PRESENTERS: DR. MAINA/DR. ONDARIFACILITATOR: DR. T. MOGIRE
01/08/2013
Legg-Calve-Perthes Disease
FIRM 1 GRANDROUND
Georg Perthes (1869-1927)
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 of head involved ,
Group II Up 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 lateral to the epiphysis
Gage's 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 Symptomatic treatment
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 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
<6yrs; good regardless of treatment 6-9years; not always satisfactory with
containment >10yrs; questionable benefit from containment,
poor prognosis Gender
Girls have worse prognosis Classification grade
Herrings lateral pillar classification Salter and thompson grade B worse prognosis Caterral classification grade
Caterral “head-at-risk” signs The five signs carry worse prognosis
Others Body weight, decreased ROM
