Total replacement of hip joint is one of the most important medical innovations of the twentieth century. More than 100,000 hip replacements are being laid each year in France.

Improved fixation, reduced wear rates and reduced implant dislocation rates remain subjects of continuous improvement.

Hip implants cemented and cementless are part of therapeutic arsenal of orthopedic surgeons for joint replacement of the defective hip.

The anchor and friction torque are both essential to the survival of hip implants. Therefore acetabular implants without cement with ceramic insert or polyethylene in a metalback or full polyethylene coated with titanium grains without metalback are proposed, but they have their own complications (Squeaking, fractures, recovery difficulties, difficult radiographic analysis, high cost for ceramics, primary stability defects, instability of the instrument set, Titanium residues in absence of metalback. An alternative to these implants may be an acetabular component without cement with polyethylene insert with an end metalback to increase both polyethylene thickness and size of the head in order to expect a low complication rate with important longevity for a lower cost.

This study was conducted to ensure the safety and effectiveness of the acetabular implant "POLYMAX"

Inclusion Criteria:

• Patient suffering from hip disease: primary or secondary hip osteoarthritis or osteonecrosis.
• Patient having been implanted with a POLYMAX implant;
• Patient having agreed to participate in a follow-up 5 years;
• Patient who have accepted the use of their data in the context of this study.
• Patient having pre-operative and post-operative data

Exclusion Criteria:

• Pre or post-operative Partial data
• Patients not available for follow up at 2 and 5 years ..
• Metabolic disease or autoimmune witch may interfere with bone growth not allowing the indication of a prosthesis without cement,
• Mental disorder or disease of proven behavior.
• Severe osteoporosis,
• Direct or indirect bone irradiation

Patient with osteoarthritis