How to treat an oblique tear of the posterior horn of the medial meniscus?

Surgery: Surgery is most likely needed to resolve your problem. Meniscus tears simply do not heal on their own, regardless of conservative treatment. It is possible that your symptoms of pain, etc will improve with time without surgery...But that doesn't mean the tear healed. In fact, the tear will most likely get bigger leading to additional damage if not taken care of soon.

Arthroscopy.: Generally speaking, arthroscopic knee surgery can take care of that for you.