A broken nose Can have many variabilities due to the trauma that occurs. If the nose bones are be broken and displaced than they will need to be reset. If the nasal bones are have been non-displaced , then you will not need any surgery. In addition the upper lateral cartilages could also be fractured off the nasal bones creating a concavity in the mid third of the nose which can also lead to nasal obstruction internally. A septal fracture usually occurs with a significant nasal fracture and a deviated septum will need to be repaired simultaneously.
It depends of how badly the nose was broken. If the bones were broken, but not displaced, usually the nose heals with little to no visible signs. Notice I said usually. Everyone and every broken nose is different. Badly broken and displaced noses are much more likely to have residual lumps, bumps, and scarring. If there is a cut on the nasal skin, it will leave a visible scar.