Your post microdiscectomy findings are common at L4-5. Modic type I changes are also common after multiple surgeries and indicates a worn-out disc that will not absorb shock and is commonly painful. If your L5-S1 is normal, a well-performed TLIF fusion at L4-5 has a 90% chance of giving you 75% relief. Don’t worry about the “mild broad based protrusion at my L4/L5” as that is also to be expected.
Dr. Corenman