AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Slipped capital femoral epiphysis (SCFE) persists as one of the most common adolescent hip disorders encountered in orthopedic practice. While the underlying defect may be multifactorial (eg, mechanical and constitutional factors), SCFE represents a unique type of instability of the proximal femoral growth plate. Clinically, the patient may report hip, medial thigh, and/or knee pain; an acute or insidious onset of a limp; and possible decreased range of motion. On x-ray films, the femoral head is seen displaced in varying degrees, posteriorly and inferiorly in relation to the femoral neck and within the confines of the acetabulum. Treatment is primarily operative internal fixation.

Frequency

United States

The prevalence is approximately 0.7-10.8 cases per 100,000 persons. The male-to-female ratio is 2.4:1. SCFE occurs in boys aged 10-16 years and girls aged 12-14 years. In the general population, 25% of SCFE cases are bilateral. Of patients with known unilateral involvement, 60-80% develop SCFE in the contralateral hip. Children who are obese are at risk for this problem.

Functional Anatomy

SCFE results from a Salter-Harris–type physeal fracture. In adolescents with SCFE, the epiphyseal growth plate is unusually widened, primarily due to expansion of the zone of hypertrophy. The hypertrophic zone, which constitutes 15-30% of the normal physis, accounts for up to 80% of the width of the physeal plate in affected patients. Histologically, abnormal cartilage maturation, endochondral ossification, and perichondral ring instability occur, leading to a disruption of the normal cartilaginous palisading architecture. Slippage occurs through this weakened area.

In most affected patients, a variable period of prodromal symptoms or a sudden mechanical traumatic episode is reported. In addition, the position of the proximal physis normally changes from horizontal to oblique during preadolescence and adolescence, redirecting hip forces from compression forces to shear forces. Other concomitant findings in the hip include inflammatory synovitis and disorganized collagen fibrils with accumulations of proteoglycans and glycoproteins within the growth plate; however, whether these changes are a cause or a result of this disorder remains undetermined.

CLINICAL

Section 3 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

• SCFE is most common in the adolescent period (ie, boys aged 10-16 y, girls aged 12-14 y). Males have 2.4 times the risk compared with females.
• The left hip is affected more commonly than the right.
• Obesity is a risk factor because it places more shear forces around the proximal growth plate in the hip at risk.
• The duration, location, and radiation of pain are important, as is the ability to bear weight.
• Genetics may play a role because the rate of familial involvement is 5-7%, with a large variability in penetrance.
• In patients younger than 10 years, SCFE is associated with metabolic endocrine disorders (eg, hypothyroidism, panhypopituitarism, hypogonadal, renal osteodystrophy, growth hormone abnormalities). Bilaterality is more common in these younger patients.
• The chronicity of the condition should be determined.
• • Prodromal symptoms (eg, hip or knee pain, limp, decreased range of motion) for less than 3 weeks are deemed acute.

  • Prodromal symptoms for more than 3 weeks are deemed chronic.

  • If a patient reports symptoms of greater than 3 weeks' duration but presents with an acute exacerbation of pain, limp, inability to bear weight, or decreased range of motion with or without an associated traumatic episode, the SCFE is categorized as acute on chronic.

  • Determine if a traumatic episode occurred.

• If a patient reports knee pain, always examine the hip because knee pain may be referred pain from the hip via the obturator nerve.
• Always examine and obtain an x-ray film of the contralateral hip to use as a comparison and to help rule out coexisting bilateral disease.
• African Americans may have a higher incidence of SCFE.
• Classification schemes are as follows:
• • Determine whether the SCFE is acute, chronic, or acute on chronic.

  • Determine whether the SCFE stable or unstable. Stable patients are able to bear weight on the affected limb with or without crutches or assistive devices. Unstable patients are not able to bear weight because of pain.

  • Determine the radiographic classification. This is determined by the percentage of displacement of the hip in relation to the neck. Type I is less than 33% displacement, type II is 33-50% displacement, and type III is greater than 50% displacement.

Physical

• Children who are obese are at higher risk for this problem.
• Determine the patient's gait pattern (eg, antalgic, Trendelenburg) and ability to bear weight.
• Determine the active and passive range of motion of both hips and knees.
• If SCFE is present, the lower extremity may rotate externally upon gentle passive flexion of the hip.
• Note any lower extremity deformity, such as external rotation or shortening.

DIFFERENTIALS

Section 4 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Legg-Calvé-Perthes disease
Synovitis
Septic joint
Chronic developmental hip dysplasia
Femoral hernia

WORKUP

Section 5 of 11  

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• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Typically, blood work is unnecessary for SCFE diagnosis except for preoperative testing.
• In patients with atypical presentations (eg, bilateral involvement in a presenting patient <10 y), rule out metabolic disorders (eg, panhypopituitarism, renal osteodystrophy, hypothyroidism, hypogonadism, growth hormone abnormalities), each with its own workup.

