For many individuals, the ache of an arthritic knee can be an unwanted companion, gradually restricting the simple joys of life, from leisurely walks in the park to ascending stairs.
Historically, choices have been quite limited, alleviating the discomfort with medication and physiotherapy, or, in more severe cases, resorting to a total knee replacement. This significant surgery substitutes the joint with metal and plastic.
But what if there’s a middle ground? A less drastic solution aimed at assisting your knee before it deteriorates further?
This is the question that a committed team of researchers and engineers at the University of Malta (from the Department of Anatomy, the Department of Mechanical Engineering, the Department of Industrial and Manufacturing Engineering, and the Department of Metallurgy and Materials Engineering), collaborating with medical specialists from and industry partner , sought to address.
Their innovative solution is known as the MaltaKnee, a device poised to be a pivotal advancement for individuals experiencing early to mid-stage knee osteoarthritis. This initiative has been supported by , through initial funding under the "MaltaKnee" project and subsequent commercialisation-focused funding named "MaltaKnee2Market".
The"MaltaKnee2Market" project was financed by Xjenza Malta (the Malta Council for Science & Technology), for and on behalf of the Foundation for Science and Technology, through the FUSION: R&I Go To Market Programme’.
- What is the MaltaKnee?
Imagine two small, soft, inflatable cushions, particularly designed to fit snugly within the knee joint. That encapsulates the essence of MaltaKnee. It features a dual-section design, comprising two primary components. The lower section is a chamber that can be delicately inserted into the knee using arthroscopic techniques, essentially keyhole surgery, while collapsed. Once properly positioned, the chamber is inflated with a sterile fluid, adapting perfectly to the individual’s knee, offering essential shock absorption and helping to distribute the load more evenly across the joint surfaces.
Above this, a thinner, flexible upper section is integrated. This section permits the natural lubricating fluid of the knee, known as synovial fluid, to flow seamlessly and ensure smooth motion. The exterior of this upper section is also designed with a unique micro-texture. It gently grips the cartilage within the knee, helping to secure the implant. Exciting preliminary evidence also indicates that this texture might stimulate the body's stem cells, potentially promoting cartilage repair.
MaltaKnee Implant
- Testing the Device: The Knee Simulator
Creating a sophisticated device like the MaltaKnee is complex. It necessitates extensive research, from selecting appropriate biocompatible materials, such as a specific type of medical-grade plastic called polycarbonate urethane, to ensuring the design endures the stresses our knees face daily. This is where the team’s specialised knee simulator comes into play.
This piece of equipment has been custom-engineered to mimic the intricate movements and loads experienced by a human knee. To enhance the comparability of the testing to a real knee environment, the team employs Thiel-embalmed human cadaver knees. Unlike conventional embalming methods, Thiel preservation maintains the tissues’ softness and flexibility, closely resembling a living joint.
Once a MaltaKnee device is methodically implanted into a cadaver knee via arthroscopic techniques, the knee is secured onto the simulator. The machine proceeds to simulate the bending (flexion) and straightening (extension) of walking, applying loads equivalent to several times body weight—just as one would experience while walking, running, or climbing stairs. This thorough testing is vital. For the primary knee device, it endured an astounding 500,000 cycles, mirroring many months of daily activity. The outcomes from these experiments have been extremely promising. The implants generally remained securely positioned and, importantly, did not rupture or exhibit significant signs of wear. Notably, the microtexture effectively marked the cartilage, indicating its role in maintaining stable contact without causing harm.
Patello-Femoral Implant
- A Specific Emphasis: The Patellofemoral Implant
Knee pain extends beyond the main joint; issues with the kneecap (patella) and the femoral groove it moves within can also arise. This condition is referred to as patellofemoral arthritis, often impacting younger, active individuals. Acknowledging this, the MaltaKnee team developed a variant of their implant specifically targeted for this area.
The implantation process for this device requires a slightly modified approach, demanding careful access to the kneecap's underside. For the simulator examinations, a minor, controlled defect was deliberately created in the cartilage of both the femur and patella before placing the implant. The objective was to determine if the implant could shield this damaged area from further deterioration during the simulated walking cycles.
The findings were quite encouraging. After 500,000 cycles, the implant remained intact, without crumpling or dislodging. More compellingly, when examining the cartilage defects, the team noted that in knees with the patellofemoral implant, the edges of the defects remained sharp and well-defined. In contrast, knees tested without the implant displayed noticeably dulled edges, indicating wear. It appears that the MaltaKnee patellofemoral implant, by providing a smooth, protective cushion, facilitates movement between the implant layers instead of directly on the damaged cartilage, effectively safeguarding it from further harm.
- What's Next for MaltaKnee?
The development of the MaltaKnee exemplifies meticulous science, innovative engineering, and a profound awareness of patient needs. Although further research and development are necessary, these encouraging results from the knee simulator, utilising realistic cadaver models, propel this promising technology significantly closer to potentially transforming the lives of individuals with knee arthritis, offering a less invasive, more efficient means of enabling comfortable movement over longer periods.
The next phase for the MaltaKnee project will focus on advancing the device towards regulatory acceptance, including alignment with international standards and the preparation of documentation required for submissions to bodies such as the FDA.
Continued device development will be paralleled by efforts to secure further investment, as significant funding is necessary to support upcoming stages, including more extensive animal trials and, eventually, clinical studies. The team is currently refining the implant design and testing prototypes under conditions that closely mimic the knee joint environment, to demonstrate both safety and efficacy. As the project progresses, additional animal studies will provide crucial data for regulatory submissions and de-risking the technology for investors.
Ultimately, these steps are essential to pave the way for future clinical trials and, in the longer term, to make MaltaKnee available as a new therapeutic option for patients with arthritis who are not candidates for traditional joint replacement.
