Paeds · rheumatology-musculoskeletal-and-sports
Perthes disease
Also known as Legg-Calve-Perthes disease · Perthes' disease · coxa plana · idiopathic avascular necrosis of the capital femoral epiphysis · osteochondritis of the femoral head
A fellowship approach to Legg-Calve-Perthes disease: idiopathic avascular necrosis of the capital femoral epiphysis in the four-to-eight-year-old child, the four radiographic phases of necrosis through fragmentation to reossification and remodeling, the Herring lateral pillar classification that drives prognosis, and the containment principle that keeps the soft femoral head moulded within the acetabulum during reossification.
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Target exams
Red flags
- A limp that persists beyond two to three weeks in a child aged four to eight is Perthes until proven otherwise, because transient synovitis resolves within days and a painless progressive limp is the signature of an avascular femoral head
- Referred pain to the knee or thigh with a stiff hip must prompt a hip radiograph, because the source is the hip in a child who localises pain distally, and a missed early Perthes loses the window when containment could preserve the head
- A child over eight at onset, a girl, or a lateral pillar group C head carries the highest risk of a poor Stulberg outcome and premature osteoarthritis, and these features demand early orthopaedic referral for a containment decision
- Loss of hip abduction with progressive lateral subluxation of the femoral head signals hinge abduction, the point at which the deformed head is levering out of the acetabulum and the containment window is closing
- A fever, a toxic child, or an elevated C-reactive protein with an irritable hip is not Perthes but septic arthritis, and the limp that meets Kocher high-risk criteria demands joint imaging and aspiration before Perthes is considered
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- Musculoskeletal medicine - recognise the limping child aged four to eight and differentiate Perthes disease from transient synovitis and septic arthritis
- Acute presentations - the persistent or painless limp with a stiff hip and referred knee pain
- Growth and development - the four-to-eight-year-old boy with a progressive limp
- Musculoskeletal medicine - apply the Herring lateral pillar classification and the containment principle to guide referral and surgical decision-making
- Orthopaedics - interpret the four radiographic phases and the Stulberg outcome classification
- Renewed curriculum for first-year trainees from 2027 - Learning goal 6: Clinical management - essential general paediatrics
- Musculoskeletal 10-12
- Growth and development 10-12
- Acute presentations 10-12
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- 2. Children presenting with musculoskeletal problems including the limping child
- 8. Musculoskeletal disorders including Perthes disease
- 4. Professional skills and knowledge: Patient management
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- General Pediatrics Content Outline - Musculoskeletal: Perthes disease
- General Pediatrics Content Outline - Universal Task 3: Physical Examination
- General Pediatrics Content Outline - Universal Task 5: Patient Management
- Patient Care 4: Clinical Reasoning
- Patient Care 5: Patient Management
- Medical Knowledge 2: Diagnostic testing
- Pediatrics: Musculoskeletal applied domain
- Pediatrics: Musculoskeletal disorders
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A six-year-old boy limps into your clinic. His mother says the limp has been present for three weeks, comes and goes, is worse after activity, and that the boy sometimes points to his knee rather than his hip. He is afebrile, well in himself, and on examination he has a mild antalgic gait and a hip that loses abduction and internal rotation. His radiograph shows a slightly smaller, denser right femoral head with a faint subchondral line. You recognise Perthes, you confirm the lateral pillar grade in the fragmentation phase, and you refer for a containment decision based on his age and his pillar height. A nine-year-old girl presents the same way but her head is already collapsing — older age at onset is the single strongest poor prognostic factor, and her window for containment is narrow. [4] [2]
Hold the whole disease as four phases. Necrosis is the silent loss of blood supply to the femoral head, which may be radiographically subtle. Fragmentation is the phase in which the dead bone resorbs and the head loses height — this is when the lateral pillar grade is assigned and when the head is soft and mouldable. Reossification is the creeping substitution of new bone into the head, the window when containment works. Remodeling is the years-long reshaping of the healed head toward, or away from, a sphere, and the final shape sets the Stulberg outcome and the lifetime osteoarthritis risk. [4] [1]
