Orthopedic Medical Device Design at Kinamed, Inc.

December 5, 2007

This article is part of Summer Stories, a special, online issue of Dukengineer Magazine, in which students wrote about their experiences in the Summer of 2007 during their time away from Duke.

by Michael Schaper, BME/ME ‘08

Michael SchaperDuring the summer, I worked at Kinamed, Inc., an orthopedic medical device engineering firm in Camarillo, Califa. Vineet Sarin, a 1995 graduate of Duke engineering, arranged for me to make the most of my time at Kinamed through tasks that incorporated project re-design, modeling, drawing, marketing, and quality assessment. My work there culminated in the publication of a case report I co-authored along with Dr. Sarin and a local orthopedic surgeon.

When I first arrived in Camarillo, I was given the task of redesigning a tray which houses a carbon-dioxide jet that aids in cleaning bone tissue so cement application for orthopedic implants is optimal, helping to assure long implant life. These orthopedic procedures may involve hip and knee joint replacement as well as replacement of the back of the kneecap and the front of the thigh bone.

In addition to orthopedic design work, I had the opportunity to work on my modeling and drafting skills by completing a variety of drawings for the company. I learned how fabrication and assembly routines affect the creation of models and drawings. For example, measurement tolerances for certain products play a large role in how distinct pieces fit together. If violated, these misappropriated tolerances can cause a product to malfunction and cause serious consequences, especially in the medical device industry.

Quality testing was another part of my training, and I performed tests assessing the quality of certain products. For example, I executed performance tests for a device that tensions surgical "cerclage cables" for bone compression procedures. I was charged with finding out whether or not certain screw threads can reliably be used in this device such that the instrument performs its task within certain preset specifications. These tasks stressed the importance of iteratively testing devices before their release into the market.

I also developed an initial prototype design for a new screw case. Instead of a solely two-dimensional arrangement, I designed the screw case to include screw housings in a Rolodex style case. This three-dimensional design added a fresh and more marketable appearance to a familiar design.

Lastly, I wrote and submitted a case report for publication in the Journal of Orthopedic Trauma which details the background and treatment of a patient with osteopetrosis, a rare bone metabolism disorder, which is characterized by dense, brittle bone. The patient required the use of an iso-elastic cerclage cable in her procedure, and this Kinamed cable played a substantial role in stabilizing the rollercoaster process of her healing.

Because of the company’s small size, Kinamed engineers interact with several departments within the company including manufacturing, marketing, quality assurance, and many others. This borderless approach to engineering broadened my internship experience. I truly enjoyed my stay in Camarillo, and the Kinamed people and programs provided me the chance to participate in invaluable real world engineering situations.