Dr. Jonathan M. Vigdorchik, Chief Science, Technology and Medical Affairs Officer, Zimmer Biomet

In this role, Dr. Vigdorchik will oversee the strategy, delivery, and management of the company's global end-to-end technology portfolio, including AI, robotics, smart implants and data. He will also oversee Zimmer Biomet's Medical Education strategy and Global Advisory Board, helping further strengthen Zimmer Biomet's clinical engagement, innovation roadmap and external scientific leadership. Dr. Vigdorchik will report to Ivan Tornos, Chairman, President and Chief Executive Officer.

"Dr. Vigdorchik is a world-class orthopedic surgeon, and he brings exactly the kind of bold, future-focused leadership we need as we continue to shape the next era of musculoskeletal care," said Tornos. "He understands how to translate clinical insight into meaningful innovation, and his leadership will help us move faster, think bigger and continue advancing our broad suite of robotic and enabling technologies. I'm confident he will play a critical role in accelerating our portfolio strategy and further differentiating Zimmer Biomet in the market."

Dr. Vigdorchik previously served as Zimmer Biomet's Chief Medical Technology Advisor, Adult Reconstruction and Hip Implants. He is a board-certified, fellowship-trained orthopedic surgeon at Hospital for Special Surgery (HSS) in New York City, specializing in hip and knee replacement surgery. Dr. Vigdorchik held several prominent academic and clinical leadership positions, including serving as Division Chief for national/international reputation and academic promotion on the Adult Reconstruction and Joint Replacement service at HSS and Director of Bone Implant Longevity Research at HSS's Griffin Research Accelerator. In addition, he is currently an Associate Professor of Orthopaedic Surgery at Weill Cornell Medical College. He is active in professional societies including The Hip Society, The Knee Society, the American Academy of Orthopaedic Surgeons (AAOS) and the American Association of Hip and Knee Surgeons (AAHKS), where he served as the Education and Communications Council Chair and earlier served as Program Chair for the 2024 AAHKS Annual Meeting.

"As a surgeon and innovator, I believe we are at an inflection point where AI, data, and advanced technology will fundamentally redefine the future of orthopedics," said Dr. Vigdorchik. "I've dedicated my career to focus on preventing complications and achieving consistently better outcomes for patients. With strength across its product portfolio, a differentiated suite of robotic and enabling technologies, and a pathway toward fully autonomous robotic technology in orthopedics, Zimmer Biomet is poised to continue pushing the industry forward. I'm excited to join the talented team in this expanded role to help advance that vision and accelerate innovation for surgeons and patients around the world."

Dr. Vigdorchik earned his medical degree from the University of Missouri – Columbia School of Medicine, completed his orthopaedic surgery residency at the Detroit Medical Center / Providence Hospital, and received fellowship training in Adult Reconstruction and Joint Replacement at HSS. He also completed an international traveling fellowship in hip preservation surgery with training at centers in Switzerland, Boston Children's Hospital, and Washington University in St. Louis.

About Zimmer BiometZimmer Biomet is a global medical technology leader with a comprehensive portfolio designed to maximize mobility and improve health. We seamlessly transform the patient experience through our innovative products and suite of integrated digital and robotic technologies that leverage data, data analytics and artificial intelligence.

With 90+ years of trusted leadership and proven expertise, Zimmer Biomet is positioned to deliver the highest quality solutions to patients and providers. Our legacy continues to come to life today through our progressive culture of evolution and innovation. 

 Three studies focus on how to optimize total knee arthroplasty (TKA) surgery using biomechanics and computer modeling, while another study discusses how three-dimensional (3-D) modeling can improve total hip arthroplasty (THA).

 What follows are some highlights from the meeting:

Undersizing Tibial Baseplates in Cementless TKA Has Negative but Small Impact for Bone–Implant Interaction: A Computational Biomechanical Study

Computational biomechanical modeling is useful for taking a closer look at how making changes to orthopedic surgery techniques affects patient outcomes. A study led by Fernando J. Quevedo-González, PhD, assistant scientist in the Department of Biomechanics at HSS, and HSS hip and knee surgeon Jonathan M. Vigdorchik, MD, used these kinds of models to determine how best to minimize the risk of complications in cementless TKA. The model was developed using preoperative scans from 12 female patients about to undergo robotic TKA and was used to ask questions about how sizing the tibial baseplate (the metal part of the prosthesis that connects to the shin bone) affects outcomes. The investigators found that, in general, decreasing the size of the baseplate increased the amount of bone at risk of failure, but this risk was small compared with normal variability of bone quality among patients and how their individual knee joints were loaded as they used their knee in performing activities of daily living. Based on this result, they concluded that baseplate undersizing can be done to optimize the placement of the tibial component of the TKA without increasing the risk of bone failure.

