Can you still develop sinusitis after septoplasty and inferior turbinate reduction?

Yes: Yes. It is still possible.

Edema: These operations are often done under anesthesia. The breathing tube can partially obstruct the sinus drainage port causing sinusitis. The surgery itself can result in edema also.

Definitely: This surgery will not prevent sinusitis which is related to other factors that affect sinus function.

Sinusitis: Even after the nose is aerated, sinus issues may persist. Discuss this problem and the treatment options with your surgeon.