ACTIFIT Artificial Meniscus Implant

The ACTIFIT artificial meniscus implant

The patient must have an intact meniscal rim, with the anterior and posterior horns present, in order to allow the Actifit to be attached. The procedure is performed arthroscopically, usually under general or spinal anaesthesia. If the original meniscal lesion cannot be sutured (repaired), the damaged tissue is removed much as in a partial meniscectomy, until an area with good blood flow is reached.

The ACTIFIT implant procedure

• A. The meniscal defect is assessed.
• B. If the defect cannot be repaired, the area is trimmed and prepared for the Actifit.
• C. The Actifit is measured to ensure a perfect fit to the affected area and cut to size on the operating table using a scalpel.
• D. The implant is then placed arthroscopically into the prepared area of the affected knee.
• E. Several suture techniques can be used to secure the Actifit to the remaining meniscal rim and to the posterior/anterior horns, such as all-inside, inside-out or outside-in.
• F. Post-surgical rehabilitation to protect the newly formed tissue during the initial remodelling phase must begin immediately, as directed by the surgeon and the physiotherapist.

Only orthopaedic and sports medicine surgeons experienced in treating patients with meniscal tears, and trained in the use of the device, may use the Actifit implant.

What is ACTIFIT?

Orteq developed Actifit for treating knee injuries because there are no options for regenerating a patient's meniscus once the damaged section has been removed through a partial meniscectomy. Every year more than 1,500,000 meniscectomies and 630,000 total knee replacements are performed in the USA and Europe. Actifit can therefore fill an unmet clinical need. We believe this biodegradable structure can be adapted for use throughout the body and will help tissue growth at a number of sites.

Actifit supports the body's natural healing process through a material that allows the affected area to become vascularised and to receive the oxygen, nutrients and fibroblasts needed for cell growth.

A meniscal injury is normally repaired by removing the damaged or torn tissue through a partial meniscectomy. This can be effective in the short term, but usually only relieves the pain partially. In many cases the pain returns over time, because of the loss of meniscal tissue and of the shock-absorbing function of a healthy meniscus. After a certain period, degenerative changes appear which, if untreated, can lead to damage to the articular cartilage, to the onset of osteoarthritis, or eventually to a total knee replacement.

Actifit is a honeycomb-like structure that allows blood to flow through it and provides an anchor for the new, growing layer of cells, so that the natural healing process can take place. Once the damaged section of the meniscus has been removed and the resected meniscus has a good blood supply, the Actifit implant is cut to size and sutured into place. Over time, the new cellular tissue matures into meniscus-like tissue. This helps restore the shock-absorbing function of the meniscus and delay the onset of osteoarthritis.

How does ACTIFIT work?

With Actifit, patients can benefit from pain relief through a single procedure. Over time, the new meniscus-like tissue grown with Actifit improves patients' chances of a future free from pain, loss of mobility, cartilage destruction and the other forms of degeneration that normally lead to osteoarthritis and total knee replacement.

Clinical and preclinical studies show that the new polymer is safe and effective. It has the ability to promote the growth of considerable quantities of meniscus-like tissue. Clinical studies in humans show a significant reduction in pain and promising results in terms of quality of life and return to pre-injury activity levels.

The meniscus and meniscal tears

The knee is the most complex joint in the body. Among the components underlying its function and complexity are the menisci — crescent-shaped fibrocartilaginous structures (the lateral and medial meniscus) located between the femur and the tibia. At least two thirds of the meniscus is thin and avascular (it has no blood supply). Around 80% of meniscal injuries occur in the avascular zone, where successful long-term tissue repair is not possible. Many of these tears commonly occur in sporting accidents, among amateurs and highly active athletes alike. A sudden twist of the knee, which can pinch or tear the meniscus, is the most frequent cause. At present, if the injury is in an avascular zone, there is only one surgical option and the tissue is removed through a partial meniscectomy. This leads to a permanent reduction in the function of the knee joint.

The meniscus — mechanical properties

The meniscus has excellent mechanical properties that allow it to act like a spring, to absorb shock like an elastic, lubricated damper, and — most importantly — to distribute forces evenly between the femur and the tibia and to provide stability throughout the knee joint.

When injuries occur in the vascularised zone of the meniscus (roughly 20% of the time), it is possible to repair the tear with sutures. Even in the vascular zone, surgical repair fails in around 20% of cases within the first two years, at which stage the only available option is to remove still more tissue. There is overwhelming clinical evidence that removing meniscal tissue leads to degenerative disease over time, followed by destruction of the articular cartilage, frequently resulting in painful osteoarthritis (degeneration of bone and cartilage) that requires a knee replacement.