The meniscus acts as joint lubricator, shock absorber, spacer and stabilizer and, more importantly, as is now fully recognised, works in close association with the articular cartilage covering the knee joint surfaces. With all these functions, it is easy to see why meniscal repair is crucial. Degeneration of either type of tissue promotes rapid joint degradation. Most therapeutic development has focused on the repair of articular cartilage, having been deemed “easier”, the reality of which has been a proliferation of articular cartilage repair methods with limited therapeutic benefit. Only in more recent years has the role of the meniscus been understood and attention turned this way.

Spontaneous healing of torn meniscus can only be obtained in the vascularised 'red' area[1], which accounts for 1/3 of the meniscus[2] and is where gaps can be reduced using meniscus arrows or sutures. The repair rate is between 60% and 80% in this ‘red’ vascular zone[3].

Spontaneous healing cannot occur in the '‘white' avascular area (2/3 of the meniscus) since the process requires a blood supply[2]. For this reason patients will usually have the damaged part of the white zone removed and in some cases the whole meniscus is removed. Research has shown that 4.5 - 8 years following partial or full removal of the meniscus joint degradation, osteoarthritis, is often noted[3]. This osteoarthritis can be extremely painful and may ultimately lead to partial or total knee replacement. It is widely acknowledged that any extension to the life of the natural joint and reduction in pain will be very valuable in terms of quality of life as well as clinically and financially.

More than 900,000 patients have meniscal tears every year in Europe[4]. Other reports estimate between 800,000[5] and 1,000,000[6] meniscal repairs in the USA making the total market 1.7 million meniscal tears per year. 7% of meniscal surgeries are repairs in the 'red' zone, that may heal spontaneously. The remainder (1,581,000 tears) require total or partial menisectomy[8]. Meniscus tears normally occur in active and younger people (it is estimated that 80% of meniscal patients are younger than 50). Meniscus tear is a common sports injury and is especially prevalent competitive athletes in football (including US and Australian rules), rugby and basketball3.

There are 4 main categories of meniscal tear, as illustrated. There are no published definitive statistics, but market experience indicates that Degenerative Tear, which so far is not expected to be treatable with Azellon’s cell bandage, due to the complicated injury pattern, accounts for approx. 20%.

The total Azellon market potential is therefore approx. 1.2 million tears p.a.

Market Azellon

The growth in meniscal tears has historically been high (10-12% growth p.a.) but is estimated to be approx. 5% - 7.5% p.a. (Azellon management estimate). (This is not population related per se. In the western world we see the twin drivers of increased activity and increased obesity impacting at opposite ends of the relevant demographic).

Patients who have partial or total menisectomy have an increased risk of developing osteoarthritis over the following 4.5 - 8 years. This is called the “classical osteoarthritic change” first described by Fairbank in The Journal of Bone and Joint back in 1948.

[1] Hennerbichleer et al., The American Journal of Sports Medicine, volume 35, number 5, page 754 to 762

[2] Peretti et al., The American Journal of Sports Medicine, volume 32, number 1, page 146 to 158

[3 ] Koski et al., Orthopaedic Clinics of North America, volume 31, number 3, July 2000, page 419 to 435

[4] MedTech, 2006

[5] MedTech Insight, August 2001, page 213

[6] According to


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