The Quiet Knee protocol, which some HSS surgeons began implementing several years ago, takes a more conservative approach to knee replacement recovery than traditional clinical protocols. This new technique focuses on controlling inflammation and swelling postoperatively through restricted mobility and passive range of motion (ROM) and aggressive cryotherapy (icing) for the first 10 days immediately following surgery. This contrasts with standard protocols, which often emphasize early and aggressive movement that can cause inflammation in surgical tissue that is healing.

All HSS total knee replacement patients from 2020 to 2024 were retrospectively reviewed as part of the study. A Quiet Knee group consisting of 271 patients received structured postoperative care and monitored telerehabilitation. One comparison group was given Quiet Knee guidance verbally, while a second cohort followed traditional early motion postoperative therapy.   

 “Patients are told they have to work really hard to get motion back after surgery—the no pain, no gain type of mentality,” said Brian P. Chalmers, MD, a hip and knee surgeon at HSS and one of the authors of the study. “The problem with that is that the more patients do in the early period of recovery—the more they bend, the more they are up and walking—the more the knee will swell.”

Every person undergoing TKA experiences pain and swelling after surgery, but the intensity differs, making the patient’s recovery process more challenging and often more painful than most other surgeries.

“It’s not uncommon to see a counterproductive early physical therapy program that is too aggressive,” Dr. Chalmers said. “In these cases, the knee becomes very swollen, which causes patients to have more pain. As the knee becomes more inflamed and patients are able to bend it less, it just becomes a cycle.”

Under the Quiet Knee protocol, patients avoid intensive physical therapy immediately after surgery, allowing the body time to heal before progressing to motion and other strength work. Early results suggest this approach helps set the stage for a smoother long-term recovery. The study also showed that the protocol significantly reduced 90-day opioid exposure by more than 25%.

“This isn't a surgeon-driven protocol or a research-driven protocol. It's a physiology-driven protocol,” said Michael P. Ast, MD, Chief of the Knee Service and Chief Medical Innovation Officer at HSS and co-author of the study. “It is a recognition of what the human body goes through in recovery from surgery. It is a very logical way of respecting the body's inflammatory response to trauma. Early on after surgery, less really is more. That is really the guiding principle of this protocol.”

Study Details

A Retrospective Cohort-Based Analysis of the “Quiet Knee” Protocol After Primary Total Knee Arthroplasty

Pravjit Bhatti, Lauren Moeller, Michael P Ast, Tony Sicheng Shen, Peter Keyes Sculco, David Jacob Mayman, Brian Chalmers

Hospital for Special Surgery (HSS), the world’s leading academic medical center specialized in musculoskeletal health, has expanded access for people in Northern New Jersey with the opening of two new facilities: HSS Paramus – Midland Ave, a full-service outpatient center (OPC) in Paramus; and the HSS Northern NJ Surgery Center in Mahwah, which marks the first-ever HSS surgery center dedicated to ambulatory procedures in the state. The facilities offer Bergen County residents greater access to world-class surgical and non-surgical care across a broad range of specialties.

“HSS has led the fields of orthopedics and rheumatology in quality and patient experience for 161 years,” said HSS President and CEO Bryan T. Kelly, MD, MBA. “The HSS Northern NJ Surgery Center in Mahwah and HSS Paramus – Midland Ave are more than just facilities—they're purpose-built extensions of the main hospital, offering the same sophisticated, highly specialized care but in a more accessible location. They reflect our commitment to serving communities by expanding care through innovation and strategic growth across the tri-state region and beyond.”

The HSS Northern NJ Surgery Center is a 7,700-square-foot facility conveniently located at 400 Franklin Turnpike, just 10 miles away from HSS Paramus – Midland Ave. The center features three operating rooms, eight pre- and post-surgical bays and on-site central sterile processing.

The Mahwah surgery center will focus on specialized care for conditions and injuries of the hip and knee, spine, foot and ankle, hand and wrist, as well as sports medicine surgery. Michael P. Ast, MD, chief of the Knee Service, Chief Medical Innovation Officer and Director of Ambulatory Surgery Center Strategy at HSS, serves as the Medical Director.

