Shoulder arthroplasty is one of the fastest-growing segments in the orthopedic market today. Over the past decade, there have been exciting design and technology improvements by innovative companies aimed at driving better patient outcomes and efficiency.
Consider the convergence of design in knee and hip replacement market, which has been evolving and refining for more than 50 years. Today, most knee and hip implant designs only differ slightly in geometry and coatings, as the market has converged on well-established solutions for patient treatment.
“In contrast, the shoulder arthroplasty market is quite the opposite as competitive designs vary drastically in terms of implant bone fixation, geometry, and the resultant biomechanics. The “optimal” design is still yet to be discovered, though innovative companies are attempting to discover it. Yet, each device company is focused on the same goal: drive better patient outcomes with more consistent results.”
Agility breeds innovation
We’re in the midst of an innovation heyday for shoulder arthroplasty devices. Eventually, the market will converge and reflect where the knee and hip market is today. But right now, we’re in an exciting time of shoulder innovation.
Most novel solutions are coming from smaller orthopedic companies. With agile engineering, quality, and regulatory departments, they can develop, test, and launch products much faster than their larger competitors, often able to take bigger leaps thanks to their lean operating structure and willingness to bring forth new ideas.
It can be difficult for larger companies to match this innovation, as the commitment to inventory volume requirements and a large established user base make bold portfolio alterations risky. Change can quickly become overwhelming to internal operations, supply chains, and contracted pricing deals that offer little flexibility.
But clinical advancements coming from successful start-ups are able to prove efficacy with early adopter teams of surgeons. They’re able to design, test and pivot to and refine offerings quickly. Eventually, larger competitors will develop their own response, or acquisition will bring start-ups into these larger brands, leading to a future market where product offerings resemble each other, with slightly different features.
Designing new implants with purpose
Innovation in the shoulder market segment is leading to products that look different from traditional devices. For instance, research continues to indicate that a more anatomically shaped, ellipsoid humeral head design better mimics the patient’s natural anatomy. However, this is not the standard just yet. Traditional designs for the last 30-plus years included a metal humeral stem with spherical humeral head, and a polyethylene-based plastic glenoid component.
Despite the differences in competitive implant design, the core principles remain the same regarding tissue approach and bone-preparation. But the theme of some innovative engineers is to preserve traditional design principles while looking forward at future healthcare market trends to devise new solutions that satisfy both needs. We call this “designing with purpose.”
The products for the humerus have evolved to shorter stems, and even “stemless” designs that still involve a micro-stem, of sorts, which require removal of the entire humeral head in preparation. Glenoid approaches can still be difficult, as a straight-on view is required of the glenoid for rotary instruments to operate and prepare the bone as needed for implantation. New angled glenoid instrumentation and implants help the surgeon address this, with less tissue dissection and forceful muscle retractions.
Another new approach to humeral treatment gaining traction is to shape the natural bone as little as possible to receive an anatomical implant, similar to total knee femoral implant designs today. The Catalyst CSR, for example, sits on the denser subchondral bone of the humeral head, with four pegs for stability. Instead of removing the entire humeral head in a single cut required of all traditional implant designs, a series of bone-sparing cuts (or MPO – multi-planar osteotomies) allow for an extremely accurate restoration of the patient’s original anatomy and center of rotation (CoR) of the shoulder joint.
There are more peer-reviewed papers in leading clinical journals detailing the short- and long-term results of an ellipsoid, non-spherical humeral head. Currently, Catalyst is the only company on the market that has clearance on the market for an ellipsoid design, and the pile of evidence is building that shows benefits in both range of motion and speed of recovery for their patients. While the CSR features this ellipsoid geometry; however, the change in humeral bone preparation, albeit streamlined, is a recognized departure from the norm, and Catalyst also wanted to bring that technological benefit to the more traditional implant construct design; thus, the impetus to launch a stemmed TSA construct was born, and in under a year, development and clearance was received for the stemmed CSR TSA system.
Innovating for flexibility, efficiency
The shoulder arthroplasty market is currently dominated (about 70%) by the reverse shoulder procedure, which has become the standard of care for older patients typically presenting with osteoarthritis of the joint (OA) and a deficient rotator cuff.
The reverse shoulder procedure is unique to the large-joint orthopedic market and is the only procedure where the joint’s ball-and-socket mechanics are flipped; the humerus receives a cup-style “socket” which rotates around a ball “glenosphere” fixated on the glenoid.
Some companies have developed “convertible” implant systems, which allow the humeral prosthesis to host either an anatomic head or a reverse socket component, giving flexibility to the surgeon to perform either operation at the time of surgery or in a future revision scenario. The convertible design allows a surgeon to convert the humeral construct between an anatomic and reverse system without the need to explant the humeral component that may be biologically integrated with the host bone, thus saving time and stress on the patient’s humeral bone.
With the launch of new convertible platforms, device manufacturers will be able to address two burgeoning market trends at once – the need for the surgeon to address their patient’s rotator cuff health intra-operatively to decide on an anatomic versus reverse prosthesis, and the benefit of an ellipsoid-head (if available with that system) if the surgeon chooses an anatomic reconstruction.
Innovating for cost efficiencies
Aside from implant design, another consistent narrative is the cost of inventory management within hospital systems. Many factors play into costs, but one area that can be directly addressed is the number of trays, instruments, and inventory required to have on hand for a shoulder arthroplasty procedure.
Today, most systems by the large OEMs require somewhere between 5 and 9 instrument trays to be processed and opened in the operating room, which has a significant time and cost impact on the sterile processing department for the hospital, especially if multiple cases are happening each day.
We’re starting to see more innovation here too, including streamlined single instrumentation tray systems. This has been a major focus by the smaller arthroplasty companies entering the market recently. In some cases, either an anatomic or reverse procedure can be completed with just one single instrumentation tray, which reduces up to 75% in implant inventory and tray processing in most comparative cases. This has been a big advantage for companies like Catalyst that offers a single tray per procedure capability.
This is a significant cost reduction innovation for Ambulatory Surgery Centers, where space and processing capabilities are at a premium.
Innovating surgical techniques
Finally, the market is also looking at advancements in procedural technique. A great example of past procedural innovation has been the refinement of the Direct Anterior approach in the hip arthroplasty space which has led to faster recovery and reduced healthcare costs nationally.
In anatomic shoulder arthroplasty, ensuring integrity of the subscapularis tendon is key to a successful outcome. Reducing soft-tissue damage can speed recovery. This has led to development of subscapularis-sparing approaches that are made significantly easier from a technical perspective using instruments designed for an angled approach to the glenoid, like Catalyst. This is a hot topic among shoulder arthroplasty surgeons and orthopedic engineers are responding rapidly. It’s exciting to see what will happen next.
Editor’s Note: Dr. Steven S. Goldberg is the founder and chief medical officer of Catalyst OrthoScience. He is the past Chief of the Division of Orthopedic Surgery at Physicians Regional Healthcare System in Naples, Fla. He has been consistently recognized as one of the top orthopedic surgeons in Southwest Florida. Dr. Goldberg has authored multiple publications for the Journal of Bone and Joint Surgery and the Journal of Shoulder and Elbow Arthroplasty, hold over ten patents for shoulder replacement products and regularly teaches surgeons around the country on new techniques and methods.