This study is a multicenter, retrospective and prospective, non-controlled, non-randomized post market clinical follow-up study. The objectives of this study are to confirm the long-term safety, performance and clinical benefits the Exception Cementless femoral stem (standard and varized) when used in primary total hip arthroplasty.

Six surgeons have prospectively collected clinical data for patients operated consecutively between January 2008 and September 2012. The patients have been operated based on the indications and contraindications listed in the Instructions For Use (IFUs) of the implant.

This study is an extension of the surgeons' data collection as an attempt from Zimmer-Biomet to fulfill its post-market surveillance obligations by recovering clinical data retrospectively and prospectively.

Study Procedure Flowchart - retrospective data collection: most patients had clinical follow-ups at pre-op, operative, immediate post-op, 3 Months, 1 year, 2, 3, 5, 7 years post-surgery during which their surgeons collected clinical data. This data will therefore only be collected by Zimmer-Biomet after the patients specifically consent to it.

Study Procedure Flowchart - prospective data collection: The informed consent signed by the patient for this study also allow Zimmer Biomet to collect the data of the standard clinical follow-up that will be conducted by the investigators at least 10 years post-surgery.

At the time of surgery, the inclusion criteria were based on the indications presented in the IFUs:

• Primary or secondary osteoarthritis
• Inflammatory impairment of the hip, rheumatoid arthritis, etc.
• Fracture of the neck of the femur
• Avascular necrosis of the femoral head
• Sequelae from previous operations on the hip, osteotomies, etc.
• Congenital hip dysplasia.
• Patient is older than 18 years old
• Patient had consented to the original data collection after his/her surgery

At the time of surgery, the exclusion criteria were based on the contraindications presented in the IFUs:

• Local or systemic infections.
• Serious muscular, neurological or vascular deficiencies in the limb concerned.
• Bone destruction or poor quality bone likely to affect the stability of the implant (Paget's disease, osteoporosis, etc.)
• Any concomitant disorder likely to affect the function of the implant.
• Allergy to one of the implant components.
• Patients weighing more than 110 kg.
• Patient incapable of following the recommendations of the surgeon

Six surgeons have prospectively collected clinical data for patients operated consecutively between January 2008 and September 2012. The patients have been operated based on the indications and contraindications listed in the Instructions For Use (IFUs) of the implant.

For this retrospective and prospective study, only the patients who had consented to the original data collection after their surgery will be contacted.

These the patients should be capable of understanding the surgeon's explanations and following his instructions, should be able and willing to participate in the last follow-up visit, and should give consent to take part in the study. The patients should meet all the inclusion criteria and none of the exclusion criteria.