Authors: Fernando J. Quevedo-González, PhD, Peter K. Sculco, MD, Cynthia Kahlenberg, MD, Joseph D. Lipman, MS, Timothy M. Wright, PhD, Jonathan M. Vigdorchik, MD.

Posterior Tibial Slope in Total Knee Arthroplasty: The Transmalleolar Sagittal Axis Underestimates Slope Compared to Traditional Intramedullary Axis

The tibial slope, one of multiple angles used to place a TKA, defines how the tibial component meets the knee and impacts the knee’s ability to bend and the strain that’s put on the ligaments throughout range of motion. A study led by HSS hip and knee surgeons Brian P. Chalmers, MD, and Steven B. Haas, MD, looked at how robotics and computer navigation influence the tibial slope in TKA. Historically, knee implants were designed using what is called the intramedullary axis to measure the tibial slope, but technology-assisted knee replacement operations determine the slope in a different way. The investigators retrospectively reviewed preoperative CT scans from 40 TKA procedures and reconstructed the 3-D geometry of the tibia and fibula to determine the slope based on the intramedullary axis. They determined that in many cases, the alternate calculation of the slope used in technology-assisted procedures resulted in a different slope in the newly implanted knee. This difference could have a negative effect on the knee’s movement and mechanics, suggesting that as more procedures are performed using robotic-assisted technology, the need to re-think implant designs to incorporate these changes is likely.

Authors: Brian P. Chalmers, MD, Fernando J. Quevedo-González, PhD, Michael P. Ast, MD, Steven B. Haas, MD.

The Initial Fixation of Cementless TKA Is Associated with the AP Translation During Gait: A Computational Study

The two main goals of TKA surgery are restoring the motion of the knee joint to as close to a native knee as possible, and ensuring that the implant is properly attached to the bone so that it lasts as long as possible and does not loosen. A novel study led by Jonathan Glenday, PhD, a postdoctoral fellow, and Fernando J. Quevedo-González, PhD, assistant scientist, both in the Department of Biomechanics at HSS, looked at the intricate relationship between attachment to the bone and joint motion, and how these two aspects of joint mechanics are related. The investigators used a computational model that included gait mechanics and anatomic information from CT scans to look at whether the anterior-posterior (AP) translation (front-to-back movement) of the femur with respect to the tibia while walking was correlated with bone-implant micromotion after surgery. Based on their models, they determined that the AP translation significantly related to the peak micromotion throughout gait, especially in the lateral portion of the knee; greater AP translation resulted in larger micromotions. This study highlights the connection between joint-level mechanics and fixation-level mechanics in TKA surgery and is the first time researchers at HSS have been able to look at both in tandem.

Authors: Jonathan Glenday, PhD, Peter K. Sculco, MD, Jonathan M. Vigdorchik, MD, Joseph D. Lipman, MS, Cynthia Kahlenberg, MD, David J. Mayman, MD, Timothy M. Wright, PhD,  Fernando J. Quevedo-González, PhD.

Three-Dimensional Functional Impingement in Total Hip Arthroplasty: A Biomechanical Analysis

Impingement after THA can lead to pain and, in the worst case, a dislocation of the prosthesis. Offset of components, which is related to the width of the hip, directly affects the impingement of the hip after surgery. Surgeons have multiple ways to alter offset during THA surgery; however, these alterations have only been studied in two dimensions. A team led by HSS hip and knee surgeon Jonathan M. Vigdorchik, MD, and former clinical fellow Eytan Debbi, MD, PhD, used 3-D models created from pre- and postoperative CT scans of 16 patients who underwent the procedure to retrospectively analyze the relationship between offset and impingement. They compared cup/liner (acetabular) offset to head/stem (femoral) offsets and looked at the effects that these configurations had on the patient’s range of motion and incidence of impingement after surgery. The investigators found that in all cases, increasing the offset reduced the amount of impingement, and increased the full range of motion of the hip. Acetabular offsets had greater impact than femoral offsets in the range of motion because they affect the offset of the center-of-rotation.

