Cartilex^®, a new method for articular cartilage surgery
Background of the work
Cartilex Method
Development Stages of the Cartilex project
Intellectual Property
The cartilex Laser. 
Short Bibliography
Vocabulary
Publication and Video
 

Cartilex^®, a new method for articular cartilage surgery
Patents UE # 2000108 , USA # 8034091 B2.

Background of the work

Arthritis
Arthritis is not just a painful condition for people, but it also affects horses and pets. The pathogenesis of osteoarthritis is likely multifactorial involving mechanical, biological, biochemical, and genetic factors [1–4].  These factors can all contribute to progressive degeneration and loss of articular cartilage.  In the earliest stages of cartilage injury and degeneration, proteolytic breakdown of the extracellular matrix, which is comprised primarily of collagen type-II and proteoglycans, occurs [2–4].  In addition, there may also be actual or functional loss of articular chondrocytes. The remaining healthy chondrocytes attempt to balance the formation and breakdown of matrix molecules. However, the balance between anabolic and catabolic processes ultimately exceeds the repair capabilities of the chondrocytes resulting in matrix destruction, cartilage loss, and eventually, osteoarthritis [3, 4].

The toll of arthritis
Horses are elite athletes just like human athletes, and any decline in ability to perform is not acceptable in many cases. There are about 60 million domestic horses worldwide. In competition horses about 10% are suffering joint problems.

In human, approximately one in six adults aged 15 years and over has arthritis. Nearly three of every five people with the disease are of working age (under 65). Arthritis ranks second and third among the most commonly reported chronic conditions in women and men, respectively. Compared to people with other chronic conditions, a higher proportion of people with arthritis reports experiencing moderate to severe pain, restricted activity and long-term disability. Osteoarthritis (OA) affects over 27 million adults in the United States today, and the prevalence is expected to increase to 67 million by 2030 [1]. 

The economic burden of arthritis
The estimate economic cost of arthritis are € billion annually in industrial countries. Long-term disability accounts for almost 80 per cent of arthritis-related costs, with 70 per cent of these costs incurred by individuals aged 35-64. For instance, Musculoskeletal diseases accounted for 10.3 per cent of the total economic burden of all illnesses in Canada in 1998, arthritis alone accounts for more than 40 per cent of drug expenditures for musculoskeletal diseases in that same year. [5] 

Diagnosis of Early Arthritis
The pathological changes in osteoarthritis start at the molecular scale and spread to the higher levels of the architecture of articular cartilage to cause progressive structural and functional damage. Early diagnosis and staging of cartilage change include supporting a clinical paradigm shift from viewing osteoarthritis as an untreatable degenerative condition to that of a potentially modifiable chronic disease process. [19-20]

Early Treatment of osteoarthritis
At present, the only early treatments to cure or attenuate the early degradation of cartilage is laser resurfacing. Since laser systems became available for arthroscopic surgery a certain number of clinical uses have been reported. One of the special applications is the smoothing of the fibrillated hyaline cartilage, which is not possible by the customary mechanical or motorized instruments without leaving in place a toothbrush-like surface with bad mechanical properties and the risk of an enlarged degeneration area. The actual advantage of a cartilage debridement had only been the elimination of locking flaps, with the danger of tearing down more of the cartilage by the shaving procedure [6]. However laser and other resurfacing instruments developed since have all some drawback [7-15].

The first use of arthroscopy in European veterinary surgery occurred in horses, and by the mid-1980s,arthroscopy in equine surgery was becoming common place. Today, arthroscopy for the diagnosis and treatment of equine orthopaedic diseases is well accepted and routine.

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Cartilex Method
There is a need to improve currently used chondroplasty techniques, to decrease damaging of significant amount of healthy cartilage while removing damaged or diseased tissue in clinical cases of early OA. Pr Pierre Ravussin has developed a new patented technique called Cartilex^® for performing articular cartilage tissue ablation in joint such as human knee or horse joint. Partial‑thickness articular cartilage lesions in adults have no propensity to heal. In the orthopaedic arts, it is known that cartilage has to be reshaped in order to treat certain joint disorders such as hyaline cartilage surface irregularities.  

Cartilex method presents a net advantage over mechanical or other techniques for articular resurfacing. By using Cardiogreen, an injectable medical dye, that attaches to the cartilage surface and absorbs the laser beam, the Cartilex method allows removing a controlled volume of damaged hyaline cartilage while suppressing collateral damage to surrounding healthy cartilage. The energy needed to remove surface cartilage is 10x less that with conventional Ho:YAG laser. Thus, the thermally affected zone is very small.  

à Very important: the result is much less operator dependent. ß 

Some preliminary research has demonstrated that laser energy can stimulate DNA synthesis and matrix production in articular cartilage. However laser has the potential to cause thermal damage when used on articular surface. Preliminary data showed that the Cartilex method (a modified diode laser technique) provides a unique possibility with a thermal damage depth less than 10 mm. This finding is in contrast with other chondroplasty techniques like erbium, holmium lasers or other techniques, where thermal or mechanical damage penetrates up to 500 mm. [7-15]

à Therefore the thermal side effects are negligible ß

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Development Stages of the Cartilex project
 

Preliminary studies were performed at the Ecole Nationale Vétérinaire d’Alfort (France) and at the Institute of Pathology of the University of Bern (Switzerland) on bovine, horse and human hyaline cartilage.