Legg-Calvé-Perthes Disease

Disease/Disorder

Definition

Legg-Calvé-Perthes disease (LCPD) is a disorder of unilateral or bilateral idiopathic avascular necrosis of the proximal femoral head (FH) in children resulting from compromise of the blood supply to the developing capital femoral epiphysis.¹ It is one of the most common causes of permanent femoral head deformity in children.²

Etiology

The cause of the disease is multifactorial involving both genetic, environmental, and nutritional factors. It frequently develops due to occlusion of either the medial circumflex artery or the lateral epiphyseal vessels, resulting in avascular necrosis of the capital femoral epiphysis.¹ Genetic factors may contribute to the susceptibility of vascular compromise.² Polymorphisms in the endothelial nitric oxide synthase gene (eNOS) have been identified in patients with LCPD.³ Environmental factors include maternal smoking and mechanical overload causing repeated subclinical trauma. Patients often have delayed bone age.² There is a higher incidence in groups of lower socioeconomic status, indicating that nutritional support may play a role.⁴

Epidemiology including risk factors and primary prevention

LCPD is a rare disease, afflicting 1 in 1200 children. It primarily affects children between ages 2 and 14 with a peak incidence at age 5 or 6 years.^1,4 The male-to-female ratio is 5:1.^1,4 It is most commonly unilateral, with about 15% of cases being bilateral.⁵ The disease is much more common in White children compared to Asian and Black children.^1,4 There is a significant geographic variation among countries. Equatorial regions have a lower incidence of the disease, whereas Northern Europe has the highest documented incidence.¹ There is a higher incidence of LCPD in less densely populated areas. ⁵ There has been a noted decline in LCPD cases in several areas, including the United Kingdom and Northern Ireland, which may be due to improvements in the standard of living.¹ Risk factors include low birth weight, obesity, exposure to secondhand smoke, socioeconomic deprivation, and hyperactive behavior.^1,5

Patho-anatomy/physiology

The pathophysiology of LCPD remains unclear, but the following processes are generally accepted:

• Blood supply to the FH is interrupted due to vulnerability to mechanical compression. The lateral epiphyseal artery disruption at its origin is demonstrated in 68% of patients in all stages of the disease.²
• Bone infarction and necrosis affect the subchondral bone, articular cartilage, and bone epiphysis.
• Revascularization occurs and new bone ossification starts. Some patients may have healthy bone growth and development.
• With progression of the disease, bone resorption, delayed bone formation, invasion of fibrovascular tissue, and subchondral fractures occur. Ischemic necrosis is also associated with increased calcium content of the necrotic bone, which is thought to make bone more brittle and prone to microdamage from normal physical activity.
• This may result in deformities in the FH and epiphyseal growth plate.^2,4

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

LCPD is a self-limited disease. It can be divided into four stages (with subgroups) based on the modified Waldenstrom radiographic classification, which has high inter- and intra-rater reliability.⁶ Determinants of the duration of each stage and total duration of the active phase is unknown, but older patients appear to have a longer duration than younger patients.

Specific secondary or associated conditions and complications

Permanent femoral head deformity in LCPD predisposes children to early onset and/or more severe course of osteoarthritis of the hip, as well as leg length discrepancy.⁸ By the 6th decade, 50% of untreated patients will develop disabling osteoarthritis requiring a total hip arthroplasty.⁹

Essentials of Assessment

History

A detailed history should include the onset, duration, quality, location, radiation of pain, exacerbating or alleviating factors, and child’s activity level. The child often participates in high impact sports, has smoke exposure, or deprivation.⁴ Typically, the parents report that the child primarily complains of hip, thigh or knee pain,⁴ or may also present with a initial painless limp.⁵

Physical examination

Examine both lower extremities to identify bilateral LCPD.

Observe for

• Atrophy of quadriceps and adjacent thigh soft tissues (can measure thigh girth to determine atrophy).
• Limited hip range of motion (ROM), especially internal rotation, extension, and abduction.
• Pain with passive hip ROM.
• Leg length discrepancy or positive Galeazzi test.⁷
• Antalgic or Trendelenburg gait (pain in the gluteus medius muscle or hip).

