild slip deformity rather than an idiopathic cam morphologic feature.

CLINICAL RELEVANCE

Although we noted a difference in the morphologic features of the head-neck junction between the two groups, the clinical significance is unclear because most differences were rather small. However, our findings suggest that the uninvolved hip in patients with unilateral SCFE may have a subtle asymptomatic cam morphologic feature that may be identified only with advanced imaging (CT or MRI). Future studies should investigate whether these morphologic changes influence development of contralateral SCFE or symptomatic femoroacetabular impingement in the contralateral hip of patients with unilateral SCFE and establish thresholds for indication of prophylactic fixation to avoid further slip and worsening of the morphologic features of the cam-femoroacetabular impingement.

Body Mass Index Affects Proximal Femoral but Not Acetabular Morphology in Adolescents Without Hip Pathology

BACKGROUND

Increased mechanical load secondary to a large body mass index (BMI) may influence bone remodeling. The purpose of this study was to investigate whether BMI is associated with the morphology of the proximal part of the femur and the acetabulum in a cohort of adolescents without a history of hip disorders.

METHODS

We evaluated pelvic computed tomographic (CT) images in 128 adolescents with abdominal pain without a history of hip pathology. There were 44 male patients (34%) and the mean patient age (and standard deviation) was 15 ± 1.95 years. The alpha angle, head-neck offset, epiphysis tilt, epiphyseal angle, and epiphyseal extension were measured to assess femoral morphology. Measurements of acetabular morphology included lateral center-edge angle, acetabular Tönnis angle, and acetabular depth. BMI percentile, specific to age and sex according to Centers for Disease Control and Prevention growth charts, was recorded.

RESULTS

BMI percentile was associated with all measurements of femoral morphology. Each 1-unit increase in BMI percentile was associated with a mean 0.15° increase in alpha angle (p < 0.001) and with a mean 0.03-mm decrease in femoral head-neck offset (p < 0.001). On average, a 1-unit increase in BMI percentile was associated with a 0.0006-unit decrease in epiphyseal extension (p = 0.03), a 0.10° increase in epiphyseal angle (p < 0.001), and a 0.06° decrease in tilt angle (p = 0.02; more posteriorly tilted epiphysis). There was no detected effect of BMI percentile on acetabular morphology including lateral center-edge angle (p = 0.33), Tönnis angle (p = 0.35), and acetabular depth (p = 0.88).

CONCLUSIONS

Higher BMI percentile was associated with increased alpha angle, reduced head-neck offset and epiphyseal extension, and a more posteriorly tilted epiphysis with decreased tilt angle and increased epiphyseal angle. This morphology resembles a mild slipped capital femoral epiphysis deformity and may increase the shear stress across the growth plate, increasing the risk of slipped capital femoral epiphysis development in obese adolescents. BMI percentiles had no association with measurements of acetabular morphology. Further studies will help to clarify whether obese asymptomatic adolescents have higher prevalence of a subclinical slip deformity and whether this morphology increases the risk of slipped capital femoral epiphysis and femoroacetabular impingement development.

A nationwide cohort study of slipped capital femoral epiphysis

OBJECTIVES

To describe the epidemiology of slipped capital femoral epiphysis (SCFE), to examine associations with childhood obesity and socioeconomic deprivation, and to explore factors associated with diagnostic delays.

DESIGN

Historic cohort study using linked primary and secondary care data from the Clinical Practice Research Datalink and Hospital Episode Statistics.

SETTING

All contacts with healthcare services, including emergency presentations, outpatient appointments, inpatient admissions and primary care visits, within the UK National Health Service.

PATIENTS

All individuals <16 years old with a diagnosis of SCFE and whose electronic medical record was held by one of 650 primary care practices in the UK between 1990 and 2013.

MAIN OUTCOME MEASURES

Annual incidence, missed opportunities for diagnosis and diagnostic delay.

RESULTS

Over the 23-year period the incidence remained constant at 4.8 (95% CI 4.4 to 5.2) cases per 100,000 0-16-year-olds. There was a strong association with socioeconomic deprivation. Predisease obesity was also strongly associated with SCFE; mean predisease z-score of body mass index was 1.43 (95% CI 1.20 to 1.68) compared with the UK reference mean. Diagnostic delays were common, with most children (75.4%) having multiple primary care contacts with relevant symptomatology, and those who presented with knee pain having significantly longer diagnostic delay (median 161 (IQR 27-278) days) than those with hip pain (20 (5-126)) or gait abnormalities (21 (7-72)).

