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Slipped Capital Femoral Epiphysis
532
Slipped Capital Femoral Epiphysis BASIC INFORMATION DEFINITION Slipped capital femoral epiphysis (SCFE) is the most common adolescent orthopedic hip disorder. It is characterized by the displacement of the capital femoral epiphysis from the femoral neck through the physeal plate (growth plate).
SYNONYMS Physiolysis of the hip SCFE Slipped upper femoral epiphysis ICD-9-CM CODES 732.2 Slipped upper femoral epiphysitis 732.9 Epiphysitis
EPIDEMIOLOGY & DEMOGRAPHICS
Prevalence ranges from 0.2 per 100,000 in eastern Japan to 10.08 per 100,000 in the northeastern United States. Male-to-female ratio is 1.5:1.0. Relative racial frequency is 1.0 for whites, 4.5 for Pacific Islanders, 2.2 for blacks, 1.05 for Amerindians, 0.5 for IndonesianMalay peoples, and 0.1 for Indo-Mediterranean peoples. Differences are theoretically based on mean body weight for each racial group or variability in acetabular depth in each racial group. Mean age of presentation is 12 years in girls (usually prior to menarche) and 13.5 years in boys (usually prior to Tanner stage IV). Main risk factor is obesity (¼ 90% weight for age and gender). Other risk factors include endocrine abnormalities, especially hypothyroidism and growth hormone deficiency; genetic disorders, such as Down syndrome and RubinsteinTaybi syndrome; and renal failure.
CLINICAL PRESENTATION History Usual presentation is nonradiating pain and altered gait. Pain is increased with physical activity. Pain may be chronic or intermittent. Fifteen percent of children and adolescents initially present with thigh or knee pain. The chronic pattern of presentation is the most common, defined by intermittent symptoms for longer than 3 weeks. Other pattern presentations include preslip, defined by pain but no displacement of the epiphysis, acute, and acute-on-chronic. Presentation with bilateral disease occurs in 20% of cases. In unilateral disease, the contralateral hip may be affected in 30% to 60% of cases. Physical Examination Affected leg is usually held in an externally rotated position. Stable SCFE (slip) is defined by the patient walking or weight bearing; unstable SCFE is defined by inability to bear weight even with crutches. Gait is usually antalgic in unilateral SCFE. Gait is waddling in bilateral SCFE.
With moderate to severe SCFE (displacement greater than one third of the diameter of the femoral neck), atrophy of the upper thigh and gluteal muscles may be present, sometimes associated with a Trendelenburg gait. Anterior hip may be tender to palpation. Abduction and external rotation of the affected leg when the hip is passively flexed from an extended position is highly suggestive of SCFE.
admitted to the hospital for bed rest and complete avoidance of weight bearing to avoid further slippage. Treatment of SCFE is a surgical procedure, usually with screw fixation: stabilization of the physis with a single cannulated screw placed in the center of the epiphysis. Prophylactic pinning of the contralateral hip in unilateral SCFE presentations is controversial.
ETIOLOGY
DISPOSITION
The proximal femur distal to the physis (growth plate) is displaced anterolaterally and superiorly in relation to the femoral head. It is unclear what factors weaken the physeal plate, but factors may include: normal periosteal thinning and widening of the physis (especially in periods of rapid growth), obesity (which increases mechanical strain on physis), genetic predisposition, endocrine and metabolic disorders that cause abnormal growth and mineralization of cartilage, trauma, inflammatory changes
DIAGNOSIS DIFFERENTIAL DIAGNOSIS
Legg-Calve´-Perthes disease Avascular necrosis of femoral head Juvenile rheumatoid arthritis Septic joint Bone tumors
LABORATORY TESTS Pursue appropriate testing for endocrine disorders, especially hypothyroidism, or renal failure if clinically indicated.
IMAGING STUDIES
Plain radiographs usually diagnose SCFE. Anterior-posterior (AP) and lateral views of both hips should be obtained. Lateral views can be frog-leg or crosstable lateral. The latter view may be better for acute unstable presentations as further manipulation may worsen the slip. Positive findings on plain radiographs show posterior displacement of the femoral epiphysis: ice cream slipping off cone. Early findings include widening and irregularity of the physis with thinning of the proximal epiphysis. Magnetic resonance imaging (MRI) may be useful for early symptomatic preslips that demonstrate normal plain radiographs. The MRI may demonstrate widening of the physis with surrounding edema.