Functional assessment

There are no established scales for functional assessment in LCPD. Due to pain and/or ROM limitations, the child may exhibit impairment in walking, running, jumping, climbing stairs, or stooping for long periods of time.⁸

Laboratory studies

When the diagnosis is unclear, initial laboratory studies can aid in ruling out other diagnoses. Complete blood count, erythrocyte sedimentation rate, and C-reactive protein may be helpful to rule out infection. These studies will be normal in LCPD.

Imaging

Diagnosis of LCPD relies on AP and frog-leg lateral radiographs, showing early osteosclerosis, cystic changes, and a “crescent sign,” with later collapse leading to femoral head deformity and arthritis.⁴

Dynamic contrast-enhanced subtraction MRI is the gold standard, offering superior sensitivity for early ischemia, correlation with bone scintigraphy, prognostic physeal assessment, and reliable disease surveillance.^2,4

Other studies include

• Computed tomography scanning can reveal zones of osteosclerosis but is non-specific.⁴
• Ultrasound, which is low risk and cost effective, but non-specific. It may help to rule out synovitis of the hip.¹⁰

Early predictions of outcomes

There are several classifications used to prognosticate outcome

• Catterall: A 4-category system that emphasizes the extent of FH involvement and outcome. The Catterall groups I, II, III, and IV represent 25%, 50%, 75%, and complete head involvement, respectively.⁹
• Salter-Thompson: Simplifies to 2 groups. Group A (Catterall I and II) infers that less than 50% of the FH is involved, and group B (Catterall III and IV) infers that more than 50% of the FH is involved.⁹

In both classifications, if less than 50% of the FH is involved, then the prognosis is good, whereas if more than 50% is involved, then there is a potentially poor prognosis (i.e., early degenerative arthritis).⁶

• Herring: Based on the height of the lateral pillar of the FH epiphysis in the fragmentation period of the disease and is divided into three groups. Group A: No involvement of the lateral pillar; Group B: Lateral pillar height loss < 50%; and group C: Height loss > 50%. The predictive value of the Herring classification is higher in the earlier stages of the disease.⁹

Other predictors of outcome

• The shape of the FH at the time of healing is a determinant for the risk of degenerative arthritis.⁹ If the FH is spherical when the disease heals, it is likely that degenerative arthritis will not develop.^11,12 FH shape can be assessed with the Stulberg classification, which including flat, ovoid, or round. ¹²
• Age of onset⁹
  • Before 6 years old: There is a better prognosis possibly due to longer time periods for revascularization and remodeling of the FH.
  • After 8 years old: There is a higher chance of poor prognosis with significant symptoms, including restricted ROM, and early degenerative arthritis.
• Children with higher BMI experience more severe LCPD due to obesity-related inflammation, vascular changes, and impaired bone development. They present more often with bilateral disease and later stages, face higher risks of lower extremity injuries, delayed bone healing, and faster disease progression than normal-weight peers. ¹²
• Demographic factors and clinical features including females, stiff hip with adduction contracture, and a longer duration from onset to healing phase, have been associated with a poor prognosis.²

Environmental

Practitioners should obtain information about the household, including the number of stairs and levels, as these can be architectural barriers to patients with impaired mobility or weight bearing restrictions.

Professional issues

If not treated, patients can have uncontrolled pain and impaired mobility that can limit quality of life or interfere with school functioning. A missed diagnosis can also lead to osteonecrosis of the FH, and a risk of legal action due to lost treatment opportunity.

Rehabilitation Management and Treatments

Available or current treatment guidelines

There are evidence-based care guidelines concerning post-operative management and conservative treatment of LCPD in children aged 3 to 12. These guidelines are mostly based on expert-derived consensus.^13,14

At different disease stages

There is general consensus that the age of the child at the onset of symptoms, the extent of FH involvement, stage of the disease, and the presence of FH extrusion must be considered when deciding the best treatment options.² Children with mild disease are able to heal and recover fully with conservative treatment⁴

Treatment is aimed at minimizing damage, not curing the disease. The goal is to prevent FH deformity, early onset cox-arthrosis, and to delay disparity between the affected and unaffected hip.⁴ Physical therapy (PT) can produce improvement in articular ROM, dysfunction, and muscular strength. Because hip ROM is often already restricted at diagnosis, gentle stretching and strengthening exercises are recommended to preserve or enhance mobility.

