Historical aspect Parker started the use of broomstick cast in 1929. Eyre-Brook introduced traction in bed for 18-24 months.
Blood supply to femoral head Retinacular arteries Metaphyseal arteries Artery of the round ligament
Blood supply to femoral head Infants 1. Metaphyseal arteries . 2. Lat epiphyseal arteries 3. Lig teres – insignificant 4 mts – 4 years 1. Lat epiphyseal 2. Metaphyseal art. decrease in number (due to appearance of growth plate).
Blood supply to femoral head 4 yrs to 7 years 1. Epiphyseal plate forms a barrier to metaphyseal vessels. Pre-adolescent 1. After 7 yrs arteries of lig teres become more prominent and anastomose with the lateral epiphyseal vessels.
Blood supply to femoral head Adolescent After skeletal maturity metaphyseal vessels again come into picture
Incidence Male : Female = 4-5:1 2.5:1 in India Age of onset earlier in females. Age – Range – 2-13 years. Most common 4-8 years. Average – 6 years. Bilateral in 10-12 % Incidence more in Caucasians as compared to Negroid, mongoloid.
Etiology Etiology not known. Coagulation disorders. Altered arterial status of femoral head. Abnormal venous drainage. Abnormal growth and development. Trauma. Hyperactivity or attention deficit disorder. Genetic component. Environmental influences. As a sequelae to synovitis.
Coagulation disorders Protein C or S deficiency Thrombophilia Hypofibrinolysis
Altered arterial status Angiographic studies have shown obstruction of superior capsular arteries and decreased flow in medial circumflex femoral arteries . The intracapsular ring has been found to be incomplete.
Abnormal venous drainage Increased venous pressure in the femoral neck Congestion in the metaphysis Venous outflow exits more distally in the diaphysis.
Abnormal growth and development A delay in Bone age of 1.5 to 2 years Low birth weight Low levels of somatomedin C
Trauma. In the developing femur (4 – 7 yrs),the major lateral epiphyseal vessels must course through a narrow passage ,which could make it susceptible to trauma.
Pathogenesis cont… Resorption stage - Invasion of vascular connective tissue. - Resorption of dead bone by Osteoclasts. - loss of epiphyseal height due to 1) Collapse of bony trabaculae. 2) Resorption of dead bone
X-Ray Metaphyseal widening and cystic changes in femoral neck
X-Ray Lateral extrusion of femoral head. Hinged abduction.
X-Ray Sagging rope sign in adults with history of perthes
Ultrasound Synovial effusion Cartilage hypertrophy in early stages
Arthrography Shows configuration of the femoral head and its relation with the acetabulum. Containment Congruity Not routinely used .
Bone Scan Diagnosis possible months before signs appear on X-Ray. Avascular areas show cold spots.
Bone Scan Convay et al classification Stage 1 is total lack of uptake
Bone Scan( stage 2) Revascularisation of a lateral column Failure to revascularise at lat column is a grave sign Also called “scintigraphic head at risk sign” Precedes radiographic head at risk sign by 2-3 mths
Bone Scan( stage 3) Gradual filling of anterolateral part
Catterall classification (based on x ray AP and Lat view). I – only anterior portion of epiphysis affected. II – anterior segment involved central sequestrum present III – most of epiphysis sequestered with unaffected portions located medial and lateral to central segment IV – all of epiphysis sequestered.
Salter Classification Type A = I & II Catterall Type B = III & IV Catterall.
