REDAPT Revision Hip System With RSA

Early Stability Assessment of the REDAPT Revision Hip System With Radiostereometric Analysis

The principal objectives of the study are to evaluate early and mid-term fixation of the REDAPT revision hip stem and acetabular cup as measured by stem subsidence and proximal cup migration at 2 and 5 years post-surgery through model-based RSA. Secondary objectives include; evaluate the progression of migration between 1 and 2 years and between 2 and 5 years, assess pre- to post-surgery patient improvement in function and health status, evaluate femoral and acetabular radiolucency at 2 and 5 years, and assess patterns of stem migrate on for different revision scenarios (preservation of the trochanters and extended trochanteric osteotomy).

This is a prospective, single arm, consecutive series study of patients undergoing revision hip arthroplasty. Patients will be grouped based on the revision implants they receive during surgery. Patients who receive a full hip revision (stem and cup), will be counted in both study groups. The two study groups are:

1. femoral stem revision (n=30 hips)
2. acetabular cup revision (n=22 hips)

Inclusion Criteria:

• Patients needing revision hip arthroplasty in which either the femoral stem or the acetabular cup, or both components, will be revised
• Ability to use study device (not requiring specialized implants)
• Patients between the ages of 18+ older
• Patients willing and able to comply with follow-up requirements and self-evaluations
• Ability to give informed consent

Exclusion Criteria:

• Acute infection requiring washout, debridement, and liner exchange
• Unresolved infection
• Undergoing stage 1 of a 2-stage revision for infection
• Known metal allergy to device components
• Active participation in another clinical study (within the past 30 days)
• Known risk for loss to follow-up (significant geographical distance from treatment centre)
• BMI>40 (severe obesity)
• Unable to provide informed consent (cognitive impairment)
• Patients requiring a bearing couple different than metal on polyethylene
• Patients requiring extreme distal press-fit revision stems (greater than 240 mm in length)
• Patients with severe defects, dysplasia, or tumor
• Inflammatory joint disease