“With the advanced technologies we’ve implemented at our ambulatory surgery center, we’re now able to safely perform a wider range of complex procedures that were once only possible in a hospital setting,” said Dr. Ast. “By expanding access in New Jersey, more patients can receive timely outpatient procedures, reducing wait times, hospital burdens, and the need to travel into New York City. At the same time, our new center is fully integrated with our main hospital, ensuring patients benefit from the same world-class diagnosis and treatment options.”

HSS Paramus – Midland Ave, located at 15 E. Midland Ave, Suite 1A, features 23 exam rooms and highly specialized physicians and staff to offer care for conditions and injuries of the foot and ankle, hand and upper extremities, hip and knee, and spine; endocrinology/metabolic bone diseases; pediatric orthopedics; physiatry; rheumatology; and sports medicine.

The nearly 31,000-square-foot facility is double the size of the existing OPC, HSS Paramus – Ridgewood Ave, allowing for an expansion of services and a state-of-the-art imaging suite including MRI, x-ray, and EOS low-dose radiation imaging. A special procedures unit for injection therapy and other advanced interventions is also available at this site. Additionally, HSS Orthopedics Now, providing quicker access to orthopedic care for sudden injuries and pain for patients 12 years and older, is available.

“I am deeply honored to lead HSS Paramus into its next chapter,” said Anil S. Ranawat, MD, sports medicine surgeon at HSS and medical director of HSS Paramus – Midland Ave. “This new facility is an exciting milestone in our unending pursuit to make comprehensive care even more accessible, enabling patients to complete their entire care journey—including testing, surgery, and more—right here in New Jersey.”

The new sites join the existing HSS location in Paramus on East Ridgewood Avenue. For more information about HSS Paramus-Midland Ave and HSS Northern NJ Surgery Center, visit www.hss.edu/locations.

Developing SR-878, a novel monoclonal antibody drug candidate targeting inflammation

SR-878, which builds upon foundational basic research discoveries made in the lab of Carl P. Blobel, MD, PhD, director of the Arthritis and Tissue Degeneration Program at the HSS Research Institute, is a monoclonal antibody drug candidate that targets inflammation in a new way.  More specifically, SR-878 targets a complex consisting of inactive Rhomboid 2 (iRhom2) and TACE/ADAM17 (ADAM17), a “master switch” for regulating the inflammatory response that is overactive in many autoimmune diseases.

ADAM17 is an enzyme involved in accelerating the body’s immune response, which has long held the interest of researchers due to its close association with an already proven target in the treatment of rheumatoid arthritis and other inflammatory diseases, the molecule TNF-alpha.

Researchers hypothesized that going after ADAM17 could prove even more effective than targeting TNF-alpha alone. “Beginning in the late 90s, there was an interest in targeting ADAM17 as another way to reduce TNF-alpha,” Dr. Blobel explains, “but it turns out, on its own, it wasn’t an optimal target because ADAM17 holds other important functions — such as protecting the skin and intestinal barrier.”

However, studies at HSS have since revealed that ADAM17 is regulated by its binding partner iRhom2. When iRhom2 is inactivated, those studies have demonstrated that the related iRhom1 can still protect against the problems observed when ADAM17 is blocked.  This research suggested that iRhom2 could be a safer and more effective target for drugs than ADAM17.

Collaborations with HSS rheumatologist Jane E. Salmon, MD, HSS Chief Scientific Officer Lionel B. Ivashkiv, MD, and HSS Physician-in-Chief Emerita Mary K. (Peggy) Crow, MD further supported this notion.  Those studies explored the effects of knocking out iRhom2 in preclinical mouse models with inflammatory arthritis as well as an autoimmune kidney disease called lupus glomerulonephritis. Their research demonstrated that the mouse models were protected from disease by blocking the TNF-alpha pathway and, in the case of lupus glomerulonephritis, also by inhibiting another pathway that contributes to inflammation, called the EGFR pathway. “We eventually realized that iRhom2 could be a very exciting target,” Dr. Blobel says.

The development of SR-878 underscores the importance of doing basic science research at academic institutions like HSS,” says Michael P. Ast, MD, orthopedic surgeon and Chief Medical Innovation Officer at HSS. “Scientific breakthroughs uncovered in the lab can be used to shape further studies that advance our understanding of complex diseases. Through the knowledge and expertise of investigators at HSS and SciRhom, we can build on the insights made together to ultimately benefit patients worldwide.”

