The cartilage that covers the surface of the joints has a translucent white appearance and a high elasticity, and is capable to absorb direct load and tangent cutting forces that arise from walking and running without immediate damage, unless a possible intense acute injury does not exceed its capacity in biomechanical resistance and self-healing; in this sense, in perspective, biological therapy of diseases of cartilage may in the future solve clinical problems that nowadays are currently treated surgically, frequently with arthroscopy or minimally invasive techniques.

In particular, in case of superficial wounds of articular cartilage, caused by acute trauma (usually in young patients) or repeated over time, or in progressive degeneration caused by gravity acceleration (older subjects), abrasion with motorized arthroscopic instruments that selectively remove damaged cartilage and treatment of bone underneath by practicing small holes with consequent bleeding (multiple perforations according to Mc Bridie) and avoiding articular charge for a few weeks after surgery, will allow articular surface healing with an uniform reparative tissue-like cartilage smooth, with good characteristics of mechanical resistance to compression even if not completely similar to articular cartilage as far as resistance to shear forces.

In cases of deep cartilaginous ulcers, one can proceed to mosaic reconstruction technique, withdrawing from the patient well formed small amounts of bone and articular cartilage from other areas not subjected to the load and implanting them into the diseased area utililising dedicated instruments.

In deep lesions of little articular areas small suitably shaped prosthesis may be implanted into the bone beneath the cartilage, with a good chance of duration in time as long as a rigorous technique implementation.

When the cartilage lesion is large and reaches the sub-condral bone in young or older patients, knee prosthesis, mono-compartmental or total, with or without the prosthesis of patella or its corrective plastic-denervation.