Typically uncontained failure issues with existing engines are addressed with a combination of increased inspections and hard time life limits (cycles and/or hours) - usually enforced by AD.
Sometimes there are changes that can be reworked into existing parts (during a shop visit) such as machining an increased radius into a high stress area to improve the crack resistance.
The trick is finding the correct inspection intervals and life limits to prevent future failures. I know this was on ongoing issue with the CF6-50 turbine discs installed on older 747 Freighters. The Feds kept changing (reducing) the inspection intervals and hard time life limits, but they kept failing at the rate of one or two a year right up to the time I retired. Fortunately they never did enough damage to serious threaten continued safe flight and landing, but I suspect if the event aircraft had been carrying hundreds of passengers instead of tons of freight, it would have gotten a lot more attention.