SURGICAL PEARLS: Stem Fixation in Revision TKA
Whether to use cemented or cementless stem fixation in a revision total knee arthroplasty (TKA) remains controversial, but it doesn’t have to be: If done well, in the appropriate circumstances, either fixation type will work, Robert T. Trousdale, MD, told attendees at ICJR’s 7th Annual Revision Hip & Knee Course.
There is no single solutions for all patients, as both cemented and cementless fixation have their advantages and disadvantages, Dr. Trousdale said, and he, in fact, uses both fixation methods in his revision practice.
The key is to understand the indications for each. For Dr. Trousdale, the indications for use of an uncemented stem in revision TKA include:
- Younger patients with good diaphyseal bone
- Canal geometry that allows for a press-fit stem; ie, no deformity distal or proximal to the knee joint that would prevent component alignment
- Limited metaphyseal bone loss or bone loss that can be reconstructed to allow a good cement interface
- Periprosthetic fractures
- Reimplantation for infection, particularly in young patients
There are some questions about uncemented stems that have yet to be answered, however:
- What is the optimal stem length?
- What is the optimal surface finish of the stem?
- What is the optimal preparation technique?
Compared with uncemented stems, cemented stems have a few advantages. For example, cemented stems provide initial and long-term fixation in fresh metaphyseal and diaphyseal bone, Dr. Trousdale said. They also provide more latitude in adjusting for abnormalities in canal geometry.
However, cemented stems are more difficult to remove than uncemented stems, and they don’t fill the canal – which means that if they aren’t properly positioned, there may be issues with component alignment.
Dr. Trousdale’s indications for use of a cemented stem in revision TKA include:
- Patients with very poor diaphyseal bone and a large canal diameter
- Canal geometry that is not appropriate for an uncemented stem, such as a large valgus bow in the tibia or a large bow in the femur
- Sclerotic or damaged metaphyseal bone that would have inadequate interface fixation even after reconstruction unless cementation was extended into the canal
Click the image above to hear more about stem fixation from Dr. Trousdale, including technical pearls and case reviews.
Robert T. Trousdale, MD, is a professor of orthopaedic surgery and the chair of the Division of Adult Reconstruction in the Department of Orthopedic Surgery at Mayo Clinic, Rochester, Minnesota.
Disclosures: Dr. Trousdale as no disclosures relevant to this presentation.