I was proposed to get an intradiscal injection of ozone, in order to reduce the volume of the disc. is it a better alternative than microdiscectomy?

Well...: This is a relatively new thing and most people don't use it. I personally do not. Not much good literature out there to support it but that doesnt mean it wont work. However, microdiscectomy is a time tested procedure and directly targets the problem and gives the surgeon visual confirmation of adequate decompression. Good luck! please do more research about the ozone procedure before signing.

Evidence?!: There are many 'alternative' treatments for disc disease, ad depending on the pathology, some might actually work. Be careful about enzyme or ozone injections into the disc, as there are no good randomized trials showing significant benefit for this.... Sometimes surgery isn't the answer either, but for leg pain+nerve compression, simple microdiskectomy works well... It depends on ur diagnosis....