부산대학교병원정형외과 김휘택 - kpos.or.kr · Signs Clinical manifestation. ①Older...
Transcript of 부산대학교병원정형외과 김휘택 - kpos.or.kr · Signs Clinical manifestation. ①Older...
Introduction
• Legg-Calvé-Perthes disease is a syndrome.
(avascular event affects the capital femoral epiphysis)
• The etiology of the disease still is not understood.
• Efficacy of treatment remains a subject of controversy.
Etiology① Disruption of the blood supply to the proximal femur
② Coagulation abnormalities
③ Abnormal growth & development: “predisposed child”
④ Trauma
⑤ Hyperactivity or attention deficit disorder
⑥ Hereditary influences (genetic component)
⑦ Environmental influences
⑧ Synovitis
1. Disruption of the blood supply
Etiology
Μedial circumflex femoral artery
Lateral ascendingcervical artery
• Narrow passage betweenthe trochanter and capsule(<8 years old): prone to injury
• Double (and perhaps more)infarction
2. Coagulation abnormalities
• Thrombophilia→ abnormal thrombotic venous occlusion
• Deficiencies in protein C and S, hypofibrinolysis, and resistance to activated protein C
• Mutation in the factor V gene(factor V Leiden)
Etiology
3. Abnormal growth and development: the “predisposed child”
• Low birth weight, delayed skeletal maturation, shorter than normal → followed by a “catch-up” phase
• Abnormalities of thyroid hormone and insulin-like growth factors
Etiology
4. Environmental influences
• High occurrence in particular urban area and the lower socioeconomic groups
Etiology
“Unifying“ hypothesis
Hyperactivechild
Minor traumaTendency to form clots
Abnormality of the clot-lysing system
Clotting in the venous systemVenous pressure
rises in the femoral neck
Clotting propagates intothe femoral head
Infarction occurs
Etiology
Epidemiology
• Onset: common in 4-8 years (2-12 years) • Boys : girls = 4 or 5 : 1• Bilateral involvement: 10%-12% of patients• More common in whites, Asians, and Central
Europeans(unusual in blacks and native Americans)
Symptoms
①Painless limping - the most common (usually first noticed by a parent)
②Pain - 2nd most frequent symptoms (groin, anterior thigh, or knee)
Clinical manifestation
• Atrophy of the gluteus, quadriceps & hamstring m.• Apparent lower extremity length inequality ① Adduction contracture② True shortening on the involved side
because of CFE collapse
Signs
Clinical manifestation
① Older child② Obesity③ Female sex④ Marked restriction of motion
Clinical at-risk factors
Clinical manifestation
Natural history
• No definite natural history studies exist of persons who were completely untreated.
①Disease severity②Patient’s age at onset of disease③Duration of disease
1. Disease severity
• Considerably variable• Moderate symptoms for 12 to 18 months• The poorest results: the greatest degree of involvement• A number of classification systems: to estimate
severity of disease.
Natural history
2. Patient’s age at onset of disease
• The most consistent factor affecting course of disease
• < 6 years - mild disease6-9 years - moderate symptoms> 9 years or later - the most severe course and
worst outcome
Natural history
3. Duration of disease
• Outcome is also affected by duration of disease• The shorter the duration, the better the final results
Natural history
Imaging studies
① Diagnose ② Stage ③ Provide prognosis ④ Follow the course of the disease ⑤ Assess results
1. Radiography: (primary tool )
Modified Waldenström classification:(radiographic staging of disease evolution)
① Initial stage② Fragmentation stage③ Reossification (healing) stage④ Residual stage
Image studies – x-ray
• Lateralization of the femoral head
• Widening of the medialjoint space (synovitis &hypertrophy of articularcartilage)
• Smaller ossific nucleus (cessation of growth of the capital epiphysis)
• Metaphyseal lucencies
• Increased density of the femoral head (accumulation of new bone on the dead bone trabeculae in the head
4. Residual stage
Gradual remodeling of head shape:①until skeletal maturity②acetabulum also remodels
Other radiographic findings
Metaphyseal cyst or lucency • Poor prognostic value→ physeal cartilage
extending into themetaphysis
→ true cyst within theepiphysis or physis,metaphysis
Image studies – x-ray
“Sagging rope” sign• Radiodense line
overlying the proximal femoral metaphysis
• Anterolateral-inferior protruded portion of the femoral head
Image studies – x-ray
• Lateral extrusion of the capital nucleus- mushroom head
• Premature physealclosure with greater trochanteric overgrowth
Changes in the physis
Image studies – x-ray
MRI• Early Dx.• Configuration of the
femoral head and acetabulum
• Revascularization
• Hinge abduction• Its use as a prognostic
tool is not proven.
