A Role for Thyroid Testing in Slipped Capital Femoral Epiphysis? 32% Rate of Abnormal Values in Tested Patients.

BACKGROUND: Hypothyroidism is a known risk factor for slipped capital femoral epiphysis (SCFE), and prior studies of hypothyroid-associated SCFE have demonstrated an incidence of up to 6%. However, there is limited evidence and no formal practice guidelines regarding whether patients presenting with SCFE should undergo screening for endocrine disorders. This study aims to investigate the incidence of abnormal thyroid function studies in patients presenting with SCFE. METHODS: This was a retrospective review of all patients aged 0 to 18 years treated for SCFE at a single pediatric hospital from January 2015 to July 2022. On presentation, patients' BMI, thyroid-stimulating hormone (TSH), free T4, vitamin D, creatinine, BUN, and HbA1c levels were documented. Follow-up and treatment for any identified endocrinopathies were noted. In addition, the chronicity, stability, and severity of their slips were recorded. RESULTS: Ninety-eight patients with 106 hips were included in this study. TSH was obtained at the time of initial presentation in 66% (n=65/98) of patients. Median TSH was 2.99 (range: 0.02 to 919, std dev: 132.4). The normal reference range for our institution is 0.5 to 4.5 mcIU/mL. Thirty-two percent (n=21/65) of patients with a documented TSH had an abnormal value. Of those patients who had an elevated TSH, 3 were diagnosed with clinical hypothyroidism and went on to treatment with levothyroxine (n=3/19, 16%), 2 patients had been started on levothyroxine before presentation (n=2/19, 11%), and 2 patients were followed in endocrinology clinic until their TSH levels had normalized without further intervention (n=2/19, 11%). CONCLUSIONS: Screening of our SCFE population revealed a 32% incidence of thyroid abnormalities which affected treatment in 24% of those patients. This is a much higher incidence of hypothyroid-associated SCFE than previously demonstrated in the literature and has prompted us to start including thyroid screening studies as a routine part of our workup for all patients with SCFE. LEVEL OF EVIDENCE: Level III.

Socioeconomic Deprivation and its Associations With Follow-up Compliance After In Situ Pinning of Slipped Capital Femoral Epiphysis.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a common cause of hip pain in adolescents and is most often treated by in situ screw fixation. Orthopaedic follow-up is critical after treatment for SCFE due to risks of complications and subsequent contralateral slip. Recent studies have shown that socioeconomic deprivation is associated with decreased fracture care compliance, but no studies have explored this relationship with SCFEs. The study aims to determine the relationship between socioeconomic deprivation and SCFE follow-up care compliance. METHODS: This study included pediatric patients treated with in situ pinning of SCFE between 2011 and 2019 at a single tertiary-care urban children's hospital. Demographic and clinical information were obtained from electronic medical records. The Area Deprivation Index (ADI) was used to quantify the socioeconomic deprivation of each. Outcome variables included patient age and status of physeal closure at the most recent appointment, in addition to the length of follow-up (mo). Statistical relationships were evaluated using nonparametric bivariate analysis and correlation. RESULTS: We identified 247 evaluable patients; 57.1% were male, and the median age was 12.4 years. Most slips were stable (95.1%) and treated with isolated unilateral pinning (55.9%). Median length of follow-up was 11.9 months (interquartile range, 4.95 to 23.1) with median patient age at final visit of 13.6 years (interquartile range, 12.4 to 15.1). Only 37.2% of patients were followed until physeal closure. The mean ADI spread in this sample was similar to the national distribution. However, patients in the most deprived quartile were lost to follow-up significantly earlier (median, 6.5 mo) than those in the least deprived quartile (median, 12.5 mo; P <0.001). Throughout the entire cohort, there was a significant, inverse relationship between deprivation and follow-up length ( rs (238) = -0.3; P <0.001), with this relationship most pronounced in the most deprived quartile. CONCLUSIONS: In this sample, ADI spread was representative of national trends, and the incidence of SCFE was distributed evenly across deprivation quartiles. However, follow-up length does not mirror this relationship; increased socioeconomic deprivation is associated with an earlier loss to follow-up (often well before physeal closure). LEVEL OF EVIDENCE: Level II-retrospective prognostic study.

