CT Evaluation Of Two Kinds Of Positioning Method Of Acetabular Prosthesis In Total Hip Arthroplasty

Objective We measured postoperative acetabular abduction and anteversion of two methods of acetabular componment positioning (refer to acetabular transverse ligament and using the acetabulum locator)on CT scans, compared which method is closer to the ideal value of the acetabular angle (anteversion of 15°, abduction of 45°), and provided a theory to service clinical practice.Methods In our hospital, we collect 60 cases of total hip arthroplasty from 2013 to 2015. Among them, male 29 cases, female 31 cases; age 55-75 year old, average 65.2 years old; body mass index (Body, Mass Index, BMI) - averaged 25.97Kg/m.The sample incluedes 30 cases of hip osteoarthritis include,10 cases of necrosis of femoral head, 8 cases of femoral neck fracture, 6 cases of rheumatoid arthritis, 6 cases of ankylosing spondylitis involves hip joint. The selected 60 cases, using the randomization method, 60 patients were randomly divided into group A:refer to the transverse acetabular ligament locating acetabular prosthesis in 30 cases; group B:using acetabular locator to position acetabular componment in 30 cases. As the respects of age, sex, body mass index and Hariss score, two groups were compared. In this study, abduction of 45°, anteversion of 15° as the ideal standard. Abduction and anteversion of the 60 patients were measured by 3D CT.We evalute which acetabular angle group is more close to the ideal value.Using the SPSS 18.0 statistical software package for the relevant analysis and data processing of the collected data.Results Homogeneity of two groups in the aspects of age, sex, BMI and Hariss scores had no significant difference (p>0.05), two groups are comparable. CT display all prostheses were obtain ideal bony fixation.no case of prosthesis is loosening. Average of abduction angle of A group is 44.97±2.99°, the average of abduction angle of B group is 51.80±5.08°,the difference was statistically significant (P< 0.05). Average of anteversion of A group is 15.13±2.73°, the average of anteversion of B group is 18.13±3.88°.The difference is statistically significant (P<0.05), which indicates that A group is more close to the ideal value of acetabular angle.Conclusions The method of refering to the transverse acetabular ligament to position acetabular prosthesis, abduction and anteversion is more close to the ideal value on CT scans, which is simple, accurate positioning, reliable.