Comparison of Signature* Personalized Patient Care versus the intramedullary alignment guides by computer-navigated registration of bone cuts in Total Knee Arthroplasty

The Biomet Signature* product for Total Knee Arthroplasty provides for patient
specific alignment guides based on MRI-images. These guides are applied during
the operative procedure and make intramedullar guiding unnecessary. Therefore,
the surgical procedure will be less invasive with shorter intervention time
with less surgical intruments needed. Also, application will probably result in
reduced blood loss and a lower thromboembolic complication rate. With the
patient-specific Signature* guides and 3D MRI-images, the surgeon can probably
determine preoperatively the ideal size and positioning of the prosthesis and
placement will probably be more precise.

Before aligning knee prosthesis according to the Signature guides, a comparison
of the allignment with the conventional method is desired.
the hypothesis of the study is that the bone cuts made according tot the
signature guides are comparable to those of the conventional intramedullary
guides.

Comparing the Signature* alignment guides with the conventional intramedullary
alignment guides by comparing the (proposed) bone cuts of Signature* with the
actual bone cuts of the conventional intramedullary alignment guides.

Clinical , non-randomized sudy

Placement of a Biomet Vanguard* knee prosthesis is done according to the
conventional standard intramedullary alignment guide. During surgery, Stryker
precisioN* Knee Navigation System is applied so cutting plane angles and
resection levels for both Signature* guides and conventional intramedullary
guides can be registered and compared.

All patients have the standard risk for a Vanguard* Complete Knee System. Time
of surgical intervention is expected to be ten to thirty minutes longer as a
result of applying the navigation system and registering the cutting plane
angles. Application of the navigation system requires placement of two
additional percutaneous pins in both femur and tibia, which will be removed
during the procedure. Preceding surgery, the patient will undergo a MRI-scan of
hip, knee and ankle. All patients will obtain the standard rehabilitation
protocol.