Synonyms: Calvé-Legg-Perthes disease, Perthes-Calvé-Legg disease
This is a self-limiting hip disorder caused by varying degrees of ischaemia and subsequent necrosis of the femoral head.Characteristic features include:
- The essential lesion is loss of blood supply (avascular necrosis) of the nucleus of the proximal femoral epiphysis.
- Abnormal growth of the epiphysis results.
- Eventual remodelling of regenerated bone.
- Usually seen in a 4- to 8-year-old boy with delayed skeletal maturity.
- Approximately 1 in 1,200 children aged under 15 years.
- Male to female ratio: 4-5:1.
- Rare in non-Caucasians.
The primary event is avascular necrosis of the femoral epiphysis, which results in delayed ossific nucleus:
- The articular cartilage is nourished by synovial fluid and continues to grow.
- The cartilage columns become distorted with some loss of their cellular components.
- They do not undergo normal ossification, which results in excess of calcified cartilage in the primary trabecular bone.
- Revascularisation proceeds from peripheral to central.
- Symptoms occur with subchondral collapse and fracture.
- It presents with pain in the hip or knee and causes a limp.
- There is pain (often in the knee) and an effusion (from synovitis).
- 10-15% of cases are bilateral, but will be at different stages and are asymmetrical.
- On examination all movements at the hip are limited:
- The early phase has limited abduction of the hip and limited internal rotation in both flexion and extension.
- There is an antalgic gait (due to pain).
- Trendelenburg gait is seen in the late phase.
- No history of trauma.
- Roll test: with the patient lying in the supine position, the examiner rolls the hip of the affected extremity into external and internal rotation. This test should invoke guarding or spasm, especially with internal rotation.
- FBC and ESR.
- Early X-rays may show widening of the joint space (the best view is frog lateral), or may be normal.
- Technetium bone scan or MRI scanning can be used to identify pathology (seen as an area of reduced perfusion).
- Later, there is a decrease in the size of the nuclear femoral head with patchy density on X-ray.
- Later still, there may be collapse and deformity of the femoral head with new bone formation. Severe deformity of the femoral head risks early arthritis.
- An arthrogram and/or MRI scan are often needed to assess congruency throughout full range of movement. A flat-topped incongruent head has the worst prognosis. It can rule out hinge abduction where the enlarged femoral head impinges on the acetabular rim.
- Hip aspiration if a septic joint is suspected.
Bilateral Perthes' disease
This requires a skeletal survey as part of the work-up.
- Multiple epiphyseal dysplasia (MED).
- Spondyloepiphyseal dysplasia tarda.
- Sickle cell disease.
Unilateral Perthes' disease
- Septic arthritis.
- Sickle cell disease.
- Spondyloepiphyseal dysplasia tarda.
- Gaucher's disease.
- Eosinophilic granuloma.
- Transient synovitis (this was thought to lead to Perthes' disease; however, it is now believed there is no causal relationship).
There is no consensus for the optimum treatment. The aim of treatment is to maintain the sphericity of the femoral head and the congruency of the femur-acetabulum relationship to prevent secondary degenerative arthritis. Early diagnosis and management can help prevent the collapse of the femoral head, progressive femoral head deformity, and impingement.
Children who have a skeletal age of 6.0 years or less at the onset of the disease do well without treatment.Operative treatment should be considered in children who are six years old or older and have over 50% femoral head necrosis when the diagnosis is made.
Physiotherapy using muscle strengthening and stretching exercises, produces significant improvement in articular range of motion, muscular strength and articular dysfunction, but these improvements are not seen on X-ray.
Surgery is indicated for children greater than age 6 years as they do better with intervention - see 'Prognosis', below.
Proximal varus osteotomy has been recommended.[2, 6]Salvage procedures are reserved for patients with severe impairment. Procedures include:
- Excision of extruded portion of head for hinge abduction.
- Acetabular osteotomy.
- Chiari osteotomy to cover femoral head.
- Lateral shelf osteotomy: although radiological measurements indicate improved coverage of the femoral head after shelf acetabuloplasty, available evidence has not shown that the procedure prevents early onset of osteoarthritis or improves long-term function.
- Valgus osteotomy to increase abduction and bring more normal medial femoral head into weight-bearing area.
- Arthrodesis at skeletal maturity (in unilateral involvement) for patients with severe functional impairment.
- Patients aged older than 9 years may benefit from combined innominate and femoral osteotomies if done in the early stages.
More than 80% of affected hips have good or very good outcomes that persist into the fourth decade of life. However, a retrospective study found that half of all patients eventually required an artificial hip after a median follow-up interval of 50 years.
Prognostic factors include age, limitation of movement, radiologically visible involvement of the femoral head, lateralisation of the femoral head in the acetabulum (subluxation), lateral epiphyseal calcification and metaphyseal cyst formation.
Age under 6 years at the onset of the disease is prognostically favorable because of the higher remodeling potential.
Residual deformities may include coxa magna (broadening of the head and neck of the femur), coxa plana (osteochondritis of the femoral head), coxa breva (structural shortening of the neck of the femur) and hinged abduction (this occurs when an enlarged femoral head is pushed laterally and it impinges on the acetabular rim when the hip is abducted).
Femoral head deformity is well tolerated in short and intermediate terms, but 50% of patients develop disabling arthritis in the sixth decade of life.
Further reading and references
Kannu P, Howard A; Perthes' disease. BMJ. 2014 Sep 23349:g5584. doi: 10.1136/bmj.g5584.
Shah H; Perthes disease: evaluation and management. Orthop Clin North Am. 2014 Jan45(1):87-97. doi: 10.1016/j.ocl.2013.08.005. Epub 2013 Sep 26.
Legg Calve Perthes Disease; Wheeless' Textbook of Orthopaedics
Nelitz M, Lippacher S, Krauspe R, et al; Perthes disease: current principles of diagnosis and treatment. Dtsch Arztebl Int. 2009 Jul106(31-32):517-23. doi: 10.3238/arztebl.2009.0517. Epub 2009 Aug 3.
Perry DC, Bruce C; Evaluating the child who presents with an acute limp. BMJ. 2010 Aug 20341:c4250. doi: 10.1136/bmj.c4250.
Herring JA, Kim HT, Browne R; Legg-Calve-Perthes disease. Part II: Prospective multicenter study of the effect of treatment on outcome. J Bone Joint Surg Am. 2004 Oct86-A(10):2121-34.
Wiig O, Terjesen T, Svenningsen S; Prognostic factors and outcome of treatment in Perthes' disease: a prospective J Bone Joint Surg Br. 2008 Oct90(10):1364-71.
Brech GC, Guarnieiro R; Evaluation of physiotherapy in the treatment of Legg-Calve-Perthes disease. Clinics. 2006 0061(6):521-528.
Hsu JE, Baldwin KD, Tannast M, et al; What is the evidence supporting the prevention of osteoarthritis and improved femoral coverage after shelf procedure for Legg-Calve-Perthes disease? Clin Orthop Relat Res. 2012 Sep470(9):2421-30. doi: 10.1007/s11999-011-2220-4.
Canavese F, Dimeglio A; Perthes' disease: prognosis in children under six years of age. J Bone Joint Surg Br. 2008 Jul90(7):940-5.
Kim HK, Herring JA; Pathophysiology, classifications, and natural history of Perthes disease. Orthop Clin North Am. 2011 Jul42(3):285-95, v. doi: 10.1016/j.ocl.2011.04.007.