PERTHES DISEASE

PERTHES DISEASE DR Darshan.C.K JSS Medical College

OverviewDefinition Vascular supply of femoral headNatural History of the diseasePathogenesis ClassificationSymtoms DiagnosisManagement

Conservative ManagementContainment proceduresSalvage procedures

Perthes disease may be defined as the self limiting form of osteochondrosis of capital femoral epiphysis of unwnown etiology that develops in children Age group: 3-10 yearsSex: males 4-5 times more than girlsBilateral in 10-12% of patients

DEFINITION

3

SYNONYMSLegg Calve-perthes diseaseLeggs stress fracture of femoral headOsteochondritis deformans juvenalisOsteochondrosis of hip jointPseudocoxalgiaCoxa plana

EpidemiologyM : F ratio 4 : 1Children between 4- 8 years of age.Occasionally as young as 2 years and teenagers have been reported.10 % of the cases have a positive family history. Abnormal presentations breech, tranverse lie.more common in Japanese, Eskimos, and Central Europeans and uncommon in native Australians, Polynesians, American Indians, and blacks.Low socio economic status, 3rd or the 4th child ususally affected. Mean parental age is also higher than normal

5

Affected children have short stature, retarded bone age, delay in skeletal maturationAnthropometric measurements confirmed the affected children were smaller in all dimensions except the head circumference with distal extremities affected more than the proximal ones.Onset of disease at an early age may culminate in normal growth in adult life, but a child with later onset tends to remain small throughout life.Epidemiology

HistoryFIRST DESCRIBED BY LEGG AND WALDENSTORM IN 1909 AND BY PERTHES ANDCALVE IN 1910

EtiologyCoagulation disorders.Arterial status of femoral head.Abnormal venous drainage.Abnormal growth and development.Trauma.Hyperactivity or attention deficit disorder.Genetic component.Environmental influences.As a sequel to synovitis.

Vascular supply2. Increased intra-articular pressure3. Intraosseous pressure - Patients has shown that the venous drainage in the femoral head is impaired, causing an increase in intraosseous pressure.4. Coagulation disorder - Associated with absence of factor C or S. - Increase in serum levels of lipoproteins,thrombogenic substance.

ETIOLOGY

5. Growth hormones - Studies have shown reduced levels of growth hormones, somatomedin A and C.6. Social conditions - Usually belong to lower socioeconomic status, reflects dietary and environmental factors.7. Trauma-the lateral epiphyseal artery which coursesthrough a narrow passage is susceptible todamage

8.. Abnormal growth and development - Bone age is lower than chronological age by 1-3 yrs,. Ex: carpal bone age: 2 yrs (Triquetral and lunate) - Usually shorter than their peers.9. Genetic factors - Inheritance 2-20%;inconsistent pattern. - More Incidence of low birth weight, abnormal birth presentations. - First degree relatives have 35% more risk , 2nd and 3rd degree relatives are 4 times more prone for perthes disease.

Blood supply to femoral headRetinacular arteriesMetaphyseal arteriesArtery of the teres ligament

At Birth Physeal plate is porous. Metaphyseal vessels easily penetrate to supply the head. Lateral and medial epiphyseal vessels contribute. Acetabular contribution absent

4 months to 4 years - Lateral epiphyseal vessels predominate, penetrating vessels gradually reduce as epiphyseal plate develops

4- 7 years only lateral and medial epiphyseal vessels supply the head.

Above 7 years artery of ligamentum teres also contributes to vascularity.12

Blood supply to femoral headInfants Medial ascending cervical or inferior metaphyseal arteries of trueta.Lat epiphysealLig teres insignificant4 mts 4 yearsLat epiphysealMed epiphyseal decrease in number.

Blood supply to femoral head4 yrs to 7 yearsEpiphyseal plate forms a barrier to metaphyseal vessels.Pre-adolescentAfter 7 yrs arteries of lig teres become more prominent and anastomose with the lateral epiphyseal vessels.

Truettas HypothesisHe postulated that the solitary blood supply in the age group 4-8 yrs makes them suceptible to ischemia.Compression of Lat epiphyseal arteries by ext.rotators.

