Clinical Efficacy Of Domestic Porous Tantalum Rod In The Treatment Of Early Avascular Necrosis Of The Femoral Head

Objective: To investigate the clinical efficacy of domestic porous tantalum rod in the treatment of early avascular necrosis of the femoral head.Methods: From July 2014 to December 2015,18 patients(19hip)diagnosed as early stage of avascular necrosis of femoral head were enrolled.All the patients accepted the operation of porous tantalum rod.There were 14 males and 4 females,aged from 30 to 62 years with an average age of 44.2 years.Among them,3 cases by hormone,7 cases(8hip)caused by alcohol,8 cases were idiopathic.According to modified Ficat staging: 4 cases were identified as stage IIa,14 cases identified as stage IIb.The efficacy of the treatment was evaluated by Harris and Womac score before operation and3,6,12 months after operation,X-ray and MRI imaging changes of the hip,and complications.Results: All patients were followed up for 8 to 24 months,with average follow-up of 16 months.No complications such as infection,wound healing problems,immunological rejection,tantalum rod breakage,loosening or displacement were observed during follow-up.At each time point after operation,Harris scores were(82.73±8.99),(84.46±10.75)and(87.22±10.0),compared with the preoperative(75.51±11.91)were significantly higher,all the differences were statistically significant(P<0.05),According to the Harris score system: 10 cases were identified as excellent,3 cases were benign,5 cases were general,1 cases were poor,and the excellent rate was 72%.Womac scores were(17.44±9.40),(12.39±7.31),and(11.06±8.41),which were significantly lower compared with preoperative score(28.28±13.10)(P<0.05).On the basis of the radiological images,17 cases'(18 hips)femoral head necrosis area did not increase obviously.The femoral head survival rate was 95%.,of which 1 case underwent total hip arthroplasty at 8 months after operation because of progressive hip pain and collapsed femoral head.The histological evaluations revealed that the presence of new bone around the biomaterial had grown into the porous tantalum.Conclusions: Domestic porous tantalum rod can effectively promote bone ingrowth,relieve pain,improve hip function,prevent the collapse of the femoral head and finally delay the total hip arthroplasty time in treatment of early avascular necrosis of the femoral head.