The purpose of this study is to evaluate the survivorship (revision rates) and patient reported outcomes (PROMs) following implantation of the Insignia hip stem in patients undergoing cementless total hip replacement surgery compared to currently available stems used for the same type of surgery.

It is hypothesised the 2-year survivorship of the Insignia stem is noninferior to the benchmark survivorship of similar stems used in the same type of surgery.

Inclusion Criteria:

• The patient has signed the study specific, Human Research Ethics Committee (HREC) approved, Patient Information Consent Form for the use of the study device
• Primary non-inflammatory degenerative joint disease (including osteoarthritis or avascular necrosis) and/or rheumatoid arthritis
• The patient is a candidate for a primary cementless THA.
• Patients who are informed of the conditions of the study and are willing to participate for the length of the prescribed follow-up period.

Exclusion Criteria:

• Active or suspected latent infection in or about the affected hip joint and the time of study device implantation.
• Any mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure or complications in post-operative care.
• Has bone stock compromised by disease, infection or prior implantation which cannot provide adequate support and/or fixation to the prosthesis.
• Is immunologically suppressed or receiving steroids in excess of normal physiological requirements (e.g. >30 days.)
• Requires revision THA or hip fusion to the affected joint.
• Has known sensitivity to device materials.
• Any involvement in an active Workers' Compensation investigation