Management of the contralateral hip in patients with unilateral slipped upper femoral epiphysis: to fix or not to fix--consequences of two strategies

[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.

Management of slipped capital femoral epiphysis: What hardware we can use in osteosynthesis <em>in situ</em>?

Epiphysiolysis (or Slipped Capital Femoral Epiphysis, SCFE) is a hip disorder involving children during prepubescence age. Traditionally, it is defined as a postero-medial slippage of the femoral epiphysis on the metaphysis, but, considering that femoral epiphysis is almost “stored” in the acetabulum, it could be better defined as laterally and anterior slippage of femoral metaphysis under the epiphysis.

Leg length discrepancy after in situ fixation with screw for slipped capital femoral epiphysis

Although leg length discrepancy (LLD) commonly occurs following in situ fixation with screws for slipped capital femoral epiphysis (SCFE), the literature regarding this issue is scarce. The purpose of this study was to evaluate the degree of LLD in patients who had been treated with in situ fixation with screws and to identify the risk factors for the development of LLD. We retrospectively reviewed 44 patients (mild slip 24, moderate slip, 20) who were treated with in situ fixation with screws for SCFE. The mean age at surgery was 12.2 years and the mean follow-up period was 6.9 years. We investigated the relationship between the final LLD, articulotrochanteric distance difference (ATDD) at skeletal maturity, and various clinical and radiographic parameters using linear regression analysis. The mean values of LLD and ATDD were 13.1 and 11.1 mm, respectively. The LLD and ATDD was significantly higher in patients with moderate slips than in those with mild slips. The degree of slip angle was associated with the degree of LLD only. While there was no significant factor affecting the LLD in moderate slips, younger age and a larger degree of slip angle were associated with the degree of LLD. The degree of slip was the only factor that affected LLD in patients with mild or moderate SCFE who underwent threaded screw fixation. Age at surgery was not associated with LLD, and there were no factors related to the degree of LLD in mild slip. Monitoring for LLD may only be necessary for patients with moderate slip who are treated with in situ screw fixation.

Safely Reducing the Incidence of Contralateral Slipped Capital Femoral Epiphysis: Results of a Prospectively Implemented Prophylactic Fixation Protocol Using the Posterior Sloping Angle

BACKGROUND

Bilateral slipped capital femoral epiphysis (SCFE) is common. The management of the contralateral hip in unilateral SCFE remains controversial. The aim of this study was to report on the clinical outcomes using a posterior sloping angle (PSA) threshold of 14.5 degrees for prophylactic fixation in preventing contralateral SCFE.

METHODS

Having previously established through a retrospective study that PSA was predictive of future slip, the authors put in place a protocol where patients with unilateral SCFE who had a PSA ≥14.5 degrees on the contralateral side were offered prophylactic fixation. Those with unilateral SCFE presenting between January 2008 and December 2018 with a minimum of 12-month follow-up were included. Patients with renal or endocrine disorders were excluded. Primary outcomes were the number of slips prevented, the number needed to treat, and the complication rate.

RESULTS

Of the 219 patients who were included, 114 (52.1%) underwent prophylactic fixation.A PSA threshold of 14.5 degrees prevented 77% of subsequent slips with a number needed to treat of 2.4 in our population. There were no cases of chondrolysis, avascular necrosis, or periprosthetic fracture associated with prophylactic pinning.

CONCLUSIONS

Prophylactic fixation using a PSA of 14.5 degrees is safe, decreases unnecessary intervention, and reduces 77% of subsequent SCFE. The PSA can increase over time and the authors recommend that the protocol be applied for the duration of follow-up.

LEVEL OF EVIDENCE

Level III.

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.

Osteonecrosis After Contralateral in Situ Prophylactic Pinning for a Slipped Capital Femoral Epiphysis: A Case Report

CASE

We report the case of an 11-year-old girl who developed osteonecrosis of the femoral head in the radiographically normal, asymptomatic left hip that had been fixed prophylactically in the context of a slipped capital femoral epiphysis (SCFE) that had been detected on the contralateral hip. The etiology of the osteonecrosis remains unknown.

CONCLUSION

This case report demonstrates that prophylactic fixation of a radiographically normal, asymptomatic hip in the context of an SCFE on the contralateral side has the potential for substantial complications. Therefore, the risk of osteonecrosis in the prophylactically pinned hip should be carefully considered because this complication may have devastating functional consequences.

