
Defination:
Idiopathic osteonecrosis of the capital femoral epiphysis of the femoral head of unknown aetiology. It is a self-limited disease. Complete revascularisation of the avascular epiphysis occures almost invariably, over a period of two yrs with or without any form of treatment, with or without femoral head deformity.
Epidemiology:
- One in 1200 children younger than 15 years is affected by LCPD.
- Males are affected 4-5 times more often than females.
- LCPD most commonly is seen in persons aged 4-9 (2-18) years, with a average age of 7 years.
- Bilateral involvement 10 -15%.
- Hereditary- children with HLA-A antigen are susceptible.
Etiology:
- Unknown
- Probably secondary to soft tissue disease.
- Any process responsible to cause interruption of blood supply to the capital femoral epiphysis.
- Hypothesis.
-Trueta’s hypothesis
-Caffey’s hypothesis
Trueta’s Hypothesis
- Blood supply to femoral head at age
< 4yrs- dual supply(metaphysial & lateral epiphysial vessel)
4-8yrs- single supply(lateral epiphysial vessel)
> 8yrs- dual supply (lateral & medial epiphysial vessel)
- So most vulnerable during 4-8yr.
- Medial epiphyseal vessels(through ligamentum teres) developes.
- earlier in blacks than whites..supports the hypothesis
- But cant define reason of male predominance.
Caffey’s Hypothesis
- Child has genetic or acquired dysplasia resulting in delayed bone age
- Thick pre-ossific cartilage of the femoral head provides inadequet protection for the vessels transversing the cartilage
- Compression of that cartilage cause infarction, more coomon in boys due to more activity
- Called it as a coronary diseae of hip.
Probable causes:
- A- Arterial ischaemia
- V- Venous obstruction- metaphysial blockage, coagulopathy
- A- Abnormal growth & development- lbw,
- hormonal abnormality
- S- Synovitis
- T- Trauma
Hereditary, Nutritional factor,hyperactivity attention disorder.
Pathology:
- The blood supply to the capital femoral epiphysis is interrupted (arteries and veins).
Bone infarction occurs, especially in the subchondral cortical bone, while articular cartilage
continues to grow. (Articular cartilage grows because its nutrients come from the synovial fluid.)Four stage-
- Incipient or stage of synovitis(lasts for 1-3wk)
- Stage of AVN(lasts for 6mo-1yr)
- Stage of fragmentation or regeneration(lasts for2-3yrs)
- Stage of residual deformity or healed lesion
Clinical features:
- Painless limp (earliest symptom).
- Hip or groin pain, which may be referred to the thigh, knee.
- Usually no history of trauma.
- Decreased range of motion (ROM), particularly with internal rotation and abduction.
- Painful antalgic gait.
- Atrophy of thigh muscles secondary to disuse (Trendelenburg sign)â€.
- Muscle spasm- mild hip contracture of 10-20 degrees may be present.
- Leg length inequality due to collapse.
Investigations:-
- Radiology- initial modality
A-P, frog-leg lateral views (every 6 weeks at the beginning, every 3-6 months later)
classify the lesion depending upon
-pathological stage (waldenstrom)
-severity (catterall, salter-thompson, lateral pillar)
-outcome (moss, stulberg)
(World Cup Shares Love, Money & Strength) - USG- synovitis
- Radio isotope scintigraphy(Tc99)- highly sensitive
- Arthrography- exact size of femoral and acetabular articular surface can be determined
- MRI- most sensitive, diagnose early, shows extent of necrosis
Waldenstrom’s classification (IFHR-Initial Foetal Heart Rate)
- Ischaemia / Necrosis –
-decrease head size due to ossification arrest
-cartilage hypertrophy of both femoral & acetabular side causing lateral displacement (may subluxation) of femoral head
- Fragmentation / Resorption-
-pathological subchondral #(Cresent sign of Caffe)
-collapse of peripheral zone(head within head appearance)
-metaphysial osteolytic band or cyst
-lasts from 6month-1 yr.
- Reossification / Healing-
-new immature bone replace necrotic bone
-vulnerable for deformity
-mushroom shaped head
Residual stage-
-involve healing, remodelling & sequelae of the disease -take 6 mo-5yrs -classical changes:- coxa magna(large head) coxa breva(short neck) coxa irregularis(irregular head) coxa valga/ vara(due to lateral/ medial arrest) gt over growth(due to gt apophysis continuous growth) OA hip(as early as at the age of 40yr)
Catterall classification
Stage 1:
- Antero-medial portion of head involved and no collapseHeal without significant sequelae.
Stage 2:
- More head involved and may – fragmentation of the involved segment.
- Regeneration without much loss of height and the end result is usually good. Metaphyseal reaction localised.
Stage 3:
- Most of the head involved-May show head within a head.
- The metaphysis is usually diffusely involved – broad neck and the epiphyseal plate is unprotected and also usually involved – results poorer.
Stage 4:
- Whole head involvement and severe collapse occurs early and restoration of the femoral head
usually less complete . - The epiphyseal plate is often involved – abnormal growth (coxa magna, coxa breva, coxa vara
and coxa valga).
