perthes disease

Legg – Calve – Perthes Disease

Dr. Ahmed Azim2nd year resident

TUTH

• Disease of children caused by idiopathic ischemic necrosis of femoral capital epiphysis which may vary in degree and severity

• Following avascular necrosis reossification always occurs

• Leads to permanent femoral head deformity and premature osteoarthritis

Legg – Calve - Perthes

Arthur T. Legg1874-1939

Jacques Calve1875-1954

Georg C. Perthes1869-1927

Henning Waldenstrom

Even after 100 years

•Perthes disease remains an enigma shrouded in controversy

Good news!!• Half the patients will recover and have little disability over their lifetime

• The other half will function well with occasional discomfort through most of their adulthood and in their 5th or 6th decade of life require hip replacement

• Only the most severely involved patients will have early hip disability

Herring JA 1996; Weinstein SL, 1985

Applied anatomy• Blood supply of head• Upto age 4 mo1. Metaphyseal vessels penetrate physis2. Lateral epiphyseal retinacular vessels3. Scanty vessels in ligamentum teres

• Metaphyseal supply gradually decrease (disappears by 4 yrs)• Vessels of ligamentum teres

developed by 7 yrs• 4 yrs – 7yrs blood supply depend

entirely on lateral epiphyseal vessels

Epidemiology• Incidence: 1 : 10,000• Usual Age: 4 – 10 yrs• Male:Female = 4:1• Billateral in 10-15%• May be part of general growth disorder• Higher incidence in underprivileged (UK epidemiologic study)

Etiology• Exact cause unknown• Affected children: small & delayed maturationVarious theories proposed• Trauma• An inflammatory process• Vascular occlusion• Thrombophilia• Insulin-like growth factor-1 pathway abnormality• Maternal smoking & second-hand smoke exposure• Type-II collagen mutation

EtiologyPrevailing Opinion Is That Legg-calvé-perthes

Disease Is A Multifactorial Disease With Genetic And Environmental Factors Playing A Role

EtiologyAssociated features• Low birth weight• Breech delivery• Short stature• Irritable hip• Disproportionate growth• ADHD• Older parents• Parents often relate to a trauma• Genetic predisposition• Coagulation disorders

Pathology• Disruption of blood supply to the femoral head, is one of the key

pathogenic event1. Microtrauma to retinacular vessels2. Increased synovial pressure

eg: Transient synovitis

3. Venous HTN 2⁰ to thrombotic occlusion

• Single ischemic episode vs. multiple ischemic events

Pathogenesis & pathology• Repeated bouts of ischaemia & infarction of femoral head →

pathologic fractures• Retinacula vessels susceptible to stretching & pressure from effusion• Increased pressure cause venous stasis• Increase in intraosseous pressure• Ischaemia & infarction leading to necrosis

Pathogenesis of femoral head deformity• Pathogenesis of the femoral head deformity following ischemic necrosis is

complex• Multiple factors contribute to the development of the deformity1. Mechanical properties of the articular cartilage and the bone are

decreased• Necrosis of the deep layer of the articular cartilage• Inability of the necrotic bone to repair microdamage• Increase in the calcium content of the calcified cartilage and the

subchondral bone making it brittle• When mechanical loading > strength of bone = subchondral fractures &

collapse

Pathogenesis of femoral head deformity2. Pathological repair process• Predominance of osteoclastic resorption• Delayed bone formation• replacement of the necrotic bone by a fibrovascular granulation tissue

3. Growth arrest of the spherical growth plate• Restoration of growth in asymmetrical manner

Pathogenesis & pathology

A flowchart depicting the pathogenesis of the femoral head deformity in Legg-Calvé-Perthes disease.

Harry K.W. Kim J Bone Joint Surg Am 2012;94:659-669

Clinical features• Typically a boy of 4-8 years who has high physical activity• Smaller than his counterparts

• C/O pain & limping• Maybe painless limp• Pain may radiate to knee• Aggravated by strenuous activity & relieved by rest

• Continuous for weeks or intermittent• Urogenital anomaly in 4%

Clinical features• Leg length discrepancy • Mild muscle wasting• ROM• Early: joint irritable, decreased ROM & painful in extremes• Later: Movements full except abduction & IR• Maybe flexion / adduction contracture

• Gait: Antaalgic or Trendelenburg / Abductor gait• Trendelenburg test: +ve

Diagnosis• Based on clinical features & Radiology• Investigations:• Routine blood investigation• X-ray• Initially normal• Subtle changes: widening of joint space,

asymmetry of ossific centres• Necrotic phase: Increased density of ossific nucleus• Fragmentation phase: Alternating patches of

density & lucency• Crescent sign (best seen on lateral view)

