Legg-Calvé-Perthes disease is an idiopathic avascular necrosis (osteonecrosis) of the femoral head in children, following a predictable course of bone death, revascularization, resorption, and reossification. [1] It typically presents between ages 4–8, affects boys 4–5× more than girls, is unilateral in ~90% of cases, and commonly manifests as a painless limp or hip/groin/thigh pain with decreased range of motion. [2-4]
1. History
- Chief complaint: Painless limp is the classic presentation; however, 84% of children in a prospective multicenter study presented with pain (mean pain score 3/10) [4]
- Location of pain: Hip, groin, anterior thigh, or referred to the ipsilateral knee — knee pain as the sole complaint is a common pitfall leading to delayed diagnosis [5]
- Timing: Insidious onset over weeks to months; chronic limp lasting >6 weeks is characteristic [5]
- Aggravating factors: Activity, prolonged weight-bearing, running, jumping
- Alleviating factors: Rest; 63% of children use pain medications, with 65% requiring them more than once per week [4]
- Functional impact: 30% of children miss school due to pain [4]
- Ask about: Prior episodes, bilateral symptoms, recent URI (to differentiate from transient synovitis), trauma history, night pain (raises concern for neoplasm)
2. Alarm Features
- Fever + hip pain + inability to bear weight → rule out septic arthritis (surgical emergency) [6-7]
- Acute, severe hip pain with inability to walk in an overweight adolescent → consider slipped capital femoral epiphysis (SCFE) [8]
- Night pain, weight loss, night sweats → consider malignancy (leukemia, Ewing sarcoma, osteoid osteoma) [5]
- Bilateral hip involvement with systemic features → consider hypothyroidism, sickle cell disease, Gaucher disease, steroid use (secondary AVN)
- Rapidly progressive loss of ROM or "head-at-risk" signs on radiograph (lateral subluxation, Gage sign, calcification lateral to epiphysis, horizontal physis, metaphyseal cysts) → urgent orthopedic referral [9-10]
3. Medications
- Analgesics: NSAIDs (ibuprofen 10 mg/kg q6–8h) are first-line for pain and synovitis
- Avoid: Prolonged corticosteroid use (can worsen AVN)
- No disease-modifying pharmacotherapy is established; research into bisphosphonates and anti-resorptive agents is ongoing but not standard of care [1][10]
- Caution: Aspirin generally avoided in children (Reye syndrome risk); use ibuprofen or naproxen
4. Diet
- No specific dietary triggers or restrictions
- Ensure adequate calcium and vitamin D intake for bone health during the remodeling phase
- Maintain a healthy weight — overweight/obesity may increase mechanical load on the femoral head; 29% of U.S. children with LCPD were overweight or obese [4]
- Adequate hydration and balanced nutrition to support bone healing
5. Review of Systems
- MSK: Hip stiffness, thigh/knee pain, leg-length discrepancy, difficulty with stairs or running
- Constitutional: Fever (suggests infection), weight loss/night sweats (suggests malignancy)
- Neuro: Gait abnormality, Trendelenburg gait
- Psych: Mood changes, school avoidance, social withdrawal — LCPD significantly impacts mental and social development [2]
- Endocrine: Growth delay (affected children are often shorter than peers) [3]
6. Collateral History and Family History
- Family history: LCPD has a familial component; first-degree relatives have increased risk. Associated with mutations in COL2A1 in some families [3]
- Household smoking: Previously reported as a risk factor; 19% of children in a multicenter study had household smoke exposure [4]
- Social history: Socioeconomic deprivation has been linked to higher incidence in epidemiologic studies
- Birth history: Low birth weight and breech presentation may be relevant
- Collateral from school: Activity limitations, PE participation, absenteeism
7. Risk Factors
- Age 4–8 years (peak incidence) [3]
- Male sex (4–5:1 male-to-female ratio) [4]
- Low socioeconomic status — consistently associated in epidemiologic studies
- Secondhand smoke exposure [4]
- Low birth weight / delayed skeletal maturation
- Short stature relative to peers [3]
- Thrombophilia / coagulopathy — some studies suggest hypercoagulable states may contribute to vascular disruption
- White race — higher incidence in Caucasian populations
8. Differential Diagnosis
- Transient synovitis — most common cause of acute hip pain in children (ages 3–8); self-limited, often post-viral; distinguished by acute onset, normal radiographs, and resolution within 1–2 weeks [5][11]
- Septic arthritis — fever, toxic appearance, refusal to bear weight, markedly elevated CRP/ESR/WBC; requires urgent aspiration [6-7]
