The Value Of Sucking The Blood From The Superior Portion Of The Femoral Head To Predict The Development Of AVNFH

Objective To investigate the clinical value of sucking the blood from the superior portion of the femoral head through holes of cannulated screw to predict the development of AVNFH . Methods 61 patients (34 males and 27 females; mean age 56.4 years ;range, 21-71years)with femoral neck fracture were enrolled from October 2003 to October 2006 and treated with cannulatcd screws. The fractures were classified according to Garden and included 10 typeⅠ(16.4%) , 20 typeⅡ(32.8%) , 24 typeⅢ(39.3%)and 7 typeⅣ(11.5%) . We divided the patients into two groups :the blood circulation abundance group and the blood circulation absence group according the status of bleeding sucked through the holes of proximal cannulated screw .The 2 groups were followed up to observed the incidence of AVNFH and according to the sensitivity ,specificity ,positive predictive value ,and negative predictive value to evaluate the validity of this way to predict the development of AVNFH . Exclusion criteria included the following : the patients with osteoporosis ; long-term using prednisolone ; with a pathologic fracture ; with hip disease ; with heavy and long-term alcohol abuse ; with heavy base disease as diabetes,chronicity renal functional defection,liver functional defection,respiratory functional defection,heart failure,ankylosing spondylitis,beriberoid disease and Rheumatoid ; with the reduction dissatisfaction. Results There are 51 patients in the blood circulation abundance group and 9 patients in the absence group .The follow-up period was more than 25 months. The mean follow-up was 41.1 months (range, 25–61 months). AVNFH developed in 11 cases (19.7%). Two patient of 51 in the blood circulation abundance group (3.92%) and 10 patients of 10 in the blood circulation absence group (100%) developed AVNFH. The sensitivity is 83.3%, specificity 100%, positive predictive value 100% and negative predictive value 96.1%. Conclusions It seems that sucking the blood from the superior portion of the femoral head through holes of cannulated screw is a simple and accurate perfusion assessment technique for predicting the development of AVNFH after a femoral neck fracture.