Differences in relative parameters of acetabulum in hip arthroplasty between CT horizontal plane and CT true pelvic plane / 中国组织工程研究

ABSTRACT

BACKGROUND: The accuracy of acetabular prosthesis placement during total hip arthroplasty has a direct effect on postoperative hip function, stability and service life. Unreasonable placement of the cup may lead to adverse events, so CT imaging should be emphasized. OBJECTIVE: To analyze the differences of acetabular parameters in hip arthroplasty between the horizontal and true pelvic planes on CT images, and to determine the possible impact on surgery outcomes. METHODS: Seventy-two cases of pelvic soft tissue disease were selected. All patients signed the informed consents, and the study was approved by the hospital ethics committee. The anteversion angle, acetabular angle, acetabular depth, acetabular width, femoral head midpoint-acetabular margin angle, abduction angle between the true pelvic plane and the horizontal plane were measured by CT positioning film and its scanning image. CT software was selected to reconstruct the three-dimensional image, and then scanned vertically with the true pelvic plane. The above parameters were measured in the same way. The differences of parameters between left and right acetabulum and two planes were compared by paired t test. Spearman correlation analysis was used to analyze the correlation between the angles between the two reference planes and the difference between the measured parameters. RESULTS AND CONCLUSION: (1) There was no significant difference in the values of the left and right acetabular parameters between the horizontal plane and the true pelvic plane (P > 0.05). (2) The pelvic tilt angle was positively correlated with the femoral head midpoint-acetabular margin angle and the acetabular anteversion angle between the two reference surfaces, and negatively correlated with the acetabular angle and acetabular depth. (3) Our results suggest that during the CT scan of the supine position, the pelvis is accompanied by a rotation condition. The parameters of the true pelvis plane as a reference are inaccurate with the directly measured acetabular parameters. Therefore, attention should be paid to the preparation of the surgical plan before surgery.