CONCLUSIONS

SCFE has a strong association with both area-level socioeconomic deprivation and predisease obesity. The majority of patients with SCFE are initially misdiagnosed and those presenting with knee pain are particularly at risk.

Addressing Pediatric Obesity in Clinic

There is an epidemic of pediatric obesity in the United States. In most cases, there is an excess in the amount of calories consumed, compared with the amount of calories expended. Numerous body systems are affected by pediatric obesity, with complications varying between boys and girls. Behavioral, genetic, and environmental factors affect the ability of children to avoid becoming obese. Primary care physicians should screen for obesity in children as much as possible. Associated risk factors for obesity should be uncovered. Methods of preventing obesity should be discussed routinely with children and their families. Healthy dietary habits are key, and so are family-oriented interventions, such as eating together at dinnertime. One hour of moderate to vigorous activity daily is recommended for children and adolescents. While pediatric bariatric surgery is an option, there are also numerous nonpharmacological and pharmacological measures available as management for pediatric obesity. Family-based approaches, such as reducing screen time, have been very successful. Non-weight-bearing exercises also help children and adolescents expend calories without causing injury to themselves. Family availability, activity preference, and developmental levels should all be considerations when managing pediatric obesity. Motivational interviewing may also be helpful, especially when customized for each specific patient and family. Clinicians will play an increasing role in terms of identifying, treating, and preventing pediatric obesity; measures that can be done in the clinic should be considered more and more.

Long-term Results of Combined Epiphysiodesis and Imhauser Intertrochanteric Osteotomy in SCFE: A Retrospective Study on 53 Hips

BACKGROUND

The management of moderate and severe slipped capital femoral epiphysis is still an issue. The main concern is represented by the choice of an intra-articular or an extra-articular osteotomy to correct the deformity. Theoretically, the intra-articular osteotomy allows the best correction, but it is technically demanding and involves a higher risk of avascular necrosis (AVN); conversely, an extra-articular intertrochanteric osteotomy (ITO) is easier and involves a lower risk of early complications, but may lead to femoroacetabular impingement, resulting in early osteoarthritis and the need for total hip replacement (THR).The aim of this study was to analyze the long-term survivorship free from THR after combined epiphysiodesis and Imhauser ITO.

METHODS

From 1975 to 2000, 45 patients (53 hips) underwent a combined epiphysiodesis and Imhauser ITO. There were 27 male and 18 female patients with an average age of 12.8±1.9 years. All cases showed a posterior sloping angle >40 degrees (mean, 69±16 degrees). The cumulative survivorship was determined according to Kaplan and Meier, with the end point defined as conversion to THR.

RESULTS

A total of 6 patients (6 hips; 11%) had a follow-up <2 years. Among them, no postoperative complications occurred. For the remaining 39 patients (47 hips, 89%), the mean follow-up was 21±11 years. Four early postoperative complications were reported (2 AVN, 2 chondrolysis). The cumulative 39 years' survivorship free from THR was 68.5% (95% confidence interval, 42.4%-84.7%). The age at surgery (hazard ratio=1.849 per year older, P=0.017) and the postoperative onset of AVN or chondrolysis (hazard ratio=10.146, P=0.010) affected the long-term prognosis significantly.

CONCLUSIONS

The combined epiphysiodesis and Imhauser ITO is a valid surgical option in moderate to severe slipped capital femoral epiphysis, preserving the natural hip for at least 39 years in the majority of the patients. Care must be taken to avoid AVN or chondrolysis. The age at surgery affects the prognosis negatively.

LEVEL OF EVIDENCE

Level III-a retrospective study.

A comparison study of radiographic and computerized tomographic angles in slipped capital femoral epiphysis

Objective

To compare proximal femur radiologic angles in patients with slipped capital femoral epiphysis and to analyze whether computerized tomography may modify the treatment.

Methods

Cross-sectional study comparing and analyzing the similarity between angles and radiologic classification of interest in slipped capital femoral epiphysis (SCFE).

Results

It was observed that the therapeutic management in slipped capital femoral epiphysis might be modified depending on the classification and radiologic acquisition method adopted.

Conclusion

Multiplanar assessment of proximal femoral deformity in patients with slipped capital femoral epiphysis is a viable option, with the potential to modify the disease classification and, consequently, the therapeutic management.