Legg Calve Perthes Disease - Doctors.am

Legg Calve Perthes Disease Joseph 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 JRA Osteomyelitis Lymphoma

-Neoplasm -Sickle Cell -Traumatic AVN -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