Inclusion Criteria

• Has total primary hip replacement indicted in the following conditions:
  • A severely painful and/or disabled joint from osteoarthritis, traumatic arthritis, rheumatoid arthritis, or congenital hip dysplasia;
  • Avascular necrosis of the femoral head;
  • Acute traumatic fracture of the femoral head or neck;
  • Certain cases of ankylosis.
• Has hemi-hip arthroplasty indicted in the following conditions:
  • Acute fracture of the femoral head or neck that cannot be appropriately reduced and treated with internal fixation;
  • Fracture dislocation of the hip that cannot be appropriately reduced and treated with internal fixation;
  • Avascular necrosis of the femoral head;
  • Non-union of femoral neck fractures;
  • Certain high sub-capital and femoral neck fractures in the elderly;
  • Degenerative arthritis involving only the femoral head in which the acetabulum does not require replacement;
  • Pathology involving only the femoral head in which the acetabulum does not require replacement.
• Further inclusion criteria,in the opinion of the Principal Investigator, for using the devices specified in this protocol as follows:
  • Individuals who are able to speak, read, and comprehend the informed patient consent (IPC) document and willing and able to provide informed patient consent for participation in the study and have authorized the transfer of his/her information to DePuy Synthes (Joint Reconstruction);
  • Individuals who are willing and able to return for follow-up as specified by the study protocol;
  • Individuals who are a minimum age of 21 years at the time of consent;
  • Individuals who are not bedridden;
  • Individuals who are willing and able to complete the Subject Hip Outcomes questionnaires (i.e., FJS-12, HOOS and Hip Evaluation) as specified by the study protocol.
• Individuals interested in participating in the parallel and optional Patient Activity Tracking portion of the study are required to link the Patient Activity Tracking device to their own well-functioning smartphone (i.e., iPhone or Android phone) via a downloaded mobile application (i.e., ActiTrak™). If a Subject does not have a smartphone, and would like to participate in the Patient Activity Tracking portion of the study, the Sponsor will be able to provide an Android type tablet to which the required app can be downloaded.
• Individuals interested in participating in the optional Patient Activity Tracking (ActiTrak™) portion of the study must be willing to wear the Patient Activity Tracking device from the time of consent preoperative (if possible, based on date of consent) and for 3 months postoperative.
• Individuals interested in participating in the optional Patient Activity Tracking (ActiTrak™) portion of the study must have the ability to return at the 3 month follow-up visit in order to return the Patient Activity Tracking device, and if applicable, the Sponsor's Android tablet back to the study site.

Exclusion Criteria:

Subjects will be excluded if, in the opinion of the Investigator, the individual meets any of the following exclusions:

• Active local or systemic infection.
• Loss of musculature, neuromuscular compromise or vascular.
• Poor bone quality, such as osteoporosis, where in the surgeon's opinion, there could be considerable migration of the prosthesis or a significant chance of fracture of the femoral shaft and/or the lack of adequate bone to support the implant(s).
• Charcot's or Paget's disease.
• For hemi-hip arthroplasty, any pathological condition of the acetabulum, such as distorted acetabuli with irregularities, protrusion acetabuli (arthrokatadysis), or migrating acetabuli, that would preclude the use of the natural acetabulum as an appropriate articular surface for the hemi-hip prosthesis.
• The subject is a woman who is pregnant or lactating.
• Existing contralateral hip that was implanted less than 6 months from the date of surgery at the time of consent into this study.
• Subjects requiring a simultaneous bilateral hip at the time of consent will be excluded; there can be only one Actis™ study hip. This also means that even if another hip system is used for the contralateral hip during simultaneous THAs, the Subject will be excluded. As noted above, Subjects who have an existing contralateral total hip replacement greater than 6 months postoperatively at the time of consent may be entered into this study if they qualify based upon the eligibility criteria and the approved labeling requirements.
• Subject had a contralateral amputation.
• Subject has participated in a clinical investigation with an investigational product (drug or device) in the last three months.
• Subject is currently involved in any personal injury litigation, medical-legal or worker's compensation claims.
• Subject, in the opinion of the Investigator, is a drug or alcohol abuser or has a psychological disorder that could affect their ability to complete patient reported questionnaires or be compliant with follow-up requirements.
• Subject was diagnosed and is taking prescription medications to treat a muscular disorder that limits mobility due to severe stiffness and pain such as fibromyalgia or polymyalgia.
• Subject has a medical condition with less than 2 years of life expectancy. Note: Diabetes, at present, has not been established as a contraindication. However, because of the increased risk for complications such as infection, slow wound healing, etc., the physician should carefully consider the advisability of hip replacement in the severely diabetic patient.