Co-Founding & Advancing SciRhom

During a visiting professorship in 2015 in Munich, Germany, Dr. Blobel met two researchers, Drs. Jens Ruhe and Matthias Schneider, who have extensive experience in preclinical development of early to clinical stage antibody projects.

Together, HSS, the three researchers, and other experienced biotech entrepreneurs and investors, co-founded SciRhom in 2016 to translate Dr. Blobel’s scientific findings into novel therapies for autoimmune diseases.

Proof of concept studies performed by HSS scientist Gisela Weskamp, PhD, have since strongly supported the notions that targeting iRhom2 with SR-878 in a preclinical model of inflammatory arthritis is more effective than targeting TNF-alpha alone and is at least as effective as blocking both TNF-alpha and the EGFR pathway together. In addition, treatment with SR-878 also has potential to block another target of existing therapies, the interleukin-6 receptor. “We anticipate that SR-878 will simultaneously block multiple disease-causing pathways and therefore has potential for superior efficacy relative to current monotherapies,” she adds.

Following on the footsteps of its pre-clinical findings, SciRhom has since expanded its board and management ranks with former executives from the global pharmaceutical industry, including Chief Executive Officer Dr. Jan Poth, former Therapeutic Area Head Immunology at Boehringer Ingelheim, and board member Dr. Wolfgang Baiker, former CEO of Boehringer Ingelheim USA.

“SciRhom’s recent Series A financing and its approval to start clinical trials are pivotal milestones in the company’s journey towards commercialization” says Vijay Nair, Managing Director at the HSS Innovation Institute. “Bringing a discovery from the lab to patients requires immense dedication and collaboration across HSS and with the biotech entrepreneurial and investment communities. Their leadership and external validation have been critical in launching the company, securing funding, attracting world-class talent, pursuing pre-clinical development, and reaching this inflection point.”

“There is a lot of enthusiasm for this approach among members of the medical and investment communities. We are tremendously excited that we can now advance the study of this drug to human trials,” says Dr. Blobel.

“The feeling of fear is very natural, and every single one of us knows that feeling,” said Stephanie Cheng, MD, DABMA, FAAMA. Dr. Cheng is an anesthesiologist at HSS and developed HSS’s protocols for using acupuncture in the operating room. “For some people, that fear can become irrational and develop into PTSD. Although exact numbers are unknown, reported estimates for the incidence of PTSD in the United States are approximately 6%, with women having twice the rate of men.

“For patients with nosocomephobia, it can make getting care in the hospital setting very hard,” she continues. “We don’t even know how many of these ‘unseen patients’ are out there because they just don’t come to the hospital.”

Current treatments for nosocomephobia include techniques such as cognitive behavioral therapy, exposure therapy, hypnotherapy, and medications.

“It’s worth noting that acupuncture isn’t even listed as a treatment on many patient information websites, despite it being well researched in PTSD patient populations,” Dr. Cheng said. “While acupuncture has been well studied with outpatient PTSD patients, specifically in the military, using it in the operating room is almost unheard of. Our study shows that offering acupuncture to patients is something that can help them feel more in control of the situation and get through surgery successfully.”

For these case studies, two patients were interviewed about their nosocomephobia and their prior hospital experiences. Using Dedoose software, six reviewers coded the interview transcripts line-by-line. The reviewers labeled meaningful words, phrases, and sentences, and created more than 600 codes. The reviewers grouped similar codes to identify themes, and then conducted a thematic analysis to generalize the study’s themes and construct its theoretical framework.

This analysis demonstrated how nosocomephobia affected patients’ perceptions of surgery and helped identify their individual fears. The researchers diagrammed the thought process of the patients to show how they considered whether they felt comfortable enough to get surgery. The appraisal process included three steps: experiencing the stressor (surgery), how they would be able to cope (acupuncture), and their mental state about whether they believed they could go through with the surgery (reappraisal).

In the case of these two patients with nosocomephopbia, acupuncture was a safe, non-invasive way for them to manage their preoperative anxiety and undergo elective surgery.

