Can detached cartilage in nose be sewn back together? Injury occured 3 weeks ago.

not only can it be sewn together it should be repaired ASAP.  the healing process can cause a significant deformity of the nostril if the cartilage is not repaired. "notching" is common with an injury like this but can be avoided.

Dear betaalpha,

Detached, ripped or torn and traumatized alar cartilages can
absolutely be repaired 3 weeks after the event.
Many doctors might wait until one year to make a surgical correction,
but having a very asymmetrical post-traumatic appearing nose can be very
traumatizing and be aesthetically displeasing appearance.

Open correction repair at 3 weeks can be performed, however,
if you wait any longer most physicians after 2-3 months would recommend you
wait one year prior to deciding to perform any reconstructive or aesthetic
rhinoplasty surgery.

I hope this information has been of some assistance and best
of luck.

For more information, please review the link below.

R. Stephen Mulholland, M.D.

Certified Plastic Surgeon

Yorkville, Toronto