Histopathological differences in bony destruction of malleus and incus following mastoidectomy.

Objectives: Upon direct inspection of surgically removed ossicles from the ears of patients with long-term post-mastoidectomy cavity problems, the extent of malleus destruction often appears greater in patients with a longer duration of cavity problems, whereas the extent of incus destruction does not appear to correlate with the duration of cavity problems. This study aimed to investigate this impression. Materials and methods: As a result of total middle-ear reconstruction, 41 ossicles (21 malleus and 20 incus bones) were obtained from 31 patients with post-mastoidectomy cavity problems. The ossicles were examined histopathologically, and the proportion of lamellar bone area to total bone area (expressed as percentage lamellar bone) was measured. We also calculated the inter-operation time, i.e. the time period between the previous mastoidectomy and the recent total middle-ear reconstruction; this parameter was used as an approximate measure of the duration of the patient's cavity problem. Correlations between percentage lamellar bone and inter-operation time were calculated for the two ossicles. Results: The range of inter-operation times was seven to 65 years. We observed a correlation between percentage lamellar bone and inter-operation time for malleus bones (r = -0.512, p <0.05), but not for incus bones. Conclusion: These results were in agreement with our pre-study impressions.