Dr. Scott Sporer’s Tips and Techniques for Revision TKA
When performing a revision total knee arthroplasty (TKA), Scott M. Sporer, MD, MS, from Rush University Medical Center in Chicago, Illinois, has 4 objectives that drive his technique:
- Recreate a stable joint with a neutral mechanical axis in most patients
- Compensate for bone loss with biologic or metal augments
- Compensate for soft tissue loss with component constraint
- Protect the extensor mechanism
At ICJR’s Winter Hip & Knee Course, Dr. Sporer shared the tried-and-true tips and techniques he relies on to ensure he is achieving these objectives in revision TKA patients.
Ensuring Good Exposure
Dr. Sporer uses the most lateral prior incision for the revision procedure, making sure that he has a 6-mm skin bridge and a full-thickness skin flap. The procedure is done with a medial arthrotomy that can be extended if necessary.
After an aggressive medial and lateral synovectomy, Dr. Sporer reestablishes the medial and lateral gutters. He says this is a critical part of the procedure: Not taking this step typically leads to struggles with the exposure, which puts the extensor mechanism at risk.
Removing the Components
Dr. Sporer uses a thin reciprocating saw blade to loosen the components instead of a wedge osteotome. The thin blade allows him to remove a small amount of bone without causing a wedge effect.
When removing the tibial component, it’s important to disrupt the cement interface posterolaterally, Dr. Sporer said. If he’s having difficulty removing the lateral side of this component, he will bring the knee into extension to get better access.
Balancing the Flexion/Extension Space
Dr. Sporer prepares the tibia first, and when he’s done, he uses a laminar spreader to get better access to the back of the knee to ensure that all scar tissue is removed. Additional femoral resection should be avoided in a revision procedure.
If the flexion gap is significantly greater than the extension gap, Dr. Sporer will examine the posterior recess to ensure that it is cleared out. If not, he will use a bovie or an osteotome to remove synovium along the posterior aspect of the femur.
Avoiding Excessive Constraint
A key point is to use the least amount of constraint without leaving the knee unstable, Dr. Sporer said. He has limited indications for a hinged component, preferring some of type of varus-valgus restraint for most patients. This will adequately manage soft tissue problems.
Being Prepared with a Plan B
When planning the revision procedure, have a plan B in mind in case the surgery does not proceed as expected. Don’t make it worse, Dr. Sporer said: Hit pause and think through what the next steps should be. Also, have a low threshold for obtaining intraoperative radiographs that could reveal why an issue has arisen.
Click the image above to watch Dr. Sporer’s presentation and learn more about how he manages revision TKA patients.
Dr. Sporer has disclosed that he receives royalties and is a paid consultant for DJO Surgical and OsteoRemedies; that he receives royalties from White Surgical; that he has stock or stock options in Myoscience; that he receives royalties and research support from Zimmer Biomet; and that he receives research support from Styrker.