SURGICAL PEARLS: Uncemented Stems in Revision TKA
Surgeons performing revision total knee arthroplasty (TKA) have 2 viable stem options: short- to moderate-length cemented constructs and longer-length uncemented constructs and both have advantages, Kevin I. Perry, MD, told attendees at ICJR’s 7th Annual Revision Hip & Knee Course.
Cemented stems, for example, can be used to “cheat” the anatomy in the canal. They provide immediate fixation and cause less end of stem pain. Uncemented stems can help prevent malalignment of the knee, can be protective of a fracture, and can be more easily removed if the patient has chronic infections.
Some surgeons believe cemented stems are superior for delivery of antibiotics, but Dr. Perry said that antibiotic delivery is still possible with an uncemented stem: The surgeon should be creating a 7- to 8-cm cement mantle with a long uncemented stem, about the same amount of cement as would be used with a cemented short- to moderate-length stem, rendering that “advantage” moot.
Dr. Perry provided a few pearls for using an uncemented stem, in addition to the long cement mantle:
- Ensure that the construct is long enough to engage the diaphysis.
- Be prepared to use a short stem if, intraoperatively, it becomes apparent that the patient’s anatomy is not conducive to the long stem.
- Prevent end of stem pain by:
- Ensuring metaphyseal fixation with sleeves and cones, which offload the implant/bone cement interface and allow for less-aggressive reaming
- Thinking about reaming as reaming out to the cortex instead of reaming into the cortex
- Reaming until the reamer is 2 fingers tight
- Avoiding aggressive impacting of the stem
Click on the image above to watch the presentation, which includes Dr. Perry’s narration of videos showing his tibial and femoral preparation techniques when using an uncemented stem in revision TKA.
Kevin I. Perry, MD, is an assistant professor of orthopaedic surgery at Mayo Clinic in Rochester, Minnesota.
Disclosures: Dr. Perry has no disclosures relevant to this presentation.