Introduction
Background
Legg-Calvé-Perthes (LPD) disease is a childhood hip disorder that results in infarction of the bony epiphysis of the femoral head. LPD represents idiopathic avascular necrosis of the femoral head. The disease is bilateral in 10-20% of patients and usually affects children aged 4-8 years. When both hips are involved, they are usually affected successively, not simultaneously. A family history is present in 6% of patients. In adults, the corresponding condition is termed Chandler disease.
Although the etiology is unclear, certain risk factors have been identified in children, including sex, socioeconomic group, and the presence of an inguinal hernia and genitourinary tract anomalies. More specifically, boys are affected 3 to 5 times more often than girls, and the incidence increases in low socioeconomic groups and in children with low birth weight. Determining the prognosis is important at the time of presentation because more than 50% of patients with LPD do not require treatment.1,2,3
Legg-Calvé-Perthes disease. Stage II disease. Note the slight widening of the left hip joint representing a small joint effusion (see also Image 1 in Multimedia). Joint widening can also be secondary to hypertrophy of the cartilage.
Legg-Calvé-Perthes disease. Axial nonenhanced CT scan through the hip joints in the same patient as in Image 15 in Multimedia more clearly shows the loss of structural integrity of the right femoral head.
Legg-Calvé-Perthes disease. Coronal T2-weighted MRIs show irregularity and flattening of cortical margins of the left femoral epiphysis. Also note a mild joint effusion and subluxation and hinge deformity of the left femoral head.
Legg-Calvé-Perthes disease. Zoomed images of the same patient as in Image 22 in Multimedia show the photopenic defect more clearly.
Pathophysiology
The primary pathologic abnormality in patients with LPD is osteonecrosis resulting in flattening and collapse of the femoral head. The articular cartilage covering the femoral head is remarkably resistant to ischemia and is usually well preserved. The basic underlying cause of LPD is insufficient blood supply to the femoral head. The epiphyseal plate acts as a barrier to the supply of blood in children aged 4-10 years, and the ligamentum teres vessels become nonfunctional, causing the head to be at risk for osteonecrosis. Healing occurs by revascularization of the necrotic femoral head.
The course of revascularization and reconstitution of the femoral head varies. The ultimate shape of the reconstituted femoral head depends on several factors, including the degree and site of necrosis and the magnitude of forces working across the femoral head. In some patients, the femoral head may return to normal, whereas in other patients, coxa plana and shortening and widening of the femoral head may develop. These changes may be associated with osteoarthrosis and intra-articular loose bodies. In most patients, the changes occurring in LPD affect only 1 hip. With bilateral disease, the changes are rarely symmetric.
Frequency
United States
The frequency in the United States is similar to the worldwide frequency.
International
Approximately 1 in 1200 children younger than 15 years is affected.
Mortality/Morbidity
The diagnosis of LPD must be made as early as possible; patients who present after the age of 8 years have a poor prognosis. The prognosis for girls is worse than that for boys, and girls usually have a more severe form of the disease.
The prognosis for patients in whom the onset of LPD occurs before the age of 6 years is favorable, with 80% having a good result; however, in children between 4 years of age and 5 years, 11 months of age who have lateral pillar involvement of classification B/C or C, the prognosis is less favorable.4
Race
LPD rarely occurs in blacks.
Sex
The male-to-female ratio is 3-5:1.
Age
Patients with LPD are typically aged 2-12 years. The mean patient age at presentation is 7 years.5
Anatomy
The femoral head is spherical and is covered by articular cartilage. The fovea is a just-off-center ovoid depression that serves as an attachment for the ligamentum teres (round ligament). The femoral head is supplied by a vascular ring at the base of the femoral neck from branches arising from the lateral and medial circumflex arteries. The superior and inferior gluteals contribute to the blood supply to a lesser extent. The anterior aspect of the vascular ring is within the joint capsule. Principally, the lateral epiphyseal arteries supply the femoral neck. The artery in the ligamentum teres supplies one third of the arterial supply to the femoral head in children but makes only a small contribution in adults.
Presentation
LPD is a dynamic condition. Results of the physical examination depend on the stage of the disease at the time of presentation. The child often has a limp with groin, thigh, or knee pain. Children who present with knee pain must be carefully examined for hip pathology. As the disease progresses, flexion and adduction contractures may develop, and lateral overgrowth of the femoral head cartilage may cause loss of abduction. Attempts at abduction lead to hinging and possible subluxation of the femoral head. Eventually, the hip may move in only the flexion-extension plane. Progressive loss of movement, adduction contractures, flexion with abduction, and obesity are poor prognostic signs. Lateral subluxation of the femoral head is also associated with a poor outcome.
Several staging schema are used to determine severity of disease and prognosis; these include the Catterall, Salter-Thomson, and Herring systems.6
The Catterall classification is based on radiographic appearances and specifies 4 groups during the period of greatest bone loss.