• Re-ossification phase: Increased epiphyseal density

Diagnosis• MRI:• Evidence of marrow necrosis• Irregularity of the femoral head,• Loss of the signal on the affected

side

Diagnosis•Bone scan:• reduced uptake early in the disease

•Ultrasound• Joint effusion

•Arthrography: To see congruity, head deformity

Classification: WaldenstromStage 1: Initial

phase

• All or part of nucleus dead. Maybe normal X-ray. Increased density of epiphysis,

• Cartilage thickening, subtle lateral subluxation via increased medial cartilage growth (Waldenstrom’s sign)

• Subcondral # (Crescent sign)• Duration: 6 months

Stage 2: Fragmentation

phase

• Areas of lucency and sclerosis• Central area separates from lateral & medial areas• Maximal flattening/collapse• Duration: 8 months

Stage 3: Reossification

phase

• New subchondral bone formation• Flattening may improve• Duration: 3-5 years

Stage 4: Residual phase

• No change in bone density• Shape of head changes • Final shape after skeletal maturity• Acetabular remodelling

Classification: Modified Waldenstrom

Classification• Catterall classification (1982)• Group I: Normal height of epiphysis & <50%of head

involved

• Group II: ½ of neucleus sclerotic & collapse of central portion

• Group III: Most of the neucleus involved, fragmentation & collapse. Metaphyseal resorption maybe present

• Group IV: Whole head, Ossific neucleus is flat & dense, marked metaphyseal resorption

Classification• Catterall classification (1982)• Head at risk signs:1. Lateral subluxation 2. Speckled calcification lateral to the

capital epiphysis3. Diffuse metaphyseal reaction

(metaphyseal cysts)4. A horizontal physis5. The gage sign, a radiolucent v-shaped

defect in the lateral epiphysis and adjacent metaphysis

Classification• Herring classification• Greater predictive

value of outcome• Based on height of

lateral pillar

Classification• Herring classification• LCPD study group Herring, Kim & Browne JBJS 2004;86:2121-2134

• 28 institutions: uniform method of treatment

• 345 hips all over age of 6

• Followed till maturity

Classification• Herring classification• LCPD study group Herring, Kim & Browne JBJS 2004;86:2121-2134

• Herring A: All do well without any treatment

• Herring B: Bone age <8 : Uniform outcome irrespective treatment• Herring B: Bone age>8: Surgery (Femoral/Salter) > Brace > No treatment

• Herring C: Bone age<8: Surgery (Femoral/Salter) > Brace > No treatment• Herring C: Bone age>8: Poor outcome irrespective of treatment

Classification• Salter-Thompson Classification

• Group A: Subchondral # involving <50 % of head

• Group B: Subchondral # involving >50 % of head

• Applicable before fragmentation

Classification: Stulberg criteria for prognosis

Class

Description Features Prognosis

I Spherical congruency Normal hip joint GoodII Spherical congruency;

Less than 2mm loss of head shape

Spherical femoral head with 1 more of:• Coxa magna• Coxa breva• Steep acetabulum

Good

III Aspherical congruency;Greater than 2mm loss of head shape

Ovoid, mushroom-shaped with 1 or more of• Coxa magna• Coxa breva• Steep acetabulum

Mild-moderate arthritis

IV Aspherical congruency Flat femoral head, abnormal neck and acetabulum

Mild-moderate arthritis

V Aspherical incongruency

Flat femoral head with normal shaped neck & acetabulum

Severe arthritis

Classification: Stulberg criteria for prognosis

I

II

III

IV V

Poor Prognostic features• Age over 10 years• Female Sex• Degree of head involvement (Caterall & Thompson)• 2+ Head at risk signs• Herring C at fragmentation stage• Premature physeal closure• Restricted ROM• Increased weight

Differential diagnosis

Practice of pediatric orthopedicsLynn Stahelli

Management:

Management• Principles:

1. Restore & maintain ROM• Increases joint nutrition• Prevents subluxation• Allow abduction• Satisfactory = 30⁰ ABD

2. Avoid treatment of patients who will do well without treatment3. Concept of containment4. Relief of symptoms

Management• Objective: preserve the sphericity of the femoral head • reduce the risk of stiffness and degenerative arthritis• preserving the emotional well-being of the child.

