Prof. Dr. med. Dieter Christian Wirtz

The revision operation in case of infection is considered the royal discipline in endoprosthetics. On one hand, the doctors have to treat the infection - depending on whether a single germ or various pathogens have infected the prosthesis and whether surrounding soft tissues like tendons or bones are also affected. On the other hand, the re-implantation of a prosthesis is a surgical challenge. In Bonn, a successful therapeutic procedure, the "Bonn Scheme," has been developed for this purpose.

However, the most common reason for a prosthesis revision is not an infection, but plain wear and tear. Artificial hip and knee joints loosen after 10 to 15 years due to mechanical stress. This loosening does not always pass unnoticed by the bone; often, the spare parts leave pronounced defects after removal. Here, one cannot simply insert a new standard endoprosthesis. Therefore, Wirtz has developed a modular system for hips and knees with a German manufacturer to reconstruct such defects in line with anatomy. Non-load-bearing bone defects are filled with donor bone and grow in. At load-bearing sites, Wirtz uses custom-fit titanium augments, which are then connected to the actual joint implant and fill the bone defect.

Not only in the operating room but also in the hospital's own research laboratory, the Bonn orthopedists are interested in bone defects and infected joints. Together with scientists from the nearby German Center for Infection Research (DZIF), they want to detect the pathogens of a joint infection before the operation in the future. "We are developing antibodies that dock to the surface of bacteria," explains Wirtz. "Combined with nuclear medical tracers, the infected areas light up in the computed tomography."

The marked areas can be targeted and removed very specifically during the surgery. With a second procedure, the surgeon should be able to determine during the operation whether the infected tissue has been completely removed. "As long as there are still germs hiding somewhere, for example in the depths of the femur, a new prosthesis will also become infected again," Wirtz explains. Only if the new implant site is germ-free can it be successful to reinsert a long-term functional prosthesis.

Ultimately, whether in the initial use or in the revision situation, endoprosthetics always aim for the restoration of quality of life. This also applies to the older, often multiply ill person. Therefore, in mid-2017, the clinic in Bonn opened the first orthopedic-trauma surgical geriatric ward in the region. Here, orthopedic surgeons work closely with internist geriatricians, specially trained nurses, and physiotherapists in an interdisciplinary team every day. With intensive and holistic care, it should be ensured that older people can live independently at home soon after the procedure with their new joint.

However, in order to fill such innovative clinic structures with life, not only professional expertise is needed, but above all motivated and committed personnel. "For my employees, friendly and empathetic communication is the top priority," emphasizes Wirtz. All clinic employees are involved in a service excellence training. "The patients should feel comfortable with us," says the clinic chief. Because "patient satisfaction contributes significantly to rapid recovery."