- Slipped capital femoral epiphysis (SCFE) — older child (10–16), often overweight, obligatory external rotation with hip flexion [8]
- Osteomyelitis — fever, focal bony tenderness, elevated inflammatory markers
- Juvenile idiopathic arthritis (JIA) — morning stiffness, polyarticular involvement, systemic features
- Bone tumors (osteoid osteoma, Ewing sarcoma, leukemia) — night pain, constitutional symptoms
- Developmental dysplasia of the hip (DDH) — leg-length discrepancy, limited abduction
- Sickle cell disease AVN — known hemoglobinopathy, bilateral involvement
- Meyer dysplasia — irregular femoral head ossification in children <4 years; benign, self-resolving
9. Past Medical History
- Prior episodes of hip pain or limp
- History of coagulopathy or thrombophilia
- Endocrine disorders (hypothyroidism, growth hormone deficiency)
- Corticosteroid use (e.g., for asthma, nephrotic syndrome)
- Sickle cell disease or other hemoglobinopathies
- Previous hip trauma or surgery
- Contralateral hip involvement (bilateral in ~10%) [3]
10. Physical Exam
- Gait: Antalgic gait or Trendelenburg gait (pelvis drops to contralateral side) [5]
- Inspection: Thigh/calf atrophy on affected side, leg-length discrepancy
- ROM (key finding): Decreased internal rotation and abduction of the hip — the most sensitive exam finding [5][9]
- Log roll test: Pain with gentle internal/external rotation of the hip
- Trendelenburg test: Positive if abductor weakness present
- Flexion-abduction-external rotation (FABER) test: May reproduce hip pain
- Palpation: Typically non-tender over the hip joint (unlike septic arthritis)
- Vital signs: Should be afebrile; fever raises concern for septic arthritis
11. Lab Studies
- Labs are primarily used to exclude other diagnoses, not to confirm LCPD
- CBC with differential: Normal in LCPD; elevated WBC suggests infection or malignancy [5-6]
- CRP and ESR: Normal or minimally elevated in LCPD; markedly elevated in septic arthritis (CRP >2 mg/dL, ESR >40 mm/hr) [7]
- Blood cultures: If septic arthritis is suspected
- Consider: Coagulation studies (protein C, protein S, factor V Leiden) if thrombophilia workup is warranted
- Thyroid function, IGF-1: If endocrine etiology suspected
- Hemoglobin electrophoresis: If sickle cell disease is a consideration
12. Imaging
- First-line: AP pelvis and frog-leg lateral radiographs [2][5]
- Early findings: Smaller/denser femoral epiphysis, widened medial joint space, subchondral fracture (crescent sign)
- Later findings: Fragmentation, femoral head flattening, metaphyseal cysts/irregularity
- May be normal early in disease — if clinical suspicion is high and radiographs are normal, obtain MRI
- MRI: More sensitive for early detection; shows marrow edema, extent of necrosis, cartilaginous changes, and synovitis; useful for staging and surgical planning [2][12]
- Ultrasound: Can detect hip effusion but is nonspecific; useful to differentiate from transient synovitis [13]
- Bone scan: Rarely needed; may show decreased uptake in the femoral head early in disease
- Arthrography: Used intraoperatively to assess femoral head containment and congruency [2]
13. Special Tests
- Radiographic Classification Systems:
- Modified Lateral Pillar Classification (Herring): Applied during fragmentation stage; Groups A, B, B/C border, C — strongest prognostic indicator along with age [14-15]
- Catterall Classification: Groups I–IV based on extent of epiphyseal involvement [16]
- Stulberg Classification (outcome): Applied at skeletal maturity; grades I–V based on femoral head sphericity and congruence [15][17]
- HAT Classification (Head, Acetabulum, Trochanter): Newer system evaluating all three components; strong correlation with functional outcomes [18]
- Waldenstrom staging: Initial/necrosis → Fragmentation → Reossification → Healed [1]
- Point-of-care ultrasound: Useful in the ED to identify hip effusion and guide further workup [13]
14. ECG
- Not routinely indicated
- Consider if planning for surgical intervention requiring general anesthesia (standard preoperative assessment)
15. Assessment
Severity stratification is based on two critical prognostic factors: [1][14]
- Age at onset:
- <6 years: Generally favorable natural history
- 6–8 years: Intermediate prognosis
- >8 years: Poor prognosis — higher risk of femoral head deformity and early osteoarthritis
- Female sex confers worse prognosis if onset >8 years [14]
- Lateral pillar classification (Herring):
- Group A: <100% lateral pillar height maintained → best prognosis
- Group B: >50% lateral pillar height maintained → good prognosis if age <8