Authors: Eytan Debbi, MD, PhD (Cedars-Sinai), Fernando J. Quevedo-González, PhD, Seth A. Jerabek, MD, Timothy M. Wright, PhD, Jonathan M. Vigdorchik, MD.

Augmented reality refers to digital information that is superimposed on a user’s view of the physical environment. An example would be a design app that allows you to visualize a 3D model of furniture or décor in your home before you buy it.

The augmented reality knee replacement platform, known as NextAR^TM TKA, received clearance from the U.S. Food and Drug Administration (FDA) in July. It utilizes a preoperative CT scan of the patient’s knee for surgical planning and the use of augmented reality glasses during surgery. The smart glasses allow the orthopedic surgeon to visualize the structures of the knee and track progress in real time directly on the operative field, without having to look over at a computer screen.

“It’s like a car that has the speedometer projected on the windshield, so you don’t have to look down when you’re driving,” says Jonathan Vigdorchik, MD, the orthopedic surgeon who performed the procedure last week at HSS. Taking the car analogy one step further, he compares the AR knee replacement platform to GPS. “Everyone knows how to drive home, but you use GPS technology to find the best and most efficient route to take.”

Dr. Vigdorchik notes that the enhanced visualization provided by the augmented reality platform allows for ultraprecise alignment and positioning of the knee implant. “Over the past few years, we’ve learned that optimal balancing of the knee ligaments results in a joint replacement that feels more natural and lowers the risk of instability,” he explains. “Every person’s knee is different in terms of their ligaments. Some ligaments are tighter, some are looser. The platform provides direct tracking of the collateral ligaments and a 3D analysis of soft tissue throughout the whole range of motion during surgery, and this allows for optimal ligament balancing for each patient.”

The compact, streamlined nature of the system could also provide economic benefits to the healthcare system, according to Dr. Vigdorchik. “It’s a portable system that can be used in ambulatory surgery centers in addition to hospital ORs,” he notes. “In addition, the high level of precision of the AR platform could decrease operating time and translate into greater efficiency. This is particularly advantageous in the current health care environment, as surgeons and hospitals may still be catching up on elective knee replacements that were deferred during the pandemic lockdown.”

Dr. Vigdorchik notes that as more surgeries are performed with the AR system, he will follow patients and collect data to see how the technology compares to robotic-assisted navigation and standard knee replacement surgeries. The ultimate goal is to provide personalized care and achieve the best outcome for each individual patient.

“For patients, it is important to know that hip and spine arthritis often coexist, and the majority of the time, an individual’s back pain is better after hip replacement surgery,” said lead study author Jonathan M. Vigdorchik, MD, a hip and knee surgeon at HSS. “However, there are certain times where you might want to have spine surgery first, and that should be discussed with a physician who can evaluate and understand both hip and spine conditions and the relationship between them.”

A complex interplay exists between the hip and the spine. Some back pain may be caused by abnormal mechanics from hip osteoarthritis. In this new study, the researchers set out to compare patients whose back pain resolved after THA with those whose back pain did not resolve and identify how to predict this using spinopelvic parameters.

“Very frequently, patients come to see us with symptoms of both back pain and hip arthritis,” said Dr. Vigdorchik. “We wanted to know what percentage of the time back pain went away after total hip arthroplasty and whether we can predict patients whose back pain will go away after their hip replacement.”

The researchers evaluated and collected demographic data on a consecutive group of 500 patients who underwent THA for unilateral hip osteoarthritis at HSS. They excluded patients with previous spine surgery or femoral neck fractures. All patients underwent standing and sitting anteroposterior and lateral X-rays of the hip and lumbar spine pre- and postoperatively. Oswestry Disability Index scores and Visual Analog Scale scores were calculated preoperatively at six weeks and postoperatively at one year.

Of the 500 patients, 41% had documented lower back pain prior to their hip surgery. Of that group, 82% had their back pain resolve after hip replacement at a minimum of one year follow-up. The average Oswestry Disability Index in these patients preoperatively was 32+/-5% (moderate disability) and post-operatively was 9+/-3% (minimal disability, p<0.001). When comparing spinopelvic parameters between the groups, all patients whose back pain resolved had a sacral slope change from standing to sitting of more than 10 degrees, while the patients whose back pain did not resolve had a change of less than 10 degrees. Sacral slope change is a parameter that clinicians examine on a lateral X-ray that shows how much the pelvis and spine move in relationship to each other during different activities, such as going from a standing to a sitting position.

