Prevalence of Hypertension in Pediatric Tibia Vara and Slipped Capital Femoral Epiphysis

Diagnosis of Slipped Capital Femoral Epiphysis: How to Stay out of Trouble?

Slipped capital femoral epiphysis (SCFE) is the most common hip disorder affecting children and adolescents aged between 9 and 16 years, affecting approximately 10 per 100,000 children per year. The diagnosis of SCFE is often delayed, leading to an increased risk of complications. This study aims to provide the latest evidence concerning the causes of diagnostic delay and risk factors for SCFE and to educate general practitioners and paediatricians to help reduce delays in diagnosis and provide earlier therapeutic intervention. A literature search was conducted in the ScienceDirect and PubMed databases according to the PRISMA statement. Suitable studies for this systematic review included 22 articles discussing the aetiology of SCFE, risk factors, and causes of late diagnosis. Causes of delayed diagnosis include underestimation by patients, initial diagnostic approach by a non-orthopaedic professional, inadequate imaging, failure to recognize morphological changes, and variation in symptomatic presentation. The underlying risk factors for SCFE are likely part of a multifactorial process which involves anatomical variations and the metabolism of leptin, growth hormone, insulin, and other metabolic parameters. This review highlights the importance of early recognition and diagnosis of SCFE and proposes an algorithm for physicians to approach children who may have this condition.

The Role of Hyperinsulinemia in Slipped Capital Femoral Epiphysis

BACKGROUND

Obesity in the prepuberal stage has been directly associated with slipped capital femoral epiphysis (SCFE). Serum insulin level increases in the prepuberal and adolescence stage, to a greater extent in the obese population. The main objective of this article was to analyze the relationship between insulin levels and SCFE.

METHODS

A case-control study was conducted between January 2018 and April 2019. The study group was formed with patients with SCFE and the control group with patients from the pediatric obesity clinic of our hospital selected during their initial evaluation. None were being treated for obesity. Anthropometric measurements of size, weight, waist circumference, and blood pressure were taken. Body mass index (BMI) and waist-height index of all patients were calculated. According to BMI for age, they were classified as normal, overweight, or obese. Serum determinations of glucose, insulin, glycated hemoglobin, lipid profile, and complete blood count were analyzed. Insulin resistance was diagnosed with Homeostatic Model Assessment (HOMA) >3. Insulin levels >13 U/mL for girls and >17 U/mL for boys were considered as hyperinsulinemia.

RESULTS

We studied 14 patients with SCFE and 23 in the control group. The mean age and BMI in both groups were similar. The elevation of serum insulin was significantly higher in the SCFE group (P=0.001) as was HOMA (P=0.005). Triglycerides and very-low-density lipoprotein were higher in the SCFE group (P=0.037 and 0.009, respectively). Glycemia, glycated hemoglobin, total cholesterol, high-density lipoprotein, low-density lipoprotein, and neutrophils showed no significant difference.

CONCLUSIONS

Patients with SCFE showed elevated levels of insulin, HOMA, triglycerides, and very-low-density lipoprotein, even higher than the control group. Our study demonstrates a significant association between abnormally high serum insulin levels and SCFE. The known effects of insulin on growth cartilage may explain the physeal mechanical insufficiency to support the abnormally high or repetitive loads in accelerated growth stages that lead to SCFE.

LEVEL OF EVIDENCE

Level III-case-control, prognostic study.

What's New in Pediatric Limb Lengthening and Deformity Correction?

Over the past 5 years, published literature regarding treatment of pediatric limb deformity and limb length discrepancy demonstrates much interest in better understanding, categorizing and treating these challenging problems. Many studies explore expanding and refining indications for traditional treatment methods like guided growth techniques. Other studies have evaluated the results of new techniques such as lengthening via mechanized intramedullary nails. Additionally, series comparing older and newer techniques such as lengthening with external devices versus mechanized nails are becoming increasingly available.

