Legg-Calve-Perthes
Disease
FIRM 1 GRANDROUND
PRESENTERS: DR. MAINA/DR. ONDARI
FACILITATOR: DR. T. MOGIRE
01/08/2013
Georg Perthes (1869-1927)
First described by
Karel Maydl
Epidemiology


Incidence 1-4/10,000
Age 4 - 10years; average 7 yrs
 As early as 2yrs as late as teens

Boys : girls 4:1

Bilateral 10-12%

No evidence of inheritance

Common in Caucasians; rare in black races
Etiology



Idiopathic
Past theories
Infection, inflammation, trauma,
congenital
Most theories involve vascular
compromise
Pathophysiology




Rapid growth occurs in relation to devt of blood
supply
Interruption of blood supply results in necrosis,
removal of necrotic tissue, and its replacement with
new bone.
Bone replacement may be so complete and perfect
that completely normal bone may result
The adequacy of bone replacement depends on
Age of the patient
 Congruity of the involved joint

Sources of blood supply



Up to 4years
 Metaphyseal vessels
 Retinacular vessels
 Ligamentum teres – scanty
4 to 7 years
 Metaphyseal vessels ceases
Above 7years
 Vessels in ligamentum teres have developed
Pathology




Goes through stages which may last 3 to 4 years
Stage1
 Ischaemia and bone death, cartilage thickens
Stage 2
 Revascularization and repair
 Dead marrow replaced by granulation tissue
 Bone revascularized and new bone laid down
 Dead bone resorbed, replaced by fibrous tissue, fragmentation
Stage 3
 Distortion and remodelling
 Restoration of femoral archtecture or collapse
 Femoral head displaces laterally in relation to acetabulum
Classification

Waldenstrom classification

Catterall classification

Salter and thompson classification

Herring classification
Caterall classification


Based on amt of involvement of femoral
epiphysis
Group I
 <1/2

Group II
 Up

of head involved ,
to half of head. Some collapse of central portion
Group III
 >1/2
of head involved with sclerosis, fragmentation
and collapse of head

Group IV
 Entire
epiphysis involved
Caterall “head-at-risk” signs

Associated with poor results

lateral subluxation (most important)
calcification
Gage's
lateral to the epiphysis
sign: V shaped defect laterally

metaphyseal cysts

horizontal growth plate
Caterall “head-at-risk” signs
metaphyseal cysts
Gage's sign
Salter and thompson classification





Describes extent of subchondal fracture in the
superolateral portion of femoral head
Type A - <50% of femoral head
Type B - >50% of femoral head
can be observed radiographically earlier and more
readily tan caterall classification
Can be applied early in course of dz to determine
management
Herring classificatin/lateral pillar
Based on degree of collapse of lateral pillar during fragmentation
stage


Goup A
 No collapse, no progressive flattening
Group B
 <50% collapse
Group C
 >50% collapse
Ritterbusch 1993
 Has the highest predictive value and interobserver reliability

Bilateral involvement

More severe dz than unilateral

Boys and girls equally affected

Independent event

Bone age delayed in perthes disease
Examination

Short stature
 Delayed

bone age
Early
 Decreased
ROM
 Antalgic gait

Late
 Decreased
ROM of motion from acetabular impingement
 Disuse atrophy of thigh muscles
 Leg lenght descrepancy
 Trendelenburg gait
Investigations




Blood tests
 haemogram, ESR, CRP
Imaging
 Plain X-rays
 Hip U/S
 Bone scintigrpahy
 MRI
Dynamic arthrography
 Assess spherity of femoral head
 Hinge abduction
Bilateral perthes
 Skeleta survey as part of work-up
Song et al MRI findings on widened
medial joint space



Initial stage
Overgrowth of cartilage
Fragmentation stage
Overgrown cartilage with widened
true medial joint space
Healing stage
Widened true medial joint space
Treatment

Goals of tratment
Maintain femoral head spherity –
containment
Avoid

severe degenerative arthritis
Guided by
Age
Severity
Limitation in ROM
Treatment cont.

Initial Mx determined by sympts severity

Analgesia

Modification of activities

Bedrest and short period of traction

Wheelchair/crutch walking discouraged

Preserve abduction

Determine bone age
Treatment: Two main choices

Conservative
 Pain
control
 Gentle exercises
 Regular re-assessment
 Avoid sport and strenous activities

Containment
 Hold
hips widely abducted in cast/brace >1yr
 Operation
 Varus
osteotomy of femur
 Innominate osteotomy of pelvis
 Both
Herring Guidelines to treatment

Children <6years


Symptomatic treatment
Children >6years; bone age more imp than chronological age

Bone age at or <6yrs

Lateral pillar A or B/ caterall I and II



Lateral pillar C/ Caterall III and IV
Bone over 6years

Herring A and B/Caterall I and II


Abduction brace or osteotomy
Herring C/Caterall III and IV


Symptomatic treatment
Outcome unaffected by treatment
Children 9yrs and older

Except in very mild cases, operative containment is the treatment of
choice
oseoclast-osteoblat interaction
Prognostic features

Age




Gender




Herrings lateral pillar classification
Salter and thompson grade B worse prognosis
Caterral classification grade
Caterral “head-at-risk” signs


Girls have worse prognosis
Classification grade


<6yrs; good regardless of treatment
6-9years; not always satisfactory with containment
>10yrs; questionable benefit from containment, poor prognosis
The five signs carry worse prognosis
Others

Body weight, decreased ROM