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.

Primary cam morphology; bump, burden or bog-standard? A concept analysis.

BACKGROUND: Cam morphology, a distinct bony morphology of the hip, is prevalent in many athletes, and a risk factor for hip-related pain and osteoarthritis. Secondary cam morphology, due to existing or previous hip disease (eg, Legg-Calve-Perthes disease), is well-described. Cam morphology not clearly associated with a disease is a challenging concept for clinicians, scientists and patients. We propose this morphology, which likely develops during skeletal maturation as a physiological response to load, should be referred to as primary cam morphology. The aim of this study was to introduce and clarify the concept of primary cam morphology. DESIGN: We conducted a concept analysis of primary cam morphology using articles that reported risk factors associated with primary cam morphology; we excluded articles on secondary cam morphology. The concept analysis method is a rigorous eight-step process designed to clarify complex 'concepts'; the end product is a precise definition that supports the theoretical basis of the chosen concept. RESULTS: We propose five defining attributes of primary cam morphology-tissue type, size, site, shape and ownership-in a new conceptual and operational definition. Primary cam morphology is a cartilage or bony prominence (bump) of varying size at the femoral head-neck junction, which changes the shape of the femoral head from spherical to aspherical. It often occurs in asymptomatic male athletes in both hips. The cartilage or bone alpha angle (calculated from radiographs, CT or MRI) is the most common method to measure cam morphology. We found inconsistent reporting of primary cam morphology taxonomy, terminology, and how the morphology is operationalised. CONCLUSION: We introduce and clarify primary cam morphology, and propose a new conceptual and operational definition. Several elements of the concept of primary cam morphology remain unclear and contested. Experts need to agree on the new taxonomy, terminology and definition that better reflect the primary cam morphology landscape-a bog-standard bump in most athletic hips, and a possible hip disease burden in a selected few.

Increased Hip Intracapsular Pressure Decreases Perfusion of the Capital Femoral Epiphysis in a Skeletally Immature Porcine Model.

BACKGROUND: Increased intracapsular hip pressure is thought to be one of the possible etiologies of femoral head avascular necrosis after intra-articular proximal femoral fractures or acute slipped capital femoral epiphysis. The purpose of this study was to evaluate the relationship between intra-articular hip pressure (IAP) and epiphyseal perfusion pressure (EPP), and its dependency on skeletal maturity using a porcine model. METHODS: Seven female Yorkshire-hybrid pigs were used to study the direct relationship between IAP and EPP. A needle inserted into the capsule provided both IAP monitoring and saline infiltration until IAP was above mean arterial pressure (MAP). Video simultaneously documented IAP, EPP, MAP. Parameters for all trials in each hip were averaged and compared between the 2 age groups. Significance was P<0.05. RESULTS: Four young hips (in pigs 10.3±1.0 wk, 27.4±2.0 kg) and 5 older hips (21.1±0.1 wk, 89.4±7.1 kg) were studied. There was no significant difference in the MAP (50.0±11.8 and 55.5±7.0 mm Hg respectively, P=0.411) between the 2 age groups. In the older hips, biphasic EPP persisted despite increasing IAP to an average of 177 mm Hg over MAP. In the young pigs, the biphasic EPP waveform ceased with increased IAP to an average of 28 mm Hg over MAP. Biphasic waveforms returned once IAP fell to an average of 5 mm Hg over MAP. CONCLUSIONS: Increased IAP resulted in tamponade of epiphyseal perfusion in the young, but not in the older hips. An intact physis may preclude intraosseous metaphyseal vessels from penetrating the epiphysis, leaving it vulnerable to retinacular artery tamponade. CLINICAL RELEVANCE: The IAP and EPP relationship has direct clinical practice implications. Hip capsulotomy and decompression in young patients with intra-articular proximal femoral fractures and increased intracapsular pressure may decrease avascular necrosis risk.

Clinical and Radiographic Characteristics of Atypical Slipped Capital Femoral Epiphysis.