“Our research is based on a limited number of cases and makes it difficult to draw any major conclusions. We need to study more patients who have a major fear of hospitals and who need surgery and see whether offering acupuncture intraoperatively can successfully get those patients through surgery,” Dr. Cheng explained. “We also need to make more patients and doctors aware that this modality is available, and that it can be really helpful to patients suffering with PTSD.”

“If the addition of intraoperative acupuncture can prove to be helpful for patients who have a fear of hospitals, then we can really change the quality of life of a segment of the population that has historically been difficult to treat. The unseen patient can finally be seen,” Dr. Cheng concluded.

Reference

1. Pa Thor PhD, Andrew Moreno MS, MD, Haoyan Zhong MS, Miriam Sheetz BS, Marko Popovic BS, Sabrina M. Strickland MD, Michael P. Ast MD, Stephanie I. Cheng MD, DABMA, FAAMA. “A Qualitative Analysis of Intraoperative Acupuncture for Nosocomephobia: The Unseen Patient.” Presented at: 6th World Congress on Regional Anaesthesia & Pain Medicine, September 6-9, 2023, Paris, France.

“There’s been considerable research and effort into reducing opioid consumption after elective surgeries, and specifically after knee replacement. Many people consider knee replacements the most painful elective surgery someone can have,” says Dr. Ast. “We’ve done a lot of great work, and we’ve already cut the amount of opioids that patients take by approximately 75% as compared to 10 years ago. But there’s still room to go, which is why we want to focus on developing novel forms of non-opioid pain medication.”

Ketamine is a well understood drug that has been approved by the US Food and Drug Administration for postoperative pain management, but it is currently only administered intravenously in the inpatient setting. A noteworthy feature of the new formulation evaluated in this study was that it was an oral medication. “Our goal was to find an effective medication that patients could take home with them,” explains Dr. Ast. “This is especially important because the average stay after total knee replacement surgery is only 24 hours, but we know that the worst postsurgical pain arises between days 3 and 10.”

Oral ketamine is already being studied as a safe alternative to opioids but has low bioavailability in its isolated form. Additionally, there are concerns about ketamine being abused, due to the feelings of dissociation that it creates. The ketamine used in this study was specially formulated for oral use and is manufactured in a way that potentially limits its ability be abused by melting or crushing.  “We’ve learned through basic science studies that nonsteroidal anti-inflammatories like aspirin can buffer the effects of other drugs by adjusting the pH. Aspirin and ketamine work together synergistically on the body’s pain receptors,” says Dr. Ast. “This allows you to use relatively low doses of the ketamine, which also aids in preventing the dissociative feelings even at larger doses.”

The trial enrolled 22 men and women between the ages of 47 and 81 who were undergoing elective total knee replacement. The criteria for enrollment were tightly controlled, including being generally in good health and having no history of opioid use. All the study participants received an oral dose of aspirin and ketamine four times a day until discharge (up to 72 hours) and were monitored for the duration of the study, including being assessed for pain using standard pain scales.

“At HSS, nothing matters more than patient safety,” Dr. Ast says. “That’s why it was so important to do this pilot study with a small number of patients who were closely followed for the entirety of their treatment before developing a larger trial.” Overall, 18 of the 22 patients reported no side effects at all from the treatment. Two of them reported feelings of dizziness. Two others withdrew from the study early because they felt they needed more pain relief.

“If this treatment proves to be as effective as we hope it’s going to be, we can imagine a world where — even after something as painful as knee replacement surgery — patients go home with only a few opioid pills to take if needed, rather than a more typical amount of 25 or 30 pills that are often provided today,” Dr. Ast says. “This could dramatically reduce the number of opioid pills that end up out on the streets every year, just from this one procedure.”

For Dr. Ast, the quest to find alternatives to opioids is personal: “Unfortunately, I grew up in an area that has been hit hard by the opioid epidemic and have seen people I knew pass away from opioid overdoses,” he says. “That’s one of the main reasons the focus of my research for the past 10 years has been on finding new forms of pain medication that can minimize opioid use and ultimately be developed and commercialized.”

A manuscript of this study is in preparation for presentation and publication. The next phase clinical trial is expected to begin at HSS in the near future.

