Legg Calve Perthes DiseaseJoseph Donnelly, M.D.December 10, 2001
Overview
History Epidemiology/ Etiology Pathogenesis
– Radiographic stages
Presentation/ Exam Imaging Treatment
History
Late 19th century: “hip infections” that resolved without surgery
First described in 1910 Early path studies: cartilaginous islands in
the epiphysis
Epidemiology
Disorder of the hip in young children Usually ages 4-8yo As early as 2yo, as late as teens Boys:Girls= 4-5:1 Bilateral 10-12% No evidence of inheritance
Etiology
Unknown Past theories: infection, inflammation,
trauma, congenital Most current theories involve vascular
compromise– Sanches 1973: “second infarction theory”
Etiology: blood supply
Pathogenesis
Histologic changes described by 1913 Secondary ossification center= covered by
cartilage of 3 zones:– Superficial– Epiphyseal– Thin cartilage zone
Capillaries penetrate thin zone from below
Pathogenesis: cartilage zones
Pathogenesis
Epiphyseal cartilage in LCP disease:– Superficial zone is normal but thickened– Middle zone has 1)areas of extreme
hypercellularity in clusters and 2)areas of loose fibrocartilaginous matrix
Superficial and middle layers nourished by synovial fluid
Deep layer relies on blood supply
Pathogenesis
Physeal plate: cleft formation, amorphis debris, blood extravasation
Metaphyseal region: normal bone separated by cartilaginous matrix
Epiphyseal changes can be seen also in greater trochanter, acetabulum
Radiographic Stages
Four Waldenstrom stages:– 1) Initial stage– 2) Fragmentation stage– 3) Reossification stage– 4) Healed stage
Initial Stage
Early radiographic signs:– Failure of femoral ossific nucleus to grow– Widening of medial joint space– “Crescent sign”– Irregular physeal plate– Blurry/ radiolucent metaphysis
Initial Stage
Initial Stage
Fragmentation Stage
Bony epiphysis begins to fragment Areas of increased lucency and density Evidence of repair aspects of disease
Fragmentation Stage
Fragmentation Stage
Reossification Stage
Normal bone density returns Alterations in shape of femoral head and
neck evident
Reossification Stage
Reossification Stage
Healed Stage
Left with residual deformity from disease and repair process
Differs from AVN following Fx or dislocation
Presentation
Often insidious onset of a limp C/O pain in groin, thigh, knee 17% relate trauma hx Can have an acute onset
Physical Exam
Decreased ROM, especially abduction and internal rotation
Trendelenburg test often positive Adductor contracture Muscular atrophy of thigh/buttock/calf Limb length discrepency
Imaging
AP pelvis Frog leg lateral Key= view films
sequentially over course of dz
Arthrography MRI role undefined
Differential Diagnosis
Important to rule out infectious etiology (septic arthritis, toxic synovitis)
Others:– Chondrolysis -Neoplasm– JRA -Sickle Cell– Osteomyelitis -Traumatic AVN– Lymphoma -Medication
Radiographic Classifications
Describe extent of epiphyseal disease Catterall classification= most commonly
used– 4 groups based on amount of femoral head
involvement– Also presence of sequestrum, metaphyseal rxn,
subchondral fx
Group I
Group II
Group III
Group IV
Lateral Pillar Classification
3 groups:– A) no lateral pillar
involvment
– B) >50% lat height intact
– C) <50% lat height intact
Salter-Thompson Classification
Simplification of Catterall Based on status of lateral margin of capital
femoral epiphysis Group A (Catterall I & II equivalent) Group B (Catterall III & IV equivalent)
Prognosis
60% of kids do well without tx AGE is key prognostic factor:
– <6yo= good outcome regardless of tx– 6-8yo= not always good results with just
containment– >9yo= containment option is questionable,
poorer prognosis, significant residual defect
Prognosis
Flat femoral head incongruent with acetabulum= worst prognosis
Do not treat in reossification stage (>15mos)
Non-operative Tx
Improve ROM 1st
Bracing:– Removable abduction orthosis– Pietrie casts– Hips abducted and internally rotated
Wean from brace when improved x-ray healing signs
Bracing
Non-operative Tx
Check serial radiographs – Q3-4 mos with ROM testing
Continue bracing until:– Lateral column ossifies– Sclerotic areas in epiphysis gone
Cast/brace uninvolved side
Operative Tx
If non-op tx cannot maintain containment Surgically ideal pt:
– 6-9yo– Catterral II-III– Good ROM– <12mos sx– In collapsing phase
Surgical Tx
Surgical options:– Excise lat extruding head portion to stop
hinging abduction– Acetabular (innominate) osteotomy to cover
head– Varus femoral osteotomy– Arthrodesis
Varus Osteotomy
Late Effects of LCP
Coxa magna Physeal arrest patterns Irregular head formation Osteochondritis dessicans
The End
