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Functional outcomes and complications in otosclerosis surgery are governed by the surgeon's experience. Thus, teaching the procedure to residents to guide them through the learning process as quickly as possible is challenging. Artificial 3D-printed temporal bones are replacing cadaver specimens in many institutions to learn mastoidectomy, but these are not suitable for middle ear surgery training. The goal of this work was to adapt such an artificial temporal bone to aid the teaching of otosclerosis surgery and to evaluate this tool. We have modified a commercially available 3D-printed temporal bone by replacing the incus and stapes of the model with in-house 3D-printed ossicles. The incus could be attached to a 6-axis force sensor. The stapes footplate was fenestrated and attached to a 1-axis force sensor. Six junior surgeons (residents) and seven senior surgeons (fellows or consultants) were enrolled to perform piston prosthesis placement and crimping as performed during otosclerosis surgery. The time required to perform the tasks and the forces applied to the incus and stapes were collected and analyzed. No statistically significant differences were observed between the junior and senior groups for time taken to perform the tasks and the forces applied to the incus during crimping and placement of the prosthesis. However, significantly lower forces were applied to the stapes by the senior surgeons in comparison with the junior surgeons during prosthesis placement (junior vs senior group, 328 ± 202.9 vs 80 ± 99.6 mN, p = 0.008) and during prosthesis crimping (junior vs senior group, 565 ± 233 vs 66 ± 48.6 mN, p = 0.02). We have described a new teaching tool for otosclerosis surgery based on the modification of a 3D-printed temporal bone to implement force sensors on the incus and stapes. This tool could be used as a training tool to help the residents to self-evaluate their progress with recording of objective measurements.

Endoscopic surgery of the middle ear is progressively gaining the interest of otologists, as technological advances have overcome some of its main drawbacks. The long learning curve required to master this technique, urges the search for models to practice it. After the validation of sheep's ear as a proper training model for microscopic stapedectomy, our objective is to demonstrate its adequacy for practicing stapes surgery but performed through a fully endoscopic approach. Endoscopic stapedectomy was performed by two surgeons in 40 sheep ears (20 specimens each). To analyze the effects of the learning curve on surgical success, complication rates and surgical time reduction, the sample was divided in two groups: group 1 being the first ten procedures of each surgeon, and group 2 the second set of stapedectomies. The impact of the operated side and the resection of the chordal spine were also studied. No statistically significant differences were found considering the operated side. A statistically significant improvement in some of the surgical steps was demonstrated comparing both groups and also after the resection of the chordal spine. Mean surgical time declined from 38 to 31.5 min (p < 0.05). Using this model for endoscopic stapedectomy, a learning curve was objectively demonstrated, along with other subjective appreciations such as improvement in depth perception and one-hand instrument handling. We believe that sheep ear is an optimal model for endoscopic middle ear surgery, as it allows for the acquisition of the skills required to master this technique.

To determine the usefulness of sheep cadaver ear as a complementary model for training of stapedectomy at residency programs, 2 of our 4 year residents were included in the study and each operated 20 sheep ears. All routine steps of stapedectomy operation were performed, and their success and complication scores were recorded. Performance of residents for stapedectomy and teflon piston placement in sheep ears were evaluated by the authors. Success of both residents improved progressively. Success and complications were impressively better in the second 10 ears than the initial 10 for each resident. Both residents had better outcomes in last 10 ears. Sheep cadaver ear is an excellent model for stapedectomy training in residency and helps to improve surgical skills. We offer sheep cadaver ear training model especially in the countries where obtaining human cadaver temporal bone is difficult.