Imaging Studies

• Obtain anteroposterior and lateral radiographs of the pelvis and bilateral hips.
• • Note any bony changes of the femoral neck and head because they may demonstrate chronic adaptive changes during alterations in hip biomechanics as the femoral head displaces.

  • Determine the amount of head displacement off the femoral neck as a percentage to classify the degree of slippage. Again, type I is less than 33% displacement, type II is 33-50% displacement, and type III is greater than 50% displacement.

  • Determine whether the Klein line is present. On the anteroposterior view of the hip, a line drawn along the superior border of the femoral neck should pass through a portion of the femoral head. If not, SCFE is diagnosed.

  • Frog-leg lateral views of the hip are not recommended because they may further displace the slip. True cross-table lateral views are encouraged.

• CT scans are not routinely performed, but they may be helpful to confirm the diagnosis or more accurately measure the degree of displacement.

TREATMENT

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Acute Phase

Medical Issues/Complications

Prophylactic treatment of the asymptomatic hip is controversial. Because of the high incidence of eventual bilateral involvement (up to 40-80%) and given that one hip is already affected, some have advocated routine prophylactic treatment of the contralateral hip at the initial time of surgery. Weigh the benefits and risks when contemplating surgery on a possibly unaffected hip. In a review of the literature, prophylactic treatment may be considered in patients younger than 10 years or patients affected by various endocrinopathies because they have higher relative risks for bilateral involvement. In a typical patient who presents with SCFE, warn the parents of possible bilateral involvement and the need for close follow-up and early operative intervention if the other hip becomes symptomatic.

Surgical Intervention

At this time, internal fixation using central percutaneous pin fixation with one or more cannulated screws is the treatment of choice. Pin fixation allows early stabilization of the slippage, enhancement of physeal closure, prevention of further slippage, and alleviation of symptoms with minimal morbidity. Gentle, rather than aggressive, reduction is necessary to decrease the incidence of vascular damage, which can lead to avascular necrosis (AVN). Fixation is often performed in situ.

Bone-graft epiphysiodesis in combination with internal fixation or casting is advocated by some surgeons, but the procedure is associated with a high learning curve, a high prevalence of AVN and chondrolysis, poor initial fixation, prolonged operative time, increased intraoperative blood loss, and loss of epiphyseal position.

Intracapsular osteotomy is considered an open reduction and internal fixation procedure with an unusually high rate of complications (20-30% rate of AVN). It is not indicated as the primary procedure for SCFEs.

Historically, spica casts were used; however, because of the high morbidity (eg, AVN, chondrolysis) and difficulty in applying and maintaining these casts, especially in patients who are obese, they have fallen out of favor.

Consultations

In patients who present at an early age (<10 y), consultation with an endocrinologist may be necessary to help rule out other metabolic disorders if the history and physical examination findings indicate other abnormalities.

MEDICATION

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No medical therapy is available for the treatment of SCFE except symptomatic pain relief. Medications may include acetaminophen, nonsteroidal anti-inflammatory drugs, or narcotics, depending on the physician's preference.

Drug Category: Analgesics/Antipyretics

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who have sustained trauma.

Drug Category: Nonsteroidal anti-inflammatory drugs

Have analgesic, anti-inflammatory, and antipyretic activities. Their mechanism of action is not known, but may inhibit cyclooxygenase activity and prostaglandin synthesis. Other mechanisms also may exist, such as leukotriene synthesis inhibition, lysosomal enzyme release, lipoxygenase activity, neutrophil aggregation, and various cell membrane functions.

FOLLOW-UP

Section 8 of 11  

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Return to Play

Following fixation, the patient is given crutches with protected weightbearing for 6-8 weeks. However, most patients are not compliant and discontinue the use of crutches after a few weeks once they have achieved an acceptable comfort level. Most children return to play once the pain has resolved. Radiographic follow-up is often continued until physeal closure is achieved to ensure the slippage has not progressed. Loss of fixation of the slip can occur but is rare.

Complications

AVN of the femoral head is thought to result from vascular damage during the time of the initial traumatic event but may result from forceful reduction during the time of surgery. The amount of energy, magnitude of epiphyseal damage and displacement, level of increased intra-articular pressure, and degree of vascular occlusion have been implicated in this process. The risk of AVN is approximately 20-50% with an attempted reduction versus less than 5% without reduction.

Chondrolysis is possible. The destruction of cartilage is believed to occur irrespective of the method of treatment. Intra-articular penetration of hardware and violation of the joint has been associated with chondrolysis. However, chondrolysis has occurred in patients who have not undergone treatment.

Leg length inequality may result from incomplete reduction, AVN, chondrolysis, or secondary coxa vara.

Osteoarthritis may result from AVN, chondrolysis, or alterations of the hip biomechanics following slippage and is a late complication.

Hardware failure, failure of epiphysiodesis, failure of slip progression, and/or infection may occur.