TREATMENT NONPHARMACOLOGIC THERAPY
All patients should be promptly referred to a pediatric orthopedic surgeon and should avoid bearing weight until evaluation. All patients with unstable SCFE and most patients with bilateral SCFE should be
Crutches are usually needed for 6 to 8 weeks postsurgery. Thirty percent to 60% of patients with unilateral SCFE will have a contralateral slip. The majority of patients will present within 18 months from diagnosis of the first slip. Many of the contralateral slips are asymptomatic, so close follow-up with the orthopedic surgeon is important. Complications of SCFE include osteonecrosis of the femoral head and chondrolysis (narrowing of the joint space and loss of articular cartilage). Both complications increase the risk of developing osteoarthritis. Prognosis is related to severity of the slip. Increasing severity of the slip increases risk of complications.
REFERRAL All patients with SCFE should be immediately referred to an orthopedic surgeon pediatric hip experience.
PEARLS & CONSIDERATIONS COMMENTS
In children with unilateral SCFE and underlying endocrine disorders, the contralateral hip will be affected in up to 100% of cases. Initial presentations of SCFE may only be symptoms of isolated thigh or knee pain. The physician must remember to also evaluate the hip, as a delay in diagnosis of SCFE can worsen the prognosis. Consider underlying endocrine, renal, or genetic disorders in children with SCFE who are younger than 10 years old, older than 16 years old, or are less than 50th percentile for weight.
SUGGESTED READINGS Hubbard AM: Imaging of pediatric hip disorders. Radiol Clin North Am 39:721, 2001. Kehl DH: Slipped capital femoral epiphysis. In Morrissey RT, Weinstien SL (eds): Pediatric Orthopedics. Philadelphia, Lippincott Williams & Wilkins, 2001, pp 999–1033. Loder RT: The demographics of slipped capital femoral epiphysis: an international multicenter study. Clin Orthop 322:28, 1996. Reynolds RA: Diagnosis and treatment of slipped capital femoral epiphysis. Curr Opin Pediatr 11:80, 1999. Wells D et al: Review of slipped capital femoral epiphysis associated with endocrine disease. J Pediatr Orthop 13:610, 1993. AUTHOR: SHARON F. CHEN, MD
Slipped Capital Femoral Epiphysis BASIC INFORMATION DEFINITION Slipped capital femoral epiphysis (SCFE) is the most common adolescent orthopedic hip disorder. It is characterized by the displacement of the capital femoral epiphysis from the femoral neck through the physeal plate (growth plate).
SYNONYMS Physiolysis of the hip SCFE Slipped upper femoral epiphysis ICD-9-CM CODES 732.2 Slipped upper femoral epiphysitis 732.9 Epiphysitis
EPIDEMIOLOGY & DEMOGRAPHICS
Prevalence ranges from 0.2 per 100,000 in eastern Japan to 10.08 per 100,000 in the northeastern United States. Male-to-female ratio is 1.5:1.0. Relative racial frequency is 1.0 for whites, 4.5 for Pacific Islanders, 2.2 for blacks, 1.05 for Amerindians, 0.5 for IndonesianMalay peoples, and 0.1 for Indo-Mediterranean peoples. Differences are theoretically based on mean body weight for each racial group or variability in acetabular depth in each racial group. Mean age of presentation is 12 years in girls (usually prior to menarche) and 13.5 years in boys (usually prior to Tanner stage IV). Main risk factor is obesity (¼ 90% weight for age and gender). Other risk factors include endocrine abnormalities, especially hypothyroidism and growth hormone deficiency; genetic disorders, such as Down syndrome and RubinsteinTaybi syndrome; and renal failure.
CLINICAL PRESENTATION History Usual presentation is nonradiating pain and altered gait. Pain is increased with physical activity. Pain may be chronic or intermittent. Fifteen percent of children and adolescents initially present with thigh or knee pain. The chronic pattern of presentation is the most common, defined by intermittent symptoms for longer than 3 weeks. Other pattern presentations include preslip, defined by pain but no displacement of the epiphysis, acute, and acute-on-chronic. Presentation with bilateral disease occurs in 20% of cases. In unilateral disease, the contralateral hip may be affected in 30% to 60% of cases. Physical Examination Affected leg is usually held in an externally rotated position. Stable SCFE (slip) is defined by the patient walking or weight bearing; unstable SCFE is defined by inability to bear weight even with crutches. Gait is usually antalgic in unilateral SCFE. Gait is waddling in bilateral SCFE.
