This depends on the cause and severity of the damage. Arthroscopy does not just permit us to see the damage to the cartilage and to record it on video for later documentation, but also gently to treat it at the same time, using micro-instruments .
Debridement
A miniature bur/cutter is used to remove the frayed edges and smooth the surface. Unstable cartilage parts have to be removed to prevent further fraying and shredding. In some cases, it also makes sense to remove parts of the synovial membrane (synovectomy).
Microfracture technique (as developed by Dr Steadman)
The beginnings of surgical freshening of cartilage date back to the 1950s (Pridie perforation). This involves the drilling of several 2 mm wide holes into the open surface of the bone to give it the appearance of a sieve. This creates "islands of regeneration", but only in very few cases continuous fibrocartilaginous scar tissue. These days, we prefer the less traumatic "microfracture technique" as developed by Richard Steadman in the early 1990s. A fine awl is used to pierce the surface of the bone to create hairline cracks and tiny holes, resulting the formation of firmer fibrocartilaginous scar tissue, which covers the entire affected area.
Microfracture technique as developed by Dr Steadman involving freshening of the bone from which replacement cartilage can develop.
Picture this in your mind like sowing grass seeds on soil that is firmly trodden down and dried: without loosening the soil before sowing, the seeds would have no chance of taking root. Piercing the surface of the bone has the same effect: it loosens the bony surface and allows the seeping out of bone marrow stem cells or blood stem cells. After sowing, the seeded area must not be walked on for several weeks, otherwise the seeds are trampled on straightaway. The same applies to the joint: walking aids must be used for a period to prevent weight being placed on the operated ankle.
Abrasion arthroplasty (as developed by Dr L.L. Johnson)
If parts of the bone are already exposed (stage 4), the options are either to debride the bone and smooth the remaining cartilage and await the degree of improvement, or to help the body recover the bald areas of bone with fibrocartilaginous scar tissue. The results can be just as good as those after microfracture. In this procedure, we cut into the exposed, extremely hardened surface of the bone with miniature cutter/burs.
Arthroscopic abrasion arthroplasty for severe stage IV chondromalacia
Because microfracturing and debridement are at best palliative in character, a sound cartilage wall around the defect and stable ligaments without axis misalignment are required. In our view, the size of the defect should not exceed 10 mm and this technique should ideally be used for less affected areas in the antero-lateral talus.