Through the HSS Innovation Institute, HSS and Lazurite will collaborate to advance surgical technology and techniques, including evaluation of specific aspects of ArthroFree and potential co-development of new arthroscopic technologies. HSS will conduct training sessions at the HSS Simulation Learning and Training Center and may also work with Lazurite on the co-development of future technologies that leverage the ArthroFree wireless camera and proprietary Meridiem™ light technology.

By eliminating conventional camera cables that tether surgeons to the surgical tower and hinder their movement, the ArthroFree System is expected to increase OR efficiency, improve OR safety and lower customer costs. With its solid-state, low-heat, high-efficiency Meridiem light technology, the system also promises to eliminate camera-related patient burns and OR fires. The modular system is designed to be drop-in compatible with existing patient data consoles, surgical displays and endoscopes found in minimally invasive operating rooms. 

“HSS is excited to collaborate with Lazurite to evaluate the ArthroFree Wireless Surgical Camera System, provide insights into a next generation of the existing device, and potentially co-develop other medical device products utilizing this technology,” said Michael P. Ast, MD, chief medical innovation officer and a joint replacement surgeon at HSS. “As HSS physicians and innovators, our goal of continuously improving patient care and outcomes includes identifying and pursuing new technologies and developing partnerships that leverage HSS’s expertise and innovative spirit with cutting-edge industry advancements to drive new innovation forward.”

“Given HSS’s substantial capabilities in research, including the experience and expertise of its medical staff and the volume of orthopedic surgeries performed there, we believe that HSS is a great partner to conduct the various non-clinical assessments and other collaborations outlined in the agreement,” said Lazurite Board Chair Mark Froimson, MD.

“We’re pleased that a world-class clinical organization like HSS sees the potential for the ArthroFree System to become the standard of care in the minimally invasive OR,” Lazurite President and General Counsel Leah Brownlee said. “HSS has been a pioneer in orthopedic research and innovation for decades. The hospital performs more than 32,000 surgical procedures annually, including more hip surgeries and more knee replacements than any other hospital in the country. We believe this will be a beneficial experience for both HSS and Lazurite.”

About Lazurite

Lazurite is a medical device and technology company. Its ArthroFree™ System—the wireless camera for arthroscopy and general endoscopy—is designed for surgeons seeking surgical tools for greater agility in the OR. ArthroFree is drop-in compatible with current OR technologies, and it promises to eliminate cable-related patient burns, OR fires, and staff trips and falls. With the ArthroFree System, Lazurite ushers in the wireless era of surgical visualization. Lazurite’s intellectual property portfolio also includes the low-heat Meridiem light technology and products in development. The pre-revenue company is located in Cleveland, OH (est. 2015), and to date has raised ~$25M from institutional investors, family offices, and more than 75 physician champions. The mission: solve impossible problems to improve people’s lives. The 10-year vision: better outcomes for 10 million patients—and thousands of clinicians, too. For more information, see: https://lazurite.co

Forward-Looking Statements

This press release includes “forward-looking statements.” Forward-looking statements can be identified by words such as: “anticipate,” “intend,” “plan,” “believe,” “project,” “estimate,” “expect,” “may,” “should,” “will,” “designed,” “milestone,” “promises,” and similar references to future periods. Examples of forward-looking statements include, among others, statements we make regarding the expected impact of the ArthroFree System on the field of minimally invasive surgery, and particularly arthroscopic surgery, and our future sales of the ArthroFree System. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based only on our current beliefs, expectations, and assumptions regarding the future of our business, future plans and strategies, projections, anticipated events and trends, the economy, and other future conditions. Because forward-looking statements relate to the future, they are subject to inherent uncertainties, risks, and changes in circumstances that are difficult to predict and many of which are outside of our control. Our actual results may differ materially from those indicated in the forward-looking statements. Therefore, you should not rely on any of these forward-looking statements. Any forward-looking statement made by us in this press release is based only on information currently available to us and speaks only as of the date on which it is made. We undertake no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise.

Lazurite™, ArthroFree™, and Meridiem™ are trademarks of Lazurite Holdings LLC.

