Ans. b (Barlow test) (Ref Maheshwari orthopedics 4th/87).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 limbus/fibrocartilaginous 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- Galeazzi's sign (level of knees compared with hip fixed to 70deg and knees flexed)+.- Ortolani's test +.- Trendelenburg's test +.- Shortening of limb and externally rotated.- Lumbar lordosis- Telescopy +.- Trendelenburg's gait in unilateral; waddling gait in bilateral DDH.# Diagnosis:- Difficult during infancy, but USG with high frequency probe (Graff's classification) is very useful.- Clinical tests:# Barlow's test (provocative test having two parts)# Ortolani test# Radiological features:- Von Rosen's 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 Shenton's 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: Salter's osteotomyNone in bilateral.Indication is pain. Rx:THR>arthrodesis