Hip or knee arthroplasties allow a relief of pain and a good functional habilitative at patients suffering from degenerative osteoarthritis of these articulations with medium and long-term good results. The main objective of this study is to compare the efficiency in short and medium-term functional impact parlance of two surgical techniques: computer-assisted surgery and mini-invasive surgery compared to the conventional techniques thanks to an innovative technology of ambulatory analysis of walking.

Inclusion Criteria:

• Weight < 100 kg
• score UCLA > 4
• prosthesis of first intention

Exclusion Criteria:

• Pregnant
• score UCLA < 4
• osteotomy near to prosthesis
• prosthesis requiring an osseous transplant
• prosthesis already set up
• infections, contagious diseases (HIV, tuberculosis, hepatitis, venereal diseases) or metastasis
• neuromuscular diseases able to perturb walking or staying
• congenital or acquired disease, or previous surgery able to have consequences on results and prosthesis survey according to the surgeon