Kenneth D. Kleist, M.D.

HealthPartners Medical Group

Regions Hospital

St. Paul, MN

What’s New in Knee What’s New in Knee ReplacementReplacement

Goals of Knee ReplacementGoals of Knee Replacement

• Improve the quality of life by improving pain and function while maintaining range of motion and avoiding complications.

• 85% of Knee replacement patients say they would have the surgery again.

TrendsTrends

What is a joint replacement?What is a joint replacement?

What is a partial knee What is a partial knee replacement?replacement?

Minimally Invasive SurgeryMinimally Invasive Surgery

• No good consensus on what this means– Less skin incision– Less tendon/muscle splitting and damage– ??? More rapid recovery

• Certainly there are benefits– Cosmetic, psychological, blood loss, recovery

• Bottom Line– Need to have pieces put in right!– Long-term survival of the joint is most

important

ApproachApproach

• Medial Parapatellar• Mini-Medial

Parapatellar• Mid Vastus• Sub Vastus• Quad Sparing

Pain Control and Rehabilitation Pain Control and Rehabilitation ProtocolsProtocols

• Regional Anesthesia increasing– Spinal or Epidural Anesthesia– Femoral Nerve Blocks– Pre-op Medicines– Pain Catheters, continuous or on

demand– Local anesthetic intra-operatively– Cryocuff for icing– Long-Acting Narcotics– Less Intravenous narcotics– Pain as a vital sign

Better Nausea ControlBetter Nausea Control

• Much more focus– Regional Anesthesia Helps– Multimodal approach

• Less intravenous narcotics• Scopolamine patches• Odansetron• Prochlorperazine • Metoclopramide

Post-operative Physical Post-operative Physical TherapyTherapy• Early mobility is helpful

– Continuous Passive Motion (CPM) the night of surgery

• Start at high flexion right away

• Set goals for range of motion

– Up on your feet the first post-operative day

– Discharge on the third post-operative day

– Transition from walker to cane to nothing

How much flex is enough?How much flex is enough?

• High flexion implants– Theoretically allow higher range of motion

• Traditional Implants 125, maybe 135 degrees• Some now up to 155 Degrees

– Caution: High flexion does not mean you definitely will get better motion.

– Setting Expectations is Important• Best predictor is pre-op motion• Knee will not be normal.

– Can make the surgery slightly easier by removing extra bone

– Can provide additional implant options.

Gender Specific Gender Specific

• 3 anatomical shape differences– Females are narrower– They have a different angle the

knee cap glides through– They have thinner area at the

front of the bone• Most companies now address this

in some way– Shape change– Sizing

Mobile Bearing TKAMobile Bearing TKA

• Rotating Platform– Plastic liner rotates in the metal– May decrease wear– May improve motion– May allow fudge factor– However may also increase wear.– More difficult to insert plastic

Highly Crosslinked Highly Crosslinked PolyethylenePolyethylene

• Relatively New– Not as accepted as in the hip

• Goal is to reduce wear– Still long-term questions

about mechanica strength to fracture resistance and delamination

– Not common used by most surgeons yet except in limited cases

• Very young patient

Other Alternative BearingsOther Alternative Bearings

• New approaches to femoral components– Ceramics– Oxidized Zirconium

Computer NavigationComputer Navigation• Still Controversial• May improve overall alignment• May improve the accuracy of sizing• Possible it may improve long term outcome• Increases time• “Garbage In, Garbage out”• May place you at a minimal risk for fracture• Awaiting long-term data

Direct to Consumer MarketingDirect to Consumer Marketing

Current State of Patient’s Current State of Patient’s Decision Making in Today’s Decision Making in Today’s

Market!Market!• The best advice is to

have a discussion with your surgeon.

• Balancing Act– Patients needs/desires– Surgeon training,

experience, and skill