16

CAFFEYS HYPOTHESISthis theory is incompatible with the high predominance of the disease in males, since the vascular supply is identical in both sexThe radiologic features are more consistent with an AVN resulting from intraepiphyseal compression of blood supply to the ossification centerRecently in POSICON 2016 they have come across DVT as one of the cause for vasularity.

PATHOGENESIS

PATHOGENESIS1) INCIPIENT OR SYNOVITIS STAGElasts for 1 to 3 weeks. The synovium is swollen, hyperemic and odematous.There is notable absence of inflammatory cells, joint fluid is increased

2) STAGE OF AVASCULAR NECROSISlasts for 6 months to 1 year.It involves only a portion of the ossific nucleus usually situated anteriorly or involves the entire nucleus.The bone architecture remains normal but lacunae are vacantBone trabeculae are crushed into minute fragments and compressed into a compact mass.The gross appearance and contour of the femoral head remains unchanged

3) STAGE OF FRAGMENTATION OR RESORPTION

Lasts for 2 to 3 years and characterised by resorption of the necrotic bone and replacement by viable bone.Subchondral fracture of necrotic bone result in multiple trabecular fragments being compressed together

4) HEALED OR RESUDIAL STAGE

The normal bone is forming along side and replacing slowly resorbing boneThe newly formed bone is immature formed of slender trabeculae and early compressed together with necrotic fragmentsThe entire ossific nucleus may be deformed assuming mushroom shaped contourFinally an enlarged femoral head (coxa magna) emerges varying in contour from a normally spherical and concentrically lodged head to a deformed flattened and eccentrically placed head

APPERANCE OF GREATER TROCHANTER:- It becomes strikinly large in some cases. Since longitudinal growth of the femoral neck may cease completely at 12 -14 years of age , whereas growth of the greater trochanter continues until 17 -18 years, a discerpancy in growth neck and the greater trochanter may result.The elevation impairs the power of pelvitrochanteric abducter muscles, manifested by positive trendelberg sign.

CLINICAL FEATURESSYMPTOMSMost childern present with mild and intermittent pain in the thigh or a limp or both.The onset of pain may be acute or insidious The classical presentation is described as a painles limp the child limps but does not complains of discomfort.Pain is agrravated by movement of hip and relived by rest.H/o of trauma usually a mild is present.

EXAMINATION:-Antalgic gait Muscle spasm secondary to irritable hip.Limitation of abduction and internal rotationShort statureFfd may be presentDIFFERENTIAL ROTATION .TRENDELENBERG TEST POSITIVE

InvestigationX-Ray AP & Frog leg Lat viewUSGArthrographyBone ScanCTMRI

Arthrography Indicated to know the contour of head and congruity of articular surface Provides reliable information regarding containment.We can assess congruity of hip in many different positions.Not routinely used .Arthrography is important only in the fragmentatory and reparative stages

CT SCAN

Not as sensitive as nuclear medicine or MRI.CT may be used for follow-up imaging in patients with LPD.

MRI SCANIt allows more precise localization of involvement than conventional radiography.MRI is preferred for evaluating the position, form, size of the femoral head and surrounding soft tissues. MRI is as sensitive as isotopic bone scanning.

Bone ScanIndicated to diagnose in early stages and to classify the severity.Diagnosis possible months before signs appear on X-Ray.Avascular areas show cold spots.Revascularisation can be detected much before radiographic evidence.

Radiographic ClassificationWaldenstroms classification.Catterall classification. Salter classificationHerrings lateral pillar classification.Modified Elizabethtown classification.

I) Stage 1(stage of increased density) - Ossific nucleus initially smaller; femoral head becomes uniformly dense; - Convex rounded enlargement develops at superior margin of neck( Gages sign). - A subchondral fracture may be seen; - radiolucencies appear in the metaphysis II) Stage 2(fragmentation stage) - Lucency appear in epiphysis; - Segments (pillars) of the femoral head demarcate the femoral head may flatten and widen - Metaphyseal changes resolve; - Acetabular contour may changeWALDENSTROMS CLASSIFICATION BASED ON RADIOGRAPHIC CHANGES

III) Stage 3(healing or reossification stage) - New bone appears in femoral head which gradually reossifies; - Epiphysis becomes homogeneous.

