Vanguard Knee Anterior Stabilized Versus Posterior Stabilized Bearing Study

A Comparative Clinical Evaluation of the Vanguard Knee System's Anterior Stabilized & Posterior Stabilized Tibial Bearings

The purpose of this study is to compare the performance of two FDA-cleared tibial bearings (replacement for cartilage in the knee) by collecting data on patients through 3 years of follow-up.

Inclusion Criteria are identical to the indications stated in the FDA approved labeling for the device 510(k) K023546, K033489, and K050222. These indications are stated below:

• Painful and disabled knee joint resulting from osteoarthritis, rheumatoid arthritis, traumatic arthritis where one or more compartments are involved.
• Correction of varus, valgus, or posttraumatic deformity.
• Correction or revision of unsuccessful osteotomy, or arthrodesis.

Patient selection factors to be considered include:

• Need to obtain pain relief and improve function
• Ability and willingness of the patient to follow instructions, including control of weight and activity level
• A good nutritional state of the patient
• The patient must have reached full skeletal maturity

Exclusion criteria will be identical to the contraindications stated in the FDA approved labeling for the device 510(k) K023546, K033489, and K050222.

These contraindications are stated below:

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

Relative contraindications include:

• Uncooperative patient or patient with neurologic disorders who are incapable of following directions
• Osteoporosis,
• Metabolic disorders which may impair bone formation
• Osteomalacia
• Distant foci of infections which may spread to the implant site,
• Rapid joint destruction, marked bone loss or bone resorption apparent on roentgenogram,
• Vascular insufficiency, muscular atrophy, neuromuscular disease,
• Incomplete or deficient soft tissue surrounding the knee