Exostoses (Surfer’s Ear)

Exostoses — Surfer’s Ear

Exostoses are benign bony overgrowths that develop within the external ear canal in response to chronic cold water and cold air exposure. They are the most common bony lesion of the ear canal, found in high prevalence in surfers, open-water swimmers, kayakers, and any individual who participates regularly in cold-water activities over years to decades. The condition is progressive — once established, the bony growths continue to enlarge with ongoing cold water exposure — and can ultimately cause ear canal obstruction severe enough to require surgery.

The term “surfer’s ear” is widely used, though the condition affects any cold-water enthusiast. Studies of competitive surfers have demonstrated exostoses in 70–80% of those surfing for more than ten years, compared with fewer than 5% of non-surfing controls.

Anatomy of the Ear Canal and Mechanism of Exostosis Formation

The external ear canal is approximately 25mm long and consists of an outer cartilaginous third and an inner bony two-thirds. The bony canal is formed from the tympanic portion of the temporal bone, covered by thin skin that adheres directly to the periosteum without an intervening subcutaneous layer. This intimate relationship between the skin and the underlying bone is relevant to both the condition and its surgical management.

The precise mechanism by which cold water stimulates bony overgrowth is not fully established, but the prevailing hypothesis is periosteal irritation. Cold water (below approximately 19°C) contacts the bony canal skin, stimulating periosteal cells to produce new woven bone. Repeated exposure over years results in progressive thickening and narrowing of the canal walls. The exostoses typically develop as multiple rounded or broad-based sessile growths arising from the anterior and posterior walls of the bony canal, near the junction of the bony and cartilaginous canal — the narrowest part, where cold water is most likely to pool.

The degree of narrowing is graded by the proportion of the canal lumen occluded:

Symptoms

The development of symptoms is directly related to the degree of canal narrowing and the tendency to trap water and debris behind the bony ridges:

• Water trapping: The most common early symptom. Water enters the ear during surfing or swimming and becomes trapped behind the narrowed section of canal, causing a persistent “full” or “blocked” sensation that may last hours or even days after water exposure. This is frequently misinterpreted as a middle ear problem.
• Recurrent otitis externa: Water and organic debris (wax, keratin, algae, dirt) trapped behind the exostoses create ideal conditions for bacterial and fungal infection. Recurrent outer ear infections — often more severe and slower to resolve than in a normal canal — are a common presenting complaint in affected surfers.
• Hearing loss: Conductive hearing loss from canal obstruction develops when the exostoses, combined with trapped wax and debris, substantially occlude the canal. This may be intermittent at first (present immediately after surfing, clearing as wax migrates) and become permanent as obstruction progresses.
• Tinnitus: Low-grade tinnitus from canal obstruction, often intermittent.
• Inability to clear wax: The normal epithelial migration that carries wax outward is impeded by the canal narrowing. Wax accumulates medially, packing against the eardrum and contributing to both hearing loss and infection risk.
• Pain: During episodes of otitis externa trapped behind the exostoses. The inelastic bony canal means that even mild infection produces severe pain.

Most patients presenting for surgical assessment are in their 30s or 40s, having accumulated the bony growth over ten to twenty years of surfing. The exostoses themselves are painless — symptoms arise from the secondary effects of canal narrowing.

Diagnosis

The diagnosis is made by otoscopic or microscopic examination of the ear canal. In mild cases the diagnosis can be made in a GP setting; more advanced exostoses require ENT assessment with a microscope to fully characterise the extent of the growth, the degree of canal occlusion, the condition of the eardrum, and the amount and nature of debris in the canal.

Formal pure tone audiometry documents any conductive hearing loss and provides a baseline for surgical planning. High-resolution CT scanning of the temporal bones is useful in advanced cases to characterise the bony anatomy in detail and to plan the surgical approach — in particular, to assess the proximity of the exostoses to the eardrum and to identify any middle ear pathology.

