Dislocation of the hip
three main types : 1- posterior. 2- anterior. 3- central.Posterior hip dislocation
It is the commonest type Mechanism of injury : Dashboard injuryOn examination : the leg is short ,adducted , internally rotated . The lower limb should be examined for sciatic nerve injury . X-ray : AP view : the femoral head is seen out of its socket and above the acetabulum ..
Treatment : Dislocation must be reduced as soon as possible under general anesthesia . The patient put on ground. The assistant steadies the pelvis , the surgeon start by applying traction in the line of the femur 90% flexion of both hip and knee , then a clunk terminate the maneuver . Followed by x-ray checking ; then put the injured limb in rest by applying skin or more beneficial skeletal traction for 3-6 weeks , the patient is allowed to walk by crutches ; if there is fracture rim of the acetabulum and the piece is large then internal fixation is mandatory .
Complication : 1- sciatic nerve injury : it occurs in 10-20 % of the cases but fortunately it usually recover , if not , then nerve exploration must be considered. 2- vascular injury : superior gluteal artery . 3- associated fractures : acetabular , femoral head , femoral neck and femoral shaft and here the dislocation may be missed .
4- avascular necrosis of the femoral head . 5-myositis ossificans. 6-unreduced dislocation 7- secondary osteoarthritis
Anterior dislocation of the hip
it is rare . Clinically : the leg is externally rotated , abducted and slightly flexed , not short . sometimes the leg is abducted to right angle . X-ray : AP view , the dislocation is obvious , any doubt is resolved by lateral view .