- Group B/C border: Exactly 50% or thin/poorly ossified lateral pillar
- Group C: <50% lateral pillar height → worst prognosis regardless of treatment [14]
Complications to consider
- Permanent femoral head deformity (aspherical head) — 59% in one non-surgical cohort [19]
- Femoroacetabular impingement
- Leg-length discrepancy
- Premature osteoarthritis — disabling arthritis develops by the 6th decade in ~50% of untreated patients; 44% had moderate-severe OA at 20-year follow-up [9][20]
- Greater trochanteric overgrowth
- Need for total hip arthroplasty in adulthood
16. Treatment Plan
Initial stabilization (ED/primary care)
- Activity restriction and protected weight-bearing (crutches)
- NSAIDs for pain control
- Urgent referral to pediatric orthopedics
Non-surgical management (mainstay for children <6 years or lateral pillar A): [1][14]
- ROM exercises — especially hip abduction and internal rotation stretching [21]
- Activity modification: Allow swimming, cycling, short walks; restrict running, jumping, trampolining, contact sports during initial and fragmentation stages [21]
- Abduction bracing/casting (e.g., Petrie casts, Scottish Rite brace) — used to maintain containment, though evidence for bracing is limited [14]
- No total non-weight-bearing is recommended at any stage [21]
Surgical management (indicated for children >8 years with lateral pillar B or B/C border): [14][22]
- Femoral varus osteotomy — redirects femoral head into acetabulum
- Salter innominate osteotomy — improves acetabular coverage
- Combined femoral + pelvic osteotomy for severe cases
- Shelf acetabuloplasty — salvage procedure for advanced cases; may provide better functional outcomes than conservative management [23]
- Hip joint distraction (arthrodiastasis) — emerging technique to unload the femoral head [1]
- Surgical outcomes: No significant difference between femoral and innominate osteotomy; both superior to non-operative treatment in older children with B/B-C hips [14]
Key treatment principle: Lateral pillar C hips have poor outcomes regardless of treatment modality. [14]
17. Disposition
From the ED/urgent care
- Discharge with orthopedic referral is appropriate for most suspected or confirmed LCPD cases
- Provide crutches, activity restriction, and NSAIDs pending follow-up
Admission criteria
- Severe pain uncontrolled with oral analgesics
- Need for traction or casting
- Concern for septic arthritis requiring aspiration/washout
- Planned surgical intervention
Specialist consultation triggers
- All confirmed or suspected LCPD → pediatric orthopedic surgery referral [2]
- Age >6 years at diagnosis → earlier orthopedic involvement given worse prognosis [19]
- Loss of ROM, progressive subluxation, or head-at-risk signs → urgent orthopedic evaluation
- Bilateral disease → consider endocrine or hematologic workup
18. Follow-Up / Return Precautions
Follow-up timing
- Initial orthopedic follow-up within 1–2 weeks of diagnosis
- Serial radiographs every 2–3 months during active disease to monitor staging and progression
- Disease course spans 2–5 years from onset to healing [1]
- Long-term follow-up through skeletal maturity is essential, as the Stulberg classification at healing strongly predicts 20-year outcomes [17][20]
Return precautions — advise families to return for
- Worsening limp or inability to bear weight
- Increasing pain despite NSAIDs
- New fever (raises concern for superimposed infection)
- Decreased hip range of motion
- Pain in the contralateral hip (bilateral involvement in ~10%)
Patient/family counseling
- LCPD is a self-limited but prolonged disease; full healing takes years
- Activity restrictions are necessary but total immobilization is not recommended [21]
- Mental health and educational support should be addressed — school absenteeism and social isolation are common [2][4]
- Long-term risk of osteoarthritis exists, particularly with aspherical femoral head outcomes; early adult follow-up is recommended [20][24]
References
1. Legg-Calvé-Perthes Disease. — Gilbert SR, Laine JC, Martin BD, Sankar WN, Kim HKW. The Journal of the American Academy of Orthopaedic Surgeons. 2025.
2. Management of Legg-Calve-Perthes Disease: A Scoping Review With Advice on Initial Management. — Beni R, Hussain SA, Monsell F, Gelfer Y. Archives of Disease in Childhood. 2025.
3. Legg-Calvé-Perthes disease. — National Library of Medicine (MedlinePlus) 2014.
4. Demographics and Clinical Presentation of Early-Stage Legg-Calvé-Perthes Disease: A Prospective, Multicenter, International Study. — Laine JC, Novotny SA, Tis JE, et al. The Journal of the American Academy of Orthopaedic Surgeons. 2021.
