Improving hip revision surgery

Abstract

When people experience pain, discomfort or motion limitation in their hip joint they can get a hip implant. This implant improves the movement and decreases the pain and discomfort. Due to several reasons such an implant needs revision after ten to fifteen years. This revision surgery is a long and invasive surgery. When an implant is fixated with bone cement this surgery is even more cumbersome. Research shows that the lifespan of cemented implants is better than uncemented, but because of the difficult surgery surgeons are choosing uncemented implants more often, leaving the patient with a lesser implant. The aim of this project is to improve hip revision surgery in such a way that surgeons would choose cemented implants over uncemented.

Observing several surgeries, interviewing different stakeholders and reading literature showed that the main issue with cemented implants is the fixation of the new implant. This new implant needs a soilless surface to attach to. Removing the cement to ensure this clean surface is really hard, riskful and time consuming. Observations made clear that there is no strict procedure for this part of the surgery and that the amount of instruments meant for cement removal is almost endless. All the found insights were translated into the following design goal:

Compose a minimal cement removal set of “my precious” instruments that could be used for HRS, that fits a fast, feasible, clear and safe cement removal procedure and lets the orthopaedic surgeon remove cement in a safe, efficient, confident and tangible way.

To achieve this design goal a new procedure, a suitable minimal instrument set and a new cement removal instrument are designed. The procedure gives the surgeon more grip on the surgery and enables routine building. The instrument set supplies the surgeon with the right amount, not too much and not too little, of instruments needed to perform cement removal. And the Guido, a drill guide that helps the surgeon with removing the part of cement that is hardest to reach, makes the cement removal faster and more safe.

The procedure and instrument set are discussed with medical professionals to validate whether it would solve the current problem. Besides that, a prototype of the Guido is made, which is tested on fake bones by three orthopaedic surgeons. The procedure, set and the Guido all were received very well and the surgeons could not wait to work with it.

The concepts seem promising, but need further development. The materialization of the product needs to be finished and a CE certificate needs to be requested to be able to test it on cadavers.