The BrightPoint^TM Epidural Needle Guidance System, Lumoptik’s first product, is a low cost, easy to use device which can help clinicians better perform epidurals using the standard-of-care Loss of Resistance (LOR) technique. BrightPoint^TM utilizes a specialized reflectometer that shows the clinician the color of the tissue at the tip of the needle in real time while inside the patient, thus providing an additional, objective indication that the needle is in the correct position. BrightPoint^TM is designed to work as part of the LOR technique, in combination with standard needles and syringes and can help clinicians perform LOR epidurals more safely and reliably than traditional methods.

“HSS looks forward to working with Lumoptik to evaluate and assess the BrightPoint^TM Epidural Needle Guidance System and work on new uses for Lumoptik’s innovative platform technology,” said Michael P. Ast, MD, chief medical innovation officer and a joint replacement surgeon at HSS. “This partnership is a great example of HSS being able to leverage all areas of its expertise, including anesthesia, in improving musculoskeletal care.”

The HSS Innovation Institute played a central role in bringing together the appropriate HSS skillsets and expertise to optimize the collaboration with Lumoptik. “Our mission to advance patient care through new technologies and partnerships aligns with the potential of Lumoptik’s technology and our anesthesia team to drive this new innovation forward,” said Doug Leach, vice president of Device Innovation at HSS.

“Using epidural anesthesia with patients who have musculoskeletal disease can be particularly challenging given the impact that arthritis and injury can have on the spine,” said Michael Singleton, MD, an anesthesiologist at HSS. “I am excited to see Lumoptik’s use of technology in an area that is ripe for modernization.”

“We are very pleased that a world class clinical organization like HSS sees the opportunity for our BrightPoint^TM Epidural System to potentially become the standard of care. We also look forward to working with them to develop additional high value medical products based on our platform technology. We believe this will be a fruitful relationship for both HSS and Lumoptik,” said Frank Lyman, CEO of Lumoptik.

About Lumoptik

Lumoptik, Inc. is a medical device company that has developed the BrightPoint^TM Epidural System to assist physicians with needle placement during epidural procedures for childbirth, spine/back pain and surgical procedures such as knee and hip replacements. Over 11 million epidural procedures are performed in the US each year with over 30 million performed worldwide. BrightPoint^TM is a platform technology with multiple potential medical uses in orthopedics, pain management, neurology, vascular access and urology. Lumoptik is a private company with a diverse investor base. For further information, please visit www.lumoptik.com or contact Frank Lyman, CEO at frank.lyman@lumoptik.com.

About Zimmer Biomet

Zimmer 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. 

For more information about our product portfolio, our operations in 25+ countries and sales in 100+ countries or about joining our team, visit www.zimmerbiomet.com or follow Zimmer Biomet on Twitter at www.twitter.com/zimmerbiomet.

 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.

Since 1979, HSS has been a pioneer in creating and bringing innovative technology to market to advance patient outcomes. HSS has led the industry in musculoskeletal innovation by supporting new ideas from inventors and by partnering with HSS experts to improve wellness, performance, and patient care. The HSS Innovation Institute was established in 2016 to accelerate state-of-the-art concepts and inventions through partnerships with industry, investors, and entrepreneurs and deepen relationships between engineers, physicians, researchers, surgeons, and scientists.

Today, the Institute is working to advance the use of patented hardware and analytical software, intelligent strength training and rehabilitation techniques, and devices to reduce pain, increase stability, correct deformities, and restore functions.

“HSS is the leader in musculoskeletal health around the world, and for decades our clinicians, scientists, and biomechanics engineers have been working side by side to advance technology and accelerate the discovery of treatment options,” said Mr. Shapiro. “We are excited to welcome Dr. Ast to our executive leadership team to help us remain laser focused on our approach to innovation, to drive forward-thinking leadership, and create new pathways that benefit patients everywhere.”

“HSS is uniquely positioned to capitalize on our expertise and leadership to continue to advance the field of musculoskeletal care across the world,” said Dr. Kelly. “The importance of collaborating is paramount now more than ever to ensure that we fulfill our responsibility to discover and improve treatment solutions for the routine and the most complex cases.”

In his new role, Dr. Ast will work closely with Mr. Harmon and the Innovation Institute team to support new, viable offerings that can improve clinical outcomes, enhance the patient experience, or lower the cost of care delivery in a meaningful way. 

