Slipped capital femoral epiphysis: rising rates with obesity and aboriginality in South Australia

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.

Capital Femoral Epiphysis with Acute Unstable Valgus Type Slip Managed with Closed Reduction and Percutaneous Fixation: A Case Report

Case

We present a case of acute unstable valgus slipped capital femoral epiphysis (SCFE) in an 8-year-old female who presented after a trip and fall. The patient was managed with emergent closed reduction and percutaneous screw fixation and prophylactic fixation of contralateral side after 6 weeks. At 18-month follow-up, the patient was symptom free with a good range of movement and no evidence of slip progression, chondrolysis or avascular necrosis of the femoral head.

Conclusion

We demonstrate that, in this case, closed reduction and percutaneous fixation provided satisfactory outcome at 18-month follow-up. This case highlights the need for both anteroposterior and lateral radiographs.

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.

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.

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.

Outcomes of distally un-threaded screw fixation of slipped capital femoral epiphysis at skeletal maturity: a matched cohort study

The most common treatment for slipped capital femoral epiphysis worldwide is in situ fixation with a threaded screw. Un-threaded screws are designed to prevent slip progression without hindering residual growth of the proximal femur. This study aimed to compare growth, remodelling and long-term outcomes after fixation with un-threaded screws and a matched cohort of patients treated with a standard screw. Six patients (nine hips) treated with un-threaded screws and 16 patients (21 hips) treated with standard screws matched for age, skeletal maturity, sex and Southwick angle were recruited. Clinical records were reviewed for patient demographics, medical history and complications. Radiographs were reviewed for residual growth and time to physeal closure. Growth velocity was calculated. Absence of cam deformity signified complete remodelling. Clinical assessment was graded from excellent to poor and patient-reported outcomes were recorded. There was significantly more growth recorded in the un-threaded screw group in femoral neck length (7.6 mm, P = 0.003), articulo-lesser trochanter distance (5.3 mm, P = 0.028), pin-joint ratio (7.439%, P = 0.006) and pin-physis ratio (8.244%, P = 0.001). The probability of revision operations due to ongoing growth was higher in this group (risk ratio: 6.57, P = 0.0008). Time to physeal closure was not significantly different, but growth velocity was significantly higher in the un-threaded group. The lower probability of cam deformity was not significant. Functional and clinical results were not significantly different at average 11.2 years' follow-up. Un-threaded screws allow for significantly more growth than standard threaded screws. The un-threaded screw could not be recommended due to the higher re-operation rates, without any proven benefit.

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.

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.

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.

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.

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.

Epidemiology of Slipped Capital Femoral Epiphysis in Ontario, Canada

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is a well-characterized disorder of the hip seen in adolescent patients. It is characterized by deformity secondary to failure through the proximal femoral growth plate, which results in posterior-inferior displacement of the epiphysis on the proximal femoral metaphysis. Long-term sequelae of SCFE may include osteonecrosis, residual deformity, leg length discrepancy, degenerative joint disease, and chronic pain. The long-term consequences of SCFE may be the source of significant morbidity for the patient, and depending of the local incidence of this condition, may represent a significant expenditure of health care resources. Historically, the true incidence of SCFE within Ontario has been approximated using US-based studies of arguably comparable patient populations. In our study, we aimed to characterize the epidemiology of SCFE in the province of Ontario.

METHODS

We used a prospectively collected, not-for-profit Ontario research database to identify recorded cases of SCFE between April 1, 2002 and March 31, 2011. Specifically, we identified all hospital discharges with an ICD-9 or 10 diagnostic codes for SCFE in the Canadian Institute for Health Information Discharge Abstract database.

RESULTS

Over the 10-year study period, there were 648 cases of SCFE with an average annual incidence rate of 5.68/100,000 in Ontario.

CONCLUSIONS

We have observed a trend toward decreasing incidence rates of SCFE in Ontario over the last 10 years. The determination for the underlying causes for the changing trends of SCFE may be relevant for initiating public health campaigns directed at reducing the incidence of SCFE LEVEL OF EVIDENCE:: Level IV-epidemiological 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.

Outcomes after slipped capital femoral epiphysis: a population-based study with three-year follow-up

PURPOSE

To evaluate outcomes three years after treatment for slipped capital femoral epiphysis (SCFE): development of avascular necrosis (AVN), subsequent surgery, hip function and the contralateral hip.

METHODS

This prospective cohort study included a total national population of 379 children treated for SCFE between 2007 and 2013. A total of 449 hips treated for SCFE and 151 hips treated with a prophylactic fixation were identified. The Barnhöft questionnaire, a valid patient-reported outcome measure (PROM), was used.

