June 2025 Edition — COA BulletinIndustry Advancements
Sharing white papers and sponsored content from industry partners. Gain a front-row view into the technologies and solutions shaping the future of the profession.
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The ROSA® Knee System 2023 Clinical Evidence Summary – Zimmer Biomet
Introduction
A report from the Agency for Healthcare Research and Quality has demonstrated that knee arthroplasty is one of the most frequent procedures in the operating room1. The success of total knee arthroplasty (TKA) is well established, and the most recent Australian and UK registry reports demonstrate 10- and 15-year cumulative percent revision (CPR) rates of 4.6% – 6.2% and 3.93% – 5.55%, respectively, for primary total knee arthroplasty associated with osteoarthritis2-4.
Despite its success, TKA continues to experience revisions related to aseptic failures, with loosening and instability being the predominant reasons5,6. Technological advances attempt to address this, but the value of these technologies remains controversial. The reasons for controversy are due primarily to the lack of long-term outcomes and survivorship data7,8. Kort et al. noted that benefits of robotic TKA include improved component positioning, but that improvements in outcomes, satisfaction, and survivorship is lacking8. Still, early outcomes are promising and Mullaji and Khalifa recently reported superior early functional outcomes when reviewing contemporary literature on robotic- assisted TKA9.
A valuable source of real-world data in orthopaedics has been the use of well-established registries10,11. Graves noted the value of registries is their unique ability to provide comparative data10. Additionally, data from registries have been shown to stipulate change in some orthopaedic practices. When looking at the 2023 annual report of the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), the data suggests that robotic knee arthroplasty is reducing the CPR rates of primary TKA at two to four years post-operatively2,12. The registry reports CPR rates of robotically assisted TKA at 1.8% (95% CI, 1.7%, 2.0%) compared to 2.2% (95% CI, 2.1%, 2.3%) for non-technology-assisted at three- years follow-up. At five-years, the difference in CPR rates between robotic-assisted and non-technology-assisted were 2.2% (95% CI, 1.9%, 2.5%) versus 2.9% (95% CI, 2.8%, 2.9%), respectively (see AOANJRR 2023 Annual Report Table KT44). Although these differences were no longer significant after adjusting for covariates, there were differences in revisions between robotic and non- technology- assisted for aseptic causes of loosening and instability (see AOANJRR 2023 Annual Report Figure KT53) 2,12.
The ROSA® Knee System is a semi-autonomous robotic arm that assists in the placement of the cutting jig along with providing ligament laxity assessments throughout the primary TKA workflow. It can be used with image- based or imageless modes13. The primary purpose of this review was to identify and summarize the literature associated with the ROSA Knee System in relation to accuracy, efficiencies, and outcomes.
Is there an Optimal Molecular Weight for Injectable Hyaluronic Acid Treatment?
Laurie Hiemstra, Olufemi R. Ayeni, and Mohit Bhandari
The Discovery of Hyaluronic Acid
In 1934, Karl Meyer and John Palmer reported in the Journal of Biological Chemistry the discovery of a unique, high-molecular-weight polysaccharide extracted from the vitreous humor of bovine eyes. Although direct comparisons between modern formulations are still limited, differences among them may significantly impact clinical outcomes. Hyaluronic acid (HA), a naturally occurring substance with viscoelastic properties, plays several key roles in maintaining joint health. These include distributing compressive forces, lubricating tissues, and regulating cellular functions.
Evidence Supports Higher Molecular Weight Hyaluronic Acid Injectables.
In individuals with knee osteoarthritis (OA)—a chronic degenerative condition affecting both cartilage and bone—supplementation using synthetic HA formulations has been available for decades. Variations in HA products, such as differences in composition, molecular weight, and biological activity, may influence the onset, duration, and safety of pain relief. Understanding the physicochemical characteristics of HA is also important when considering its potential to slow or prevent further joint degeneration.
Evidence suggests that higher molecular weight formulations of Hyaluronic Acid perform significantly better than lower molecular formulations. While all formulations seem to have some benefit, larger treatment effects have been reported with higher molecular weights. Reviews suggest outcomes from prior meta-analyses are consistent with statistically significant improvements in pain, function and stiffness up to 26 weeks. However, outcomes based on molecular weight (MW), demonstrate significantly improved pain outcomes for higher compared with lower MW HAs.
In Higher Molecular Weight Hyaluronic Acid Formulation, is there an Optimal Molecular Weight?
Preclinical studies suggest that the strong binding affinity of HA with optimal molecular weight stimulates endogenous HA production1. Steric hindrance describes how a molecule’s physical structure can affect its ability to bind to cellular receptors. Optimal molecular weight has been defined at between 500 000 Da and 4M Da.
