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We report the investigation of the cause of isolated malleus fractures based on four recent patients at our clinic and five patients reported to us by Swedish otosurgeons. In recent years we have treated four patients with isolated malleus fractures. Colleagues in the Swedish Society of Otosurgeons were encouraged to send us reports on patients with diagnosed isolated malleus fractures, resulting in five more cases. A literature review focusing on the cause and management of this injury was also conducted. Eight of nine patients in the Swedish material had the same history. The patients had inserted a finger into the external auditory canal (most often after a bath) and then pulled it out. Immediately afterwards they experienced a short pain and a hearing loss. An audiogram revealed a conductive hearing loss. After exploration of the middle ear, the most common operation performed was ossiculoplasty. In the present material the most common cause of isolated malleus fractures was a sudden negative pressure in the external auditory canal created by a quick outward movement of a finger in the external ear canal. Since this fracture appears to be infrequent, it can easily be missed at otomicroscopic examination. Tympanometry and pneumatic otomicroscopy are helpful diagnostic tools.

Hypothesis: In the literature several surgical methods have been reported that aim to improve hearing in patients with isolated malleus fractures; however, it is still not clear which method gives the best results.

Background: In this study, laser Doppler vibrometry (LDV) was used to compare the outcome of different surgical methods on malleus fractures in fresh frozen human temporal bones.

Methods: Fractured malleus shafts of defrosted human temporal bones were repaired with bone cement, with a malleus prosthesis from cortical bone, or with a partial ossicular replacement prosthesis (PORP) from cortical bone, and LDV measurements were obtained for analysis.

Results: The best result was achieved with the bone cement only, applied directly at the site of the fracture. The malleus prosthesis and the PORP gave similar results.

Conclusion: All three surgical methods gave good results, but when the distal end of the fractured malleus can be attached close to the proximal end, the technique using only cement tends to be the best option. If the parts are too far apart, a malleus prosthesis or a PORP would be good options.

Objective: To compare stapes vibrations in different partial ossicular replacement prosthesis (PORP) applications.

Methods: Stapedial vibrations were measured on fresh frozen human temporal bones with laser Doppler vibrometry. Eight different types of common ossiculoplasty methods were compared regarding recovery of stapes vibrations in relation with the normal ossicular chain. The PORPs were divided into three groups: 1) PORPs with the lateral contact only with the tympanic membrane, 2) PORPs with lateral contact only to the malleus handle, and 3) PORPs with lateral contact with both the malleus handle and the tympanic membrane.

Results: The PORPs with lateral contact only to the malleus handle performed better than the PORPs with lateral contact to the tympanic membrane only at 2 kHZ, but the best recovery was found in the group with contact both to the malleus handle and the tympanic membrane.

Conclusion: The best sound transmission might be achieved by placing a PORP in contact with both the tympanic membrane and the handle of the malleus.