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Avascular (Aseptic) Necrosis of the Femoral Head (Hip), Pediatric

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Avascular (Aseptic) Necrosis of the Femoral Head (Hip), Pediatric

Basics

Description

  • Avascular (aseptic) necrosis results from the interruption of the blood supply to bone (either traumatic or nontraumatic occlusion).
  • The femoral head is the most common site.
  • A particular type of self-limiting idiopathic avascular necrosis of the hip that occurs in children is known as Perthes disease (see the "Perthes Disease" chapter).

Risk Factors

Pathophysiology

  • Death and necrosis of bone with gradual return of blood supply
  • Necrotic bone gradually resorbed and replaced by new bone
  • During bone resorption, structural integrity of femoral head may be reduced, leading to collapse.

Etiology

  • TraumaticHip fractureHip dislocationSlipped capital femoral epiphysisComplication of casting, bracing, surgery
  • NontraumaticIdiopathic (older, after physeal closure); similar to adult avascular necrosisIdiopathic (younger, before physeal closure, Perthes disease)Caisson diseaseSickle cell diseaseSeptic arthritisSteroids or chemotherapyMalignancy (leukemia)Gaucher diseaseViral infection (HIV, CMV)Radiation therapyHypercoagulable states
  • Hip fracture
  • Hip dislocation
  • Slipped capital femoral epiphysis
  • Complication of casting, bracing, surgery
  • Idiopathic (older, after physeal closure); similar to adult avascular necrosis
  • Idiopathic (younger, before physeal closure, Perthes disease)
  • Caisson disease
  • Sickle cell disease
  • Septic arthritis
  • Steroids or chemotherapy
  • Malignancy (leukemia)
  • Gaucher disease
  • Viral infection (HIV, CMV)
  • Radiation therapy
  • Hypercoagulable states

Diagnosis

History

  • Onset (gradual or after traumatic event)
  • Association with the following:TraumaMedications (steroids or chemotherapy)Casting, splinting, surgery (iatrogenic)Pain, limpingStiffness (decreased range of motion)Perthes disease may occasionally be bilateral or occur in contralateral hip at a later time point.
  • Trauma
  • Medications (steroids or chemotherapy)
  • Casting, splinting, surgery (iatrogenic)
  • Pain, limping
  • Stiffness (decreased range of motion)
  • Perthes disease may occasionally be bilateral or occur in contralateral hip at a later time point.

Physical Exam

  • GaitLimpingAntalgic ("against pain") gait (shortened stance phase relative to swing phase)Trendelenburg gait
  • Note range of motion:Flexion and extensionAbduction and adductionInternal and external rotation
  • Hip joint irritability (short arc rotation)
  • Signs of other disease processes associated with avascular necrosis (e.g., sickle cell disease)
  • Physical examination pearlLoss of internal rotation is usually the first and most affected loss of motion seen.
  • Limping
  • Antalgic ("against pain") gait (shortened stance phase relative to swing phase)
  • Trendelenburg gait
  • Flexion and extension
  • Abduction and adduction
  • Internal and external rotation
  • Loss of internal rotation is usually the first and most affected loss of motion seen.

Diagnostic Tests & Interpretation

  • Laboratory examinations should be normal in most forms of avascular necrosis of the femoral head.
  • Exceptions:Sickle cell diseaseSeptic arthritisChemotherapy
  • Sickle cell disease
  • Septic arthritis
  • Chemotherapy
  • Radiographic findings:SclerosisSubchondral fractureCollapseReossificationRepair
  • Magnetic resonance imaging (MRI)Bone edemaIf contrast medium used, area of reduce blood flow evident
  • Bone scanReduced signal in affected hip
  • Other potential findings:CystsPhyseal growth arrest (young)Early osteoarthritisSubluxation
  • Sclerosis
  • Subchondral fracture
  • Collapse
  • Reossification
  • Repair
  • Bone edema
  • If contrast medium used, area of reduce blood flow evident
  • Reduced signal in affected hip
  • Cysts
  • Physeal growth arrest (young)
  • Early osteoarthritis
  • Subluxation