Herring Lat Pillar Group-A no involvement of the lateral pillar, with no density changes and no loss of height of the lateral pillar Group-B hips have lucency in the lateral pillar and may have some loss of height , but not exceeding 50% of the original height. Group-C hips are those with more lucency in the lateral pillar and >50% loss of height
Prognostic Factors1. Age at diagnosis <6 yrs – good 6 – 9 yrs – fair >9 yrs - poor5. Extent of involvement6. Sex7. Catterall “head at risk” signs
Catterall “head at risk” signs Clinical Radiographic
Clinical2. Progressive loss of hip motion more so abduction.4. Obese child
Radiographic3. Gage sign5. Calcification lateral to epiphysis7. Diffuse metaphyseal rarefaction9. Lateral extrusion of femoral head11. Growth disturbance of physis
CE angle of Weiberg Indicator of acetabular depth It is the angle formed by a perpendicular line through the midpoint of the femoral head and a line from the femoral head center to the upper outer acetabular margin. Normal = 20 to 40 degrees Angle >25 = good, 20-25= fair, < 20 = poor
Salters extrusion Index If AB is more than 20% of CD it indicates a poor prognosis
Salters extrusion angle Normal is 50 degrees or more
Epiphyseal index & quotient Epiphyseal 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 <0.4 = poor
Mose Classification Good < 1 mm Fair < 2 mm Poor > 2 mm
Stulberg classificaton Class I – Shape of the femoral head was basically normal. Class II – Loss of head height but within 2 mm to a concentric circle on AP and frog leg X-Ray Class III – Deviates more than 2 mm and acetabulum contour matches the head contour Class IV – Head Flattened, Flattened area <1cm. Acetabulum contour matches the head contour Class V – Collapse of femoral head, Acetabular
Stulberg classificaton Class I & II – Spherically congruent. Class III & IV – Congruous Incongruity OR Aspherical congruity. Class V – Incongruous incongruity OR Aspherically incongruent.
Stulberg classificaton Class I Shape of the femoral head is basically normal.
Stulberg classificaton Class II Loss of head height but within 2 mm
Stulberg classificaton Class III Deviates more than 2 mm
Stulberg classificaton Class IV Head Flattene d
Stulberg classificaton Class V Collapse of femoral head, Acetabular contour does not change
Differential diagnosis Tuberculosis of the hip AVN due to leukemia, lymphoma, gauchers disease, hemoglobinopathies etc Meyers dysplasia AVN following dislocation. Transient synovitis
Treatment Objectives - To produce a normal femoral head and neck - To produce a normal acetabulum - A congruous hip which is fully mobile - To prevent degenerative arthritis of the hip later in life
Treatment Treatment efforts are directed towards - Restoration and maintenance of full mobility of the hip - Containment of the femoral head. - Resumption of weight bearing and full activity as soon as possible
Treatment Caterall group 1 and group 2 ( < 7 years) No Herring group 1 & Treatment group 2 (< 6 years)
TreatmentTreatment is divided into 3 phases Initial Phase – restore & maintain mobility Active Phase – Containment and maintainance of full mobility. Reconstructive phase – correct residual deformities.
Treatment ( Initial Phase ) Physiotherapy – active and passive range of motion exercises to restore motion Traction – B/L skin traction and gradually abducting over 1-2 weeks till full abduction is regained.
Treatment ( Active Phase ) Consists of containment of the femoral head within the acetabulum. This can be achieved by orthosis or by surgery
Treatment (Orthosis) Non Ambulatory weight releiving 1. Abduction broomstick plaster cast 2. Hip pica cast Ambulatory Both limbs included 1. Petrie Abduction cast 2. Toronto orthosis 3. Newington orthosis 4. Birmingham brace 5. Atlanta Scotish Rite Brace
Treatment (Orthosis) Orthotic treatment is discontinued when the disease enters the reparative phase and healing is established.
The radiographic evidence of healing are 1. Appearance of irregular ossification in the femoral head. 2 . Increased density of femoral head should disappear. 3 . Medial segment of femoral head should increase in size and height. 4 . Metaphyseal rarefaction involving the lateral cortex of the metaphysis should ossify. 5 . There should be intact lateral column.
Treatment ( Surgical) Femoral varus osteotomy. Inominate osteotomy. Combined femoral and inominate osteotomy Valgus osteotomy Shelf arthroplasty