Catterall staging is as follows:
- Stage I — Histologic and clinical diagnosis without radiographic findings
- Stage II — Sclerosis with or without cystic changes with preservation of the contour and surface of femoral head
- Stage III — Loss of structural integrity of the femoral head
- Stage IV — Loss of structural integrity of the acetabulum in addition
The Salter-Thomson classification simplifies the Catterall classifications by reducing the groups to 2. The first, called group A, includes Catterall groups I and II; for patients in this group, less than 50% of the head is involved. The second, called group B, includes Catterall groups III and IV; for patients in this group, more than 50% of the head is involved. For both classifications, if less than 50% of the ball is involved, the prognosis is better, whereas if more than 50% is involved, the prognosis is potentially poor.
The Herring classification addresses the integrity of the lateral pillar of the head. In lateral pillar group A, there is no loss of height in the lateral one third of the head, and there is little density change. In lateral pillar group B, there is a lucency and less than 50% loss of lateral height. Sometimes, the head is beginning to extrude from the socket. In lateral pillar group C, there is more than 50% loss of lateral height.
Preferred Examination
Plain radiography remains the major modality for the evaluation of LPD. Staging of the disease is based on plain radiographic findings.1,7,8
Scintigraphy is a useful technique in early disease when plain radiographic findings may be normal; with scintigraphy, abnormalities become apparent earlier in the course of disease than they do with plain radiography.
CT scans allow early diagnosis of bone collapse and curvilinear zones of sclerosis early in the disease process when plain radiography is less sensitive. CT scans can also demonstrate subtle changes in the bone trabecular pattern.
Ultrasonography is useful in the preliminary diagnosis of transient synovitis of the hip and the onset of LPD.9 Hip effusion with capsular distention is well depicted on sonographic images.10,11,12,13,14
MRI is as sensitive as isotopic bone scanning and allows more precise localization of involvement than conventional radiography.15,16,17,18,19,20
Angiography, venography, and arthrography have limited roles in the diagnosis of LPD.
Limitations of Techniques
Plain radiographic findings may be entirely normal in early symptomatic disease.
Although abnormalities become apparent with scintigraphy earlier in the course of disease than they do with radiography, abnormal scintigraphic findings are nonspecific; findings may be positive in patients with trauma, synovitis, and infections.
CT scans allow the early diagnosis of bone collapse, but the use of CT is limited by the comparatively higher radiation dose.
Ultrasonography is useful in the preliminary diagnosis of transient synovitis of the hip and the onset of LPD, but the diagnosis is based on a demonstration of hip effusion, which is a nonspecific finding.
MRI is as sensitive as isotope bone scans and allows more precise localization of involvement than conventional radiography, but the changes seen as bone marrow edema and joint effusions are nonspecific.
Angiography, venography, and arthrography are invasive procedures and do not provide significantly better clinical information for guiding therapeutic options.
Differential Diagnoses
Eosinophilic Granuloma, Skeletal
Septic Arthritis
Sickle Cell Anemia, Skeletal
Other Problems to Be Considered
Bilateral disease
Hypothyroidism
Multiple epiphyseal dysplasia (The disease is usually bilateral and symmetric.)
Spondyloepiphyseal dysplasia tarda
Sickle cell disease
Unilateral disease
Septic arthritis
Gaucher disease
Eosinophilic granuloma
Spondyloepiphyseal dysplasia
Hemophilia
Transient synovitis
Avascular necrosis
Developmental dysplasia of the hip (when overtreated can cause avascular necrosis of the femoral head)
More on Legg-Calve-Perthes Disease |
 Overview: Legg-Calve-Perthes Disease |
| Imaging: Legg-Calve-Perthes Disease |
| Follow-up: Legg-Calve-Perthes Disease |
| Multimedia: Legg-Calve-Perthes Disease |
| References |
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References
Resnick D. Osteochondroses. In: Bralow L, ed. Bone and Joint Imaging. 2nd ed. Philadelphia: WB Saunders Co;1996: 960-6.
Wheeless CR. Legg Calve Perthes Disease. In: Wheeless' Textbook of Orthopaedics [online]. Available at: http://www.medmedia.com/orthoo/242.htm. Accessed April 18, 2002. [Full Text].
Poul J. Diagnosis of Legg-Calvé-Perthes disease. Ortop Traumatol Rehabil. Oct 30 2004;6(5):604-6. [Medline].
Rosenfeld SB, Herring JA, Chao JC. Legg-calve-perthes disease: a review of cases with onset before six years of age. J Bone Joint Surg Am. Dec 2007;89(12):2712-22. [Medline].
Sharma S, Shewale S, Sibinski M, Sherlock DA. Legg-Calvé-Perthes disease affecting children less than eight years of age: a paired outcome study. Int Orthop. Jan 9 2008;[Medline].
Van Campenhout A, Moens P, Fabry G. Serial bone scintigraphy in Legg-Calvé-Perthes disease: correlation with the Catterall and Herring classification. J Pediatr Orthop B. Jan 2006;15(1):6-10. [Medline].
Meadows C, Monsell F, Ramanan AV. Normal x rays in Perthes disease. Arch Dis Child. Mar 2008;93(3):211. [Medline].
