SURGICAL PEARLS: Tips and Techniques for Primary TKA from Dr. Daniel Berry
The surgeon’s attention to detail makes the difference between an excellent outcome and an okay outcome in total knee arthroplasty (TKA), and it should, says Daniel J. Berry, MD, from Mayo Clinic in Rochester, Minnesota, translate to better durability of the implant and a happier patient.
At ICJR’s Winter Hip & Knee Course, Dr. Berry shared his top 5 tips for achieving an excellent outcome, with a focus on aspects of primary TKA that surgeons may not be considering, but that Dr. Berry says can help prevent complications and improve results.
The importance of the exposure in a TKA is underappreciated, Dr. Berry said, but it’s a key part of the success of the procedure: A good exposure will lead to an easy operation, while poor exposure will leave the surgeon struggling and more likely to make technical errors that can lead to complications.
Dr. Berry focused on one such complication: distal medial skin wound healing and drainage problems, which he said will usually occur in the anteromedial inferior flap of tissue at the bottom of the medial side of the wound.
The solution, he said, is avoid subcutaneous flap elevation, and in his presentation, he demonstrates his technique for incising to the bone just medial to the patellar tendon. In addition, the surgeon should ensure full-thickness medial periosteal elevation to leave a good layer of tissue for closing at the end of the procedure. This is key to a watertight closure.
Imperfect bone cuts will lead to iterative mistakes in implant position, limb alignment, and balance, Dr. Berry said.
For the femur and tibia, Dr. Berry makes the initial cut with the standard jig, understanding that the saw won’t always perfectly follow the jig. After the cut, he puts the jig back on, puts the paddles on, and double checks whether the cut is correct. If not, he takes the saw and trims the bone, repeating the procedure until the cut is perfect in flexion and extension, varus and valgus.
For the patella, Dr. Berry does a freehand cut first, making sure he undercuts. He then measures the patella in all 4 quadrants to ensure the thickness is what he had preplanned. If not, he trims it as needed and measures again.
Ligament Balancing: Pie Crusting
Traditional releases on the medial and the lateral sides are difficult to titrate, Dr. Berry said. The pie crusting technique allows the surgeon to better control the releases than would occur with simply stripping tissue from the bone.
When the patient has a valgus deformity, Dr. Berry uses the pie crusting technique on the lateral side, starting anteriorly on the iliotibial band and making small pie crust perforations in the tight fibers. After adding the trial implant, Dr. Berry will go back and make additional perforations posteriorly if the fibers are still tight.
For a varus deformity, Dr. Berry performs traditional medial releases, starting with moderate release from the tibia. If the fibers are still tight, he will fine-tune the medial collateral ligament release. Using an 18-gauge needle, he makes multiple small perforations – being careful not to do too much – at different levels, moving from front to back.
Tibial Tray Position
Problems occur when the tibial tray is not properly centralized on the tibia: Medial or lateral overhang will cause pain, while incorrect positioning will cause issues with patellar tracking.
The key is to know where the lateral border of the tibia is located. Dr. Berry will find this point and then mark it with cautery; this helps him know exactly where to position the tibial tray. Any medial tibial osteophytes can be trimmed after the tray is positioned.
Subtle flexion instability occurs when the flexion gap exceeds the extension gap. This is a common reason for unsatisfied TKA patients, Dr. Berry believes.
The solution is fairly simple: Test anteroposterior stability in flexion with the trial implant in place. If it’s too loose, balance the gap, which usually can be accomplished with additional femoral resection.
Click the image above to watch Dr. Berry’s presentation.
Dr. Berry has disclosed that he receives royalties from DePuy Synthes.