Adult Hammer Anvil Joints And Normal Anvil Stirrup Joints Hrct Manifestations And Clinical Significance

Objective To approach the normal manifestations of incudomalleolar joint and incudostapedial joint in adults,and to evaluate their clinical value.Method Forty-six adults’normal HRCT images of incudomalleolar joint and incudostapedial joint were analyzed retrospectively, their forms were classified; the asymmetry of incudomalleolar joint and incudostapedial joint was observed, and the asymmetrical cases were counted; a comparatively simple HRCT measuring method of incudomalleolar joint and incudostapedial joint was studied, and the joint spaces were measured. Statistical analyses of measured results were made.Results There were three types of incudomalleolar joint, including uniform arc(77ears,83.7%)、serrate(9 ears,9.8%) and trumpet-shaped types(6 ears,6.5%).There were two types of incudostapedial joint, directly joined joint(31 ears,33.7%) and indirectly joined joint(61 ears,66.3%). Of the forty-six cases, there were 5 cases(10.9%) with asymmetrical incudomalleolar joints, and 3 cases with asymmetrical incudostapedial joints(6.5%).The measuring results of incudomalleolar joints on standard axis and that of incudostapedial joints on oblique MPR images were 0.45 mm and 0.43 mm respectively, the standard deviations were 0.10 and 0.12 mm respectively.Conclusions The normal HRCT manifestations of incudomalleolar joint and incudostapedial joint could provide objective foundations for the diagnosis of incudomalleolar joint and incudostapedial joint dislocation in some special conditions.