Non-Surgical Management

Not all exostoses require surgery. Where the canal is not fully obstructed and symptoms remain manageable, regular microsuction cleaning of the ear canal under microscopic vision — performed every six to twelve months — can remove accumulated wax and debris and reduce the frequency of infections. This approach is appropriate for Grade 1 and some Grade 2 exostoses, and for patients with medical contraindications to surgery. It is not a permanent solution for progressive Grade 2–3 disease.

Prevention of further growth is equally important. Wearing appropriate ear protection during cold-water activities slows and may halt progression. The options are:

• Custom-moulded silicone ear plugs: Made from an impression of the ear canal, providing a comfortable, secure fit. More effective than generic plugs at maintaining the canal’s natural moisture and temperature. Recommended for regular surfers.
• Generic vented silicone plugs: Readily available without prescription. Less effective than custom moulds but substantially better than no protection.
• Neoprene wetsuit hood with ear flaps: Covers the entire ear and prevents cold water contact. Widely used by competitive surfers in cold water. Some surfers find hoods uncomfortable or impractical in warmer conditions.
• Swim cap: Provides some protection for swimmers. Less effective than plugs as water can still enter around the edges.

Surgical Treatment — Canalplasty

Surgical removal of exostoses — canalplasty — is the definitive treatment for Grade 3 disease and symptomatic Grade 2 disease that has not been adequately managed conservatively. The aim is to widen the bony canal to its normal diameter, restore the ear’s natural self-cleaning mechanism, and eliminate the water-trapping problem.

The Procedure

Surgery is performed under general anaesthesia. The approach is typically post-auricular (through an incision hidden in the natural crease behind the ear), which provides the best access for the high-speed surgical drill. In some cases with limited exostoses, a trans-canal approach without an incision behind the ear is possible.

The steps are as follows:

1. An incision is made in the post-auricular crease, concealed behind the ear. The soft tissue is mobilised and the bony canal approached from behind.
2. Under the operating microscope, the ear canal skin overlying the exostoses is carefully elevated away from the bone using fine dissecting instruments. Preserving this skin in good condition is critical — it will be used to re-line the widened canal once the drilling is complete. This is the most technically demanding part of the procedure.
3. A high-speed surgical drill with diamond burrs is used to remove the bony overgrowths, working from medial to lateral under continuous microscopic visualisation. Irrigation cools the drill and prevents thermal injury to the eardrum and canal skin.
4. The eardrum is examined and any middle ear pathology addressed.
5. The preserved canal skin is laid back down to cover the drilled bone. Where skin has been thinned or damaged, a small split-thickness skin graft from the post-auricular region may be used to fill any bare areas.
6. The post-auricular incision is closed with dissolving sutures, and a soft canal dressing is placed.

Each ear requires approximately two to three hours of operating time. Both ears can be done in the same anaesthetic in selected patients; more commonly they are staged several months apart to allow full healing of the first ear before the second is operated.

Recovery

Risks and Complications

• Canal skin failure: The elevated canal skin may not re-adhere perfectly, leaving areas of exposed bone that granulate. This is managed with regular canal cleaning and drops but can prolong recovery.
• Eardrum perforation: The exostoses may be adherent to the eardrum in severe cases, and drilling in close proximity to the drum carries a small risk of perforation. This typically heals spontaneously or may require subsequent repair.
• Hearing change: Most patients experience improvement in hearing. A small risk of sensorineural hearing loss from drill vibration or thermal injury to the inner ear exists, particularly in advanced disease where drilling is close to the oval window.
• Canal stenosis: Excessive scar formation during healing can re-narrow the canal. Regular post-operative surveillance is important to identify and address this early.
• Recurrence: If the patient returns to cold-water activities without ear protection, exostoses will regrow over subsequent years. Prevention is essential after surgery.
• Tinnitus: A small proportion of patients report new or changed tinnitus post-operatively, usually temporary.

Contact us to arrange a consultation → | Outer Ear Infections → | Hearing Loss →