Clinical application of CT measurement in primary total hip arthroplasty of DDH patients

Objective To investigate the clinical effect of preoperative computed tomography (CT) measurement of acetabulum femoral neck combined anteversion in primary total hip arthroplasty (THA). Methods From March 2016 to may 2018, 48 patients (90 hips) with developmental dysplasia of the hip (DDH) who were treated with THA in the orthopaedic department of Jiangmen Central Hospital were measured by X-ray and spiral CT three-dimensional reconstruction technology before operation, and the best combined anteversion angle of acetabulum was determined before implementing THA, which was CT group; the remaining 42 patients were not measured by CT before operation, which was X-ray group. The difference of acetabulum cup anteversion angle, acetabulum femoral neck combined anteversion angle and preoperation angle were evaluated by three-dimensional computed tomography (3D-CT) in CT group. Results There was no significant difference in operative time, intraoperative blood loss, time of getting out of bed and length of lower limbs between the two groups (P>0.05). In CT group, the acetabulum cup anteversion and acetabulum femoral neck anteversion were close to the pre-operative angle at 2 and 3 months postoperatively (P>0.05). The Harris hip score of CT group was significantly higher than that of X-ray group at 2 and 3 months after operation, and the incidence of deep vein thrombosis was 6.25%, significantly lower than that of X-ray group (21.43%) (P 0.05). Conclusions For DDH patients who received THA for the first time, preoperative CT measurement of acetabulum femoral neck combined with anteversion is conducive to the formulation of the best combined anteversion adjustment scheme, which can obtain the maximum initial stability, improve the surgical effect and reduce the occurrence of dislocation of prosthesis. Key words: Tomography, X-ray computed; Acetabulum; Femur neck; Hip dysplasia; Arthroplasty, replacement, hip