Generally, patients with Catterall classifications I or II can be treated conservatively, whereas Catterall classifications III or IV often require surgical intervention.  The short-term goal is reduction of pain and stiffness of the hip. The principal of treatment is containment of the femoral head within the spherical acetabulum to allow spherical re-ossification. Restoring the epiphysis to its central position within the acetabular cup helps guide remodeling of the weight-bearing portion of the proximal femoral epiphysis.¹⁵

Nonsurgical Treatment

• Restriction of activity with rest for 5 to 7 days is recommended to relieve hip pain or stiffness.⁴ Crutches and non-weight bearing status are used if symptoms are severe.¹⁶ Swimming is recommended, while running-based activities should be avoided. Long-term immobilization is not recommended as it can have detrimental outcomes including muscle atrophy, contractures, and weight gain.¹⁵
• Nonsteroidal anti-inflammatory drugs should be used for acute pain and inflammation.
• Orthosis with progressive hip abduction for 7 to 10 days and casting to immerse the femoral head into the coxal cavity may be helpful, which is followed by arthrography if the joint fails to mobilize.^4,17
• Supervised PT is supplemented with a customized home exercise program. PT should be individualized according to disease stage and surgical status. Home exercise programs should emphasize gentle hip abduction and internal rotation stretches, alongside strengthening to enhance hip stability while minimizing joint stress
• If there is contracture of the adductor muscles, treatment with botulinum toxin combined with intense PT may improve hip abduction.Additional studies are needed to establish the efficacy of modalities to increase femoral head strength or improve blood supply such as balneotherapy, glycosaminoglycans, bisphosphonates, plasma therapy, extracorporeal shock wave therapy, pulsed electromagnetic fields, and hyperbaric oxygen in LCPD children.^1,17,18,19
• No robust evidence was found from non-randomized studies regarding the most effective non-surgical interventions for LCPD children.¹⁷

Surgical Treatment

• If FH deformity prevents hip abduction due to a contracture, percutaneous hip adductor release may be performed followed by containment therapy once the joint has been maximally abducted.²⁰ Femoral Varus Osteotomy and Salter Osteotomy are the most commonly employed containment procedures.²¹
• In the late stages (for children aged 8 years and older), the recommended shelf arthroplasty is considered a salvage procedure as it can cause hip incongruency in order to preserve acetabular coverage.^20,22 A valgus femoral osteotomy overcomes the hinging and brings a more congruent surface of femoral head under the acetabulum.² It is indicated for those with active disease with non-containable hips or recovered disease with painful hinge abduction.²⁰
• Arthrodiastasis (distraction of a joint), provides unloading of the hip joint to protect femoral head integrity. Treatment showed favorable outcomes in hip mobility, pain, and radiographic parameters, but is associated with higher morbidity of recurrent pin-tract infection, therefore is not recommended as the primary treatment in the early stages of LCPD.^21,23
• Skeletally mature individuals are candidates for cheilectomy, which only corrects FH deformities.²⁰
• Total hip replacement may be needed later in life if severe osteoarthritis develops.

Coordination of care

A multidisciplinary team includes physiatry, PT, occupational therapy (OT), and orthopedics. The physiatrist plays a role in monitoring symptoms, treating contractures of hip adductor muscles, prescribing PT and pain medications, obtaining radiographs, determining weight-bearing status, and referring to a pediatric orthopedist. It is important that all patients establish care with a team to determine treatment options. Follow-up visits focus on symptoms, hip mobility, and disease progression.

Measurement of treatment outcomes including those that are impairment-based, activity participation-based and environmentally-based.

