Contents

Introduction

Perthes disease (Legg-Calvé-Perthes disease) is an idiopathic osteonecrosis/avascular necrosis of capital femoral epiphysis of the femoral head.

Type of aseptic osteochondroses of childhood
♂:♀::4:1, typically in 3-7 years

History

The disease was described nearly simultaneously in the year 1910 by G. C. Perthes in Germany, A. T. Legg in the United States, and J. Calvé in France.

Aetiology

Clinical risk factors for a poor outcome:

Later age of onset
Overweight
Severe limitation of the range of motion
Female sex

Pathophysiology

Avascular necrosis of the epiphysis
↓
Impairs enchondral ossification of femoral head

Stages of Legg-Calves-Perthes (Waldenström):

Initial stage:
- Infarction produces a smaller, sclerotic epiphysis with medial joint space widening
Fragmentation stage:
- Result of revascularization process with bone resorption producing collapse with subsequent patchy density and lucencies
- Radiological findings:
  - Begins with presence of subchondral lucent line (crescent sign)
  - Femoral head appears to fragment/dissolve
- Lateral pillar classification based on this stage
Reconstitution stage:
- Ossific nucleus undergoes reossification with new bone appearing as necrotic bone is resorbed
Healed stage:
- Femoral head remodels until skeletal maturity

ijortho-49-10-g001 — The stages of evolution of Perthes’ disease. The early part of the disease is from the onset till Stage IIa (early fragmentation stage). The late part of the disease is from Stage IIb to Stage IIIb. Intervention aimed at preventing femoral head deformation is only feasible during the early part of the disease | Joseph, B. (2015). Management of Perthes’ disease. Indian Journal of Orthopaedics, 49(1), 10–16. https://doi.org/10.4103/0019-5413.143906

Clinical features

Hip/groin pain
- Present during physical activity
- Radiates to thigh & knee (25% cases)
- Bilateral (asymmetrical, asynchronous involvement) (10-15% cases)
Limping gait
Different length of legs (due to adduction contracture or collapsed epiphysis)

Diagnosis

Imaging

X-ray:

Pelvic survey film and lateral hip x-ray:
- Establish diagnosis
- Enable classification, prognostic assessment, and follow-up of the course of the disease

11832_2015_671_fig1_html — AP and frog lateral radiographs prototypical of the presentation of female Perthes disease, with femoral head fragmentation and loss of height of the lateral pillar | Georgiadis, A. G., Seeley, M. A., Yellin, J. L., & Sankar, W. N. (2015). The presentation of Legg-Calvé-Perthes disease in females. Journal of Children’s Orthopaedics, 9(4), 243–247. https://doi.org/10.1007/s11832-015-0671-y

Head-at-risk signs (1971, Catterall):
- Gage sign (V-shaped radiolucency in the lateral portion of the epiphysis and/or adjacent metaphysis
- Lateral epiphyseal calcification
- Lateral subluxation of the femoral head
- Horizontal proximal femoral physis
- Metaphyseal cyst (added later to the original 4 at-risk signs described by Catterall)

dtsch_arztebl_int-106-0517_002 — Involvement of the entire epiphysis, with the height of the lateral pillar less than half normal (Herring type C, Catterall type IV). In addition, note lateralization (arrow) and metaphyseal cysts, both of which are “head-at-risk” signs. | Nelitz, M., Lippacher, S., Krauspe, R., & Reichel, H. (2009). Perthes disease: current principles of diagnosis and treatment. Deutsches Arzteblatt International, 106(31–32), 517–523. https://doi.org/10.3238/arztebl.2009.0517

Ultrasonography (USG):

Supplementary technique to diagnose changes of the femoral head and, in particular, any accompanying synovitis or effusion

Magnetic resonance imaging (MRI):

Identifying the early stage of Perthes disease in the absence of changes on plain films, as well as in cases where the differential diagnosis would otherwise be difficult.
Dynamic MRI (eg. arthrography): Diagnosing any accompanying “hinge abduction” (lateral side of the femoral head contacts the acetabular margin) during preoperative planning

Prognostic classification

dtsch_arztebl_int-106-0517_001 — Herring’s “lateral pillar” classification, depending on the height of the lateral pillar (necrotic area marked in red) | Nelitz, M., Lippacher, S., Krauspe, R., & Reichel, H. (2009). Perthes disease: current principles of diagnosis and treatment. Deutsches Arzteblatt International, 106(31–32), 517–523. https://doi.org/10.3238/arztebl.2009.0517

Lateral Pillar (Herring) Classification
Group A	Lateral pillar maintains full height with no density changes identified
Group B	Lateral pillar >50% height
B/C Border	Lateral pillar narrowed (2-3mm) or poorly ossified with approximately 50% height
Group C	Lateral pillar <50%

Differential diagnosis

Coxitis fugax
Juvenile idiopathic arthritis (JIA)
Osteomyelitis
Meyer’s dysplasia
- Absence of clinical symptoms and of the staged radiological progression that typifies Perthes disease
Epiphyseal dysplasia
Spondyloepiphyseal dysplasia
Chondroblastoma
So-called “Perthes” due to hip dysplasia
Cortisone-induced necrosis of the femoral head

Management

dtsch_arztebl_int-106-0517_003 — Treatment algorithm for Perthes disease, depending on the patient’s age and risk factors | Nelitz, M., Lippacher, S., Krauspe, R., & Reichel, H. (2009). Perthes disease: current principles of diagnosis and treatment. Deutsches Arzteblatt International, 106(31–32), 517–523. https://doi.org/10.3238/arztebl.2009.0517

Goals of treatment:

Improved mobility
Reduction of mechanical stress
Preservation of joint congruence (containment)