Nelson D, Zenios M, Ward K, Ramachandran M, Little DG. The deformity index as a predictor of final radiological outcome in Perthes' disease. J Bone Joint Surg Br. Oct 2007;89(10):1369-74. [Medline].
Wingstrand H. Significance of synovitis in Legg-Calve-Perthes disease. J Pediatr Orthop B. Jul 1999;8(3):156-60. [Medline].
Zawin JK, Hoffer FA, Rand FF, Teele RL. Joint effusion in children with an irritable hip: US diagnosis and aspiration. Radiology. May 1993;187(2):459-63. [Medline].
Eckerwall G, Hochbergs P, Wingstrand H, Egund N. Sonography and intracapsular pressure in Perthes'' disease. 39 children examined 2-36 months after onset. Acta Orthop Scand. Dec 1994;65(6):575-80. [Medline].
Eggl H, Drekonja T, Kaiser B, Dorn U. Ultrasonography in the diagnosis of transient synovitis of the hip and Legg-Calve-Perthes disease. J Pediatr Orthop B. Jul 1999;8(3):177-80. [Medline].
Naumann T, Kollmannsberger A, Fischer M, et al. Ultrasonographic evaluation of Legg-Calve-Perthes disease based on sonoanatomic criteria and the application of new measuring techniques. Eur J Radiol. Sep 1992;15(2):101-6. [Medline].
Wirth T, LeQuesne GW, Paterson DC. Ultrasonography in Legg-Calve-Perthes disease. Pediatr Radiol. 1992;22(7):498-504. [Medline].
Jaramillo D, Galen TA, Winalski CS. Legg-Calve-Perthes disease: MR imaging evaluation during manual positioning of the hip--comparison with conventional arthrography. Radiology. Aug 1999;212(2):519-25. [Medline].
Sebag G, Ducou Le Pointe H, Klein I. Dynamic gadolinium-enhanced subtraction MR imaging--a simple technique for the early diagnosis of Legg-Calve-Perthes disease: preliminary results. Pediatr Radiol. Mar 1997;27(3):216-20. [Medline].
Hosokawa M, Kim WC, Kubo T, et al. Preliminary report on usefulness of magnetic resonance imaging for outcome prediction in early-stage Legg-Calve-Perthes disease. J Pediatr Orthop B. Jul 1999;8(3):161-4. [Medline].
Song HR, Dhar S, Na JB, et al. Classification of metaphyseal change with magnetic resonance imaging in Legg-Calve-Perthes disease. J Pediatr Orthop. Sep-Oct 2000;20(5):557-61. [Medline].
de Sanctis N, Rega AN, Rondinella F. Prognostic evaluation of Legg-Calve-Perthes disease by MRI. Part I: the role of physeal involvement. J Pediatr Orthop. Jul-Aug 2000;20(4):455-62. [Medline].
de Sanctis N, Rondinella F. Prognostic evaluation of Legg-Calve-Perthes disease by MRI. Part II: pathomorphogenesis and new classification. J Pediatr Orthop. Jul-Aug 2000;20(4):463-70. [Medline].
Doria AS, Cunha FG, Modena M, Maciel R, Molnar LJ, Luzo C, et al. Legg-Calvé-Perthes disease: multipositional power Doppler sonography of the proximal femoral vascularity. Pediatr Radiol. Apr 2008;38(4):392-402. [Medline].
Stücker MH, Buthmann J, Meiss AL. Evaluation of hip containment in legg-calvé-perthes disease: a comparison of ultrasound and magnetic resonance imaging. Ultraschall Med. Oct 2005;26(5):406-10. [Medline].
Sinigaglia R, Bundy A, Okoro T, Gigante C, Turra S. Is conservative treatment really effective for Legg-Calvé-Perthes disease? A critical review of the literature. Chir Narzadow Ruchu Ortop Pol. Nov-Dec 2007;72(6):439-43. [Medline].
Glueck CJ, Tracy T, Wang P. Legg-Calve-Perthes disease, venous and arterial thrombi, and the factor V Leiden mutation in a four-generation kindred. J Pediatr Orthop. Oct-Nov 2007;27(7):834-7. [Medline].
Hubbard AM, Dormans JP. Evaluation of developmental dysplasia, Perthes disease, and neuromuscular dysplasia of the hip in children before and after surgery: an imaging update. AJR Am J Roentgenol. May 1995;164(5):1067-73. [Medline].
Jaramillo D, Kasser JR, Villegas-Medina OL. Cartilaginous abnormalities and growth disturbances in Legg-Calve- Perthes disease: evaluation with MR imaging. Radiology. Dec 1995;197(3):767-73. [Medline].
Joo SY, Lee KS, Koh IH, Park HW, Kim HW. Trochanteric advancement in patients with Legg-Calvé-Perthes disease does not improve pain or limp. Clin Orthop Relat Res. Apr 2008;466(4):927-34. [Medline].
Further Reading
Keywords
Legg-Calvé-Perthes, Legg-Perthes disease, Perthes disease, idiopathic avascular necrosis of the proximal femoral epiphysis, pediatric hip disorder, childhood hip disorder, epiphyseal bone infarction, femoral head infarction, Chandler disease, LPD, LCP
