Proposed Topic (Most preferred): :
HA Young Investigators Session (Projects to be presented by HA staff who had joined HA for 10 years or less)
Proposed Topic (Second preferred): :
Research and Innovations (new projects / technology / innovations / service models)
Authors (including presenting author) :
Ho SH
Affiliation :
Prosthetic & Orthotic Department, Pamela Youde Nethersole Eastern Hospital
Introduction :
A 18-year-old female amputee was left transradially amputated and had been using cosmetic prostheses since childhood. Because of her limited elbow range of motion (ROM) and muscle power, which are caused by her short residual limb length, the patient cannot use a functional prosthesis. However, she was very interested in music and would like to learn how to play the ukulele. She wished to study music in school after graduation. There are some off-the-shelf prosthetic terminal devices (TD) on the market for playing guitar, but their designs highly demand elbow flexion and rotation. Therefore, it is believed that these TDs may not be suitable for the patient. A patient-specific prostheis with customized TD may need to be designed and fabricated for her to play the ukulele.
Objectives :
Since the patient’s amputated side elbow ROM and muscle power are limited by the short stump length, a patient-specific functional prosthesis should be specially designed and fabricated for playing the ukulele. The prosthesis should be lightweight so that the patient can easily move her residual limb with it. At the same time, it should not require the patient’s elbow to flex and rotate so much to be controlled. It should also be adjustable, so that the prosthetist and patient can adjust its alignment to fit the patient’s needs easily.
Methodology :
The prosthesis was designed and fabricated using several CADCAM software and devices. The patient's stump was first digitized by scanning it with a 3D scanner. The STL file was then imported to Cube, a P&O CADCAM software, to design the supracondylar prosthetic socket and its adaptor. Subsequently, the TD, which directly contacts the prosthetic socket and guitar pick, was designed using an engineering CADCAM software, Fusion 360. The final product consists of two joints: a ball-and-socket joint and a sliding joint, which allow the prosthetist to adjust the prosthesis alignment. Finally, the prosthetic socket and TD were fabricated by a 3D printer using PLA material.
Result & Outcome :
After several visits and trials, the patient can now learn to play the ukulele with the printed functional prosthesis. This case report shows that with the use of recent advanced technology combined with our background knowledge about prosthetics and engineering, more patient-centered prosthetic management can be provided to the amputee. It does not only physically help the patients but also provides psychological support to a certain extent.
