Legg Calve Perthes disease Flashcards
1
Q
What is Perthes disease?
A
- Idiopathic AVASCULAR NECROSIS Of the PROXIMAL FEMORAL EPIPHYSIS IN CHILDREN
2
Q
What is the epidemiology of perthes?
A
- 1:6000 in scotland
- 4-8 years most common
- male: female ratio 5:1
- more common in urban populations vs rural
- bilateral in 12% pts- but NEVER at the same STAGE
risk factors
- FHx
- Low birth weight
- abnormal birth presentation
- delayed skeletal maurity and activity ++ ADHD
- children exposed to second hand smoke
- asian, inuit, central european decent
3
Q
What conditions has Perthes been associated with?
A
- ADHD- 33% cases
- Dlayed bone age- 89%
4
Q
What is the percentage of bilateral cases?
A
- 12-15% but not at same stage of disease
- *** think Multiple epiphyseal dysplasia MED- skeletal survey
5
Q
Can you describe the pathology? Who described it?
A
- WALDENSTROM
- INTIATION - infarction-> smaller sclerotic epiphysis with medial joint space widening
- FRAGMENTATION- head appears to fragment- result of revascularisation and bone resorption-> collapse and increase in density- lateral pillar classification based on this stage
- REOSSIFICATION-ossific nucleus undergoes reossification as new bone appears as necrotic bone is resorbed- may last 18months
- REMODELLING/HEALING- femoral head remodels-> Coxa Magna ( larger head), coxa planar ( flattened) coxa Breva( short neck), until skeletal maturity
6
Q
Who described the lateral pillar classification? When it is determined?
A
- HERRING!!
- During the BEGINNING OF THE FRAGMENTATION STAGE by waldenstrom
- usually at 6 months after onset of symptoms
- has best interobserver agreement
- designed to give prognostic information
7
Q
What is the herring classification based on?
A
- Height of the LATERAL pillar of the CAPITAL FEMORAL EPIPHYSIS on AP IMAGING OF THE PELVIS
8
Q
Can you describe the herring/ lateral pillar classification
A
- Group A- lateral pillar full height
- Group B- maintains >50% height
- Border B/C- lateral pillar narrowed 2-3mm or poorly ossified with approx 50% height
- recently added to increase consistency and prognosis of classifciation
- Grade C- <50% height of lateral pillar maintained
9
Q
How does the grade determine prognosis ?
A
- Group A- uniform good outcome
- Group B- POOR OUTCOME w BONE AGE >6 yrs
- Group C- POOR Outcome in all patients
10
Q
What does a pt with perches present with?
A
Symptoms
- Insidious onset
- may cause PAINLESS LIMP
- INTERMITTENT knee pain, hip, groin or thigh pain
11
Q
What do you find on physical exam?
A
- Hip stiffness with loss of INTERNAL ROTATION and ABDUCTION
- TRENDELENBERG GAIT- head collapse-> decreased tension of abductors
- ANTALGIC GAIT
- LLD- LATE finding
12
Q
What are the signs on radiograph?
A
- AP and frog lateral
- MEDIAL JOINT SPACE WIDENING - EARLY
- IRREGULARITY of femoral head ossification
- CRESENT SIGN- subchondral fracture!!
13
Q
is bone scan useful?
A
- Yes
- can confirm suspected case of LCP
- decrease uptake(cold lesion) can predict changes on radiograph
14
Q
What happens in the histology?
A
- Femoral epiphysis and physis exhibit areas of disorganised cartilage with areas of hypercelluarity and fibrillation
15
Q
What is your differential dx ?
A
- Multiple epiphyseal dysplasia
- spondyloepiphyseal dysplasia
- Sickle cell disease
- Gaucher’s disease
- Hypothyroidism
- Meyers dysplasia
16
Q
what are the tx aims? why?
A
- Keep the femoral head contained
-
Maintain good motion
- containment limits deformity and minimises loss of sphericity of the femoral head
- Reduces subsequent degenerative changes
17
Q
what is tx for lateral pillar A or B age <8 ?
A
- observe alone activity restriction and protected wb
- during earlier stages until reossification is complete bracing and casting controversial - aim to keep hip mobile
- all pts require clinical and radiographic follow up until completion of disease process
- All children <8 yrs in pillar A/B did well REGARDLESS of tx
18
Q
what are good outcomes associated with ?
A
- Good outcomes correlate with spherical head
- 60% don’t require operation
- good outcomes with lateral pillar A and caterall group 1
- all patients will need clinical ad radiological follow up until completion of disease process
19
Q
What are the indications of surgery?
A
- Lateral pillar B , B/C with children >8yrs ( bone age 6 years)
- Lateral pillar C with child <8yrs
20
Q
What would surgery involve?
A
-
Femoral osteotomy
- proximal varus osteotomy- to provide containment
- pelvic osteotomy- salter, triple inominate, dega or pemberton, later Chiari/Shelf for salvage
21
Q
What are the outcomes of perthes?
A
- Herring lateral pillar types A/B in age <8 did well regardless of tx
- Types B / BC over 8 years had imporved outcomes with surgery
- Type C had poor outcomes regardless of tx
22
Q
What is the prognosis of Perthes?
A
- Important prognostic variables
- age of patient at presentation- Bone age
- Sphericity of femoral head & congruency at skeletal maturity ( Stulberg classification)
- _Prognosis worse with _
- age bone age >6 at presentation
- female sex
- decreased hip ROM- Abduction
-
prognosis improved with
- Age bone age <6 at presentation
23
Q
What is the natural hx of Perthes?
A
- Pt do well untiil 5th/6th decade of life in which degenerative changes of hip become present
- approx 1/2 of pts develop premature OA 2ary to aspherical femoral head
24
Q
What did Cattrell describe?
A
- A classification system based on degree of head involvement
- Group 1- involvement of anterior epiphysis only to Group 4 - total head involvement. added at risk signs to indicate a more severe disease course
- The 5 at risk signs which indicate a more severe disease course including
-
Gage Sign
- radiolucency on hte shape of a V in the lateral portion of the epiphysis
- Calcification lateral to epiphysis
- Lateral subluxation of femoral head
- Horizontal physis
- Metaphyseal cysts