“There is definitely a group of patients whose back pain predictably goes away after hip replacement surgery, and those are people who have flexible spines,” said Dr. Vigdorchik. “When we took standing and sitting lateral X-rays, and we saw specific changes in patients with flexible spines, those were the patients whose back pain very reliably went away. Their back pain was exacerbated or even caused by their hip arthritis. Then there were certain patients who had a stiff, degenerative spine whose back pain did not go away, and that is because their spine arthritis had progressed to the point beyond which the hip was causing an effect.”

The findings should help clinicians counsel patients. “If clinicians get these X-rays and they see the certain things we saw, they can counsel their patients that their back pain will reliably go away after their hip replacement, and that it is safe to do the hip replacement first as opposed to going through spine surgery first for the back pain,” said Dr. Vigdorchik.

Previously, surgeons were unaware why certain hip replacement patients experience dislocations. However, recently a new assessment tool before revision hip replacement surgery has significantly reduced the rate of recurrent dislocations compared to a standard evaluation. The new tool was created by Jonathan M. Vigdorchik, MD and colleagues at Hospital for Special Surgery (HSS) and NYU Langone Orthopedic Hospital. Their study is accepted for publication in a 2019 issue of The Bone & Joint Journal. 

"We were very surprised that the dislocation rate was only 3% for patients who received the new presurgical assessment compared to 16% for those who did not," says Dr. Vigdorchik, a hip and knee surgeon at HSS. "We knew that spine function affects hip replacement outcomes, but not to this magnitude." Dr. Vigdorchik and colleagues also found that without this new evaluation method, 77% of inappropriately positioned hip implants would not have been identified.  

The new classification tool, called the Hip-Spine Classification in Revision Total Hip Arthroplasty (THA), allows surgeons to evaluate spinal function and mobility when planning revision surgery by analyzing a series of X-ray images of the spine and hip, taken from lying down, standing and sitting positions. 

The study evaluated outcomes for 222 patients who underwent revision hip replacement for recurrent instability from January 2014 to January 2017 at HSS and NYU. The researchers compared results for 111 patients who received the new spine function assessment to a matched group of 111 patients who did not. 

Analyzing the images, which included calculating the changes in pelvic tilt between standing and sitting positions, provided more robust information about how patients’ spine function affected hip alignment than a standard assessment that only examined images taken in the lying down position. The images were taken with advanced imaging equipment (EOS), but Dr. Vigdorchik says that the new assessment protocol can also be used with standard X-rays. 

The tool assigns a simple score to each patient’s results: "1" for normal spine alignment or "2" for a loss of the normal curvature at the base of the spine called a flatback deformity; and "A" for normal spine mobility or "B" for a stiff spine. The score informs the approach for revision surgery. 

"We also discovered a group of patients with spine stiffness that often go unrecognized," says Dr. Vigdorchik. "In a group of 61 patients who had not had previous spine surgery, our tool revealed that 74% had stiff spines, allowing us to take this into account when planning their revision surgeries." While spinal stiffness is a risk factor for future dislocations it is usually anticipated only in patients who have had prior spinal fusion procedures. However, our findings showed that this is not always the case. 

Surgeons at HSS and NYU started adopting the new assessment approach in 2014. "We hope our study draws awareness to the need for spinal evaluation and that more centers conducting hip replacement surgery will implement our protocol to help their patients," says Dr. Vigdorchik. "Few centers in the world are looking at this. Based on our work to date, we are collaborating with colleagues at Stanford University and the Mayo Clinic to conduct a multi-center study to collect more evidence. We hope that one day, this approach becomes the standard of care."

Dr. Vigdorchik and colleagues received an award for the best poster at the AAOS 2018 Annual Meeting for a previous study that reported the impact of using the new tool for patients having a first hip replacement surgery. "Our most recent results for patients undergoing revision surgeries add to our previous work in the frontline setting and underscore the importance of conducting a robust evaluation of spine function before hip replacement surgery. We have reached an era where we can prevent many errors in hip replacement before even doing the surgery with a proper and complete pre-surgical evaluation," said Dr. Vigdorchik.