What Is the Prevalence of Cam Deformity After Prophylactic Pinning of the Contralateral Asymptomatic Hip in Unilateral Slipped Capital Femoral Epiphysis? A 10-year Minimum Followup Study

BACKGROUND

Prophylactic pinning of the asymptomatic and normal-appearing contralateral hip in patients with unilateral slipped capital femoral epiphysis (SCFE) remains controversial. Understanding the minimal 10-year clinical, functional, and radiographic outcomes of the contralateral asymptomatic hip in unilateral SCFE may be helpful in the decision regarding whether the benefits associated with potentially preventing a SCFE are outweighed by the risk of additional surgery.

QUESTIONS/PURPOSES

Among patients with SCFE treated with prophylactic pinning of the asymptomatic and contralateral hip, we sought (1) to determine the complications and reoperations; (2) to evaluate the development of cam deformities and the frequency and severity of osteoarthritis progression; and (3) to characterize hip pain and function as measured by the Harris hip score (HHS) and the Hip Disability and Osteoarthritis Outcome Score (HOOS) at minimal 10-year followup.

METHODS

Between 1998 and 2005 all patients with SCFE seen at our institution were treated with the modified Dunn procedure and all were offered prophylactic pinning of the contralateral asymptomatic hip. Of the 41 patients who underwent the unilateral modified Dunn procedure and who had an asymptomatic contralateral hip, 37 patients (90%) underwent pinning of that contralateral hip. Of those, 33 patients (80%) were available for clinical and radiographic evaluation for this retrospective study at a minimum of 10 years (mean followup 12 ± 2 years) after surgery. Three patients of the 37 patients only had 10-year clinical followup, including questionnaires sent by mail and telephone, because they refused further radiographic followup and one patient was lost to followup. The group included 19 males and 17 females whose age at surgery was a mean of 13 ± 2 years. Medical charts were reviewed and patients were asked about complications and additional surgical procedures. Most recent postoperative radiographs were evaluated for measurement of the alpha angle, head-neck offset, epiphysis orientation, and osteoarthritis grading according to Tönnis classification and minimum joint space width. The presence of a cam deformity was defined by an alpha angle measurement > 60° on the AP radiograph and/or > 55° on the lateral radiograph. Hip function and pain were assessed by the HHS and HOOS outcome measures.

RESULTS

No complications with prophylactic in situ pinning were recorded. Four of 36 (11%) patients underwent subsequent surgical treatment for cam-type femoroacetabular impingement (FAI), and hardware removal was performed in four hips (11%). The mean alpha angle was 53° ± 8° on the AP radiograph and 49° ± 8° on the lateral view at followup. In total, 10 of 33 hips (30%) had a cam morphology at the femoral head-neck junction and four (12%) were symptomatic and underwent FAI surgery. Six of 33 patients (18%) developed an asymptomatic cam morphology at the femoral head-neck junction; in three of 33 hips (9%), the cam deformity instead of lesion were visible only on the lateral projection, and 9% were visible on both the AP and lateral projections. The preoperative offset of the femoral head-neck junction was 10 ± 3 mm on the AP view and 11 ± 4 mm on the lateral view. At followup, the AP offset was 7 ± 3 mm and the lateral offset was 6 ± 3 mm, and on the lateral view, the offset was < 10 mm in eight hips (22%). No patient had radiographic signs of hip osteoarthritis (Tönnis Grade 0). The mean minimum joint space width was 4 ± 0.4 mm. The mean HHS for the 32 patients who did not undergo subsequent surgery was 97 ± 5 at latest followup. The mean postoperative HOOS was 94 ± 8 for the 32 patients at latest followup.

CONCLUSIONS

At a minimum followup of 10 years after prophylactic pinning of a contralateral asymptomatic hip, most patients achieve excellent hip scores; however, a substantial proportion will develop a symptomatic cam deformity despite prophylactic pinning. No patient had signs of osteoarthritis at a minimum of 10 years, but almost one-third of the patients who underwent prophylactic pinning developed a cam deformity.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Diagnostic and Therapeutic Challenges of a Slipped Capital Femoral Epiphysis in a Low and Middle Income Country: A Case Report and Literature Review

Background:

Slipped Capital Femoral Epiphysis (SCFE) is an incapacitating orthopedic disease, particularly affecting older children and adolescents and caused by the sliding of the proximal femoral epiphysis on the metaphysis. SCFE has a clinical polymorphism, compounded with a certain diagnostic variability among health practitioners and the relatively high cost of its surgical management contribute to the diagnostic delay observed in most developed countries as well as developing ones. Herein, we report the case of SCFE in an adolescent Cameroonian, with emphasis on its diagnostic and therapeutic challenges in Low and Middle-Income Countries (LMICs), in a bit to improve on timely recognition and management by clinicians in these settings.

