Last updated: November 4, 2014
Synonyms: Legg-Perthes disease; primary osteochondritis of the hip.
ICD-9 Code: 732.1.
ICD-10 Code: M91.1
Definition: A noninflammatory disorder caused by ischemic necrosis of the hip (capital femoral epiphysis), with subsequent collapse and/or remolding of the femoral head.
Etiology: Unknown but may be associated with vascular or thrombolytic disorders. Associations with deficiency of protein C or S and factor V Leiden deficiency or trauma have been reported.
Pathology: Core biopsies show fat necrosis and ischemic vascular changes.
Demographics: Boys are more frequently affected (male:female, 4:1). Usual age at onset is between 3 and 12 years. It is estimated that Legg-Calvé-Perthes disease affects one in 1,300 children.
Cardinal Features: Children usually present with painless limping, but with time, pain becomes evident, especially during exertion. On examination, unilaterally limited internal rotation and abduction of the hip is seen, although bilateral hip disease in ~10%. Lab tests (e.g., CBC, ESR) are normal.
Complications: Rarely there is delayed bone growth and short stature.
Imaging: Abnormalities depend on the stage and age of patient. Initially, an irregular and smaller epiphyseal plate, indistinct metaphysis and widening of the joint may be seen. With progression, the femoral head becomes fragmented, flattened, and sclerotic and is displaced laterally within the joint. Changes in the acetabulum has long-term implications on outcome and surgery. Preservation of the acetabulum offers the chance of maturational remodeling of the femoral head. Scintigraphy may be abnormal before radiography and early on shows decreased uptake, but with revascularization, uptake increases. In most centers, MRI remains the modality of choice in making the earliest diagnosis of femoral head disease and can identify ischemia, revascularization, and concurrent synovitis.
Keys to Diagnosis: Consider Legg-Calvé-Perthes disease in any child with hip pain or limp before puberty.
Treatment: Immediate orthopedic referral is recommended for patients with Legg-Calvé-Perthes disease. Mild cases may not require treatment. Loss of hip movement requires mechanical measures to keep the femoral head contained within the acetabulum (with weight-bearing abduction braces) such that with time and healing, the head is remolded by the intact acetabulum. This is best accomplished in those younger than age 6 years with >50% femoral head involvement.
Surgery: Recommended for advanced cases with pain and includes intertrochanteric rotational osteotomy.
Prognosis: Seventy to 90% of patients are active and pain free on long-term follow-up (20–40 years later). Function is often normal, although x-rays are not. Favorable outcomes were seen in younger children and earlier onset of healing. Those with disease onset after 6 to 8 years may have a poorer prognosis. The shape of the femoral head at the time of skeletal maturity best predicts the outcome.
Lindsley CB, Asher MA, Olney BW. Legg-Perthes and other hip diseases in children. In: Hochberg MC, Silman AJ, Smolen JS, et al., eds. Rheumatology, 3rd ed. Edinburgh: Mosby, 2003:987–990.
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;123:68–73.PMID:12721683