When hip prostheses are replaced, the old bone cement in the femur must first be removed, which is a complicated procedure. Recognizing this, scientists at Laser Zentrum Hannover (LZH; Hannover, Germany) are developing an endoscope-based laser system with which doctors should be able to remove the old cement more gently and do so with improved vision.
Retention time in the body for hip prostheses averages 10–15 years. To ensure that they hold well, they are often fixed in the thigh bone with bone cement. The old bone cement has to be removed completely when replacing the prosthesis. Up to now, surgeons need to remove it with great effort mechanically or via ultrasound, both of which are very time-consuming.
The LZH scientists are developing a rigid endoscope through which a laser beam and a camera are guided. With the device, the surgeon could segment the old cement with the laser to facilitate the removal, while the video image of the camera allows the surgeon a direct view of the process inside the bone. Its integrated selective illumination is supposed to enhance the contrast between cement and bone, making it easier for the surgeon to navigate within the bone and differentiate between bone and bone cement.
The Biophotonics Group at LZH will develop the spectroscopic analysis of aged bone cement, the laser ablation process, and a clinical demonstrator. The long-term goal is to reduce the duration of the surgery and make the procedure safer and less invasive for patients.
The project LaZE (Laser Cement Removal) – "Development of an endoscopic system for chromatically contrasted imaging and laser-based removal of bone cement in revision endoprosthetics" is funded by the Else Kröner-Fresenius-Stiftung (EKFS). The scientists will work closely with Helios ENDO-Klinik Hamburg to integrate clinical feedback directly into the development.
For more information, please visit lzh.de.
Source: Laser Zentrum Hannover (LZH) press release – August 13, 2020