Anatomical variations of Koerner's septum: a computed tomography-based, single-centered study.

Abstract

Koerner's septum (KS) is a bony plate located at the junction of the petrous and squamous parts of the temporal bone. The reported prevalence of KS varied between studies. KS variations are associated with various pathologies and pose difficulties during surgeries. The study aims to determine the KS frequency in Omani patients and analyze its association with sex and side. The present study investigated the KS topography in 344 computed tomography (CT) scans of normal temporal bones of adult Omani patients at Sultan Qaboos University Hospital. The presence of KS and its parts (complete or incomplete), as well as its thickness at three anatomical landmarks were recorded. Additionally, sex and laterality differences in KS parameters were analyzed using a Chi-square test. The overall frequency of KS among Omani subjects was 39.5%. The complete KS was observed only in 14% of cases. The thickness of KS was 0.78 ± 0.21 mm, 0.93 ± 0.28 mm and 0.78 ± 0.21 mm at the head of the malleus (HM), the superior semicircular canal (SSC) and the tympanic sinus (TS), respectively (p<0.01). KS was present most constantly at the level of HM (64.7%), followed by SSC (57.4%), and less constantly at the level of TS (49.3%). KS frequency was similar in both males than females (41.9% vs 37.3%), with statistically insignificant difference (p = 0.38). No side differences were observed concerning KS frequency (p = 0.955). The KS frequency in Omani subjects within the range of previously reported studies. It is incomplete in most of the cases and constantly present at the level of HM. Its thickness is more at the level of SSC.