Mini Stem Radiostereometric Analysis Study

A Randomized Controlled Trial to Compare Implant Migration of the MIS Stem Versus The Synergy Total Hip System by Radiostereometric Analysis

The objectives of this study are to assess migration of the MIS Stem compared to the Synergy Hip System using Radiostereometric Analysis (RSA), and to assess the long-term safety and effectiveness of the study device. This study will document any device-related surgical or post-operative complications and adverse radiographic observations.

Subjects meeting the entrance criteria specified in this protocol will be randomized as they become available.

The purpose of the current investigation is to compare migration of the device after implantation with a modular, short hip stem called the "MIS Stem" or a standard THA using the Synergy Hip System using RSA. The intended use of this product is for patients with inflammatory and non-inflammatory degenerative joint disease who require a primary total hip replacement.

Inclusion Criteria:

• Subject has hip disease that requires a total hip arthroplasty.
• Subject is willing to consent to participation in the study.
• Subject plans to be available for follow-up through study duration.
• Subject is of stable health and is free of or treated and stabilized for any condition that would prose excessive operating risk.

Exclusion Criteria:

• Subject has insufficient femoral bone stock.
• Subject has had major non-arthroscopic surgery to the study hip.
• Subject has physical, emotional or neurological conditions that would compromise the subjects compliance with postoperative rehabilitation and follow-up.
• Subject has a known sensitivity to materials in the device.