My husband has multiple meniscus tears in his knee how long will he be off work after surgery since there is more than one?

Meniscus: Multiple tears vs single tear should not impact recovery time. If tears are trimmed/cleaned up, recovery is very rapid since bad tissue is removed and nothing has to mend. Not uncommon to be back to work within a few days (depending on type of work). Rarely at your age, tears need repair/stitching. In that case recovery much longer as the meniscus needs to heal. Can take 6 weeks or more.