Describe the injuries of the pinna, external canal and tympanic membrane.

Injuries of the Pinna

• The pinna is exposed and projecting, so it is injured readily; its rich blood supply from both the posterior auricular and superficial temporal arteries means it heals remarkably well and needs minimal debridement
• Haematoma auris is the injury that must be understood. Blunt trauma — classically in wrestling, BOXING and rugby — shears the perichondrium off the cartilage, and blood collects in the subperichondrial plane
• The danger follows from a fact of anatomy: the auricular cartilage has NO blood supply of its own and is nourished entirely by the overlying perichondrium. A haematoma therefore separates the cartilage from its only source of nutrition

Injuries of the Canal and Drum

• Canal injuries arise from cotton buds, hairpins and instrumentation, from syringing, from a blow to the jaw driving the condyle backward through the anterior canal wall, and from temporal bone fracture
• Bleeding from the canal after head injury raises three possibilities — a simple canal laceration, a ruptured tympanic membrane, or a temporal bone fracture; and CSF otorrhoea must be excluded, which is suggested by clear fluid, a halo sign on tissue, and confirmed by beta-2 transferrin assay
• Traumatic perforation of the tympanic membrane follows a slap or blow to the ear, which is much the commonest cause in India and frequently follows assault; a blast; diving or a fall onto water; instrumentation; and lightning strike
• Features — sudden pain, bleeding, conductive deafness and tinnitus; the perforation is characteristically irregular with everted, blood-stained margins, which distinguishes it from a chronic perforation
• Vertigo or sensorineural loss suggests inner ear injury — a perilymph fistula or ossicular dislocation — and is a warning sign requiring specialist assessment rather than reassurance
• Management of a traumatic perforation is conservative, and this is the key point: the great majority — around 80 to 90% — heal spontaneously within 6 to 8 weeks
• The essential instruction is to keep the ear dry — no swimming, no drops, no syringing, cotton wool and petroleum jelly while bathing. Topical drops and syringing are contraindicated, since they introduce infection into the middle ear and convert a healing perforation into chronic suppuration
• Do not prescribe antibiotic drops routinely; oral antibiotics are given only if the ear was contaminated (as after a dirty injury or water entry)
• Review at 6 to 8 weeks with audiometry; myringoplasty is offered only if the perforation persists beyond 3 months or the hearing loss is disproportionate.
• Barotrauma and blast injury may also cause haemotympanum, ossicular disruption and sensorineural loss
• Document carefully in every traumatic perforation — the mechanism in the patient’s words, the appearance and the audiogram — since these frequently follow assault and generate legal proceedings
• Cartilage is fed only by perichondrium, which is the whole reason a haematoma of the pinna is an urgent problem
• Evacuation is the easy half of the treatment; preventing re-accumulation is what determines whether the ear deforms
• Use a moulded pressure dressing or bolster sutures and review daily, since re-accumulation is common and silent