SURGICAL PEARLS: Releases, Cuts, and Closure in Primary TKA
In a presentation at ICJR’s Pan Pacific Orthopaedic Congress, Alexander P. Sah, MD, demonstrated his technique for primary total knee arthroplasty (TKA) from incision to closure.
Dr. Sah, from the Institute for Joint Restoration in Fremont, California, offered these tips, tricks, and surgical pearls:
Tip 1: Obtain good initial exposure through adequate medial release.
This is a key point in primary TKA, Dr. Sah said: A surgeon who has not done an adequate medial release – and so does not have enough exposure on the medial side – will typically struggle to insert the trial implant and liner.
Using an electrocautery device, Dr. Sah dissects around the periphery of the knee, all the way to the back side. For a varus knee, he will go more distally to do the medial release. For a valgus knee, he does not go as distal.
Tip 2: Be prepared to adjust your technique for femoral sizing and tibial resection according to the knee implant system you’re using
Dr. Sah prefers to do his distal femoral cuts first, and he demonstrated how he changes the sequence of events according to the type of femoral cutting guide available with the knee system he’s using.
With one of the systems, the femoral cutting guide has a handle and he’s able to use that to place the guide flush with the distal cut of the femur for accurate sizing. But the cutting guide with another system does not have a handle. With that system, he cuts the distal femur and then does a tibial resection. This gives him more space to insert the sizing guide.
Bonus Tip: Protect the soft tissue when making the posterior medial femoral cut
While on the topic of femoral cuts, Dr. Sah shared a tip he learned from Aaron Rosenberg, MD: Place a Z retractor under the medial femoral condyle and rotate it out. It will then be essentially impossible to cut the medial collateral ligament while making the medial femoral cut.
Tip 3: The spacer block not only checks the flexion and extension gaps, but it also offers a first check of alignment
When Dr. Sah removes the meniscus, he checks his femoral and tibial cuts to ensure he has removed any bone lip or extraneous soft tissue that would impede the spacer block. He uses the spacer block as a provisional method of checking alignment, which would be “off” if the cuts were not clean.
Before inserting the tibial tray, he predrills holes for the screw pins. This avoids the possibility of the tray rotating or moving posteriorly when the pins are hammered in.
Tip 4: Ensure adequate exposure of the femur before cementing the implant
Good exposure, facilitated by retractor placement, not only helps with the process of cement application, but also makes it easier to remove extraneous cement after the implant has been placed. The surgeon should also make sure the area is free of soft tissue and fat before cementing.
Tip 5: Optimize wound management
Watertight closure of the arthrotomy is essential for minimizing drainage from the wound and reducing the risk of dehiscence. Dr. Sah said good wound closure is an important part of enhanced recovery, allowing patients to leave the hospital sooner.