Case Presentation:

A 10-year-old girl has presented with unilateral right thigh pain of more than one year duration associated with a limping gait and no fever. Before the referral to our health facility, she consulted several general practitioners in rural areas and pediatricians in the city with no definite diagnosis. On the basis of the clinical and the imaging studies, the diagnosis of stable right SCFE with moderate displacement was made. Under general anesthesia, the patient underwent open reduction and internal fixation with three pins under c-arm fluoroscopy. Clinical and radiological follow-up till one year after surgical intervention were satisfactory. The pins were removed after one year of fixation confirming a good bone fusion in plain x-ray. Her clinical examination and radiological follow-up three years after removal of the pins were satisfactory.

Conclusion:

The case report illustrates that SCFE often a missed diagnosis in LMICs. This is worrisome because delayed diagnosis may lead to long-term complications such as avascular necrosis and early degenerative joint disease. Although the above case was missed by several clinicians and finally diagnose late, the present case highlights the need for a high index of clinical suspicion in order to timely diagnose and timely manage SCFE to avert potential long-term physical disabilities and psychological trauma in children.

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.

Asynchronous slipped capital femoral epiphysis in a patient with a seizure disorder: case report and review of the literature

Debate remains about the appropriate treatment of the asymptomatic side following treatment of a unilateral slipped capital femoral epiphysis (SCFE). A 12-year-old boy with a seizure disorder presented with an unstable SCFE on the left hip following a seizure. He underwent percutaneous pinning of the left only. At 8 months postoperatively, he returned with an unstable slip of the right hip, again following a seizure. No literature discussing the treatment of patients with risk of SCFE and seizure disorders was identified. Further study may identify an increased incidence of contralateral slip following an initial slip in this population. If a greater risk exists, contralateral prophylactic fixation at time of index surgery may be indicated.

Fixation in slipped capital femoral epiphysis avoiding femoral-acetabular impingement

Background

The appropriate treatment in mild slipped capital femoral epiphysis (SCFE) should not only prevent further slipping of the epiphysis but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. The aim of this study was to quantify length of the remodeling phase mediated by growth of the femoral neck, after treatment of SCFE with a screw designed to prevent premature closure of the physis and provide stability.

Methods

Between 2001 and 2011, 38 patients with unilateral mild SCFE were treated by fixation in situ using a modified screw which does not cause premature physeal arrest. Twenty-four patients were investigated for clinical and radiological evidence of femoroacetabular impingement immediately after surgery, at 6- and 12-month follow-ups. Statistical analysis was performed comparing measurements of neck length and the α angle of the affected and contralateral side.

Results

Mean α angle immediately after pinning was 56.2 ± 10.6° on the anteroposterior view and 91.4 ± 8.2° on the lateral view. These measurements significantly improved at 6 months post-op to 48.9 ± 5.4° on the anteroposterior view and 51.2 ± 6.5° on the lateral view (p < 0.0001). At 12 months from surgery, AP view α angle was 43.0 ± 2.8° (p < 0.0001) and lateral view was 44.2 ± 4.1° (p < 0.0001). We observed a similar growth rate and speed of the femoral neck of both the affected and unaffected sides during the first year of treatment. The clinical results in all patients were rated as excellent.

Conclusion

Our data supports the use of a surgical technique that allows residual growth of the femoral neck following mild SCFE and permits restoration of the anatomy of the proximal femur while avoiding development of femoroacetabular impingement following mild SCFE.

Treatment of stable slipped capital femoral epiphysis: systematic review and exploratory patient level analysis

Background

Several aspects of slipped capital femoral epiphysis (SCFE) treatment remain controversial. Loder’s work has been instrumental in changing our understanding and approach to the management of the condition when he introduced the concept of “slip instability” and showed that avascular necrosis (AVN) developed in 47% of unstable slips but none of the stable slips. As the two types of SCFE behave differently in terms of presentation, progress and complications, we approached them as two different conditions to highlight these differences. This paper focuses on treatments of stable SCFE.

Materials and methods

An extensive literature search was carried out from multiple databases. One thousand six hundred and twenty-three citations were screened. Three hundred and sixteen full publications were obtained for further scrutiny. Fifty-eight studies (2262 hips) were included in the review. These studies evaluated 6 interventions. AVN was chosen as a surrogate for bad outcome. Secondary outcomes were chondrolysis (CL), femoro-acetabular impingement (FAI), osteoarthritis (OA) and patients’ reported outcomes. The latter were pooled when they met our predefined criteria.

