Cefzil

We report a rare case of fracture of the malleus and multiple ossicular dislocation. The fracture and dislocation of the ossicular chain occurred in a welding worker who suffered from a welding flame bum and self-induced earpick trauma of his left ear. The fractured malleus was dug out by the patient shortly after the accident. Otoendoscopic examination revealed a near total perforation of the tympanic membrane and incus protrusion into the upper part of the external auditory canal. CT scanning indicated a corresponding abnormality of the middle ear. We believe that the welding spatter that fell into the ear canal induced a near total perforation of the tympanic membrane and possibly somehow loosened the ossicular chain. The subsequent self instrumentation by the patient caused further damage of the middle ear. We recommend that protection should be provided to both eye and ear for the welders.

Key words: Earpick; Welding flame; Ear trauma; Ossicular dislocation; ossicular fracture.

Introduction

Middle ear injuries can be induced by different aetiologies including temporal bone fractures, barotrauma, direct instrumentation, and surgical intervention. Among the publications of ossicular damage resulting from these causes, multiple ossicular dislocation and protrusion into the external canal are rarely reported [1]. Although earpick-induced ossicular damage has been reported in a substantial number of cases with separation of the incudostapedial joint,stapedial abnormality and perilymph fistula [2], no report linking earpick damage to the middle ear as seen in the case that we present here has been found in a Medline search. We report a rare case of fracture of the malleus and dislocation of multiple ossicles caused by earpick trauma in the wake of a welding flame burn of the ear canal and tympanic membrane.

Case report

A 35 year old man was referred to our hospital on 16th of January 2003 complaining of left ear pain and hearing loss one day after an accident in which welding spatter lodged in his left ear canal whilst he was working welding a ship. He had experienced severe pain in the ear immediately after the event. This gradually subsided over two hours. Some twenty minutes after the accident the patient used a spoonlike earpick to remove a bony fragment from deep in his ear canal and we identified this as the malleus that had been fractured at its manubrium (Figure 1). The patient denied any pre-existing ear symptoms, particularly otorrhoea, hearing loss, vertigo, tinnitus such as one may expect with otitis media or other ear disease. There was no vertigo after the accident as would usually occur with a perilymph fistula.

On examination we observed a healthy man with no other burns of the skin of the scalp, face or neck. Under otoendoscopy haemorrhagic tissue was identified at the inner end of the external canal but the tympanic membrane could not be identified.

Pure tone audiometry revealed a mixed hearing loss with a sensorineural component in the high frequencies (Figure 2).

High-resolution computer tomography (HRCT) of the temporal bone was performed and indicated some soft tissue opacity and disruption of the ossicular chain in the middle ear (Figure 3).

The patient was treated with oral antibiotic Cefzil (0.5g /day) and vitamin B preparations and scheduled for a second endoscopic examination after one week.

At the second examination haemorrhagic debris was removed from the deep part of the canal allowing identification of a near total perforation of the tympanic membrane. The incus was identified protruding through the defect with the lenticular process lying against the superior wall of the ear canal (Figure 4). This was left in place. There were no signs of active bleeding or leak of clear fluid. The antibiotic treatment was continued.

Tympanoplastic surgery has been scheduled for the near future.

Discussion

Tympanic membrane perforation and injury to the ossicular chain are frequently reported after head trauma, barotrauma and direct instrumentation, even including surgery. Ossicular injury usually occurs as separation of the incudostapedial joint, the incudomalleal joint and dislocation of the incus. Dislocation of the stapes from the oval window also occurs. The most common form of ossicular chain lesion following head injury is separation of the incudostapedial joint [3] while fractures of the malleus, incus or stapes are described as uncommon [4]. In Kojima's study of 10 ears from 10 patients with earpick-induced ossicular trauma, stapedial abnormality was seen more commonly than other ossicular dislocations (9/10 vs 5/10) [2].

The pattern of earpick-induced damage as seen in the present case with near total tympanic membrane perforation, a fracture dislocation of the malleus and dislocation of the incus is rare. Earpick-induced middle car trauma has been reported in a substantial number of cases [12]. However, none of the reported cases showed as extensive damage as seen in the current case.

In this case the welding flame burn is assumed to have damaged the tympanic membrane and perhaps caused some ossicular abnormalities. There was immediate pain but the earpick instrumentation added almost no extra pain. The earpick had a sharp spoonlike end that presumably acted like a surgical instrument.

