To ensure this, the incudomalleolar
joint was initially found in the axial plane; then, by moving caudally, the distance between the long process of the incus and the lateral attic wall was measured perpendicular to the attic wall at the exact level of the superior margin of the external ear canal (Figure 1c).
Types of the ossicular injuries include incudostapedial joint separation; incudomalleolar
joint separation; incus dislocation; malleoincudal complex dislocation; stapediovestibular dislocation; and fractures of malleus, incus, and stapes (1).
They could identify several key structures such as incudomalleolar
articulation, tympanic segment of the facial nerve, lateral semicircular canal and aditus ad antrum, all without provoking lesions in the middle ear structures.
Most of these cartilage areas are located in the incus body near to the short crus and the articulation area of the incudomalleolar
joint (Figures 3(b) and 3(d)).
(7) RA is a disease characterized by inflammation of the synovial membrane of the diarthrodial joints, which include arthrodesis of the middle ear, (incudomalleolar
and incudostapedial joints) causing CHI in up to 1.9% of the cases.
This condition includes: synovial destruction of the incudostapedial (Incus, see diagram) and incudomalleolar
(Malleus, see diagram) joints, which help transmit vibrations in the inner ear that are perceived as sound; these, like other joints in the body, can be affected by RA.
Then the posterior ear canal wall was worn thin to gradually open the attic forward and to expose the incudomalleolar
Anthropometry of the incus and incudomalleolar
and incudostapedial joints in humans: a direct anatomical study.
Disarticulation of the incudostapedial joint and/or incudomalleolar
joint may occur, so it is extremely important to carefully examine both joints in order to achieve the best potential outcome for hearing.
Structure Young's modulus Density (N/[m.sup.2]) (kg[m.sup.-3]) Eardrum Pars flaccida 3.20 x [10.sup.7] 1.20 x [10.sup.3] Pars tensa 1.00 x [10.sup.7] 1.20 x [10.sup.3] Ossicles Malleus Head 1.41 x [10.sup.10] 2.55 x [10.sup.3] Neck 1.41 x [10.sup.10] 4.53 x [10.sup.3] Handle 1.41 x [10.sup.10] 3.70 x [10.sup.3] Incus Body 1.41 x [10.sup.10] 2.36 x [10.sup.3] Short process 1.41 x [10.sup.10] 2.26 x [10.sup.3] Long process 1.41 x [10.sup.10] 5.08 x [10.sup.3] Stapes 1.41 x [10.sup.10] 2.20 x [10.sup.3] Joint Incudomalleolar
joint 1.41 x [10.sup.10] 2.39 x [10.sup.3] Incudostapedial joint 4.00 x [10.sup.6] 1.20 x [10.sup.3] TABLE 2: Boundary conditions of the middle ear FE model.
Posterior growth may extend further, involving the incudostapedial joint and the stapes suprastructure, as well as up towards the incudomalleolar
joint, around the incus, and into the attic.
We report a case of synovial chondromatosis of the middle ear (i.e., the incudomalleolar
joint) in a 64-year-old woman, and we describe the clinical, radiologic, and intraoperative findings in this case.