BACKGROUND: Slipped capital femoral epiphysis (SCFEs) can be idiopathic or atypical (associated with renal failure, radiation therapy, and endocrine disorders). It is important to estimate the likelihood that atypical SCFE shows different clinical and radiographic characteristics and complications with typical SCFEs. METHODS: We retrospectively reviewed 53 patients (66 hips) with SCFEs managed between 1995 and 2016. Sex, age, weight, height, the duration of symptoms the laterality of the slip, and complications were recorded. Bilateral hip and lower extremity long bone radiographs were utilized to record slip angle, genu valgus deformity. Statistical analyses were performed. RESULTS: Among 53 children (32 boys and 21 girls) with 66 SCFEs, 22 children had 29 atypical SCFEs, and 31 children had 38 typical SCFEs. The average age at the time of presentation for the initial SCFEs was 10.9±0.3 years. The average duration of symptoms was 14.1±21.8 weeks. The average Southwick slip angle difference was 23.3±14.8 degrees. There are 43 mild, 13 moderate, and 10 severe SCFEs. 58 were classified as stable, and 8 were unstable. There were significant differences in terms of average age (10.4±2.6 y for atypical SCFEs, 11.2±1.4 for typical SCFEs; P=0.036), average weight (36.2±22.3 kg for patients with atypical slips, compared with 56.9±9.9 kg for those with typical slips; P<0.001), height (132.1±17.6 cm for those with atypical slips, compared with 148.9±12.1 for those with typical slips; P<0.001), and the body mass index (19.4±5.6 kg/cm for those with atypical slips, compared with 25.8±4.6 for those with typical slips; P<0.001). In the group of 22 children with atypical slipped capital epiphysis, there were 19 children with neoplasm (8 neuroblastomas, 3 medulloblastomas, 3 retinoblastomas, 2 ependymomas, 1 craniopharyngioma, 1 Wilms tumor, 1 immature teratoma), 4 children with primary endocrine disorder. We categorized atypical SCFEs in 3 groups by etiology; endocrine disorder-associated (ENDA) SCFEs, chemotherapy-associated (CTA) SCFEs, and radiation therapy-associated (RTA) SCFEs. Subjects of RTA were included if exposed to pelvic irradiation or total body irradiation. There were 4 ENDA, 9 RTA, and 16 CTA. Atypical SCFEs had significantly more valgus slips (P<0.001) and genu valgus deformity (P<0.001) compared with in the group of typical slipped capital epiphysis. Among the group of atypical SCFEs, children with CTA had significantly low body weight, height, and body mass index. CONCLUSIONS: The markedly greater incidence of valgus displacement of proximal femoral epiphysis and genu valgum in childhood cancer survivors with pelvic irradiation and chemotherapy may be associated with atypical SCFE. The authors conclude that in pediatric cancer survivors with hip pain, consideration should be given to atypical SCFE with valgus slip and long-term follow-up of lower extremity alignment. LEVEL OF EVIDENCE: Level III-retrospective comparative study. See instructions for authors for a complete description of levels of evidence.

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.

Musculoskeletal complications following total body irradiation in hematopoietic stem cell transplant patients.

Total body irradiation (TBI) is commonly used in conditioning regimens for allogeneic hematopoietic stem cell transplantation (HSCT) to treat benign and malignant disease. Though life-saving, these therapies place patients at risk for important side effects, including musculoskeletal complications such as short stature, osteonecrosis, slipped capital femoral epiphysis, and the development of benign and malignant bone tumors. With an increasing number of HSCT survivors, there is a growing need for awareness of the musculoskeletal complications of HSCT and TBI.

Pseudohypoparathyroidism type 1B in a patient conceived by in vitro fertilization: another imprinting disorder reported with assisted reproductive technology.