Inner ear damage is not uncommonly seen in association with direct middle ear injury[5,6,7,8,9,10]. With such injury one would expect the patient to experience disequilibrium and sensori-neural or mixed hearing loss. Trauma to the ossicular chain is likely to cause some inner ear damage. Such damage has been seen in the current case. As there was no charred material in the middle ear we assume that the inner ear trauma was induced by the direct instrumentation rather than the welding spatter.

HRCT is the method of choice for evaluation of ossicular trauma [11,4]. Meriot et al. has recommended different CT strategies in order to identify ossicular dislocation and fracture on axial imaging [4]. Otoendoscopy in this case proved to be an efficient method of examination for assessing the degree of middle ear trauma particularly at the second examination. Otomicroscopy would be equally useful.

A perilymph fistula will frequently accompany injuries to the stapes such as subluxation or fracture. In this current case no perilymph leak was identified and the patient did not experience disequilibrium. Further assessment of the stapedial status will be made at the time of tympanoplastic surgery.

In the current case welding goggles were used to protect the eyes and the front of the head and neck. The position of the welders head, however, allowed direct intrusion of the welding spatter into the ear. We have recommended better protection of the ears for welders.

In this case who had widespread inflammation in both ear canal and middle ear, we used Cefzil for prevention of infection. This is always recommended in traumatic perforations if hygienic situation of the ear could be problematic. We never use eardrops if no infectious secretion can be seen in the middle ear or around the perforation. Vitamin B family medication is prescribed whenever sensorineural hearing loss exists, such as in our case, to promote the recovery of this component of hearing loss.

Normally we would perform tympanoplastic surgery for middle ear trauma only when the patient has a totally "dry and clean" middle ear. And we would repair the ear drum and ossicular chain in one stage if possible. The operation can be undertaken under local or general anesthesia.

Acknowledgement

The authors thank Dr. Vincent Cousins, a principle specialist from Melbourne of Australia, for his excellent ideas in terms of the writing of the manuscript.

Reference

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5. Meriot P, Marsot-Dupuch K. Imaging of post-traumatic tinnitus, vertigo and deafness. J Radial 7999; 80(12 Suppl): 1780-7

6. Cripps NP, Glover MA, Guy RJ. The pathophysiology of primary blast injury and its implications for treatment. Part II: The auditory structures and abdomen. J R Nav Med Serv 1999; 33; 13-24

7. Suzuki M, Shigemi H, Mogi G.The leaking labyrinthine lesion resulting from direct force through the auditory canal: report of five cases. Anns Nasus Larynx 1999; 26; 29-32

8. Berger G, Finkelstein Y, Avraham S, Himmelfarb M.Patterns of hearing loss in non-explosive blast injury of the ear. J Laryngol Otol 1997; 111; 1137-41

9. Patterson JH Jr, Hamemik RP. Blast overpressure induced structural and functional changes in the auditory system. Toxicology 1997; 121; 29-40

10. Wolf M, Kronenberg J, Ben-Shoshan J, Roth Y. Blast injury of the car. Mil Med 1991; 156: 651-3

11. Chen SS, Lao CB, Chiang JH, Chang CY, Lirng F, Guo WY, Shao KN, Teng MM, Chang T.High resolution computed tomography of temporal bone fracture. Zhonghiia Yi Xue Za Zhi (Taipei) 1998; 61: 127-33

WEI LIU, YIQING ZHENG, YONKANG OU, YAODONG XU, JIANHUI DING and SUIJUN CHEN

Department of Otolaryngology, 2nd Affiliated Hospital with Sun Yat-Sen University

Guangzhou

China

Wei Liu M.D., Ph.D.

Yiqing Zheng M.D.

Yongkang Ou M.D.

Yaodong Xu M.D.

Jianhui Ding M.D.

Suijun Chen M.D.

Department of Ololaryngology,

2nd Affiliated Hospital With Sun Yat-Sen University,

# 107 Yan Jiang Road, Guangzhou 510120, PR China.

Correspondence and reprint:

Wei Liu,

Department of Otolaryngology,

2nd Affiliated Hospital With Sun Yat-Sen University,

# 107 Yan Jiang Road,

Guangzhou 510120, PR China;

E-mail: 1 woo24@hotmail.com

Tel: 86 20 81332431

Fax: 86 20 61642563

Copyright Australian Society of Otolaryngology Head & Neck Surgery Ltd. Jun 2004
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