3 6 S U P P L E M E N T T O O U T P A T I E N T S U R G E R Y M A G A Z I N E A U G U S T 2 0 1 6
degrees in the tibial tray. These tend to be more technically challenging to
implant, but the wear rate is very low. Fixed-bearing implants have the polyethyl-
ene component in place and tend to be easier to manipulate, though they typical-
ly have a higher rate of wear. "Both styles of implants have excellent results,"
says Dr. Della Valle. "The decision of which one to use typically comes down to
surgeon familiarity. They get comfortable with a certain implant or technique in
their residency and tend to stick with that."
• Reprocessing needs. One factor that can impact your choice of unicompart-
mental knee systems is the size and capacity of your facility, says Dr.
Levengood. While partial replacements require less instrumentation than total
joints, your surgeons may still need several large trays of power tools and
instruments to implant conventional off-the-shelf systems. Smaller, more
streamlined facilities might be better served with patient-specific implant sys-
tems that include single instrument trays, cutting guides and the implants need-
ed for individual patients, says Dr. Levengood. For patient-specific systems
patients must get a pre-op CT scan, which the implant manufacturer uses to cre-
ate a customized implant and cutting jig. The manufacturer sends the jig,
implant and tools for the procedure to the facility in a single box.
Patient-specific implant systems help to control your supply inventories. "You
don't have to use the standard heavy instrumentation, which means you don't
have to sterilize all those tools," says Dr. Levengood. "If you're trying to boost
turnover times and move cases through more efficiently, reprocessing numerous
trays of complex instruments can be a hassle." With patient-specific systems,
everything the surgeon needs arrives pre-sterilized and is disposable, which
makes setting up cases and cleaning rooms between cases a lot simpler.
• Patient-specific components. In addition to patient-specific implants, some
manufacturers offer patient-specific cutting guides. Patients undergo a pre-op
MRI or CT scan, which manufacturers use to design a custom, disposable cut-
ting jig that guides the surgeon's cuts in the bones of the joint to improve the fit
of an off-the-shelf implant. Though studies haven't definitively shown that
