Post head injury, the patient had conductive deafness and on examination, tympanic membrane was normal and mobile. Likely diagnosis is:

Fracture temporal bone (more commonly longitudinal) extending to external canal: tympanic membrane is frequently torn and inner ear is spared.Blood or CSF in external and middle ear.Damage to ossicle (most frequent being incudo-stapedial joint) resulting in more severe and permanent conductive deafness.Aseptic necrosis of long process of incus can lead to late conductive deafness. Tympanic membrane is normal and mobile: In hemotympanum - tympanic membrane will appear red/blue (due to presence of blood pigments) so it is ruled out. ... Logan Tumer1Oth/ed p441 Otosclerosis and EAC sclerosis do not occur in case of head injury and hence they are ruled out