RESULTS

In all, 90 hips had a severe slip, 61 of these were clinically unstable. AVN developed in 25 of the 449 hips. Six of 15 hips treated with capital realignment developed AVN. A peri-implant femur fracture occurred in three slipped hips and in two prophylactically pinned hips. In three of these five hips technical difficulties during surgery was identified. In 43 of 201 hips scheduled for regular follow-up a subsequent SCFE developed in the contralateral hip. Implant extraction after physeal closure was performed in 156 of 449 hips treated for SCFE and in 51 of 151 prophylactically fixed hips. Children with impaired hip function could be identified using the Barnhöft questionnaire.

CONCLUSION

Fixation in situ is justified to remain as the primary treatment of choice in SCFE. Overweight is more common in children with SCFE than in the average population. Prophylactic fixation is a safe procedure when performed using a correct technique. The number of patients who developed AVN after capital realignment is of concern. We recommend rigorous follow-up of both hips, including PROM evaluation, until physeal closure.

LEVEL OF EVIDENCE

II - prospective cohort study.

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.

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.

SCFE: clinical aspects, diagnosis, and classification

PURPOSE

This article seeks to improve treatment outcomes in slipped capital femoral epiphysis (SCFE) by outlining advances in diagnosis, understanding of pathomechanics, and mechanically-based classification.

METHODS

Review of clinical experience with SCFE at our high-volume centre, interaction with other clinical experts, and literature review has allowed a current perspective to be articulated.

RESULTS

SCFE remains an important clinical problem, with late diagnosis still frequent. Improved understanding of the ubiquity of femoroacetabular impingement has guided current classification and treatment protocols.

CONCLUSION

SCFE is an important clinical problem, with high historical rates of impaired hip function both in childhood and adulthood. Great opportunities exist for improved outcomes following earliest possible clinical diagnosis, modern imaging, and mechanically-based classification of involved hips to allow optimal treatment.

Vitamin D Deficiency in Slipped Upper Femoral Epiphysis: Time to Physeal Fusion

BACKGROUND

Slipped upper femoral epiphysis (SUFE) has an incidence of 1 to 7 per 100,000 adolescents in the United Kingdom and its link with obesity is well established. With an increasing number of pediatric orthopaedic patients presenting with vitamin D deficiency, the aim of our study was to establish the prevalence of vitamin D deficiency in SUFE patients presenting to an orthopaedic department in the United Kingdom and whether a low vitamin D level increases the time to proximal femoral physeal fusion after surgical fixation.

METHODS

A total of 27 pediatric patients, with a female to male ratio of 17:10 and a mean age of 11.5 years (SD=1.99), range 8 to 16 years, presented with a SUFE and their vitamin D level was assessed during the study period, June 2007 to July 2012 (inclusive). The majority of these patients (85.2%) were assessed as vitamin D deficient, with a serum 25-(OH)D<52 nmol/L. The time taken for >50% physeal fusion on anteroposterior radiography after surgical fixation reported in the literature is 9.6 months, with no reported vitamin D deficiency or insufficiency.

RESULTS

In our study, the median time to physeal fusion in the vitamin D-deficient and vitamin D-insufficient patients was 25 months (interquartile range, 17 to 43 mo; mean of 29 mo, SD=16.8). A negative correlation was also observed between vitamin D level and the time taken for physeal fusion after surgical fixation.

CONCLUSIONS

We conclude that a high prevalence of vitamin D deficiency has been observed in our SUFE patients. Comparing the time taken for physeal closure of 9.6 months in the literature with vitamin D-deficient patients, this is prolonged. Indeed, a negative correlation has been shown between vitamin D level and time to physeal fusion. This study highlights the need for regular vitamin D status assessment in SUFE patients to allow early implementation of treatment with vitamin D supplementation. The impact of vitamin D screening and supplementation on SUFE outcomes should be investigated further.

Arthroscopic treatment of femoroacetabular impingement following slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SCFE) may lead to symptomatic femoroacetabular impingement (FAI). We report our experience of arthroscopic treatment, including osteochondroplasty, for the sequelae of SCFE. Data were prospectively collected on patients undergoing arthroscopy of the hip for the sequelae of SCFE between March 2007 and February 2013, including demographic data, radiological assessment of the deformity and other factors that may influence outcome, such as the presence of established avascular necrosis. Patients completed the modified Harris hip score (mHHS) and the non-arthritic hip score (NAHS) before and after surgery. In total, 18 patients with a mean age of 19 years (13 to 42), were included in the study. All patients presented with pain in the hip and mechanical symptoms, and had evidence of FAI (cam or mixed impingement) on plain radiographs. The patients underwent arthroscopic osteoplasty of the femoral neck. The mean follow-up was 29 months (23 to 56). The mean mHHS and NAHS scores improved from 56.2 (27.5 to 100.1) and 52.1 (12.5 to 97.5) pre-operatively to 75.1 (33.8 to 96.8, p = 0.01) and 73.6 (18.8 to 100, p = 0.02) at final follow-up, respectively. Linear regression analysis demonstrated a significant association between poorer outcome scores and increased time to surgery following SCFE (p < 0.05 for all parameters except baseline MHHS). Symptomatic FAI following (SCFE) may be addressed using arthroscopic techniques, and should be treated promptly to minimise progressive functional impairment and chondrolabral degeneration.