“We are honored to welcome Dr. Ast to the Innovation team,” said Jordan Harmon, VP, Chief Innovation and Commercialization Officer at HSS. “Creating innovative healthcare solutions requires collaboration between clinical, administrative, and business experts. The HSS Innovation Institute will benefit greatly from Dr. Ast’s expertise in these areas. Dr. Ast will bring his vast knowledge and pioneering expertise from both a medical and business perspective, which will be invaluable as we navigate the healthcare landscape of tomorrow.”

“As a surgeon with both academic and private practice experience, I understand the challenges of a clinical practice and how innovation can offer solutions,” said Dr. Ast. “I look forward to utilizing my background in value-based care implementation, advanced technology for surgical training, and data integration and analytics to help achieve the goals of the HSS Innovation Institute.”

Dr. Ast added that innovation is more than product development. “As healthcare becomes more complex, we must continue to innovate care delivery strategies, education, and data management,” he explained. “Looking to the future, innovative solutions in healthcare will require a multifaceted team effort with viewpoints from the clinical, administrative, and business sides.”

As a member of the Adult Reconstruction and Joint Replacement Service at HSS, Dr. Ast’s clinical practice focuses on rapid-recovery, short-stay, and outpatient joint replacement surgery. He has extensive experience in robotic and computer-assisted surgery. Dr. Ast is a published researcher and noted speaker nationally and internationally on topics including technology in and around the surgical episode, healthcare economics and the business of clinical orthopaedics. Dr. Ast completed his fellowship in Adult Reconstruction and Joint Replacement surgery at HSS and went on to develop and direct one of the largest and most successful outpatient joint replacement programs in the northeast before returning to HSS in 2018.

Time to walking, length of surgery, pain at discharge and rates of complications and readmissions at 90 days after surgery were clinically and statistically the same for patients who had surgery with either approach. This study is available online as part of the AAOS 2020 Virtual Education Experience.

Anterior and posterior approaches are the two most common incision locations for performing a hip replacement. Both are located mostly on the side of the body, with some slight differences. Anterior incisions are more to the front of the hip and are visible when standing facing a mirror. Posterior incisions are further around the curve of the hip and are not visible from the front. Surgeons at HSS use an anterior or a posterior approach according to their preference, training and expertise.

Results from previous studies comparing the two surgical approaches have been unclear. Some used comparison groups that were not matched for age and body-mass index; others did not compare surgeries from the same period.

“Today’s advertising can be confusing, as it creates a mixed message about whether there are clinical benefits with a particular surgical approach. We wanted to find out what the evidence shows when the approaches are appropriately compared,” explains senior author Michael P. Ast, MD, a hip and knee surgeon at HSS. “Our results showed that surgical approach didn’t matter. At HSS, both methods provided the same excellent outcomes for our patients.”

Dr. Ast and surgical colleagues examined outcomes for 138 patients who had hip replacements at HSS in 2019 and were discharged the same day. Patients received the same care before, during and after surgery, according to HSS protocols. The researchers grouped patients according to whether they had received an anterior or a posterior incision, with 69 in each group. Age, sex and body-mass index of each group were matched.

There were no statistically significant differences in outcomes between the two groups at any timepoint within the first 90 days post-surgery. There were no reoperations in either group and complications were very low, affecting only two patients in the anterior approach group and three patients in the posterior approach group. For all patients, early ambulation was associated with earlier discharge and decreased use of pain medication while still in the hospital.

“We now have evidence to show that incision location does not matter in total hip replacement,” says Dr. Ast. “What does matter is surgical expertise, careful patient selection for outpatient procedures and high-level care before, during and after surgery.”

To corroborate these findings with a larger study, Dr. Ast and colleagues continue to collect patient outcome data for the two groups in their prospective database. Their goal is to re-run the analysis when they have data for 500 patients in each group. “At HSS, we perform about 4,000 hip replacements every year, so we are excited to continue this study to meet that goal,” Dr. Ast says.

Researchers compared knee and hip replacementoutcomes and costs for both inpatient and outpatient surgery. Michael P. Ast, MD, a hip and knee surgeon at HSS, performed the inpatient procedures at a university medical center and the outpatient surgeries at a community-based ASC.