IV) Stage 4( healed or remodelling stage) - Femoral head is fully reossified and remodels to maturity; - Acetabulum also remodels

CRESCENT/CAFFEY SIGN

'segmental fracture' also termed by Caffey as submarginal fracture which is represented by a localized area of increased density continuous with the remainder of the EOC.

Sagging rope sign-radio dense line overlying proximal femoral metaphysis, a result of growth plate damage with metaphysial response.

WALDENSTROM SIGN

-Slight lateral displacement of the femoral head and smallness of theE0C -best determined in the Lauenstein (frogleg) view

Radiographic changes in metaphysis. - Apparent very early in the disease process. - Changes are of prognostic value, hips with cystic changes were twice likely to have poor outcomes as hips without cysts.Changes in neck of femur - Deformity in neck can develop earlier than head. - Upper part of neck is expanded and metaphyseal end becomes rounded. - neck progressively becomes shorter and wider

Changes in acetabular cavity - Distance between medial pole of head and floor of socket is increased(Waldenstroms sign) - Ligamentum teres grossly swollen and congested.- Floor is altered to adapt shape of head, hollowed out abruptly. - There may be irregular ossification, cystic and increased radiodense areas

Catterall classification (1971)I only anterior portion of epiphysis affected.II anterior segment involved, central sequestrum presentIII most of epiphysis sequestered with unaffected portions located medial and lateral to central segmentIV all of epiphysis sequestered.

Catterall's ClassificationGRADE 1 : Only the anterior part of the epiphysis is involved. It differs from the other group that no collapse occurs and there is complete absorption of the involved segment without sequestrum formation and height of the epiphysis is maintained.

Catterall's ClassificationGROUP 2 :- In this variety more of the anterior part of the epiphysis is involvedCollapse with the formation of a dense collapsed segment or sequestrum. Despite collapse occurs the viable fragments maintain the epiphyseal height. Metaphyseal change -usually a well defined cyst which is transitory and disappears with healing. The sequestrum is separated from the viable posterior--segments by a V which when present, is characteristic of this group.

Catterall's ClassificationGroup-3 : Only a small part of the posterior epiphysisis is involved. Ap view shows a appearance of a "head within a head".In the later stages there is a collapsed sequestrum centrally placed with very small amount of normal appearing bone on the medial and lateral sides. Metaphyseal changes - more generalised and when extensive are frequently associated with broadening of the neck.

Catterall's ClassificationGROUP 4 : whole epiphysis is sequestrated. On AP view total collapse of the epiphysis may be seen producing a dense fine. Displacement of the epiphysis can occur not anteriorly but posteriorly producing a mushroom like apperance of the head.The metaphyseal changes may be extensive

HEAD AT RISKGage's sign triangular section of osteoporosis on lateral femoral headlateral calcification lateral subluxation horizontal alignment of the growth plate Diffuse metaphyseal reaction.

Caterall head-at-risk signmetaphyseal cysts

Gages signRarefaction in the lateral part of the epiphysis and subjacent metaphysis.

SALTER AND THOMSONS CLASSIFICATION

Type A = I & II CatterallType B = III & IV Catterall.

51

HERRINGS CLASSIFICATION

Prognostic FactorsAge at diagnosisExtent of involvementSexCatterall head at risk clinical signs

ClinicalProgressive loss of hip motionIncreasing abduction contractureObese child

Classification of PrognosisUniplanar methods - CE angle of Weiberg. - Salters extrusion Index. - Epiphyseal index. - Epiphyseal quotient. Biplanar methods - Stulberg classification.

CE angle of WeibergIndicator of acetabular depth It is the angle formed by a perpendicular lines through the midportion of the femoral head and a line from the femoral head center to the upper outer acetabular margin. Normal = 20 to 40 degreesAngle >25 = good, 20-25= fair,< 20 = poor

Salters extrusion IndexIf AB is more than 20% of CD it indicates a poor prognosis

Epiphyseal index & quotientEpiphyseal index = greatest height of the epiphysis divided by its width.

Epiphyseal quotient = Epiphyseal index of involved hip divided by the index for uninvolved hip. >0.6 = good 0.4-0.6 = fair