Pseudohypoparathyroidism type 1B (PHP1B) is characterized by renal tubular resistance to parathyroid hormone (PTH) leading to hyperphosphatemia, hypocalcemia, elevated PTH, and hyperparathyroid bone changes. PHP1B is an imprinting disorder that results from loss of methylation at the maternal GNAS gene, which suppresses transcription of the alpha subunit of the stimulatory G protein of the PTH receptor. Emerging evidence supports an association between assisted reproductive technologies (ART) and imprinting disorders; however, there is currently little evidence linking PHP1B and ART. We present a twin boy conceived by ART to parents with no history of subfertility who presented at age 12 with bilateral slipped capital femoral epiphysis and bilateral genu valgum deformity. Clinical and laboratory investigation revealed markedly elevated PTH, low ionized calcium, elevated phosphorus, TSH resistance, and skeletal evidence of hyperparathyroidism, leading to the diagnosis of PHP1B. A partial loss of methylation at the GNAS exon A/B locus was observed. The patient's dizygotic twin sibling was asymptomatic and had normal laboratory evaluation. This is the second reported case of a child with PHP1B conceived by ART, further supporting the possibility that ART may lead to an increased risk for imprinting defects.

Prepubertal onset of slipped capital femoral epiphysis associated with hypothyroidism: a case report and literature review.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a common hip disorder characterized by displacement of the capital femoral epiphysis from the metaphysic through the femoral epiphyseal plate. SCFE usually occurs during puberty, with obesity a common risk factor. We experienced a rare case of SCFE associated with hypothyroidism in a prepubescent patient who was not obese. CASE PRESENTATION: The patient was an 8-year-old boy suffering from bilateral SCFE with hypothyroidism. The patient's growth had started to slow at 4 years of age, and at 8 years he was of short stature. During his evaluation for SCFE management, primary hypothyroidism was diagnosed due to the presence of anti-thyroid peroxidase and anti-thyroglobulin antibodies. After the patient was treated for hypothyroidism, which improved his thyroid function, surgery was performed for bilateral SCFE. CONCLUSIONS: Among the 42 patients with SCFE associated with hypothyroidism in the literature, most SCFE occurred during puberty or in adults with delayed epiphyseal closure. Only two patients (4.8%), including the present patient, were ≤9 years old. Although being overweight or obese is common for patients with SCFE associated with hypothyroidism (76.0%), it was not observed in the present case. Persistent hypothyroidism, however, may be a risk factor for SCFE even before puberty and without obesity.

Validity and Clinical Consequences of a Rotational Mechanism for Slipped Capital Femoral Epiphysis.

BACKGROUND: Recent anatomic data supports a mechanism for slipped capital femoral epiphysis (SCFE) where the metaphysis rotates on the epiphysis through the eccentrically located epiphyseal tubercle as a pivot. The validity of such a mechanism and its clinical consequences have not been well investigated. METHODS: This cadaveric study defined the normal location of the calcar ridge line in 100 paired femora and compared them with 11 SCFE specimens, and with 25 immature femora where the metaphysis was rotated 30, 60, and 90 degrees on the epiphysis to model progressive SCFE. Coronal, sagittal, and axial plane deformity were measured on the rotational model to define the characteristic deformity caused by rotation, and lateral epiphyseal foramina stretch was measured to quantify the protective effect of an eccentric pivot. RESULTS: The posterior displacement of the fovea with respect to the calcar ridge line was 1±5 mm for the controls, versus 23±10 mm for the SCFE specimens (P<0.0005), and posterior displacement increased with incremental rotation in the rotational model (P<0.0005). The rotational model found minimal varus deformity, but substantial extension and retroversion, with deformities of 0±5, -16±12, and -38±9 degrees, respectively, at 90 degrees of rotation. The eccentric pivot mitigated lateral epiphyseal vessel stretch by 55% to 70%. CONCLUSIONS: This study provides strong anatomic support for a rotational mechanism for stable SCFE. When the metaphysis is rotated on the epiphysis acutely, minimal varus deformity is created, while substantial retroversion occurs. As this rotation occurs the eccentric pivot protects the lateral epiphyseal vessels, and likely accounts for the low rate of avascular necrosis observed in stable SCFE. CLINICAL RELEVANCE: If SCFE is treated in an open manner then the presence of a chronic rotational deformity should be considered. When planning osteotomies for deformity after a stable SCFE, any suspected varus component should be carefully investigated as it may represent retroversion deformity brought into view by external rotation posturing of the leg.

Somatic HRPT2 Mutation (Arg234X) of Parathyroid Carcinoma Associated with Slipped Capital Femoral Epiphysis: A First Case Report.