Read the full article at Becker's ASC Review.

In 2017, more than 47,000 Americans died after overdosing on opioids, such as heroin or fentanyl, a potent synthetic drug, government data show. Some 1.7 million more had a substance abuse disorder involving a prescription opioid. 

Patients who undergo joint replacement surgeries of all kinds conventionally have received an opioid prescription for their recovery—presenting critical opportunity for reducing the reliance on these medications and preventing abuse of the drugs. 

HSS is taking a multi-pronged approach to the problem, explained Michael P. Ast, MD, an orthopedic surgeon at the institution. HSS recently launched a hospital-wide initiative to reduce opioid use among its patients and to better understand when the powerful drugs are appropriate to prescribe, and in what quantities. The initiative has involved surgeons, anesthesiologists, nurses and other members of the care team.

A primary focus of the pain-management pathway is the emphasis on multimodal analgesia. The practice involves the combination of local anesthetics, nonsteroidal anti-inflammatory drugs, IV acetaminophen and, possibly but not necessarily, opioids. Multimodal analgesia for knee and hip replacement surgeries has been associated with a decrease in the use of opioids, according to the American Society of Anesthesiologists (https://www.asahq.org/about-asa/newsroom/news-releases/2018/03/multimodal-approach-to-pain-management-reduces-opioid-use).

Another aspect of the initiative involves research, and HSS currently has more than a dozen ongoing studies to assess alternatives to opioid analgesia. "We’re doing things like intraoperative and post-op acupuncture therapy and we’re looking at alternative treatments in the form of nerve blocks," said Peter K. Sculco, MD, orthopedic surgeon at HSS and also senior author on the study said. "We’re also looking at understanding prescribing patterns and how that affects how patients use their medication—if they are given a smaller prescription will they use less over time?"

The effort also has a strong patient-centered component. The new pain-management pathway includes educational programs for patients undergoing joint surgeries, including new additions to the preoperative education to manage pain expectations, early intervention by the pain management team for patients on preoperative or chronic opioids, and a multi-disciplinary inpatient team to treat and educate patients on alternatives to opioids for pain management. Although still in its early phase, data so far show that the pathway has led to a significant decrease in the use of opioids with no sacrifice in pain control. 

Dr. Sculco and his colleagues presented their findings at the 2019 annual meeting of the American Academy of Orthopaedic Surgeons in Las Vegas (exhibit SE35).

Other authors include: Ameer Elbuluk, MD; Michael Alexiades, MD; and Michael Cross, MD; all from HSS.

For more information on opioid prescription and pain management at HSS, please view the February 2019 issue of HSS Journal.

"If you are otherwise healthy, do not smoke, live at home with another person for support after surgery and are motivated to get back to your life quickly, then you are likely a good candidate for same-day discharge," explains Dr. Ast who notes that each person’s anatomy and complexity of the joint condition should be considered.

His patient Sue explains how she became mobile very quickly after same-day knee surgery. "My advice to potential patients is make sure that you are prepared at home – both with family and friends you can lean on and the actual tools you need to recover. Don’t be afraid to go home on the same day, it encourages you to begin your personal recovery sooner," she adds.

Read the full article at DailyVoice.com.

According to the article, HSS has been evaluating Osso VR platform to train surgeons about surgical procedures and equipment.

"The point is to try to get new surgeons to go through, learn and practice the procedure in a virtual environment," said Michael P. Ast, MD, hip and knee surgeon at HSS. "New surgeons or experienced surgeons can practice it on their own hundreds of times before ever performing the actual procedure on a patient."

"If we can shift the learning of those aspects into the virtual world, we can allow surgeons to concentrate on the more individualized aspects of surgical care when they do perform the surgery on a patient," Dr. Ast added.

Read the full article at InformationWeek.com.

During a recent webinar, Michael P. Ast, MD, hip and knee surgeon at HSS, explained how patient match technology can help with equipment limitations for outpatient arthroplasty.

According to Dr. Ast, patient match technology "promotes efficiency in set up and sterilization, in case efficiency itself, and also has some clinical benefits without violation of the intramedullary canal".

He encouraged viewers to lean on their industry partners as ASCs grow outpatient total joint programs.

Read the full article at BeckersASC.com.