A Look at Knee Implants Beyond the Market Leaders

The big four—Stryker, DePuy Synthes, Zimmer Biomet, and Smith+Nephew—comprise most of the knee replacement market and it’s difficult for smaller companies to break in. However, there are some orthopedic companies that have created novel attributes for their knee replacement implants that allowed them entry into the market.

Just outside the top 10, Exactech’s knee replacement implants include Truliant, Optetrak, and InterSpace. The Truliant porous knee launched last August, expanding the line to a non-cemented option. The implant mimics cancellous bone’s trabecular nature with optimal pore size and porosity. The implant’s topography facilitates durable bonding for immediate and long-term fixation.

Like the rest of the Truliant knees, it’s supported by the Exactech GPS Knee Application computer-assisted surgery. TKA Pro supports a surgeon’s preferences with customizable workflows through real-time visual data and guidance. Furthering its smart technology platform, Exactech also completed its first total knee replacement surgeries using Newton soft tissue management technology last August. The Newton intra-articular device combines dynamic ligament balancing and real-time guidance for a personalized, intra-op solution. It captures active balance data through the whole arc of motion with the patella in place and integrates with ExactechGPS. It’s part of the firm’s Active Intelligence smart solutions franchise.

“We are excited to introduce this game-changing technology for total knee replacement surgery,” Adam Hayden, Exactech chief marketing officer and senior VP of Large Joints, told the press. “Newton is yet another example of Exactech pioneering innovations that provide orthopaedic surgeons with intelligent insights to make smart decisions throughout the journey of care.”

Conformis combines its iFit Image-to-Implant tech with advanced manufacturing capabilities to develop, manufacture, and market individually sized and shaped knee replacement implants. The firm’s flagship iTotal iCR cruciate-retaining (CR) implant has been the subject of a number of studies demonstrating improved clinical outcomes compared to traditional implants. Last September, Conformis shared results of a 433-patient retrospective study for iTotal CR that showed 98.5 percent implant survivorship, 89 percent satisfaction, and a high mean functional outcome score of 82.

Last May, the firm nabbed U.S. Food and Drug Administration (FDA) 510(k) clearance for its Identity Imprint knee replacement. The latest generation implant combines predetermined implant sizes with standard and patient-specific surgical instrumentation, using a 3D “best fit” algorithm to choose the implant best meeting geometric and anatomic requirements based on a patient’s CT scans. The first implantation of Identity Implant took place last August.

The company also launched its Image-to-Implant Platinum services program in late 2021. The service gives patients the opportunity to upgrade to a personalized Identity knee system by paying a fee for incremental deluxe services. Conformis expects to roll the service out fully to its customers by Sept. 1 this year.

“Our Identity Imprint knee system is a tremendous new addition to our product portfolio that leverages our technical innovations and data from tens of thousands of personalized implant designs. It is a terrific option for those surgeons who want more traditional intraoperative flexibility and faster product availability. We will be able to provide a patient-matched Identity Imprint system in three weeks versus the six weeks’ lead time for the iTotal Identity fully personalized system,” Mark Augusti, Conformis president and CEO, said in a press release. “This offering is extremely well-positioned to meet the needs of the ASC care setting, but will provide value to in-patient hospital care as well, especially in the post-COVID environment.”

MicroPort’s portfolio of knee replacement implants includes the Evolution and Advance franchises. These contain a medial-pivot knee system—the first on the market, according to the company when introduced in 1998. The medial-pivot insert aims to replicate normal motion and natural function by reproducing native knee structure with a highly conforming surface on the medial side. Evolution knee implant surgeries are supported by the company’s Evolution Kinematic Alignment technology, which lets the surgeon recreate the knee’s natural joint line before arthritis.

In December, MicroPort celebrated its first U.S. surgery using Pixee Medical’s Knee+, an FDA-cleared augmented reality (AR) total knee surgery surgical application, with its Evolution knee. The platform provides real-time instrument positioning in the surgeon’s field of view via smart glasses. According to the company, it requires minimal training because it doesn’t change the technique for 90 percent of surgeons using a conventional technique and those who haven’t used navigation or robotics. Last June, MicroPort’s Advance knee also celebrated a “15A” Orthopaedic Data Evaluation Panel (ODEP) rating—a 15-year benchmark ODEP assigns for knee implants. Fifteen years in the longest benchmark that ODEP assigns.

Medacta touts the GMK, Cinetique, and Evolis implants. The core of its total knee systems is the medially stabilized GMK knees. The company also features a patient-matched instrument platform for total knee surgeries that includes 3D pre-operative planning and patient-specific instruments. Medacta’s NEXTAR augmented reality-based surgical platform consists of advanced planning tools and soft tissue assessment, a tracking system, and augmented reality.

In October, Medacta released MyKnee R (revision) within its MySolutions Personalized Ecosystem. The tool creates patient-specific, 3D printed blocks that can be placed on a failed primary knee implant in situ to easily proceed with replacement. The tool engineers a 3D reconstruction of the patient’s joint through a CT scan to accurately plan positioning of new GMK prostheses.