TAKE HOME MESSAGE

Arthroscopy of the hip can be used to treat femoroacetabular impingement successfully following SCFE. However, this should be performed promptly after presentation in order to prevent irreversible progression and poorer clinical outcomes.

The oblique plane deformity in slipped capital femoral epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is commonly treated with in situ pinning. However, a severe slip may not be suitable for in situ pinning because the required screw trajectory is such that it risks perforating the posterior cortex and damaging the remaining blood supply to the capital epiphysis. In such cases, an anteriorly placed screw may also cause impingement. It is also possible to underestimate the severity of the slip using conventional radiographs. The aim of this study was to describe and evaluate a novel method for calculating the true deformity in SCFE and to assess the interobserver and intraobserver reliability of this technique.

METHODS

We selected 20 patients with varying severity of SCFE who presented to our institution. Cross-sectional imaging [either axial computed tomography (CT) scans or magnetic resonance imaging (MRI) scans] and anteroposterior (AP) pelvis radiographs were assessed by four reviewers with varying levels of experience on two occasions. The degree of slip on the axial image and on the AP pelvis radiographs were measured and, from this, the oblique plane deformity was calculated using the method as popularised by Paley. The intraclass correlation coefficient (ICC) was calculated to determine the interobserver and intraobserver reliabilities between and amongst the raters.

RESULTS

The interobserver reliability for the calculated oblique plane deformity in SCFE ICC was 0.947 [95 % confidence interval (CI) 0.90-0.98] and the intraobserver reliability for the calculated oblique plane deformity of individual raters ranged from 0.81 to 0.94. The deformity in the oblique plane was always greater than the deformity measured in the axial or the coronal plane alone.

CONCLUSION

This method for calculating the true deformity in SCFE has excellent interobserver and intraobserver reliability and can be used to guide treatment options. This technique is a reliable and reproducible method for assessing the degree of deformity in SCFE. It may help orthopaedic surgeons with varying degrees of experience to identify which hips are suitable for in situ pinning and those which require surgical dislocation and anatomical reduction, given that plain radiographs in a single plane will underestimate the true deformity in the oblique plane.

LEVEL OF EVIDENCE

Level II diagnostic study.

A reduction in body mass index lowers risk for bilateral slipped capital femoral epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is occurring in greater numbers, at increasingly younger ages, and more frequently bilaterally (BL-SCFE). Obesity is one risk factor for SCFE. However, it is unclear whether postoperative decreases or increases in body mass index (BMI) alter the risk of subsequent contralateral SCFE.

QUESTIONS/PURPOSES

We therefore determined whether (1) BMI percentile was a risk factor for BL-SCFE; and (2) postoperative increases and/or decreases in BMI percentile influenced the risk for BL-SCFE.

METHODS

We retrospectively reviewed the records of 502 patients surgically treated for SCFE and identified 138 (27%) with BL-SCFE and 364 (73%) with unilateral SCFE (UL-SCFE); 173 patients, 60 (35%) with BL-SCFE and 113 (65%) with UL-SCFE met our inclusion criteria. Risk factors included sex, age, slip stability, slip chronicity, slip angle, and obesity. Percentile BMI was recorded at the time of first SCFE surgery, at the time of last followup for patients undergoing UL-SCFE, and at the time of second SCFE surgery for patients undergoing BL-SCFE.

RESULTS

Sex, age, slip stability, and slip angle were not associated with BL-SCFE. Postoperative obesity (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.2-9.7) and acute slip chronicity (OR, 2.9; 95% CI, 1.3-6.7) had higher risks for sequential BL-SCFE. Obese patients who became nonobese postoperatively had a decreased risk of sequential BL-SCFE compared with those who remained obese (OR, 0.16; 95% CI, 1.2-116.5).