Slipped Capital Femoral Epiphysis in Children without Obesity

OBJECTIVE

To evaluate rates and characteristics of slipped capital femoral epiphysis (SCFE) in children who are not obese to prevent missed diagnoses and subsequent complications.

STUDY DESIGN

A multicenter, retrospective review identified all patients with SCFE from January 1, 2003 to December 31, 2012. Patients were excluded if they received previous surgery at an outside institution, had no recorded height and weight, or had medical co-morbidity associated with increased risk of SCFE. Body mass index (BMI) percentile for age was calculated and categorized for each patient (patients without obesity vs with obesity).

RESULTS

In total, 275 patients met inclusion criteria. Average BMI was 91.2 percentile (range: 8.4-99.7). Thirteen percent (34 patients) were considered "normal weight" (BMI 5%-85%), 17% (48 patients) were considered "overweight" (BMI 85%- 95%), and 70% (193 patients) were considered "obese" (BMI >95%). Average BMI percentile was higher in male than female patients (93.2 ± 12.7 vs 88.5 ± 21.4, P = .034). Patients without obesity were older compared with patients with obesity (12.2 ± 1.7 vs 11.7 ± 1.6 years, P = .015). Fewer patients without obesity were seen at the hospital in the southwest. The southwest had fewer patients without obesity than the northeast (18.3% vs 36.1%, P = .002). Patients without obesity were more likely to present with a severe slip as graded by Wilson percent displacement (27.2% vs 11.4%, P = .007) and an unstable slip (32.9% vs 14.7%, P = .001).

CONCLUSION

Rates of nonobese SCFE in this study are higher than reported in the previous literature. Normal weight patients with SCFE are more likely to be older, female, and present with a severe and unstable SCFE.

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.

Leptin Elevation as a Risk Factor for Slipped Capital Femoral Epiphysis Independent of Obesity Status

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is strongly associated with childhood obesity, yet the prevalence of obesity is orders of magnitude greater than the prevalence of SCFE. Therefore, it is hypothesized that obesity is not, by itself, a sufficient condition for SCFE, but rather one component of a multifactorial process requiring preexisting physeal pathology. Leptin elevation is seen to varying degrees in patients with obesity, and as leptin has been shown to cause physeal pathology similar to the changes seen in SCFE, we propose that leptin may be a factor distinguishing between patients with SCFE and equally obese children without hip abnormalities.

METHODS

Serum leptin levels were obtained from 40 patients with SCFE and 30 control patients with approximate body mass index (BMI) matching. BMI percentiles were calculated according to Centers for Disease Control and Prevention population data by patient age and sex. Patients were compared by demographic characteristics, leptin levels, odds of leptin elevation, and odds of SCFE.

RESULTS

The odds of developing SCFE was increased by an odds ratio of 4.9 (95% confidence interval [CI], 1.31 to 18.48; p < 0.02) in patients with elevated leptin levels, regardless of obesity status, sex, and race. When grouping patients by their obesity status, non-obese patients with SCFE showed elevated median leptin levels at 5.8 ng/mL compared with non-obese controls at 1.7 ng/mL (p = 0.006). Similarly, obese patients with SCFE showed elevated median leptin levels at 17.9 ng/mL compared with equally obese controls at 10.5 ng/mL (p = 0.039). Serum leptin levels increased in association with obesity (p < 0.001), with an increase in leptin of 0.17 ng/mL (95% CI, 0.07 to 0.27 ng/mL) per BMI percentile point.

CONCLUSIONS

To our knowledge, this study is the first to clinically demonstrate an association between elevated serum leptin levels and SCFE, regardless of BMI. This adds to existing literature suggesting that SCFE is a multifactorial process and that leptin levels may have profound physiological effects on the development of various disease states. Despite a strong association with adiposity, leptin levels vary between patients of equal BMI and may be a vital resource in prognostication of future obesity-related comorbidities.

LEVEL OF EVIDENCE

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