A 14-year-old boy was admitted to the orthopedic clinic of Rajavithi Hospital complaining of pain in the left hip. A year earlier, pain had developed in his left joint and had gradually increased in intensity in both hips. A month before he was referred, radiographs obtained at another hospital showed bilateral slipped capital femoral epiphysis (SCFE). The patient's biochemical laboratory data showed hypercalcemia, hypophosphatemia, and a high level of intact parathyroid hormone (iPTH) compatible with primary hyperparathyroidism. HRPT2 gene analysis found heterozygosity for c. 700 C > T mutation (Arg234X) of HRPT2 gene at exon 7. This is the first report in the literature about somatic mutation of the HRPT2 gene of parathyroid carcinoma associated with slipped capital femoral epiphysis.

Delayed Slipped Capital Femoral Epiphysis After Treatment of Femoral Neck Fracture in Children.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) after the treatment of femoral neck fracture is a rare entity in children that poses important treatment challenges. CASE DESCRIPTION: We describe the presentation and management of two patients, a 12-year-old girl and a 6-year-old girl, each of whom developed SCFE at 5 months and 9 months, respectively, after operative treatment of femoral neck fracture. LITERATURE REVIEW: Five similar cases have been reported in the literature. Along with our two case studies, the average age of all seven patients was 8.9 years (range, 3.6-12 years; boys, 8.9 years; girls, 9 years). None of the children was in a high weight percentile or had any known endocrinologic disorder. Two had asymptomatic mild SCFE, whereas the others felt unexplained pain with ambulation when the slippage was brought to their attention. Although it is not possible to prove a causal relationship between the initial fracture and the subsequent SCFE, clinical factors such as implant irritation, early return to weightbearing, delayed union or nonunion, coxa vara, and avascular necrosis warrant consideration as potentially related to the subsequent slip. CLINICAL RELEVANCE: The onset of SCFE after surgical treatment of a femoral neck fracture may reflect inadequate treatment of the fracture. For best practice, we should perform a gentle anatomic reduction, appropriate internal fixation for femoral neck fracture in skeletally immature patients. Postoperative cast immobilization and delayed weightbearing are also important to avoid complication. It is essential for pediatric orthopaedic surgeons to be aware of this clinical scenario to allow prompt recognition and patient treatment.

Pelvic Incidence and Acetabular Version in Slipped Capital Femoral Epiphysis.

BACKGROUND: The etiology of slipped capital femoral epiphysis (SCFE) is multifactorial, but the role of sagittal balance of the pelvis as a contributing factor to its development has not been well studied. Our primary purpose was to determine whether a smaller pelvic incidence (PI), a position-independent anatomic parameter that regulates pelvic orientation, could be a factor that increases shear stress in the epiphyseal growth plate and potentially contributes to the development of SCFE. We also set out to determine whether acetabular retroversion was associated with SCFE. METHODS: We obtained 14 cadaveric pelvi from the Hamann-Todd Osteological Collection whose femurs showed evidence of post-SCFE deformity. Two hundred age-matched, sex-matched, and race-matched pelvi were used as controls. PI and acetabular version were measured using standardized lateral photographs and goniometers, respectively. T tests were performed to evaluate for differences in measured parameters between groups. RESULTS: The mean PI was 40.6±6.1 degrees for SCFE specimens and 47.4±9.9 degrees for normal specimens (P=0.01). The mean version of SCFE and normal acetabula was 15±7 and 17±6 degrees, respectively (P=0.39). There was also no significant difference in version between SCFE acetabula and the contralateral, uninvolved acetabular of the same specimen (15±7 vs. 17±8 degrees, P=0.33). CONCLUSIONS: Specimens with SCFE deformity demonstrated a smaller PI than a large cohort of normal control specimens. We found no significant difference between acetabular version of specimens with and without SCFE deformity. Contralateral or unaffected acetabuli of SCFE specimens were not more retroverted than the affected side of the same specimen. CLINICAL RELEVANCE: Sagittal balance of the pelvis, and particularly decreased PI, may play an important role in the development of SCFE. The influence of mechanical factors beyond the hip joint in the development of SCFE should be considered by clinicians.

