• Clinical science

Legg-Calvé-Perthes disease


Legg-Calvé-Perthes disease (LCPD, or Perthes disease) refers to an idiopathic, avascular necrosis of the femoral head. It may occur unilaterally or bilaterally and typically manifests between the ages of four and ten. Children experience hip pain on weight-bearing, which often projects to the ipsilateral knee and causes an antalgic gait. Early stages are only detectable on MRI but progress of the disease can be tracked and graded using conventional x-ray. Surgery is performed if x-ray reveals signs that indicate an unfavorable prognosis. The aim of surgical intervention is to cover the femoral head as completely as possible with the hip socket, thus retaining its anatomical position. In mild forms of the disease, reduced weight-bearing and physical therapy are indicated. Important prognostic factors include the age of onset and the extent of femoral head involvement.


  • Sex: > (4:1) [1]
  • Age: 4–10 years
  • Incidence (in children < 15 years): 1–3:20,000 [2]

Epidemiological data refers to the US, unless otherwise specified.


  • Idiopathic disease
  • Multiple factors might promote the development and progress of the condition, including: [1]


Lateral pillar classification [6]

This classification possesses the highest clinical relevance because it correlates best with long-term outcome. The crucial criterion in this classification is the height of the lateral third (“lateral pillar”) of the femoral head.

Modified (Herring) Lateral pillar classification
Group A Height of the lateral pillar is 100% (no involvement)
Group B Height of the lateral pillar is > 50%
Group C Height of the lateral pillar is < 50%

Other classifications [7]


Avascular necrosis of the femoral head due to a mismatch between the rapid growth of the femoral epiphyses and the slower development of adequate blood supply to the area

Clinical features

  • Antalgic gait (on weight-bearing leg)
  • Pain in the hip or the upper leg, sometimes projecting to the knee
    • Insidious onset, pain may fluctuate depending on physical activity [8]
    • Often exacerbated by internal rotation
    • FABER test (Flexion, ABduction, and External Rotation) might be positive.
    • Groin tenderness on palpation [8]
  • Restricted range of movement; is usually present, especially regarding internal rotation and abduction, and can cause the child to limp. [9]
  • Hinge abduction: refers to the lateral femoral head bumping into the ventrolateral acetabulum when the leg is abducted, possibly involving pain, a palpable clunk, and restriction in the range of movement
  • Contralateral involvement in ∼ 10% of cases [8]

Legg-Calvé-Perthes disease should be considered in a child with knee pain.


Differential diagnoses

Differential diagnosis of hip pain in children [11]

Differential diagnosis of pediatric hip pain
Disease Pathophysiology Clinical features Diagnostic findings
Transient synovitis
  • 4–10 years of age
  • Sex: > (2:1)
  • URI in recent weeks
  • No fever
  • Transient hip pain
  • Laboratory: normal
  • Imaging
    • Normal x-ray
    • Effusion on ultrasound that should improve over the course of several days
Septic arthritis
  • Infection either by hematogenous spread of bacteria or direct contamination
  • Any age
  • Acute onset of pain and fever
  • Fever > 38.5°C
  • Child may refuse to bear weight.

Slipped capital femoral epiphysis

  • 10–16 years of age
  • Acute on chronic dull pain with antalgic gait
  • No fever
  • Vague hip and knee pain
  • Laboratory: normal
  • Imaging: X-ray shows displacement of the femoral head.
Legg-Calve-Perthes disease
  • Mismatch between the rapid growth of the femoral epiphyses and the slower development of adequate blood supply to the area
  • 4–10 years of age
  • Insidious onset
  • No fever
  • Vague hip and knee pain (may fluctuate with activity)
  • Can cause the child to limp
  • Laboratory: normal
  • Imaging: x-ray
    • Early stages: often without pathological findings
    • Advanced disease: increased lucency of the femoral head and widened joint spaces
Developmental dysplasia of the hip
  • Laboratory: normal
  • Imaging: Ultrasound before 4 months and x-ray after 4 months are diagnostic.

Transient synovitis (also known as toxic synovitis) [12]

  • Epidemiology
    • Common cause of acute hip pain among children
    • Peak incidence: 4–10 years of age
    • Sex: > (2:1)
  • Pathophysiology: nonspecific inflammation and hypertrophy of the synovial membrane
  • Clinical features
    • Unilateral and transient hip or groin pain
    • Recent upper respiratory tract infection in up to 50% of the patients
  • Diagnosis
    • Laboratory
      • Mostly normal findings
      • Some cases present with mild leukocytosis and ESR elevation.
    • Imaging
      • Normal x-ray findings
      • Effusion on ultrasound that should improve over the course of several days
  • Treatment: conservative (e.g., NSAIDs)

The differential diagnoses listed here are not exhaustive.


  • Conservative treatment: limited weight bearing, physical therapy
    • Indicated in: [13]
    • Casting and bracing can also be used until femoral head deformity develops or range of motion worsens. [14]
  • Surgery: femoral osteotomy


  • Early osteoarthritis of the hip joint due to any of the following: [1]
    • Incongruence between the femoral head and acetabulum
    • Shortening of the femoral neck featuring trochanteric elevation, which can manifest as Trendelenburg sign
    • Lateralization and coxa magna (broadening of the femoral head), which can manifest as hinge abduction

We list the most important complications. The selection is not exhaustive.


