Digital Preop-planning of Total Hip Arthroplasties (PLANORTHO)

Residual leg length discrepancy is a common issue after total hip arthroplasty(THA). Digital preoperative planning may improve the accuracy of the surgical procedure and may help the surgeon to precisely predict implants sizes

Total hip arthroplasties (THAs) are used to restore locomotion. More than 150,000 THAs are performed each year in France. Better outcomes require a restoration of limb lengths and anatomy. Post-operative discrepancy is the main cause of complaints and financial compensation in the US after THA. As such, the investigators aim to use preoperative digital planning using TraumaCad to optimize the restoration of the center of rotation of the hips. Preoperative planning are usually performed using anteroposterior standard radiographs, which are scaled to an inaccurate scale. The TraumaCad system (Brainlab®) allows the adjustment of the scales to each patient and the virtual positioning of the implants in order to simulate the intervention for the restitution of the geometrical parameters of the hip.

The primary endpoint is the postoperative residual discrepancy measured on the radiographs on postop day 3 in millimeter compared using standard planning methods compared to TraumaCad.

Secondary endpoints is comparisons of the reproducibility of the femoral implants sizes predicted by the software

Secondary endpoints is the comparison of pelvis parameters in the 2 groups (offset, positioning of the implants) postoperatively. The angle of femur axis and the center of rotation of hip will be measure on the radiography of day 3

Inclusion Criteria: being older than18 years, osteoarthritis as the indication for THA Exclusion Criteria: THAs after femoral neck fractures, revision surgery, major architectural anomaly (Bone tumor, prior fracture of the pelvis, hip dysplasia), patients under legal protection, pregnancy or breast-feeding