Adolph V. Lombardi Jr., MD
January 22, 2025 / OrthoSpineNews / – In a rapidly evolving healthcare landscape, joint replacement surgeries remain a pivotal focus for improving patient mobility and quality of life. As knee and hip replacements surge in demand, driven by aging populations and advancements in surgical technology, understanding the latest trends is more crucial than ever. In this exclusive interview, Dr. Lombardi Jr., a leading orthopedic surgeon with extensive experience in joint replacement procedures, shares insights into the key developments of 2024, from innovative techniques to patient outcomes, and offers a glimpse into what 2025 may hold for the future of these transformative surgeries.
What recent trends and future directions have we seen around knee replacement?
Dr. Lombardi:
One of the most significant trends we are seeing is the transition from cemented to cementless technology in total knee replacement. Advancements in 3D printing enable us to construct tibial components that have multiple modalities of fixation, which include a press-fit keel and four pegs. The vital element here is the highly porous nature of the 3D interface, delivering more than 70% porosity.
These new systems have become available and FDA-approved over the past several years. For example, the Zimmer Biomet OsseoTi® Porous Metal Technology uses human CT data in combination with 3D printing technology to build a structure that directly mimics the architecture of human cancellous bone.
While cementless femoral components achieve good fixation, the tibial side has faced a different set of issues. It’s a flat surface, and we know that the knee moves from anterior to posterior, from medial to lateral, and is subject to rotational forces. These forces generated on top of the tibia may cause problems with fixation. However, with the added features of new designs and the ability of 3D printing to create high porosity ingrowth surfaces, cementless tibial fixation is a growing trend.
On the patellar side, many U.S. surgeons embrace the concept of selective patellar resurfacing. I personally resurface the patella in every patient. There may be controversy among my colleagues about whether newer metal-backed patellar implant are going to fail, but I think the modalities of fixation of the polyethylene to the metal have been significantly enhanced.
Cementless TKA saves time as well. If you do five cases a day and you’re saving 10 minutes for each case because you’re not waiting on cement to set, that’s 50 minutes of your day. These time savings will become more important as demand for knee replacements increases and efficiency becomes more important.
Today I approach all my patients assuming I will perform a cementless TKA. I determine whether I’m going to use cemented or cementless fixation by taking the tibial keel brooch, and if I can push it into the tibia surface by hand, which is rare, then I’m cementing that patient.
According to American Joint Replacement Registry (AJRR) data, the percentage of cementless TKA has increased to 22% as of 2023. I expect that this trend will accelerate, and within the next few years it’s going to be over 50%.
In the future there will be headgear that a surgeon can wear to deliver anatomical information. I envision this to be another time saver, another tool that makes me more accurate. For example, Enovis has introduced some new artificial intelligence (AI) to support total knee replacement procedures. This technology is utilized to make the distal femoral and proximal tibial resections, and is allowing us to optimize placement of the components.
There are two technologies currently on the market that offer dynamic tensors. Corin has the Apollo™ and the BalanceBot™, which provide exact ligament tension data before we make any bone resections. Using the surgeon’s defaults, the robot will provide a plan for bone resections to establish a well-balanced knee. The robot will then assist in executing that plan. The other system that provides data on ligament tension is called the Cori by Smith & Nephew.
We are keeping an eye on THINK Surgical, which is disrupting the market. They are innovating with a hand-held device called the TMINI®, and most importantly, are system agnostic. They do not have a knee system so they contract with TJO, Enovis, Medacta, and a number of other smaller orthopedic development companies, as well as a pilot with Zimmer Biomet. They’re touting themselves as the robot for the surgery center and the robot that is agnostic.
Can you provide similar perspectives on Total Hip Arthroplasty?
The hip replacement market on the femoral side has become predominantly a triple-tapered collared stem. This is becoming the way of the world and in the last couple of years we have seen every hip device manufacturer come up with some kind of triple-tapered collared stem. I believe the marketplace is shifting in that direction. The literature is showing that adding a collar, especially in the elderly female osteopenic patient lowers the incidence of periprosthetic fracture, which is what we’re concerned about in cementless fixation.
For example, Zimmer Biomet just added an implant called the Z1™, a triple tapered hip stem that I predict will become their number one hip seller next year. This will most likely take over for the single tapered stem known as the Taperloc®. Stryker, Smith & Nephew, and DePuy are growing market share for these devices.
These stems are brooch only preparation, which allows them to be done through more minimally invasive incisions including the direct anterior approach. This trend aligns with the growth of the anterior approach to THA. Data coming from the Annual Meeting of the American Association of Hip and Knee Surgeons (AAHKS) demonstrates that the anterior approach is growing in usage.
The other major trend we see in THA is AI technology. We are seeing an emergence of fluoroscopically based AI technology. This new AI technology can take a fluoroscopic image and immediately inform the surgical team that a cup is in 40° of inclination and 20° of anteversion.
When you insert the stem, the AI will automatically tell you the leg length difference and offset. This trend will continue as more products, such as OrthoGrid, enter the market with AI enhanced robotics.
I envision the future of orthopedic surgery will become a combination of robotics merged with AI and augmented reality. While some surgeons may resist having a robot in the OR, I believe that surgeons will gravitate to some kind of glasses that can deliver 3D perception.
This is currently available in the HipInsight™ System (Zimmer Biomet). A pre-surgical CT scan of your total hip patient is analyzed to optimize the position of both the acetabular component and the femoral component for your patient. HipInsight is a platform that analyzes these data and provides a suggestion on the best position for this patient. Surgeons wear a pair of goggles showing a hologram guiding them on positioning the acetabular component, and also giving them information on leg length and offset.
Since younger surgeons are accustomed to playing video games and have used AI and augmented reality goggles for gaming, I believe this will be an easily adopted technology for young surgeons to utilize. These trends will only improve outcomes in TKA and THA. Any tools that can improve our 3D perception of where everything is before we make a bone cut can significantly improve orientation and makes us better surgeons.
These new AI tools will also help us with tibial resections. Surgeons committed to kinematic alignment can use assistance in making the tibial resection in 3, 5, or 7 degrees of varus. The problem is that the human eye can’t tell 3, 5, or 7 degrees of varus, but the human eye can make a resection that is perpendicular to the tibial axis.
Another development in THA is the Reverse Hip Replacement System (Reverse HRS). I am a lead investigator on the Hip Innovation Technology Reverse HRS pivotal U.S. FDA investigational device exemption (IDE) study. The IDE Study is being conducted to determine the safety and effectiveness of this new hip implant. Safety will be assessed through the collection of device-related adverse events and patient quality of life metrics. Effectiveness will be evaluated using clinical, radiologic, and patient-reported outcomes. I believe the Reverse HRS will fill a special role for patients at risk for postoperative dislocation.
Five years of patient data collected in Canada using radio-stereometric analysis (RSA) demonstrate excellent fixation and suggest significant improvement from preoperative to postoperative in patient and physician measures. I believe the Reverse HRS will perform well in this U.S. study. The Reverse HRS has been extensively tested in over 100 standard and unique pre-clinical, bench level experiments assessing the product safety and clinical benefits anticipated for the reverse system design.
I believe any patient with significant spinal-pelvic issues will benefit from this Reverse HRS. Patients with a fused spine, or those who are stuck sitting or stuck standing will be ideal candidates for this emerging device. It will also play a role in patients at risk for dislocation, such as people with alcoholism, dementia or Alzheimer’s, Parkinson’s, or who have suffered a subcapital fracture.
