Doctors’ and researchers’ willingness to apply the possibilities afforded by additive manufacturing toward medical research has resulted in yet another potential medical application for 3-D printed prosthetics. The Radiological Society of North America (RSNA) is wrapping up the last portion of its annual meeting, and today a research team from the University of Maryland introduced their findings that 3-D printing could be used to create prosthetics for the inner ear that will increase the accuracy of a complicated procedure aimed at improving hearing.
Doctors Jeffrey D. Hirsch, David Eisenman, and Richard Vincent conducted a study which utilized additive manufacturing to produce prosthetic ossicles, the tiny bones in the inner ear which can become damaged due to trauma or infection, resulting in hearing loss which requires surgery to repair. Currently, surgeries to create and implant ossicular prostheses has a relatively high failure rate, with successful procedures accounting for only 55 to 75 percent of operations conducted.
The ossicular bones are about the size of a grain of rice, and several factors make finding the right fit, as well as maintaining the stability and functionality of the implant post-surgery, a tenuous prospect. One problem that 3-D printing may be able to quell is the change in inner-ear structure in the time between a pre-operative CT scan and the day of surgery. Because the characteristics of the ear bone often change as the result of infection or trauma, an implant created before the day of surgery may not fit quite as soundly as it appeared that it would when the CT scan was conducted. The relative immediacy of 3D printing a prosthetic based on images taken during the surgery is thought to increase the chance that an implant remains viable post-operation.
While 3D printing of ossicular implants has been used to afford students practice conducting surgeries, the research project done by the team of Maryland researchers was the first of its kind. Though cadavers, not live patients, were used to conduct the study, each of the implants created with additive manufacturing was considered to be a “snap fit”, according to Hirsch. He added that, should implants be impregnated with stem cells, the artificial ossicles could become even more likely to produce sound for longer periods in recipient patients.