VIDEO VIGNETTE: Converting a UKA to a TKA
Richard A. Berger, MD, from Rush University Medical Center in Chicago, Illinois, performs more unicondylar knee arthroplasty (UKA) procedures annually than most orthopaedic surgeons in the US.
Because UKAs tend to have a higher failure rate than total knee arthroplasties (TKA), Dr. Berger is also well-versed in converting UKAs to TKAs when necessary, typically when osteoarthritis progresses beyond a single condyle and causes an increase in knee pain.
At ICJR’s Revision Hip & Knee Course, Dr. Berger demonstrated his procedure for converting to a TKA and offered his surgical pearls to improve the success of the conversion.
Dr. Berger views converting the UKA to a TKA as more similar to a primary TKA than to a revision TKA, the latter of which typically involves more significant bone loss. In fact, a patient who is being converted to a TKA from a UKA generally has good:
- Bone stock
- Ligamentous balance
- Preoperative motion, with balanced gaps
In addition, these patients rarely have more than minimal patella baja.
In the OR, Dr. Berger treats the procedure like a primary knee. He does not remove the UKA components, and instead makes bone cuts while the components are still in place. He admits this means he may make a more generous bone cut than he would in a primary procedure, but he can generally compensate with a thicker tibial tray.
If he were to remove the UKA components first, he said, he would need to treat the procedure as revision and would likely be facing greater bone loss.
Click the image above to watch Dr. Berger’s presentation.