5. Evaluating the Child With a Limp. — Morancie NA, Helton MR. American Family Physician. 2023.
6. Acute Bacterial Arthritis in Children: Guidelines From the Pediatric Infectious Diseases Society and Infectious Diseases Society of America. — Jobi-Odeneye AO. American Family Physician. 2024.
7. The Painful Hip: Evaluation of Criteria for Clinical Decision-Making. — Eich GF, Superti-Furga A, Umbricht FS, Willi UV. European Journal of Pediatrics. 1999.
8. Slipped Capital Femoral Epiphysis: Rapid Evidence Review. — Webb CW, Liu R, Bouchereau-Lal N. American Family Physician. 2025.
9. Legg-Calve-Perthes Disease. — Skaggs DL, Tolo VT. The Journal of the American Academy of Orthopaedic Surgeons. 1996.
10. Legg-Calvé-Perthes Disease. — Kim HK. The Journal of the American Academy of Orthopaedic Surgeons. 2010.
11. Transient Synovitis, Septic Hip, and Legg-Calvé-Perthes Disease: An Approach to the Correct Diagnosis. — Cook PC. Pediatric Clinics of North America. 2014.
12. Risk Factors for Femoral Head Deformity in the Early Stage of Legg-Calvé-Perthes Disease: MR Contrast Enhancement and Diffusion Indexes. — Yoo WJ, Choi IH, Cho TJ, et al. Radiology. 2016.
13. Evaluation of a Point-of-Care Ultrasonography Decision-Support Algorithm for the Diagnosis of Transient Synovitis in the Pediatric Emergency Department. — Zoabi M, Kvatinsky N, Shavit I. JAMA Network Open. 2021.
14. Legg-Calve-Perthes Disease. Part II: Prospective Multicenter Study of the Effect of Treatment on Outcome. — Herring JA, Kim HT, Browne R. The Journal of Bone and Joint Surgery. American Volume. 2004.
15. Legg-Calve-Perthes Disease. Part I: Classification of Radiographs With Use of the Modified Lateral Pillar and Stulberg Classifications. — Herring JA, Kim HT, Browne R. The Journal of Bone and Joint Surgery. American Volume. 2004.
16. Radiographic Classifications in Perthes Disease. — Huhnstock S, Svenningsen S, Merckoll E, et al. Acta Orthopaedica. 2017.
17. The Modified Stulberg Classification Is a Strong Predictor of the Radiological Outcome 20 Years After the Diagnosis of Perthes' Disease. — Huhnstock S, Wiig O, Merckoll E, Svenningsen S, Terjesen T. The Bone & Joint Journal. 2021.
18. A Unifying Radiographic Description of Legg-Calvé-Perthes Disease at Skeletal Maturity: The Head, Acetabulum, Trochanter Classification. — Herring JA, Kim HKW, Jo C, Hadden WJ. The Journal of Bone and Joint Surgery. American Volume. 2025.
19. The Outcomes of Non-Surgically Managed Perthes' Disease : A 15-Year Retrospective Cohort Study and Predictors of Disease. — Cheok T, Christiansen J, Bhardwaj S, et al. The Bone & Joint Journal. 2025.
20. A Prospective Multicenter Study of Legg-Calvé-Perthes Disease: Functional and Radiographic Outcomes of Nonoperative Treatment at a Mean Follow-Up of Twenty Years. — Larson AN, Sucato DJ, Herring JA, et al. The Journal of Bone and Joint Surgery. American Volume. 2012.
21. Recommendations for Physiotherapy and Physical Activity for Children With Legg-Calvé-Perthes Disease: A Survey of Pediatric Orthopedic Surgeons and Physiotherapists in Sweden. — Melin L, Rendek Z, Hailer YD. Acta Orthopaedica. 2023.
22. Legg-Calvé-Perthes Disease at 100: A Review of Evidence-Based Treatment. — Herring JA. Journal of Pediatric Orthopedics. 2011.
23. Radiographic and Functional Outcomes of Shelf Acetabuloplasty Versus Conservative Management in Legg-Calvé-Perthes Disease: An Age- And Gender-Matched Study Including Healthy Controls for Isokinetic Hip Muscle Strength. — Demirel M, Sulejmani İ, Gökçeoğlu Y, et al. R International Orthopaedics. 2025.
24. Legg-Calvé-Perthes Disease. — Leroux J, Abu Amara S, Lechevallier J. Orthopaedics & Traumatology, Surgery & Research : OTSR. 2018.