• Determined by • Age• Extent of involvement• Stage of disease• Head at risk signs

Management: Age• The older the child the poorer the outcome

• Role of “biological plasticity”

• Extremely poor outcome in adolescents

Management: Age• Age < 5-6 years

• 50% - 70% do well without treatment• Little evidence that treatment alters outcome• Symptomatic treatment to regain ROM• Regular follow-up

• Consider containment for persistent loss of ABDUCTION

Management:• Concept of containment

• Harrison & Menon stated; “ if the head is contained within the acetabular cup, then like jelly poured into a mold the head should be the same shape as the cup when it is allowed to come out after reconstitution”

Management:• Methods of containmentNon-operative• Braces & casts

Operative• Femoral osteotomy• Innominate osteotomy• Shelf procedure• Combination of femoral &

innominate osteotomy• Tripple pelvic osteotomy

Management:Non-operative• >60% do not require surgery• Observation, activity restriction, traction

& physiotherapy• Indications:• <6 years age• Herring A

• Bracing / Casting1. Petrie cast2. Scottish Rite brace

Management• Bed rest with skin traction until the synovitis

subsides (4 to 14 days)• Children 2 to 3 years old can be observed and do

not need aggressive treatment.

Management• If significant loss of motion & lateral

subluxation:• Closed reduction + adductor tenotomy• Petrie cast

• Satisfactory clinical results can be obtained at long-term follow-up despite an unsatisfactory radiographic appearance (Cambell’s operative orthopedics)

Management: Containment Surgery• Timing of surgery: More important than the type of surgery

• Should be done before irreversible deformation of the femoral head occurs

Management• Inominate osteotomy• Advantages:• anterolateral coverage of the femoral head,• lengthening of the extremity• avoidance of a second operation for plate removal

• Disadvantages:• Inability to obtain proper containment• Increased acetabular & joint pressure• Increase leg length causing relative adduction

Management• Inominate osteotomy

Innominate osteotomy using quadrangularGraft (Canale et al)

Salter innominate osteotomy

Management• Lateral Shelf procedure

• Indicated in older children in later stages• Not candidates for femoral osteotomy• Insufficient remodeling capacity• Shortening of limb would cause persistent limp

• Recently indicated in early active stages1. Lateral acetabular growth stimulation2. Prevention of subluxation3. Shelf resolution after femoral epiphyseal

reossification

Management• Lateral Shelf procedure

Management• Varus derotational osteotomy• Advaantages

• Seats the head deeply in acetabulum• Removes vulnerable ant/lat portion from acetabular edge• Decrease joint reaction forces

• Disadvantages• excessive varus angulation (especially in an older child)• Limb shortening• Trendelenburg gait• Nonunion• Hardware removal• Premature closure of the capital femoral physis may cause

further varus deformity & trachantric overgrowth

Management

ManagementArthrodiastasis• Distraction of joint• Widens joint space• Unloading of joint• Allows fibrous repair of cartilage defects• Preserves congruency• Articulated fixator allows 50⁰ flexion

Management: Residual deformities & complications

Hinge abduction Coxa breva

Trochanteric

overgrowth

Coxa irregularis FAI Early OA

ManagementReconstructive surgeries and salvage procedures• Valgus osteotomy• Cheilectomy• Shelf procedure• Chiari osteotomy• Trochanteric advancement

ManagementNewer strategies• Anti-resorptive therapy• RANKL inhibitor – Denosumab (inhibits osteoclast formation)• Bisphosphonates (Decrease osteoclast activity)

• Bone anabolic therapy to stimulate new bone formation• Effects of BMP administration on bone formation in the

context of femoral head osteonecrosis are being investigated

• Intraosseous administration of bisphosphonates

Conclusion• A disease surrounded by various unknown factors and several controversies• Etiology remains unclear – multiple theories – common end point• Although LCPD cannot be prevented, progress has been made regarding risk stratification

and minimizing its deleterious effects on the hip primarily via operative treatment• Multiple classification systems exist – non predictive of final outcome in early stages• No common consensus on treatment plan• Age & degree of involvement most important

• <6yr : non-operative• >6yr: containment surgery if Herring B / C• 8+ yrs: poor outcome regardless of Tx, ; salavage procedures

• Current basic science research efforts and clinical studies hold out the promise of providing patients with even better long-term results in the future.

THANK YOU

• Next presentation: Slipped capital femoral epiphysis• Dr. Sirish Adhikari

References• Campbell’s Operative Orthopedics 12th ed• Practice of paediatric orthopedics 2nd ed (Lynn Stahelli)• Apley’s system of orthopedics 9th ed• Tachdjian’s pediatric orthopedics• Pathophysiology and New Strategies for the Treatment of Legg-Calvé-

Perthes DiseaseHarry K.W. Kim, MD, MS, FRCSC ; J Bone Joint Surg Am, 2012 Apr 04; 94 (7): 659 -669 .

• Legg-Calve-Perthes Disease: Where Are We 100 Years Later? Charles T. Mehlman, D.O., M.P.H., FAOAO, Professor of Pediatric Orthopaedic Surgery; Jessica Blair McCourt, M.P.A.S, PA-C, Pediatric Orthopaedic Physician’s Assistant, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio

perthes disease

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