CONCLUSIONS

Only postoperative obesity and an acute slip were risk factors for sequential BL-SCFE. BMI reduction to lower than the 95% percentile after SCFE surgery was associated with lower risk for BL-SCFE development. The data suggest early supervised therapeutic weight management programs for patients treated for UL-SCFE are important to reduce risk of subsequent SCFE.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Incidence and gender differences of slipped capital femoral epiphysis in the Netherlands from 1998-2010 combined with a review of the literature on the epidemiology of SCFE

PURPOSE

The incidence of slipped capital femoral epiphysis (SCFE) among children living in the Netherlands has never been published.

METHODS

The national hospitalization registration system of the Netherlands was searched for the incidence of surgical procedures for SCFE in the Netherlands among different pediatric age groups between 1998 and 2010. International Classification of Diseases, 9th Revision codes were used.

RESULTS AND CONCLUSION

The incidence of surgical procedures for SCFE during the last decade was 11.6 per 100,000 children aged 5 to 19 years. No statistical difference in the incidence of SCFE was found between boys and girls, although the incidence of SCFE did significantly increase in girls during the study period. Based on our analysis, the Netherlands appears to be the first country in which no difference in the incidence of SCFE among boys and girls has been reported. However, during the study period there has been a concomitant increase in the number of girls with SCFE.

Hip ontogenesis: how evolution, genes, and load history shape hip morphotype and cartilotype

BACKGROUND

Developmental hip disorders (DHDs), eg, developmental dysplasia of the hip, slipped capitis femoris epiphysis, and femoroacetabular impingement, can be considered morphology variants of the normal hip. The femoroacetabular morphology of DHD is believed to induce osteoarthritis (OA) through local cumulative mechanical overload acting on genetically controlled patterning systems and subsequent damage of joint structures. However, it is unclear why hip morphology differs between individuals with seemingly comparable load histories and why certain hips with DHD progress to symptomatic OA whereas others do not.

QUESTIONS/PURPOSES

We asked (1) which mechanical factors influence growth and development of the proximal femur; and (2) which genes or genetic mechanisms are associated with hip ontogenesis.

METHODS

We performed a systematic literature review of mechanical and genetic factors of hip ontogeny. We focused on three fields that in recent years have advanced our knowledge of adult hip morphology: imaging, evolution, and genetics. WHERE ARE WE NOW?: Mechanical factors can be understood in view of human evolutionary peculiarities and may summate to load histories conducive to DHD. Genetic factors most likely act through multiple genes, each with modest effect sizes. Single genes that explain a DHD are therefore unlikely to be found. Apparently, the interplay between genes and load history not only determines hip morphotype, but also joint cartilage robustness ("cartilotype") and resistance to symptomatic OA. WHERE DO WE NEED TO GO?: We need therapies that can improve both morphotype and cartilotype. HOW DO WE GET THERE?: Better phenotyping, improving classification systems of hip morphology, and comparative population studies can be done with existing methods. Quantifying load histories likely requires new tools, but proof of principle of modifying morphotype in treatment of DDH and of cartilotype with exercise is available.

Slipped capital femoral epiphysis: prevalence, pathogenesis, and natural history

BACKGROUND

Obesity is a risk factor for developing slipped capital femoral epiphysis (SCFE). The long-term outcome after SCFE treatment depends on the severity of residual hip deformity and the occurrence of complications, mainly avascular necrosis (AVN). Femoroacetabular impingement (FAI) is associated with SCFE-related deformity and dysfunction in both short and long term.

QUESTIONS/PURPOSES

We examined obesity prevention, early diagnosis, reducing AVN and hip deformity as strategies to reduce SCFE prevalence, and the long-term outcomes after treatment.

METHODS

A search of the literature using the PubMed database for the key concepts SCFE and treatment, natural history, obesity, and prevalence identified 218, 15, 26, and 49 abstracts, respectively. WHERE ARE WE NOW?: A correlation between rising childhood obesity and increasing incidence of SCFE has been recently reported. Residual abnormal morphology of the proximal femur is currently believed to be the mechanical cause of FAI and early articular cartilage damage in SCFE. WHERE DO WE NEED TO GO?: Reducing the increasing prevalence rate of SCFE is important. Treatment of SCFE should aim to reduce AVN rates and residual deformities that lead to FAI to improve the long-term functional and clinical outcomes. HOW DO WE GET THERE?: Implementing public health policies to reduce childhood obesity should allow for SCFE prevalence to drop. Clinical trials will evaluate whether restoring the femoral head-neck offset to avoid FAI along with SCFE fixation allows for cartilage damage prevention and lower rates of osteoarthritis. The recently described surgical hip dislocation approach is a promising technique that allows anatomic reduction with potential lower AVN rates in the treatment of SCFE.