[The effect of traction treatment on blood flow in the immature hip--an animal study].

9 immature pigs (age: 8-12 weeks) underwent longitudinal traction with 10%, 30%, and 50% body weight followed by overhead traction with 10% and 30% body weight. Microcirculation of the femoral head was monitored by a laser-doppler flow probe and macrocirculation within the lateral circumflex artery by an ultrasonic perivascular transit time flow probe. Changes in blood flow during each traction period were compared to the preceding resting period and expressed in percentages. With any type of longitudinal and overhead traction a trend towards an improvement in micro-and macrocirculation of the hip joint was observed although no significant differences could be detected. Our results encourage the use of traction as a concept in management of developmental dislocation of the hip.