Abstract：
BACKGROUND: Congenital ossicular chain anomalies are rare conductive hearing loss conditions that remain difficult to diagnose even with high-resolution computed tomography (CT). The preoperative diagnosis is helpful for surgical planning and counseling patients regarding treatment outcomes.
METHODS: We report a case involving a 14-year-old boy presenting with left conductive hearing loss without history of trauma for 5 years, physical examination showed normal otoscopic examination bilaterally and high-resolution CT showed absent of stapes suprastructure and footplate. Subsequent diagnosis was done via endoscopic middle ear exploration which revealed an absent long process of the incus, stapes suprastructure and footplate, but with intact oval window membrane. The residual incus was removed, and a tragal perichondrium graft was used over the oval window. A total ossicular replacement prosthesis was placed between the malleus and oval window to repair the chain. Postoperatively, the patient had no complications. Preoperative pure tone average revealed an air/bone result of 52/8 dB. Follow-up after surgery at 6 months showed a pure tone average air/bone result of 15/3 dB. The air-bone gap was reduced from 44 to 12 dB.
CONCLUSIONS: Congenital absence of the stapes suprastructure and footplate remains a rare condition compared to the myriad of middle ear anomalies in the literature.
METHODS: We report a case involving a 14-year-old boy presenting with left conductive hearing loss without history of trauma for 5 years, physical examination showed normal otoscopic examination bilaterally and high-resolution CT showed absent of stapes suprastructure and footplate. Subsequent diagnosis was done via endoscopic middle ear exploration which revealed an absent long process of the incus, stapes suprastructure and footplate, but with intact oval window membrane. The residual incus was removed, and a tragal perichondrium graft was used over the oval window. A total ossicular replacement prosthesis was placed between the malleus and oval window to repair the chain. Postoperatively, the patient had no complications. Preoperative pure tone average revealed an air/bone result of 52/8 dB. Follow-up after surgery at 6 months showed a pure tone average air/bone result of 15/3 dB. The air-bone gap was reduced from 44 to 12 dB.
CONCLUSIONS: Congenital absence of the stapes suprastructure and footplate remains a rare condition compared to the myriad of middle ear anomalies in the literature.
摘要：
背景：先天性听骨链异常是罕见的传导性听力损失疾病，即使使用高分辨率计算机断层扫描（CT）也难以诊断。术前诊断有助于手术计划和指导患者治疗结果。
方法：我们报告一例14岁男孩，出现5年无外伤史的左传导性耳聋，体格检查显示双侧正常的耳镜检查，高分辨率CT显示骨上结构和足板缺失。随后的诊断是通过内窥镜中耳探查进行的，该探查显示了一个不存在的长过程。stapes骨结构和脚踏板，但有完整的椭圆形窗膜。残留的砧木被移除，在椭圆形的窗户上使用了羊皮软骨膜移植物。将整个听骨置换假体放置在锤骨和椭圆形窗口之间以修复链条。术后,患者无并发症。术前纯音平均值显示空气/骨骼结果为52/8dB。手术后6个月的随访显示纯音平均空气/骨结果为15/3dB。空气-骨骼间隙从44dB减小到12dB。
结论：与文献中无数的中耳异常相比，先天性骨结构和脚板缺失仍然是一种罕见的疾病。
方法：我们报告一例14岁男孩，出现5年无外伤史的左传导性耳聋，体格检查显示双侧正常的耳镜检查，高分辨率CT显示骨上结构和足板缺失。随后的诊断是通过内窥镜中耳探查进行的，该探查显示了一个不存在的长过程。stapes骨结构和脚踏板，但有完整的椭圆形窗膜。残留的砧木被移除，在椭圆形的窗户上使用了羊皮软骨膜移植物。将整个听骨置换假体放置在锤骨和椭圆形窗口之间以修复链条。术后,患者无并发症。术前纯音平均值显示空气/骨骼结果为52/8dB。手术后6个月的随访显示纯音平均空气/骨结果为15/3dB。空气-骨骼间隙从44dB减小到12dB。
结论：与文献中无数的中耳异常相比，先天性骨结构和脚板缺失仍然是一种罕见的疾病。
