Relationship Between X-ray Measurement Of The Position Of Acetabular Prosthesis And Revision Of Hip Arthroplasty Caused By Early Aseptic Loosing Of Bio-prosthesis

Objective: To investigate the relationship between X-ray parameters of the position of the acetabular prosthesis(including horizontal and vertical distances of the hip center,femoral eccentricity,anteversion and abduction angles)and the hip revision caused by early aseptic loosing of bio-prosthesis after the primary total hip arthroplasty.Methods: We retrospectively studied 851 patients who underwent the first-time total hip arthroplasty at our department from January 2010 to January 2017.Then we collected the data of 80 patients who fulfilled the inclusion and exclusion criteria.Among them,there were a total of 23 patients with aseptic loosening of the bio-prosthesis and undergoing revision of hip arthroplasty(the experimental group)aged 45~76 years with an average age of 63.30 ± 8.02 years,including 14 males and 9 females,and their reasons for the primary hip arthroplasty were avascular necrosis of the femoral head(5 cases),femoral neck fractures(12 cases)and hip osteoarthritis(6 cases),and the time from the first-time hip arthroplasty to revision was 2~5 years,with an average of 3.22 ± 1.00 years.There were 57 patients with on revision of hip arthroplasty(the control group)aged 39-86 years with an average age of 60.37±12.31 years,including 24 males and 33 females,and their reasons for the first-time hip arthroplasty were avascular necrosis of the femoral head(23 cases),femoral neck fractures(20 cases)and hip osteoarthritis(14 cases).The horizontal and vertical distances of hip center,femoral offset,anteversion and abduction angles of the experimental group were measured on the pelvis plain film within one week after the primary hip arthroplasty,at the last follow-up,before and after the revision,respectively.And the horizontal and vertical distances of hip center,femoral offset,anteversion and abduction angles of the control group were measured within one week after the first-time hip arthroplasty and at the last follow-up.Statistical analysis was conducted to explore the relationship between the Xray parameters of the position of the acetabular prosthesis and the hip revision caused by the aseptic loosening of the bio-prosthesis.Results: The abduction angle of the experimental group was 30.00°~50.00°,which was significantly smaller than that of the control group(P<0.05).The vertical distance of the rotation center of the experimental group was in the range of-5.00 mm to 5.00 mm,which was significantly smaller than that in the control group(P<0.05).The anteversion angles in both two groups were 5.00°~25.00°with no significant difference(P>0.05).The difference of eccentric distance between the two groups was-4.00~4.00 mm with no significance(P>0.05).And the difference of horizontal distance between the two groups was-5.00~5.00 mm with no significance(P>0.05).The abduction angle and vertical distance of hip center were risk factors for hip revision caused by early aseptic loosing of bio-prosthesis.Conclusion: X-ray measurement parameters of acetabular position after primary total hip arthroplasty are correlated with hip revision in early stage of aseptic loosening of bioprosthesis.The height difference of the rotation center between the operation side and health side should be controlled within 5mm,and the abduction angle should be controlled within 30°~50° during the primary total hip arthroplasty,which could reduce risk of revision caused by early aseptic loosing of bio-prosthesis.