Salter – Thompson Classification
Stage A:
-Lateral portion of femoral capital epiphysis present .
-extent of subchondral # less than 50% head involved.Stage B:
-Lateral portion of femoral capital epiphysis absent – extent of subchondral # more than 50% head involved (Lateral margin of epiphysis protects epiphysis from stress)
Lateral pillar classification of Herring
Intact lateral pillar act as a wt bearing syupport to protect the central avascular segment
Group-A
-minimal density change in lateral pillar
-no loss of heightGroup-B
-density change in lateral pillar
-loss of height < 50%Group-C
-Early density change in lateral pillar
-loss of height > 50%
Determine treatment and prognosis
Moss Classification
- Normally the shape of the femoral head doesn’t deviate more then 1mm from a given circle on both AP & Frog leg view.
If shape fall
< 2mm= fair outcome > 2mm= poor outcome
Stulberg’s Classification
- Classified from group I-V
- Tells about prognosis.prognosis is poor if Head at risk sign present
-small osteoporotic segment on lateral side of epiphysis
-lataeral displacement of femoral head
-horizontally oriented growth plate
-calcification lateral to epiphysis(Gage’s sign)
-diffuse metaphyseal change
Extensive involvement of epiphyseal ossification center
Age > 6yrs
Early closure of epiphyseal plate
Advanced stage at the time of presentation
Female sex
Differential diagnosis (ICE-H):
Inflammatory:-
-Toxic synovitis(transient synovitis)
-Septic Arthritis (mc- tubercular)
-juvenile Arthritis (juvenile rheumatoid arthritis)Haematological:
-Sickle cell anemia
-Thallasemia
-Haemophilia
-ITP
-Leukemia
-Gaucher,s diseaseCongenital:
-skeletal dysplasia(multiple/ spondyloepiphyseal dysplasia)Endocrine:
-Hypothyroidism
Goal of treatment:
- Elimination of hip irritability.
- Restoration & maintenance of good ROM.
- Prevention of epiphyseal extrusion & subluxation.
- Attainment of spherical head on healing.
Options:
- – Observation
- – intermittent symptomatic trt
- – Definitive early trt
A.nonsurgical/ B. surgical
1.Observation:-
- Trt of choice for all children < 6yrs
- For children > 6yrs with catteral grs1,2 & salter-thompson gr-A
- Radiographic examination every 3 monthly required
- Persistant loss of motion or evidence of loss of containment may necessiatate a short course (2- 6mo) of non surgical trt
2. Intermittent symptomatic trt:-
- Bed rest
- Abduction traction
- Stretching exercises
Need radiological follow up
3. Definitive early trt:
Indication:-
-age> 6yr
-Catterall gr-3,4 & Salter-Thompson gr-B
-Loss of containment of head on AP veiwContraindication:
-Caterall Gr-1 case
-Caterall Gr-2,3 case in less than 5yrs of age with no signs of head at risk
-Severe flattening of head
-Healed cases
-cases with hinged acetabulum
3A. Non surgical methods:
- Initial traction and gradual abduction with internal rotation
- Orthosis application
-Atlanta Scottish Rice brace
-Toronto Brace of Bobechko
-Hugston A frame
-Broom Stick Plaster
-Petrie and Bitenc abduction cast
-Newington abduction ambulation brace - Bracing is discontinuid when there is roentgenographic evidence of new subchondral bone,seen in both AP & Frog leg views and measuring subluxation chance from CE angle of Wiberg*.
- Contraindication- incompliant, psychiatric pt
- Disadvantage- jt stiffness, pressure sores, need for frequent change
*Centre-edge angle (Wiberg`s angle)
5-8 years ~19 degrees, 9-12 years ~25 degrees, 13-20 years 26-30 degrees
3B. Early Surgical methods:
Advantage-
– Ability to obtain containment of head
– Period of restriction is two month
– No end point is necessary for trt as the containment is permanent
Methods:-
- Innominate osteotomy (Salter’s)-
iliac osteotomy with rotation of entire acetabulum with pelvis and ischium downward, outward & forward with symphysis pubis acting as a hinge. - Varus derotation osteotomy(Canale & beaty)-
subtrochanteric osteotomy (lateral opening wedge/ reverse wedge) with lateral platting . Useful for 8-10yrs old child without limb length discrepancy.
- Combined innominate and femoral osteotomy
- Reconstructive surgery(for significant deformity)
-Muscle (abductor and iliopsoas) release and abduction cast
-Valgus extension osteotomy
-Cheilectomy
-Shelf augmentation procedures
-Chiari osteotomy
-Trochanteric advancement
Summary:-
- Definition
- Etiology- AVAST, Trueta n Caffey’s hypothesis
- C/F
- Ix- radiology(WCSLMS classification), USG, Scintigraphy, Arthography, MRI
- D/d- ICE-H
- Trt- Observation, Intermittent symptomatic trt, definite early trt(nonsurgical & surgical)