The usual sequel of inflammation is necrosis, especially at the incudostapedial
joint, on the lenticular process and the distal part of the long process of the incus, but destruction of the stapes superstructure or, rarely, of the malleus handle can also occur.
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).
After cutting stapedial tendon, incudostapedial
joint is dislocated with right angle prick.
From the posterior tympanic artery, a branch with large diameter leaves the blood vessel near the incudostapedial
joint (Figure 2(a)) and runs on the medial side of the incus' mucosa to the base of the long crus where it enters the bone through a nutrition foramen (Figure 2(c)).
It is important to note that patients with eroded, but still connected, incudostapedial
joints were excluded from this study.
(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.
In the meantime, the posterior external ear canal wall was worn thin downward to expose the incudostapedial
joint and stapes, and to eliminate the infectious foci in the posterior tympanum.
Anthropometry of the incus and incudomalleolar and incudostapedial
joints in humans: a direct anatomical study.
joint separation is the most common ossicular injury and is seen as widening of the joint on CT.
There are reports of luxation of the incudomalleal or incudostapedial
joints and the dislocation of the stapes from the oval window , but they are mostly the consequence of an attempt of extraction by inexperienced clinician.
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.