I have bursitis in my hips and I have found that that CBD bath soaks and topicals help me. That said, everyone is different in how they react to cannabis, including topicals. I think it is also dependent on the source of the pain. I do not think it will help your miniscus heal, although it may help take down some inflammation. I use a high ratio CBD to THC tincture on a daily basis to help manage pain and inflammation.
I am not a doctor and this post represents my opinion only. I hope this helps!
If by help for a torn meniscus you mean reducing the pain and discomfort associated with the problem then I think there is every reason to try various cannabis preparations, including topicals. If by help you mean actually healing a torn meniscus, I would not expect any form of cannabis is going to do that. The effects of topical cannabis are limited to the local area of application, as little or none enters the general circulation when applied to the skin via lotions, salves, or balms. While there may be effects closer to the surface where swelling and inflammation cause discomfort, I doubt much cannabis, if any, will enter the knee joint itself where the torn meniscus is located. Bursitis, the inflammation of one of the fluid filled sacs that cushion the movement of tendons and muscles across bony prominences, has been reported by many patients to respond well to topical cannabis. In acute bursitis, especially in the shoulder, sometimes heat can actually increase the inflammation. If so, icing for 5 to 10 minutes every few hours may be something else to try. There are no contraindications I know of to applying cannabis to intact skin. It may be found in a variety of formulas ranging from “whole plant” preparations to CBD only extracts. I’m inclined toward the holistic approach and favor whole plant balms and salves, but I’d say it is worth trying a variety of preparations to see if one is particularly helpful.