  • Factors associated with a less favorable prognosis include: [15][7]
    • Older age of onset (≥ 6 years)
    • Extensive damage to the femoral head (> 50%)
    • Female sex
  • 1. Mills S, Burroughs KE. Legg Calve Perthes Disease (Calves Disease). StatPearls. 2020. pmid: 30020602.
  • 2. U.S. National Library of Medicine. Legg-Calvé-Perthes disease. https://medlineplus.gov/genetics/condition/legg-calve-perthes-disease/#frequency. Updated September 1, 2014. Accessed October 5, 2020.
  • 3. Vosmaer A, Pereira RR, Koenderman J, Rosendaal F, Cannegieter S. Coagulation Abnormalities in Legg-Calvé-Perthes Disease. The Journal of Bone and Joint Surgery-American Volume. 2010; 92(1): pp. 121–128. doi: 10.2106/jbjs.i.00157.
  • 4. Eric Gordon J, Schoenecker PL, Osland JD, Dobbs MB, Szymanski DA, Luhmann SJ. Smoking and socio-economic status in the etiology and severity of Legg–Calvé–Perthesʼ disease. Journal of Pediatric Orthopaedics B. 2004; 13(6): pp. 367–370. doi: 10.1097/01202412-200411000-00003.
  • 5. Bahmanyar S, Montgomery SM, Weiss RJ, Ekbom A. Maternal Smoking During Pregnancy, Other Prenatal and Perinatal Factors, and the Risk of Legg-Calve-Perthes Disease. Pediatrics. 2008; 122(2): pp. e459–e464. doi: 10.1542/peds.2008-0307.
  • 6. Farsetti P, Tudisco C, Caterini R, Potenza V, Ippolito E. The Herring lateral pillar classification for prognosis in Perthes disease. Late results in 49 patients treated conservatively. J Bone Joint Surg Br. 1995; 77-B(5): pp. 739–742. doi: 10.1302/0301-620x.77b5.7559701.
  • 7. Rampal V, Clément JL, Solla F. Legg-Calvé-Perthes disease: classifications and prognostic factors. Clinical cases in mineral and bone metabolism : the official journal of the Italian Society of Osteoporosis, Mineral Metabolism, and Skeletal Diseases. 2017; 14(1): pp. 74–82. pmid: 28740529.
  • 8. National Organization for Rare Disorders. Legg Calvé Perthes Disease. https://rarediseases.org/rare-diseases/legg-calve-perthes-disease/. Updated January 1, 2016. Accessed October 15, 2020.
  • 9. Skaggs DL, Tolo VT. Legg-Calvé-Perthes Disease. J Am Acad Orthop Surg. 1996; 4(1): pp. 9–16. doi: 10.5435/00124635-199601000-00002.
  • 10. Forster MC, Kumar S, Rajan RA, Guy Atherton W, Asirvatham R, Thava VR. Head-at-risk signs in Legg-Calvé-Perthes disease: Poor inter- and intra-observer reliability. Acta Orthop. 2006; 77(3): pp. 413–417. doi: 10.1080/17453670610046334.
  • 11. Nigrovic PA. Overview of hip pain in childhood. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/overview-of-hip-pain-in-childhood. Last updated May 9, 2016. Accessed March 8, 2017.
  • 12. Whitelaw CC, Varacallo M. Transient Synovitis. StatPearls. 2020. pmid: 29083677.
  • 13. Leroux J, Abu Amara S, Lechevallier J. Legg-Calvé-Perthes disease. Orthopaedics & Traumatology: Surgery & Research. 2018; 104(1): pp. S107–S112. doi: 10.1016/j.otsr.2017.04.012.
  • 14. Joseph B. Management of Perthes′ disease. Indian Journal of Orthopaedics. 2015; 49(1): p. 10. doi: 10.4103/0019-5413.143906.
  • 15. Wiig O, Terjesen T, Svenningsen S. Prognostic factors and outcome of treatment in Perthes’ disease. J Bone Joint Surg Br. 2008; 90-B(10): pp. 1364–1371. doi: 10.1302/0301-620x.90b10.20649.
  • Gaillard F et al. Perthes disease. https://radiopaedia.org/articles/perthes-disease. Updated December 22, 2016. Accessed December 22, 2016.
  • Harris GD. Legg-Calve-Perthes Disease. In: Jaffe WL. Legg-Calve-Perthes Disease. New York, NY: WebMD. http://emedicine.medscape.com/article/1248267. Updated May 4, 2015. Accessed December 22, 2016.
  • Souder C. Legg-Calve-Perthes Disease (Coxa plana). http://www.orthobullets.com/pediatrics/4119/legg-calve-perthes-disease-coxa-plana. Updated December 22, 2016. Accessed December 22, 2016.
  • Perry DC, Machin DM, Pope D, et al. Racial and geographic factors in the incidence of Legg-Calvé-Perthes' disease: a systematic review. American Journal of Epidemiology. 2012; 175(3): pp. 159–66. doi: 10.1093/aje/kwr293.
last updated 10/16/2020
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