The Iowa Hip Score and Nonarthritic Hip Score are used in addition to the Stulberg classification to evaluate functional outcomes in LCPD.²⁴

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

Surgery may eliminate longer-term bracing and allow earlier resumption of activities. Operative and nonoperative treatments had comparable rates of good outcome of about 77%. The prognosis is better with early detection (under the age of 8 years).^16,20 Patients younger than 6 years had better outcome with nonoperative than with operative management, whereas the opposite was true for children of 6 years and older.²² When deciding on surgical intervention, the younger population tends to have a slightly better outcome with pelvic rather than femoral osteotomy. Varying reports give conflicting results on prognosis between genders with some showing females with worse prognosis and some with no gender differences. Bilateral cases tend to have poorer prognosis.¹⁹

Cutting Edge/Emerging and Unique Concepts and Practice

Antiresorptive agents may provide useful adjunctive therapy. Animal studies show that that combining bone morphogenetic protein (BMP2) with bisphosphonates reduces bone resorption, enhances new bone formation, and preserve the femoral head shape.^1,2,25 Traditional BMP2 carriers caused leakage and heterotopic ossification, while orthopedic biomaterials limited bone penetration. A novel BMP2-loaded hydrogel with transphyseal bone wash achieved broad, contained intraosseous delivery, improving therapeutic potential.²⁵ Another study has evaluated treatment with Strontium ranelate in rat models, which has shown prevention in collapse of the ischemic FH and enhanced trabecular thickness.²⁶

Gaps in the Evidence-Based Knowledge

There is a lack of basic science studies to understand the causative factors, nature of vascular changes, intricate events of bone and cartilage damage, and particle removal and eventual repair.

There is a need for well-designed, prospective, controlled studies to explore new treatment options for advanced LCPD, since neither conservative nor operative management showed desirable clinical outcomes. In addition, antiresorptive and anabolic agents need further investigation to assess their clinical efficacy in the treatment of LCPD.²⁵