With moderate to severe SCFE (displacement greater than one third of the diameter of the femoral neck), atrophy of the upper thigh and gluteal muscles may be present, sometimes associated with a Trendelenburg gait. Anterior hip may be tender to palpation. Abduction and external rotation of the affected leg when the hip is passively flexed from an extended position is highly suggestive of SCFE.
admitted to the hospital for bed rest and complete avoidance of weight bearing to avoid further slippage. Treatment of SCFE is a surgical procedure, usually with screw fixation: stabilization of the physis with a single cannulated screw placed in the center of the epiphysis. Prophylactic pinning of the contralateral hip in unilateral SCFE presentations is controversial.
ETIOLOGY
DISPOSITION
The proximal femur distal to the physis (growth plate) is displaced anterolaterally and superiorly in relation to the femoral head. It is unclear what factors weaken the physeal plate, but factors may include: normal periosteal thinning and widening of the physis (especially in periods of rapid growth), obesity (which increases mechanical strain on physis), genetic predisposition, endocrine and metabolic disorders that cause abnormal growth and mineralization of cartilage, trauma, inflammatory changes
DIAGNOSIS DIFFERENTIAL DIAGNOSIS
Legg-Calve´-Perthes disease Avascular necrosis of femoral head Juvenile rheumatoid arthritis Septic joint Bone tumors
LABORATORY TESTS Pursue appropriate testing for endocrine disorders, especially hypothyroidism, or renal failure if clinically indicated.
IMAGING STUDIES
Plain radiographs usually diagnose SCFE. Anterior-posterior (AP) and lateral views of both hips should be obtained. Lateral views can be frog-leg or crosstable lateral. The latter view may be better for acute unstable presentations as further manipulation may worsen the slip. Positive findings on plain radiographs show posterior displacement of the femoral epiphysis: ice cream slipping off cone. Early findings include widening and irregularity of the physis with thinning of the proximal epiphysis. Magnetic resonance imaging (MRI) may be useful for early symptomatic preslips that demonstrate normal plain radiographs. The MRI may demonstrate widening of the physis with surrounding edema.
TREATMENT NONPHARMACOLOGIC THERAPY
All patients should be promptly referred to a pediatric orthopedic surgeon and should avoid bearing weight until evaluation. All patients with unstable SCFE and most patients with bilateral SCFE should be
Crutches are usually needed for 6 to 8 weeks postsurgery. Thirty percent to 60% of patients with unilateral SCFE will have a contralateral slip. The majority of patients will present within 18 months from diagnosis of the first slip. Many of the contralateral slips are asymptomatic, so close follow-up with the orthopedic surgeon is important. Complications of SCFE include osteonecrosis of the femoral head and chondrolysis (narrowing of the joint space and loss of articular cartilage). Both complications increase the risk of developing osteoarthritis. Prognosis is related to severity of the slip. Increasing severity of the slip increases risk of complications.
REFERRAL All patients with SCFE should be immediately referred to an orthopedic surgeon pediatric hip experience.
PEARLS & CONSIDERATIONS COMMENTS
In children with unilateral SCFE and underlying endocrine disorders, the contralateral hip will be affected in up to 100% of cases. Initial presentations of SCFE may only be symptoms of isolated thigh or knee pain. The physician must remember to also evaluate the hip, as a delay in diagnosis of SCFE can worsen the prognosis. Consider underlying endocrine, renal, or genetic disorders in children with SCFE who are younger than 10 years old, older than 16 years old, or are less than 50th percentile for weight.
SUGGESTED READINGS Hubbard AM: Imaging of pediatric hip disorders. Radiol Clin North Am 39:721, 2001. Kehl DH: Slipped capital femoral epiphysis. In Morrissey RT, Weinstien SL (eds): Pediatric Orthopedics. Philadelphia, Lippincott Williams & Wilkins, 2001, pp 999–1033. Loder RT: The demographics of slipped capital femoral epiphysis: an international multicenter study. Clin Orthop 322:28, 1996. Reynolds RA: Diagnosis and treatment of slipped capital femoral epiphysis. Curr Opin Pediatr 11:80, 1999. Wells D et al: Review of slipped capital femoral epiphysis associated with endocrine disease. J Pediatr Orthop 13:610, 1993. AUTHOR: SHARON F. CHEN, MD