<prompt> Provocative Test for detecting CDH?Peterson testBarlow testPerkins testVon Rosen tests  <response>: Ans. b Barlow test Ref Maheshwari orthopedics 4th87.All newborn babies should be screened for hip instability by a skilled examiner using the Barlow and Ortolani tests. The baby should be relaxed and the hips flexed to 90 degree. It is possible to reduce a dislocated hip by abduction and gentle forward pressure Ortolani or dislocate an unstable hip by adduction and gentle backward pressure Barlow. In both cases a soft clunk is felt as the hip reduces or dislocates repectively.DEVELOPMENTAL DISLOCATION DYSPLASIA OF THE HIP Etiology:- Hereditary predisposition to jt laxity- Hormone induced jt laxity in females- Breech malposition Pathology:- Femoral head dislocated upwards and laterally- Femoral neck is excessively anteverted- Acetabulum shallow- Ligamentum teres hypertrophy- Inverted limbusfibrocartilaginous labrum of acetabulum- Stretched capsule of hip joint- Adaptive shortening of adductor muscles and hip joint, Findings in older children:- Limitation of hip abduction- Asymmetrical thigh folds- Higher buttock fold on affected side- Galeazzis sign level of knees compared with hip fixed to 70deg and knees flexed.- Ortolanis test .- Trendelenburgs test .- Shortening of limb and externally rotated.- Lumbar lordosis- Telescopy .- Trendelenburgs gait in unilateral; waddling gait in bilateral DDH. Diagnosis:- Difficult during infancy, but USG with high frequency probe Graffs classification is very useful.- Clinical tests: Barlows test provocative test having two parts Ortolani test Radiological features:- Von Rosens view helpful in diagnosis- Signs in older children: Delayed appearance of ossific centre of head of femur Retarded development of ossific centre of femoral head Sloping acetabulum Lateral and upward displacement of ossific centre of femoral head Break in Shentons line Rx:Birth to 6 months6 months-6 yrs6 yrs-10 yrs11 yrs onwardsClosed manipulation maintained in plaster cast or von Rosen splint.Up to 2 yrs: reduction by closed methods.After 2 yrs: Salters osteotomyNone in bilateral.Indication is pain. Rx:THRarthrodesis 