How long will it take for deltoid muscle to strenghten after total shoulder replacement?

Probably 6 months: A shoulder replacement is a complicated procedure where the muscular rehab it critical i would figure it will continue to get stronger with rehab for at least 6 months.

Immediately: Shoulder replacements don't typically violate or damage the deltoid muscle (we are very careful not to!), so the deltoid muscle does not typically need strengthening. Most shoulder replacements need 6-12 weeks of rest before you are allowed to stress the rotator cuff tendon that has been cut and reattached at surgery. After this time, therapy is focused more on motion.

Time can vary: The recovery time for deltoid function is less important for total shoulder replacement as strength and function relies more on the rotator cuff. It's recovery however in reverse total shoulder replacement is an important factor in function afterwards. Deltoid strength usually requires anywhere between 3-12 months to improve. The better your strength before surgery the quicker the recovery.