SURGICAL PEARLS: Tips and Techniques for Revision TKA from Dr. Matt Austin
At ICJR’s Winter Hip & Knee Course in Vail, Colorado, Matthew S. Austin, MD, from The Rothman Institute in Philadelphia, Pennsylvania, provided his top 5 tips and techniques for revision total knee arthroplasty (TKA).
This is typically an overlooked step, Dr. Austin said. He teaches fellows the importance of preoperative planning for revision TKA, emphasizing that most of the thinking involved in the procedure should be done before entering the operating room (OR). The questions to ask – and answer – during preoperative planning include:
- What is the problem?
- Can I solve the problem? Do I have the skills to solve the problem?
- Who is my patient? Is the patient young or old, and what is the quality of the bone?
- What tools, including implants and augments, do I need to solve the problem?
- Am I prepared to tackle a worst-case scenario involving bone loss and ligament damage?
Be sure to communicate the plan to the OR staff, perioperative staff, implant representatives, and human tissue bank. Keep the plan simple to communicate effectively.
KISS – Keep It Simple, Stupid
When it comes to revision surgery Dr. Austin believes in the KISS principle. He minimizes the number of instrument trays available and ensures that the instrument table is clear of instruments not commonly used. This makes for simpler sterilization processing and creates a better workspace for the surgical technician.
Exposure and Component Removal
Dr. Austin uses the most lateral, usable existing incision for the exposure and makes sure to create thick skin flaps. Revision surgery, he said, is “MIS” surgery: Maximally Invasive Surgery.
To achieve great exposure, be patient and use an extensile medial parapatellar approach, Dr. Austin said. Perform an extensor mechanism tenolysis as well as a synovectomy to clear the gutters until the implants are fully exposed. A quadriceps snip may be necessary if these steps do not provide sufficient exposure, he said, or the surgeon may need to do a tibial tubercle osteotomy in difficult cases. The “banana peel” and VY turndown are rarely used.
When the components are fully exposed, an oscillating saw is used to disrupt the cement-component interface. After the saw, a wide osteotome is used on the tibial side and a narrow osteotome is used on the femoral side. To disimpact the tibial component, Dr. Austin keeps the punch as central as possible on the tibial component.
When removing cement from the tibial canal, Dr. Austin first uses a burr to create a central defect in the cement mantle. This allows him to “collapse” the remaining cement into this defect using an osteotome, imparting less force on the bone during cement removal.
Dr. Austin primarily uses osteotomes to disrupt the cement-component interface of the femoral side. It is important to disrupt enough of this interface to allow the component to be removed with minimal force.
Soft tissue is then cleared from the posterior aspect of the knee to provide a clear view of remaining cement on the posterior condyles. This cement is removed using a burr.
After the components have been removed, Dr. Austin begins reaming by hand to feel where the canal is located. Whether using cemented or uncemented stems, Dr. Austin tends to ream into the diaphysis to get a feel for the alignment.
Minimize Complex Instrumentation
All that’s needed for a straightforward revision is reamers, trial components, and maybe a box cutting guide, Dr. Austin said. The only steps necessary are reaming for the length and diameter of the stem and the length and diameter of the boss on the tibial and femoral sides. So, get rid of all the complex instrumentation!
The reaming process is started by hand and completed using power reaming. The tibia and femur are reamed at the same time, as this is more efficient. With the reaming completed, Dr. Austin inserts the trial femoral component to mark the position of the femoral box and then uses the box cutting guide to complete the box cut.
The knee is balanced with the trial components in place, and the level of the joint line is judged by measuring the distance from the medial epicondyle to the distal femoral condyle of the trial. Dr. Austin aims for that distance to be about 3 cm.
Treat Revision Patients Like Primary Patients after Surgery
In his practice, Dr. Austin uses the same rehabilitation and pain management protocols for revision patients as for a primary TKA patients. He has found that revision and primary patients greatly appreciate being pain-free without opioids.
Click the image above to watch Dr. Austin’s presentation.
Dr. Austin has no disclosures relevant to his presentation.