DSA observation of hemodynamic response of femoral head with femoral neck fracture during traction: a pilot study.

Objective: To investigate the early influence of traction on blood supply to the femur head after femoral neck fractures using digital subtraction angiography (DSA).

Methods: Prospective case series. Methods: University Level I trauma center. Methods: Nine patients who sustained a unilateral femoral neck fracture underwent selective femoral artery DSA within 2-23 days after their injury. Methods: DSA of the medial and lateral circumflex femoral artery was performed for all 9 fractured hips before traction. Repeat DSA study of the femoral head circulation was performed after the addition of 3 kg of traction in 7 patients and 5 kg of traction in 6 patients. For comparison, DSA was also performed on the uninjured hip in 8 of the 9 patients. Methods: Blood circulation of the femoral head was evaluated by observing morphology of the feeding arteries, perfusion volume, venous drainage, and the circulation time of the microvasculature.

Results: Femoral neck fracture damaged the retinaculum artery and led to femoral head hemodynamic disorder in all 9 cases. Application of linear traction and repeat DSA decreased femoral head perfusion (faint arterial imaging and delayed venous display) in all patients' retinaculum arteries except the inferior branch compared with the pretraction imaging. These findings were more pronounced as the traction was increased from 3 to 5 kg. These findings were significant (P < 0.05).

Conclusions: Traction impairs blood perfusion to the femoral head. Blood flow in the retinacular arteries was reduced and venous drainage impeded. Traction may be one of the major causes of femoral head osteonecrosis after femoral neck fracture.