Results

The type of surgical intervention was an important risk factor. Pinning in situ (PIS) was associated with the lowest AVN rate (1.4%). Moreover, the CL, FAI and OA rates were relatively low in patients who underwent PIS. These were not translated into high patient satisfaction rates among these patients, with only 47% reporting an “excellent” outcome. In contrast, 87% of patients who underwent Ganz surgical dislocation reported an “excellent” outcome. The Ganz surgical dislocation was associated with an AVN rate of 3.3%; double that observed in pinning in situ.

Conclusion

Pinning in situ is the best treatment for mild and moderate stable slip. Ganz surgical dislocation gives higher patient satisfaction for severe stable slip but the risk of AVN is doubled compared with pinning in situ. Devices that allow continued growth may be better than standard screws.

Level of evidence

Level III.

Slipped capital femoral epiphysis: a population-based study

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is the most common hip disorder in children 9-15 years old. This is a population-based study in Sweden presenting the epidemiology for SCFE.

METHODS

In a prospective cohort study, we analysed pre- and postoperative radiographs, medical records for all children treated for SCFE in Sweden 2007-2013, demographic data, severity of slip and surgical procedures performed.

RESULTS

We identified 379 Swedish children with primary SCFE 2007-2013; 162 girls, median age 11.7 (7.2-15.4) years, and 217 boys, median age 13 (3.8-17.7) years. The average annual incidence was 4.4/10000 for girls and 5.7/10000 for boys 9-15 years old. Obesity or overweight was found in 56% of the girls and in 76% of the boys. As an initial symptom, 66% of the children had hip/groin pain and 12% knee pain. At first presentation, 7% of the children had bilateral SCFE. Prophylactic fixation was performed in 43%. Of the remaining children, 21% later developed a contralateral slip. Fixation with implants permitting further growth was used in >90% of the children. Femoral neck osteotomy was performed for 11 hips.

CONCLUSIONS

The annual average incidence 2007-2013 in Sweden showed a mild increase for girls. The male-to-female ratio was lower than previous regional data from Sweden. Overweight or obesity is one major characteristic for boys with SCFE but to a less extent for girls. Knee pain as initial symptom cause a delay in diagnosis. Most hospitals in Sweden treat <2 children annually.

Complications Related to the Treatment of Slipped Capital Femoral Epiphysis

Slipped capital femoral epiphysis (SCFE) is a condition of the immature hip in which mechanical overload of the proximal femoral physis results in anterior and superior displacement of the femoral metaphysis relative to the epiphysis. The treatment of SCFE is surgical, as the natural history of nonsurgical treatment is slip progression and early arthritis. Despite advances in treatment, much controversy exists regarding the best treatment, and complication rates remain high. Complications include osteonecrosis, chondrolysis, SCFE-induced impingement, and related articular degeneration, fixation failure and deformity progression, growth disturbance of the proximal femur, and development of bilateral disease.

Two cases of avascular necrosis after prophylactic pinning of the asymptomatic, contralateral femoral head for slipped capital femoral epiphysis: case report and review of the literature

BACKGROUND

In a child with a unilateral slipped capital femoral epiphysis (SCFE), the treatment of the radiographically normal, asymptomatic contralateral hip remains controversial. The risks of a subsequent slip have to be measured against the risks involved with an additional surgical procedure. Proponents of prophylactic pinning believe that fixation with a single cannulated screw is a safe method to prevent secondary arthrosis from a missed minor slip. Others argue that in most cases it is an unnecessary procedure and with careful follow-up, any issues with the asymptomatic, normal hip can be identified early and addressed.

METHODS

We retrospectively look at 2 cases where avascular necrosis (AVN) developed in the prophylactically pinned asymptomatic and radiographically normal hip in the setting of an identified SCFE on the contralateral hip.

RESULTS

Two cases of AVN developed in the prophylactically pinned hips within 8 months of the initial pinning procedure.

CONCLUSIONS

This case report demonstrates that prophylactic pinning of an asymptomatic, radiographically normal hip in the setting of a SCFE on the contralateral side is not a benign procedure and is one that has potential for significant complications. The risk of AVN in the prophylactically pinned hip needs to be taken into careful consideration as this risk can have devastating consequences to the patient.

LEVEL OF EVIDENCE

Level IV.

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.