Have a look through the learning portfolio for articles around joint cartilage, repair, arthritis
https://www.kneeguru.co.uk/KNEEnotes/learning-portfolioThis site will give you an insight into possible but options, but they vary by country, some are not really done now, some are very expensive and/or experimental (all surgical options will involve a long recovery and rehab with no guarantees).
If going the surgical route, you’ll need a specialist who does these procedures, not any old knee surgeon
http://www.kneeclinic.info/problems_articular_cartilage.php (a little old but things haven’t moved on much, it’s a U.K. site from a specialised centre)
How old are you? As that may also influence what can be done. However, it’s always best to rehab fully and exhaust all conservative options first. Depends also on symptoms, size, depth and exact location of defect
Good luck