How long does a trimalleolar fracture take to heal?

Depends: This depends on several factors, including the severity of the fracture, whether it was open, whether surgery was done and if so, the type of surgery, and also associated medical conditions such as diabetes or smoking. A healthy patient should be well on the way to healing within 6 - 8 weeks, however the subsequent rehab which is required can take 1 - 3 months.

8-12 weeks: Initially and then 1-2 years gradually afterwards.