Can Subclinical Rickets Cause SCFE? A Prospective, Pilot Study.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a common disorder of the growing hip; however, its etiology remains unknown. Vitamin D (25-OH) is a major regulator of bone homeostasis and calcium metabolism. Vitamin D deficiency is one of the major causes of rickets, and rickets has been associated with SCFE. Increased body mass index (BMI) has been linked to SCFE and obese children are known to have lower vitamin D levels. Therefore, we hypothesize that children who develop SCFE may have subclinical rickets predisposing them to the development of physeal disease. METHODS: This was a pilot, prospective study designed to determine the relationship between vitamin D, bone, muscle, and fat in patients with SCFE. We enrolled 20 consecutive patients with idiopathic SCFE aged 9 to 14 years. Upon diagnosis, vitamin D, PTH, T4, and thyroid-stimulating hormone blood levels were obtained. A single-slice computed tomography was used to measure cortical bone density (CBD) of the femur. Demographics, BMI, and the results obtained were compared to generate a relationship between vitamin D levels and SCFE. RESULTS: Twenty patients were enrolled, 13 males and 7 females, at an average age of 12 years (range, 9 to 14 y), and mean BMI% was 93.9 (range, 81.3 to 99.5). There were 15 stable and 5 unstable SCFE. Overall, mean and SD values for vitamin D, 25-OH were within the normal range (43.9 ± 13.5). We found no difference in values in vitamin D between nonobese (BMI < 95%) and obese (BMI ≥ 95%) subjects (34.8 ± 16.8 vs. 51.6 ± 22.4, P = 0.144). Moreover, we found no difference in CBD between these 2 groups (1126 ± 33.1 vs. 1147 ± 41.2, P = 0.333). There was no relation between blood values of vitamin D and measures of CBD. CONCLUSIONS: Although obese children are known to have lower levels of vitamin D and a higher prevalence of SCFE, we found no correlation between low vitamin D and the development of SCFE in this subset of patients.

Childhood cancer survivors exposed to total body irradiation are at significant risk for slipped capital femoral epiphysis during recombinant growth hormone therapy.

BACKGROUND: Childhood cancer survivors treated with cranial or total body irradiation (TBI) are at risk for growth hormone deficiency (GHD). Recombinant growth hormone (rhGH) therapy is associated with slipped capital femoral epiphysis (SCFE). We compared the incidence of SCFE after TBI versus cranial irradiation (CI) in childhood cancer survivors treated with rhGH. PROCEDURE: Retrospective cohort study (1980-2010) of 119 survivors treated with rhGH for irradiation-induced GHD (56 TBI; 63 CI). SCFE incidence rates were compared in CI and TBI recipients, and compared with national registry SCFE rates in children treated with rhGH for idiopathic GHD. RESULTS: Median survivor follow-up since rhGH initiation was 4.8 (range 0.2-18.3) years. SCFE was diagnosed in 10 subjects post-TBI and none after CI (P < 0.001). All 10 subjects had atypical valgus SCFE, and 7 were bilateral at presentation. Within TBI recipients, age at cancer diagnosis, sex, race, underlying malignancy, age at radiation, and age at initiation of rhGH did not differ significantly between those with versus without SCFE. The mean (SD) age at SCFE diagnosis was 12.3 (2.7) years and median duration of rhGH therapy to SCFE was 1.8 years. The SCFE incidence rate after TBI exposure was 35.9 per 1,000 person years, representing a 211-fold greater rate than reported in children treated with rhGH for idiopathic GH deficiency. CONCLUSIONS: The markedly greater SCFE incidence rate in childhood cancer survivors with TBI-associated GHD, compared with rates in children with idiopathic GHD, suggests that cancer treatment effects to the proximal femoral physis may contribute to SCFE.

Bilateral slipped capital femoral epiphysis in a male adolescent with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), chronic renal failure, and severe hyperparathyroidism.