References

1. Joseph B, Shah H, Perry DC. Epidemiology, natural evolution, pathogenesis, clinical spectrum, and management of Legg-Calvé-Perthes. J Child Orthop. 2023;17(5):385-403.
2. Ibrahim T, Little DG. The Pathogenesis and Treatment of Legg-Calvé-Perthes Disease. JBJS Rev. 2016 Jul 19;4(7).
3. Ding, X. Endothelial nitric oxide synthase gene polymorphism is associated with Legg-Calvé-Perthes disease. Experimental and Therapeutic Medicine 2016;11:5, 1913–1917.
4. Rodriguez-Olivas A, et al. Legg-Calve-Perthes disease overview. Orphanet Journal of Rare Diseases 2022; 17:125.
5. Ng T, Liu R, Kulkarni VA. Legg-Calvé-Perthes Disease: Diagnosis, Decision Making, and Outcome. Curr Sports Med Rep. 2024;23(2):45-52.
6. Hyman, J. E., Trupia, E. P., & Wright, M. L. Interobserver and intraobserver reliability of the modified Waldenström classification system for staging of Legg-Calvé-Perthes disease. Journal of Bone and Joint Surgery American Volume 2015;97:8, 643-650.
7. Morancie NA, Helton MR. Evaluating the Child With a Limp. Am Fam Physician. 2023 May;107(5):474-485. PMID: 37192073.
8. Rampal, V., Clement, J. L., & Solla, F. Legg Calve Perthes Disease: classification and prognostic factors. Clinical Cases in Mineral and Bone Metabolism 2017;14:1, 74-82.
9. Kim H, Herring JA. Pathophsysiology, classifications, and natural history of Perthes disease. Orthop Clin N Am 2011;42:285-295.
10. Dimeglio A, Canavese F. Imaging in Legg-Calvé-Perthes disease. Orthop Clin North Am2011;42:297-302.
11. Huhnstock S, Wiig O, Merckoll E, Svenningsen S, Terjesen T. The modified Stulberg classification is a strong predictor of the radiological outcome 20 years after the diagnosis of Perthes’ disease. Bone Joint J. 2021 Dec;103-B(12):1815-1820. doi: 10.1302/0301-620X.103B12.BJJ-2021-0515.R1. PMID: 34847712.
12. Beckish L, Ging M, Mosman M, Kelley C, Wilkin L, Wills O, Adams M, Pinion C, Bilica C, Anderson A, Sims M, Beckish M, Schmitt DM. Diagnosis and Management of Legg-Calvé-Perthes Disease in the Obese Pediatric Population. J Orthop Physician Assist. 2024 Jul-Sep;12(3):e24.00013. doi: 10.2106/jbjs.jopa.24.00013. PMID: 39759267; PMCID: PMC11698501.
13. https://www.physio-pedia.com/Legg-Calve-Perthes Disease
14. Galloway AM, Keene DJ, Anderson A, Holton C, Redmond AC, Siddle HJ, Richards S, Perry DC. Clinical consensus recommendations for the non-surgical treatment of children with Perthes’ disease in the UK. Bone Joint J. 2024 May 1;106-B(5):501-507. doi: 10.1302/0301-620X.106B5.BJJ-2023-1283.R1. PMID: 38688522.
15. Braun S, Adolf S, Brenneis M, Boettner F, Meurer A. Legg-Calvé-Perthes disease- surgical treatment options. Arch Orthop Trauma Surg. 2025 Mar 12;145(1):186. doi: 10.1007/s00402-025-05801-3. PMID: 40072635; PMCID: PMC11903597.
16. Murphy KP, et al, . Musculoskeletal conditions. In: Alexander MA, Matthews DJ, editors,Pediatric Rehabilitation: Principles and Practice. 6th edition. New York, NY: Demos Medical Publishing 2021:380-382.
17. Galloway AM, van-Hille T, Perry DC, Holton C, Mason L, Richards S, Siddle HJ, Comer C. A systematic review of the non-surgical treatment of Perthes’ disease. Bone Jt Open. 2020 Dec 2;1(12):720-730.
18. Massari L, et al. Biophysical stimulation with pulsed electromagnetic fields in osteonecrosis of femoral hed. J Bone Joint Surg Am. 2006; 88 suppl 3:56.
19. Camporesi EM, et al. Hyperbaric oxygen therapy in femoral head necrosis. J Arthroplasty. 2010; 25: 118.
20. Bralto M et al. Global differences in the treatment of Legg-Calve-Perthes disease: a comprehensive review. Archives of Orthopaedic and Trauma Surgery 2021; 141: 1-16
21. Maleki A, Qoreishy SM, Bahrami MN. Surgical Treatments for Legg-Calvé-Perthes Disease: Comprehensive Review. Interact J Med Res. 2021 May 3;10(2):e27075. doi: 10.2196/27075. PMID: 33938444; PMCID: PMC8129878.
22. Tukitiyeva N et al. Methods of treatment of Legg-Calve-Perthes Disease (Review). Georgian Med News 2021; (313):127-134.
23. Alsager GA, Aljafar F, Alrabai HM. Systematic review and meta-analysis of the efficacy of hip distraction in Legg-Calve-Perthes disease. J Musculoskelet Surg Res. 2025;9:193-201. doi: 10.25259/JMSR_497_2024
24. Larson AN, Sucato DJ, Herring JA, et al. A prospective multicenter study of Legg-Calvé-Perthes disease: functional and radiographic outcomes of nonoperative treatment at a mean follow-up of twenty years. J Bone Joint Surg Am 2012;94:584-592.
25. Ma C, Park MS, Alves do Monte F, et al. Local BMP2 hydrogel therapy for robust bone regeneration in a porcine model of Legg-Calvé-Perthes disease. NPJ Regen Med. 2023;8(1):50.
26. Chen, YP., Tan, A., Ho, WP. et al. Effectiveness of Strontium Ranelate in the Treatment of Rat Model of Legg–Calve–Perthes Disease. IJOO 52, 380–386 (2018).

Bibliography

Joseph B. Prognostic factors and outcome measures in Perthes disease. Orthop Clin N Am 2011;42:303-315.

Novais ED, Clohisy J, Siebenrock K. Treatment of symptomatic healed Perthes hip. Orthop Clin N Am 2011;42;401-417.

Original Version of the Topic

Rajashree Srinivasan, MD, Anwar Zaman, MD. Legg Calve Perthe Disease. 1/30/2014

Previous Revision(s) of the Topic

Yuxi Chen, MD, Ashley Kakkanatt, MD, and Jinpu Li, MD. Legg Calve Perthe Disease. 6/26/2018

Yuxi Chen, MD, Marjorie Morales, MD, Emilee Bell, DO, Mihir Jani, MD. Legg-Calve-Perthes Disease. 12/14/2022

Author Disclosure

Yuxi Chen, MD
Ipsen, Research grants, principal investigator

Yolanda Pham, MD, MPH
Nothing to Disclose

Jordan Schnoll, MD
Nothing to Disclose

Michelle Nunez Garcia, MD
Nothing to Disclose