Differential Diagnosis

  • TraumaOsteochondral fractureImpaction fractureEpiphyseal/physeal fracture
  • InfectionOsteomyelitisSeptic arthritis
  • Neoplastic process: epiphyseal tumors (chondroblastoma, Trevor disease, etc.)
  • Rheumatologic processes
  • Skeletal dysplasia, particular if bilateral hip involvement
  • Osteochondral fracture
  • Impaction fracture
  • Epiphyseal/physeal fracture
  • Osteomyelitis
  • Septic arthritis

Treatment

Medication

  • NSAIDs may reduce pain by decreasing associated inflammation but may also reduce new bone formation.
  • If associated with corticosteroid use, discontinuation or elimination of steroids may be helpful if appropriate.
  • Bisphosphonate therapy may help preserve joint shape.

Additional Therapies

  • Maintain range of motion (physical therapy, traction, continuous passive motion).
  • Contain the femoral head in the acetabulum (see treatment principles listed in "Perthes Disease" chapter).
  • Duration of therapy variable, depending on cause
  • Reduced weight bearing on affected hip may help prevent collapse.

Surgery/Other Procedures

  • Femoral or acetabular reorientation
  • Core decompression to stimulate new blood supply

Ongoing Care

Diet

  • Thought not to alter disease process
  • Recommend general balanced diet
  • During immobilization, excessive weight gain may occur.

Prognosis

  • Depends on extent of femoral head collapse
  • Good if mild involvement and patient is young
  • When to expect improvement: variable, depending on cause
  • Moderate to severe cases often have significant collapse and end up requiring a total hip replacement.

Complications

  • Joint collapse with decreased range of motion, pain, limping
  • Osteoarthritis
  • Physeal arrest with growth disturbance
  • Subluxation
  • Early osteoarthritis
  • Growth arrest

Additional Reading

  • Lahdes-Vasama T, Lamminen A, Merikanto J, et al. The value of MRI in early Perthes' disease: an MRI study with a 2-year follow-up. Pediatr Radiol. 1997;27(6):517-522. [View Abstract]
  • Mont MA, Jones LC, Hungerford DS. Nontraumatic osteonecrosis of the femoral head: ten years later. J Bone Joint Surg Am. 2006;88(5):1117-1132. [View Abstract]
  • Roposch A, Mayr J, Linhart WE. Age at onset, extent of necrosis, and containment in Perthes disease. Results at maturity. Arch Orthop Trauma Surg. 2003;123(2):68-73. [View Abstract]
  • Shipman SA, Helfand M, Moyer VA, et al. Screening for developmental dysplasia of the hip: a systematic literature review for the US Preventive Services Task Force. Pediatrics. 2006;117(3):e557-e576. [View Abstract]
  • Tokmakova KP, Stanton RP, Mason DE. Factors influencing the development of osteonecrosis in patients treated for slipped capital femoral epiphysis. J Bone Joint Surg Am. 2003;85-A(5):798-801. [View Abstract]

Codes

ICD09

  • 733.42 Aseptic necrosis of head and neck of femur
  • 732.1 Juvenile osteochondrosis of hip and pelvis

ICD10

  • M87.059 Idiopathic aseptic necrosis of unspecified femur
  • M91.10 Juvenile osteochondrosis of head of femur, unspecified leg
  • M87.052 Idiopathic aseptic necrosis of left femur
  • M87.051 Idiopathic aseptic necrosis of right femur
  • M91.11 Juvenile osteochondrosis of head of femur, right leg
  • M91.12 Juvenile osteochondrosis of head of femur, left leg

SNOMED

  • 444904004 aseptic necrosis of head of femur (disorder)
  • 111255008 Avascular necrosis of the capital femoral epiphysis (disorder)
  • 15739006 Juvenile osteochondrosis of hip AND/OR pelvis (disorder)

FAQ

  • Q: What type of medication is most often associated with avascular necrosis of the hip?
  • A: Corticosteroids
  • Q: For avascular necrosis in children (Perthes disease of the hip, for example), is younger or older age associated with a better prognosis?
  • A: Younger age (<8 years)