Evaluation of Arthroplasty Treatment

In 2022, around 255,000 total hip arthroplasties and around 200,000 total knee arthroplasties were implanted in Germany and treated on an inpatient basis.

However, studies show that 15-30% of patients are not satisfied with the postoperative outcome of total knee arthroplasty. Various factors, such as preoperative pain and mental and physical health, are important for subjective satisfaction. For the objective functional results, other factors such as the indication, age and lifestyle are added, which can influence the postoperative result.

These figures initially relate to primary joint replacement. However, it is not uncommon for a repeat procedure, known as a revision, to be indicated postoperatively. In Germany, for example, 12.6% of knee endoprostheses required revision in 2018. Studies have shown that the most common reasons for hip revision are aseptic loosening in 23% of cases, functional instability in 22% and periprosthetic infection (PPI) in 22%. With an incidence of 1-2% and increasing case numbers, PPI is a relevant problem in arthroplasty treatment. In the postoperative course, a bacterial infection of the prosthesis-bearing bone, the joint and/or the surrounding tissue occurs. If symptoms persist or the prosthesis is unstable, a one-stage or two-stage prosthesis replacement with subsequent antibiotic therapy is performed. When choosing the treatment, the focus should be on improving quality of life, which includes reducing pain, maintaining function and, last but not least, reducing infection-related morbidity and mortality.

In order to be able to comprehensively track the course of treatment of joint surgery patients (preoperative condition, surgery performed, subsequent hospitalization, postoperative outcome, any subsequent complications and further interventions), structural and temporally consistent documentation and examinations of patients are required.

The aim of the study is to correlate the multiple parameters that influence the course of treatment and the surgical outcome and thus obtain a holistic picture of the patient in order to improve joint surgery care.

Primary questions:

• How does the physical and mental health status of patients change after joint surgery?
• How does the body composition change after joint revision?
• How does the perceived pain change perioperatively?

Secondary questions:

• What is the impact of joint surgery and hospitalised stay on functional characteristics such as muscular status of patients?
• What influence does the chosen procedure (one-stage vs. two-stage/long vs. short interval) in revision arthroplasty have on the course of treatment?
• How does the global and local bone density adapt after the use of metaphyseal components in knee joint replacement?
• Utilisation of osteoarthritic cartilage cells for testing novel therapeutic methods to stimulate cartilage regenerative processes.
• Do osteoarthritic cartilage cells from different donors differ in their functional phenotype?
• What role does the immune system play in the pre-, peri- and postoperative course of joint surgery?
• How can joint infection be better diagnosed and treated?

Inclusion criteria

• There is an indication for primary knee or hip replacement or revision.
• The subject is over 18 years of age.
• Written consent is given if the subject is fully responsible.

Exclusion criteria

• A known pregnancy
• A known mental or pain-associated illness
• Illness of an airborne infectious disease with an increased risk of mortality and morbidity
• Patient intolerances or restrictions that make participation in the study impossible