Prognosis

Most patients with SCFEs who are treated with in situ percutaneous pinning do well. However, in those cases with severe slippage and resultant deformity, long-term sequelae may result (eg, AVN, chondrolysis, leg length discrepancy, stiffness, osteoarthritis). While conservative modalities (eg, therapy, analgesics, orthotics, assistive aids) are used initially for symptomatic relief, operative intervention may be indicated. Young patients with unremitting pain, loss of motion, and stiffness secondary to chondrolysis, AVN, or osteoarthritis may require salvage hip arthrodeses. In hips that are incompletely damaged, proximal osteotomies may aid in redirecting joint forces to less damaged areas of the articular femoral head.

Education

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center and Sports Injury Center. Also, see eMedicine's patient education article Repetitive Motion Injuries.

MISCELLANEOUS

Section 9 of 11  

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• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• AVN of the femoral head: This is believed to be a result of the initial injury and extent of the disease process rather than a result of the operative procedure. Persons with acute SCFE are more at risk of AVN than persons with chronic SCFE. This may require further operative intervention in the future.
• Chondrolysis: This is usually an iatrogenic result of pin placement within the hip. This is a devastating complication, which may require further operative intervention in the future.
• Limp
• Leg length discrepancy
• Development of SCFE in the contralateral hip

MULTIMEDIA

Section 10 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  A Klein line is a line drawn along the superior border of the femoral neck that would normally pass through a portion of the femoral head. If not, slipped capital femoral epiphysis is diagnosed.
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Media type:  X-RAY

Media file 2:  X-ray film of a hip following operative percutaneous fixation of a slipped capital femoral epiphysis
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Media type:  X-RAY

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
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• Follow-up
• Miscellaneous
• Multimedia
• References

• Aronson DD, Carlson WE. Slipped capital femoral epiphysis. A prospective study of fixation with a single screw. J Bone Joint Surg Am. Jul 1992;74(6):810-9. [Medline].
• Betz RR, Steel HH, Emper WD, Huss GK, Clancy M. Treatment of slipped capital femoral epiphysis. Spica-cast immobilization. J Bone Joint Surg Am. Apr 1990;72(4):587-600. [Medline].
• Brenkel IJ, Dias JJ, Davies TG, Iqbal SJ, Gregg PJ. Hormone status in patients with slipped capital femoral epiphysis. J Bone Joint Surg Br. Jan 1989;71(1):33-8. [Medline].
• Crawford AH. Slipped capital femoral epiphysis. J Bone Joint Surg Am. Oct 1988;70(9):1422-7. [Medline].
• Hägglund G, Hansson LI, Ordeberg G, Sandström S. Bilaterality in slipped upper femoral epiphysis. J Bone Joint Surg Br. Mar 1988;70(2):179-81. [Medline].
• Kehl DK. Slipped capital femoral epiphysis. In: Lovell WW, Winter RB, Morrissy RT, Weinstein SL, eds. Lovell & Winter's Pediatric Orthopaedics. 4^th ed. Philadelphia, Pa: Lippincott, Williams & Wilkins; 1996.
• Kelsey JL, Keggi KJ, Southwick WO. The incidence and distrubition of slipped capital femoral epiphysis in Connecticut and Southwestern United States. J Bone Joint Surg Am. Sep 1970;52(6):1203-16. [Medline].
• Klein A, Joplin RJ, Reidy JA. Roentgenographic features of slipped capital femoral epiphysis. AJR Am J Roentgenol. 1951;66:361.
• Krahn TH, Canale ST, Beaty JH, Warner WC, Lourenço P. Long-term follow-up of patients with avascular necrosis after treatment of slipped capital femoral epiphysis. J Pediatr Orthop. Mar-Apr 1993;13(2):154-8. [Medline].
• Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD. Acute slipped capital femoral epiphysis: the importance of physeal stability. J Bone Joint Surg Am. Aug 1993;75(8):1134-40. [Medline].
• Pritchett JW, Perdue KD. Mechanical factors in slipped capital femoral epiphysis. J Pediatr Orthop. Jul-Aug 1988;8(4):385-8. [Medline].
• Stanitski CL. Acute Slipped Capital Femoral Epiphysis: Treatment Alternatives. J Am Acad Orthop Surg. Mar 1994;2(2):96-106. [Medline].
• Ward WT, Stefko J, Wood KB, Stanitski CL. Fixation with a single screw for slipped capital femoral epiphysis. J Bone Joint Surg Am. Jul 1992;74(6):799-809. [Medline].
• Weiner DS, Weiner S, Melby A, Hoyt WA Jr. A 30-year experience with bone graft epiphysiodesis in the treatment of slipped capital femoral epiphysis. J Pediatr Orthop. Mar 1984;4(2):145-52. [Medline].
• Wells D, King JD, Roe TF, Kaufman FR. Review of slipped capital femoral epiphysis associated with endocrine disease. J Pediatr Orthop. Sep-Oct 1993;13(5):610-4. [Medline].
• Zubrow AB, Lane JM, Parks JS. Slipped capital femoral epiphysis occurring during treatment for hypothyroidism. J Bone Joint Surg Am. Mar 1978;60(2):256-8. [Medline].

Article Last Updated: Jun 8, 2006