The aim of the study was to evaluate THA using Robodoc system for osteoarthritis of the hip joint.

The Robodoc system consists of: 1. the Orthodoc computer workstation that simultaneously displays computerised tomography images of patient’s femur and a selected prosthesis, 2.a five-axis robot, 3.the operating room display, 4. the control cabinet.

Follow up were 3months and 1 year on 27cases (Male 5, Female 22). Selected stems: Zimmer anatomic, 13, Versis 14(VSS,7, VSL,7). Mean age 57.9. Among 27 cases of osteoarthritis, one is after osteotomy and two are after osteonecrosis. Pain, ROM, Radiographs and ADL were evaluated using JOA hip score system. Sockets were fixed with cementless conventional technique.

Mean operating time, 2 hours and 40min.; Mean bleeding, 455 ml; Mean Ant. Version, 29.26 degree (22.0–39.7); Level of osteotomy of the femur neck, Mean, 9.19 mm from the trochanter minor. JOA hip score after THA, 82.20. In one case, 5 mm sinking occurred 5 days after the operation. No intraoperative femoral fractures and varus or valgus insertion of stems occurred in 27cases. The thigh pains were nothing. The patients were discharged at 4weeks after the operation with one crutch. The results showed statistically better fit and fill of the femoral component in the Robodoc system.

The Robodoc system is thought to be safe and effective in producing radiographically superior implant fit and positioning without fractures and other complication. Precise fit of the implant may be increase bone-to-implant contact, providing stress transfer from prosthesis to bone and more bone growth into prosthesis.