Although the incidence of developmental dislocation of the hip (DDH) has been significantly reduced by better clinical assessment and especially by the availability of sonographic hip screening, there are still some DDH cases which present at later ages beacause of late or missed diagnosis The functional methods applied to treat DDH of the hip were met with great success and also relatively low complication rates however a general consensus exists that they should not be attempted after 6 months of age. And various treatment strategies applied like closed reduction tenotomy open reduction conbined with pelvic osteotomies only and/or surgical proceduresare required.
Developmental dysplasia of the hip (DDH) is a dynamic disorder and the malformations of anatomic structures are the result of gentle persistently applied forces in dislocating direction. When hips are placed in adduction and knees in full extension, hip muscles (mainly adductors, iliopsoas, hamstrings) act in dislocating direction of the hip. swaddle

By placing the hip in adduction, the dysplastic acetabulum is unable to balance the forces which action the femoral head. A dislocating force L is produced, which gradually directs the femoral head over the postero-superior rim of the acetabulum. Additional anatomic changes gradually ensue- flattenening of the acetabular rim, elongation ligamentum teres, inversion of limbus, constriction and narrowing of the hip capsule and eventually the increased acetabular obliquity allow the femoral head to dislocate completely. The treatment of DDH with the method of Hoffmann—Daimler is based on the following principal: By placing the hip in flexion, the resultant L force is redirected and the femoral head is pulled gradually caudally and causes it to travel back to the acetabulum (fig2 b). Simultaneously all anatomic changes gradually fully reverse25 where at the end the femoral head reduces (phase A). These principal is the same for all successful functional treatments, like Pavlik method.
As patient with DDH gets older the anatomic changes that ensue gradually are becoming substantial obstacles to closed reduction . The formation of a capsular isthmus, the hypertrophic elongated ligamentum teres femoris, the inverted labrum and the shortened and contracted muscles (adductors, iliopsoas, hamstrings) makes the reduction of the femoral head by any closed treatment and even by corrective surgery, progressively more difficult. The capsule assumes an hourglass shape and by chinese finger trap mechanism the dislocated femoral head is no longer reducible.