Kamrava Brandon, Gerstenhaber Jonathan A, Amin Mamta, Har-El Yah-El, Roehm Pamela C
*Department of Otolaryngology †Department of Bioengineering, Temple University ‡Department of Anatomy and Cell Biology §Department of Neuroscience ||Department of Neurosurgery, Temple University School of Medicine, Philadelphia, Pennsylvania.
Otol Neurotol. 2017 Jul;38(6):839-845. doi: 10.1097/MAO.0000000000001403.
Custom prostheses could be used to recreate the ossicular chain and improve hearing.
Ossicular discontinuity or fixation occurs in 55% of cases of conductive hearing loss, with most cases involving the incus. Reconstruction has been achieved by a variety of methods; however, there has been little improvement in hearing outcomes in decades.
Precise measurements of anatomic dimensions, weight, and center of gravity were taken from 19 cadaveric incudes. These measurements were combined with measurements from the medical literature and micro-computed tomography (micro-CT) of cadaveric temporal bones to generate a rasterizable incus model. As a proof of concept, incudal replacements including possible anatomic variations were then three-dimensionally (3-D) printed and inserted into a cadaveric temporal bone.
Our measurements of cadaveric incudes corresponded well with those from the medical literature. These measurements were combined with anatomical information from micro-CT allowing identification of critical features of the incus, which remained constant. Other model features were modified to increase stability and facilitate synthesis, including broadening and thickening of the lenticular process and the incudomalleolar articulation. 3-D printed incudal replacements based on this model readily fit into a cadaveric temporal bone and successfully bridged the gap between malleus and incus.
We have generated a model for custom 3-D synthesis of incudal prostheses. While current 3-D printing in biocompatible materials at the size required is limited, the technology is rapidly advancing, and 3-D printing of incudal replacements with polylactic acid (PLA) is of the correct size and shape.
定制假体可用于重建听骨链并改善听力。
在55%的传导性听力损失病例中会出现听骨连续性中断或固定，大多数病例累及砧骨。已经通过多种方法实现了重建；然而，几十年来听力结果几乎没有改善。
从19个尸体砧骨获取解剖尺寸、重量和重心的精确测量值。这些测量值与医学文献中的测量值以及尸体颞骨的微型计算机断层扫描（微型CT）测量值相结合，生成可光栅化的砧骨模型。作为概念验证，然后对包括可能的解剖变异的砧骨替代物进行三维（3-D）打印，并插入尸体颞骨中。
我们对尸体砧骨的测量结果与医学文献中的测量结果非常吻合。这些测量结果与微型CT的解剖信息相结合，从而能够识别砧骨的关键特征，这些特征保持不变。对其他模型特征进行了修改以提高稳定性并便于合成，包括扩大和加厚豆状突以及砧锤关节。基于该模型的3-D打印砧骨替代物很容易适配到尸体颞骨中，并成功地弥合了锤骨和砧骨之间的间隙。
我们已经生成了一个用于定制3-D合成砧骨假体的模型。虽然目前以所需尺寸进行生物相容性材料的3-D打印受到限制，但该技术正在迅速发展，并且用聚乳酸（PLA）进行3-D打印的砧骨替代物尺寸和形状正确。