Overview & Definition
Legg-Calve-Perthes disease is the idiopathic avascular necrosis of the capital femoral epiphysis in a growing child. The femoral head loses its blood supply, the bone and marrow die, and the body then resorbs the dead bone and replaces it with new bone over a course of eighteen to thirty-six months. The disease is self-limiting in that it always heals, but the shape of the healed head determines whether the child enters adult life with a normal hip or with a flattened head destined for early osteoarthritis. The illness is named for the three authors who described it independently in 1910 — Legg, Calve, and Perthes. [4] [3]
The clinical hallmark is the persistent limp of a young child. The child is typically a boy between four and eight years old who has limped for weeks, who is often afebrile and well, and whose pain is mild, intermittent, and sometimes referred to the knee or the thigh. The hip examination shows a loss of motion, most reliably a loss of abduction and internal rotation, and a muscle spasm that splints the joint. The contrast with transient synovitis is the key first fork: transient synovitis resolves within a week or two, while Perthes persists and progresses, and any limp that lasts beyond two to three weeks in this age group is Perthes until the radiograph and the clinical course settle the question. [4] [3]
The disease stands apart from the other causes of the limping child because it is chronic and because the role of the general paediatrician is to recognise it early, exclude the urgent mimics, and refer for a containment decision based on age and lateral pillar grade. The mistake to avoid is to accept the limp as a minor injury or to discharge the child with a diagnosis of transient synovitis when the limp has persisted. The safeguard is the rule that a limp beyond two to three weeks in a four-to-eight-year-old earns a hip radiograph and, if the picture fits, a referral. [4]
References12ShowHide
- [1]Herring JA, Kim HT, Browne R, et al. Legg-Calve-Perthes disease. Part II: Prospective multicenter study of the effect of treatment on outcome. Journal of Bone and Joint Surgery (American Volume), 2004.PMID 15466720
- [2]Wiig O, Terjesen T, Svenningsen S. Prognostic factors and outcome of treatment in Perthes' disease: a prospective study of 368 patients with five-year follow-up. Journal of Bone and Joint Surgery (British Volume), 2008.PMID 18827249
- [3]Terjesen T, Wiig O, Svenningsen S. The natural history of Perthes' disease. Acta Orthopaedica, 2010.PMID 21067434
- [4]Herring JA. Legg-Calve-Perthes disease at 100: a review of evidence-based treatment. Journal of Pediatric Orthopaedics, 2011.PMID 21857427
- [5]Larson AN, Sucato DJ, Herring JA, et al. A prospective multicenter study of Legg-Calve-Perthes disease: functional and radiographic outcomes of nonoperative treatment at a mean follow-up of twenty years. Journal of Bone and Joint Surgery (American Volume), 2012.PMID 22488614
- [6]Kim HK, da Cunha AM, Browne R, et al. How much varus is optimal with proximal femoral osteotomy to preserve the femoral head in Legg-Calve-Perthes disease? Journal of Bone and Joint Surgery (American Volume), 2011.PMID 21325585
- [7]Terjesen T, Wiig O, Svenningsen S. Varus femoral osteotomy improves sphericity of the femoral head in older children with severe form of Legg-Calve-Perthes disease. Clinical Orthopaedics and Related Research, 2012.PMID 22101403
- [8]Kim HK, Wiesman KD, Kulkarni V, et al. Perfusion MRI in Early Stage of Legg-Calve-Perthes Disease to Predict Lateral Pillar Involvement: A Preliminary Study. Journal of Bone and Joint Surgery (American Volume), 2014.PMID 25031369
- [9]Huhnstock S, Wiig O, Merckoll E, et al. The modified Stulberg classification is a strong predictor of the radiological outcome 20 years after the diagnosis of Perthes' disease. The Bone and Joint Journal, 2021.PMID 34847712
- [10]Neal DC, Alford TH, Moualeu A, et al. Prevalence of Obesity in Patients With Legg-Calve-Perthes Disease. Journal of the American Academy of Orthopaedic Surgeons, 2016.PMID 27471901
- [11]Loder RT, Browne RH, Millis A, et al. The time of the insult/triggering event in Legg-Calve-Perthes' disease determined by incubation period modeling and the age distribution of children with Perthes'. Iowa Orthopaedic Journal, 2012.PMID 23576924
- [12]Sankar WN, Lavalva SM, McGuire MF, et al. Does Early Proximal Femoral Varus Osteotomy Shorten the Duration of Fragmentation in Perthes Disease? Lessons From a Prospective Multicenter Cohort. Journal of Pediatric Orthopaedics, 2020.PMID 31524767