New Techniques and Technologies in TKA
Total knee arthroplasty (TKA) is a successful procedure, with more than 90% survivorship in long-term follow-up studies. The surgical techniques and implant designs used in TKA are firmly established, allowing for these excellent results.
So why would surgeons want to change anything about TKA?
Because as with most surgical procedures, there’s still room for improvement.
At the Transatlantic Congress in New York last year, 5 experienced knee surgeons reviewed the pros and cons of new techniques and technologies for TKA that have the potential to improve patient satisfaction, implant alignment, and soft tissue balancing.
Wolfgang Fitz, MD
Restoration of normal anatomy and normal knee kinematics is the Holy Grail of TKA – but how can it be achieved?
Wolfgang Fitz, MD, from Brigham & Women’s Hospital in Boston, Massachusetts, thinks custom prostheses may be a place to start. In this presentation, he reviews how normal knee kinematics change depending on the activity, and how normal knee kinematics are lost after TKA with an off-the shelf implant.
Dr. Fitz also discusses current literature on custom implants, with early results indicating they have the potential to better approximate normal knee kinematics. He says they allow for more lateral condyle roll-back and normal rotation patterns, leading to higher weight-bearing flexion and, in the end, better patient satisfaction.
Click the image below to watch Dr. Fitz’s presentation.
Emmanuel Thienpont, MD, MBA
Patient-specific instruments (PSI) promise improved component alignment, reduction in surgical time, fewer surgical instrument trays, fewer surgical steps, among other proposed benefits. But have these promises been realized?
Emmanuel Thienpont, MD, MBA, from University Hospital Saint Luc in Brussels, Belgium, reviews the literature and discusses the current state of PSI from the standpoint of each of these stakeholders:
- Device manufacturers
Dr. Thienpont notes that the current literature compares PSI systems based on different radiologic studies, different 3D software, and different anatomic landmarks, making it difficult to draw conclusions. More research that compares like parameters is needed to truly evaluate the available PSI systems.
Click the image below to watch Dr. Thienpont’s presentation.
Navigation in the Surgical Field
Giles R. Scuderi, MD
The success of TKA is in no small part due to these long standing surgical principles:
- Soft tissue balancing
- Accurate bone resection
- Accurate component alignment
- Good component fixation
But even experienced orthopaedic surgeons experience alignment outliers – knees in which component alignment is not exactly as planned.
In this presentation Giles R. Scuderi, MD, from the Northwell Health Orthopaedic Institute shows how a gyroscope-based computer navigation system can assist surgeons in becoming more precise and achieve more reproducible alignment than with conventional instruments alone.
Dr. Scuderi includes surgical videos that demonstrate how this navigation system complements conventional instruments. He also reviews literature showing how the system minimizes alignment outliers, with outcomes similar to optical navigation systems.
Click the image below to watch Dr. Scuderi’s presentation.
Ali Oliashirazi, MD
Achieving accurate alignment is one of the primary goals of TKA and with the use of computer-aided surgery (CAS), Ali Oliashirazi, MD, says the new surgeon has the potential to achieve component alignment as accurately as the experienced surgeon.
So why are surgeons in the US using CAS in only 3% of cases, versus 22% in Australia?
Dr. Oliashirazi, from the Joan C Edwards School of Medicine at Marshall University, Huntington, West Virginia, discusses the current barriers to mass adoption of CAS in the US and reviews the conflicting data in the literature.
He shares his experience with using CAS and summarizes his thoughts on the current state of CAS in TKA, making recommendations for when he believes CAS should be considered.
Click the image below to watch Dr. Oliashirazi’s presentation.
Jonathan Vigdorchik, MD
In this presentation, Jonathan M. Vigdorchik, MD, from Hospital for Joint Diseases in New York, reminds attendees of Dr. John Insall’s often-quoted maxim, “Total knee arthroplasty is a soft tissue procedure.”
Although most new technologies for TKA aim to improve the accuracy of bone cuts and implant alignment, intraoperative sensors aim to improve soft tissue balancing, thereby improving functional outcomes.
Dr. Vigdorchik reviews how using intraoperative pressure sensors can assist the surgeon in achieving medial and lateral compartment loads that are equal or comparable, as well as comparable pressure responses to varus and valgus stress.
Click the image below to watch Dr. Vigdorchik’s presentation.