Total hip arthroplaty (THA) using direct anterior minimal invasive (AMI) surgery is an attractive option to achieve a quicker habilitation. However, high complication rates were reported and very often related to technical difficulties at the time of surgery. We hypothesized that 3D preoperative planning may allow to anticipate these difficulties and to decrease the complications rates when using an AMI approach. A prospective observational study included 191 consecutive patients who underwent a primary cementless THA using an AMI. A 3D CT-scan based pre-operative planning was performed in order to anticipate the potential difficulties that may be encountered especially regarding the hip anatomy reconstruction and the implants stability. The components size and position were planned in order to restore the leg length, the offsets, and the anteversions. Postoperatively, a CT scan was performed in order to compare the final anatomy to the planning.Introduction
Material and methods
According to the literature, the gait does not return to normal after THA. However, the three-dimensional hip anatomy is usually not assessed before and after surgery. Our hypothesis was that an accurate reconstruction of the hip anatomy, based on a three-dimensional preoperative planning, may normalize the gait after THA. 18 consecutive patients, graded Charnley A, aged of 59.3 ±13 years, underwent THA for unilateral primary osteoarthritis using a direct anterior minimal invasive approach. A 3D computerised planning was performed, the implants size and position were chosen in order to restore, the leg length, the off-set, the centre of rotation and the anteversion angles (Figure 1). At 1 year follow up, a 3D gait analysis was performed and included 29 parameters describing the kinetics and the kinematics. Each patient was compared to himself using the contra-lateral healthy hip, as well as to a group of 13 healthy volunteers.Introduction
Material and method
