Unable to engage surgeons to participate in the study

The primary purpose of this pilot study is to evaluate the accuracy of cup placement between two instrumentation technologies: Cutting Guide and Conventional Instrumentation.

Using a more advanced surgical technique may assist surgeons and patients in a variety of ways including identifying a specific-size for the prosthesis prior to surgery, increasing operating room efficiency, and reducing the number of traditional instruments needed. This may reduce cost associated with the instrument inventory and instrument sterilization. Operating time may also be reduced, potentially decreasing the patient's risk of infection. However, before these hypotheses can be tested, it is important to fully understand the efficacy and accuracy of Signature Custom Guides and their use in Total Hip Arthroplasty.

Inclusion Criteria:

• Subjects with one of the following indication:
• Noninflammatory degenerative joint disease including osteoarthritis and avascular necrosis.
• Rheumatoid arthritis.
• Correction of functional deformity.
• Treatment of non-union, femoral neck fracture, and trochanteric fractures of the proximal femur with head involvement, unmanageable by other techniques.

Additional inclusion criteria include:

• Subjects requiring primary total hip arthroplasty
• 20 to 75 years of age
• Subjects with a diagnosis of osteoarthritis or traumatic arthritis
• Subjects willing to return for follow-up evaluations.
• Subjects who can read, understand study information and give written consent without representation of a legally authorized representative.
• Bilateral patients are included if staged.
• Only Posterior Lateral Approach can be used for inclusion in this study

Exclusion Criteria:

- Exclusion criteria should be in accordance with Contraindications for the Biomet primary acetabular cup.

Absolute contraindications include: infection, sepsis, osteomyelitis, and failure of a previous joint replacement.

Additional contraindications include:

• Subjects whose bony structure deviates substantially from the general norm sufficiently to require non-standard implants. Specific examples of these are total dislocation of the hip, severe coxa vera deformity, and severe forms of multiple epiphyseal dysplasia
• Subjects unable to cooperate with and complete the study
• Dementia and inability to understand and follow instructions
• Neurological conditions affecting movement
• Pregnancy

Additional exclusion criteria include:

• Surgical approach other than posterior lateral.
• Simultaneous bilateral procedures

6 months

Early termination leading to small numbers of subjects analyzed