Image studies
Hinge abduction
Scintigraphy• Tc 99m bone scan• Transient photopenia:
false diagnosis • Periodic bone scans:
useful for prognosis & to follow the course of the disease
Image studies
Arthrography• Assess the congruity of the
hip in many different positions
• Most often used in the early diagnosis of hinge abduction
Image studies
Ultrasonography
• Not widely used
• Demonstrate effusion (synovitis) in early stages
• Assess the shape of the femoral head in later stage
Image studies
Computed tomography• Not typically used
• Demonstrate 3D images of the shape of the femoral head and acetabulum
Image studies
Pathogenesis of deformity
①Growth disturbance in the CFE and physis②Related to the disease process③Repair process itself④ Iatrogenic
1. Growth disturbance in the CFE and physis
Patho. - deformity
Growth plate closure
Hinge abduction• Central arrest→ short neck (coxa breva)
with trochanteric overgrowth• Lateral arrest→ tilts the head externally and
into valgus with trochantericovergrowth
2. Related to the disease process
• Superficial layers of articular cartilage:“overgrow” as they are nourished by the synovial fluid
• Deeper layers - devitalized by the disease process
→ collapse (epiphyseal trabecula) and deformity
Patho. - deformity
3. Repair process itself
• The applied stresses on the femoral head
• Molding action of the acetabulum on the femoral
head
• Deformed femoral head may deform the acetabulum
Patho. - deformity
4. Iatrogenic
• Caused by trying to contain a non-containable femoral head (either non-surgically or surgically)
Patho. - deformity
Classification systems(Based on severity of disease)
①Catterall classification
②Salter-Thompson classification
③Lateral pillar classification
Group I Group II
Group III Group IV
No metaphysela reactionNo sequestrumNo subchondral fracture line
Sequestrum present – junction clearMetaphyseal reaction – antero/lateralSubchondral fracture line – anterior half
Sequestrum – large – junction scleroticMetaphyseal reaction – diffuse antero/lateralSubchondral fracture line – posterior half
Whole head involvementMetaphyseal reaction – central or diffusePosterior remodelling
Catterall classification
Catterall classification• Amount of CFE involvement / during the fragmentation stage
Classification
Central or diffuse
Diffuse anterolateral
AnterolateralNoMetaphysealreaction
Post. marginPost. 1/2Ant. 1/2NoSubchondralFx. Line
Whole headLargePresentNoSequestrum
EntireUp to 75%Up to 50%Ant. 25%CFE involvement
Group IVGroup IIIGroup IIGroup I
• Disadvantage
- High degree of interobserver variability- Not applicable as a therapeutic guide for average of
8 months after onset
Classification
Catterall classification
Salter-Thompson classification
• Based on the extent of the subchondral fracture (initial)
• Group A - less than 50% of the femoral head (good Px)Group B - more than 50% of the femoral head (poor Px)
Classification
Salter-Thompson classification
• Advantage - good interobserver reliabilitycan be applied early in the course of disease
• Disadvantage - not all patients are diagnosed early duringthe phase of the subchondral fracture
Classification
Lateral pillar classification
Classification
• Based on the height of the lateral pillaron an AP view (early fragmentation stage)
• Intact lateral pillar- acts as a weight bearing support to protect the central avascular segment
height maintainednarrow pillar little ossification
Pillar B/C border50% heightno collapse of central part
50% heightminimal density of lat. pillar
Lateral pillar classification
Classification
A loss of more than 50% of the original height of the lateral pillar (the worst outcome)
a) a very narrow pillar (2-3 mm wide) that is >50% of the original height
b) a lateral pillar with very little ossification but with at least50% of the original height
c) a lateral pillar with exactly 50% of the original height thatis depressed relative to the central pillar
Lateral pillar maintains at least 50% of its height (intermediate outcome)
No involvement of the lateral pillar (the best outcome)Group A
Group B
Group C
Group B/Cborder (new)
Radiographic result
• Very limited and not cover the myriad possible outcomes
• Fitting contour of the healed femoral head on the AP & lateral radiographs to a template of concentric circles.
• Good outcome – 1mm ↓Fair outcome – 2mm ↓Poor outcome – 2mm ↑
Mose classification
• Draw best fit circle with center on the center perpendicular line
Circle method
Radiographic result
• The lateral film-does the same circle fit?Stulberg III : greater than 2mm from circle fit
>2mm
No
Radiographic result
Stulberg classification
A femoral head with collapse, usually central, within a round acetabulumGroup V
A femoral head with at least 1 cm of flattening of the weight-bearing area on one or both viewsGroup IV
An ovoid femoral head that dose not fit within 2mm of the circle on one or both viewsGroup III
A round femoral head that fits within 2mm of the same circle on both the AP and the forg-leg lateral radiographsGroup II
A femoral head that cannot be distinguished from normalGroup I
• Based on residual femoral head shape
Radiographic result
Stulberg classification
• Group I and II - good long-term prognosisGroup III and IV - mild to moderate degenerative
changes in late adulthoodGroup V - painful arthritis in early adulthood
Radiographic result
Effective in predicting subsequent arthritic changes
Prognostic risk factors
1) Gage’s sign: a radiolucent V-shaped defect in thelateral epiphysis and metaphysis
2) Calcification lateral to the epiphysis3) Diffuse metaphyseal reaction4) Lateral subluxation of the femoral head5) Horizontal physis
1. Radiographic head-at-risk signs (Catterall)
- Catterall groups III and IV- Salter-Thompson group B- Lateral pillar group C- Lateral pillar group B (> 8 years old)
2. Hips at risk for a poor prognosis
Long-term prognosis① Age at onset: (young/old) ② Degree of involvement: (small/large)③ Duration of disease: (short/long)④ Congruency of the hip joint:
i) the most important predictorii) Careful containment of the head is important
Differential diagnosis
HemophiliaMultiple epiphyseal dysplasia
Eosinophilic granulomaLymphoma
Spondyloepiphyseal dysplasia
Infectious (inflammatory) DsGauchers disease
HypothyroidismUnilateral changesBilateral changes