UNLABELLED: Slipped capital femoral epiphysis (SCFE) is the most common orthopedic hip disorder affecting otherwise healthy adolescents. The majority of SCFE cases are classified as idiopathic; rarely, it may be secondary to different endocrinopathies including hyperparathyroidism due to chronic renal failure (CRF). However, over the last decades, the association between SCFE and CRF has almost disappeared, probably due to better management of renal osteodystrophy. Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC, OMIM no. 248250) is a rare autosomal recessive tubulopathy characterized by renal wasting of calcium and magnesium leading to hypomagnesemia, hypercalciuria, nephrocalcinosis, and CRF. Patients usually show hyperparathyroidism before the onset of advanced CRF caused by FHHNC-related metabolic disturbances. We report on a 15-year-old patient with FHHNC and CRF who developed extreme hyperparathyroidism and high-grade bilateral SCFE after self-discontinuation of supportive treatment of underlying conditions. CONCLUSION: We believe that SCFE was caused not only by untreated CRF but also by metabolic disturbances related to FHHNC. To prevent this complication, careful management of disturbances of calcium, phosphate, and magnesium homeostasis seems to be crucial.

Patients with unstable slipped capital femoral epiphysis have antecedent symptoms.

BACKGROUND: The characteristics of patients who sustain unstable slipped capital femoral epiphyses (SCFEs) are not well described compared to their counterparts who sustain stable SCFE. Although patients with unstable slips are usually identified owing to acute symptoms, it is unclear whether these patients have premonitory symptoms that could heighten the awareness of treating physicians to the possibility of an unstable slip and lead to timely diagnosis and treatment. QUESTIONS/PURPOSE: We determined whether most patients experienced pain and limp before developing an unstable SCFE. METHODS: We retrospectively reviewed 582 patients and identified 82 (41 boys, 41 girls; 85 hips) with unstable SCFEs. Patient records were reviewed for sex, age at onset, weight at onset, and presence and location of pain and/or limp before the unstable slip. Boys averaged 13 years of age at the time occurrence and weighed on average in the 77th percentile. Girls averaged 12 years of age at the time of occurrence and weighed on average in the 79th percentile. RESULTS: For all patients, 73 of 82 (88%) had pain in their hips, thighs, or knees for an average of 42 days before sustaining unstable SCFEs. Sex distribution was equal for patients with unstable SCFEs. CONCLUSIONS: Patients who sustained unstable SCFEs had premonitory pain in the limb. Early recognition and an appropriate diagnosis provide a critical opportunity to prevent a morbid unstable SCFE. LEVEL OF EVIDENCE: Level IV, diagnostic study, See Instructions for Authors for a complete description of levels of evidence.

Increased acetabular depth may influence physeal stability in slipped capital femoral epiphysis.

BACKGROUND: Multiple mechanical factors affecting the hip have been associated with the development of slipped capital femoral epiphysis (SCFE). Whether acetabular depth plays a role in the development of a SCFE has not been elucidated. QUESTIONS/PURPOSES: (1) What is the prevalence of a deep acetabulum in SCFE? (2) Is the presence of a deep acetabulum associated with physeal instability? (3) Is the presence of a deep acetabulum associated with the occurrence of a contralateral SCFE? METHODS: We retrospectively reviewed 232 patients (156 males) who presented with a unilateral SCFE. Fifty (22%) subsequently developed a contralateral SCFE. The involved and uninvolved sides were evaluated for the presence of a deep acetabulum (DA). Preoperative radiographic parameters, slip stability, development of a contralateral SCFE, and demographic factors were then compared between patients with and without DA. RESULTS: DA was present in 120 hips (52%) with a SCFE. DA was more common in females (55 of 76 [72%]) than males (65 of 156 [42%]). Patients with DA presented with a higher lateral center-edge angle (33° versus 31°), slip angle (52° versus 43°), and with a lower body mass index (28.1 versus 30.0 kg/m(2)). Increased acetabular depth was more common in patients with an unstable SCFE (29 of 41 [71%]) than those with a stable SCFE (91 of 191 [48%]). The presence of DA either on the affected side or the contralateral side did not predict a contralateral SCFE. CONCLUSIONS: Despite not predicting a contralateral SCFE, DA may influence physeal stability if a SCFE does develop. Therefore, the contralateral hip with DA should be closely monitored. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.