An observational study in Surgery, Knee Arthropathy and Hip Arthropathy, sponsored by University Hospital, Bonn. Recruiting at 1 site in Germany. Open to participants aged 18 Years to 100 Years. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by University Hospital, Bonn · Observational
The aim of the study is to examine patients after knee and hip endoprosthesis in the longitudinal section and to evaluate the surgical outcome.
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:
Secondary questions:
University Hospital, Bonn is the lead sponsor of 154 studies on the registry; 28 are open to participants now.
Counted across the registry records on this site, refreshed daily.
In this longitudinal study, subjects will be recruited from the patient population of the orthopaedic outpatient clinic of the Clinic and Polyclinic for Orthopaedics and Trauma Surgery at the University Hospital Bonn. A total of 300 patients will be included. This explorative study design is based on the number of cases and the number of operations performed in recent years at the University Hospital Bonn, which amounts to approx. 550 arthroplasty operations per year.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Patients who receive a primary knee prosthesis.
Procedure: Joint replacement
Patients who receive a primary hip prosthesis.
Procedure: Joint replacement
Patients who receive a revision of the knee prosthesis.
Procedure: Joint replacement
Patients who receive a revision of the hip prosthesis.
Procedure: Joint replacement
Patients routinely receive a joint replacement.
Also known as: Endoprothetics, Arthroplasty
SF 12 Questionnaire
Health-related quality of life assessed by the SF-12 (score for physical components (PCS) and total score for mental components (MCS) - higher values mean better health, lower values mean worse health with a statistical mean of the total score of 50 (SD 10) (1-100)
Time frame: preoperative (approx. 1Day), postoperative (approx. 7 Days), 6-8 weeks postoperative
Hand-held dynamometer
Hand grip force using a hand dynamometer in absolute values (in kg).
Time frame: preoperative (approx. 1Day), postoperative (approx. 7 Days), 6-8 weeks postoperative
Dual-Energy X-Ray Absorptiometry
Bone density values by DXA measurement (T- or Z-values as deviation of the measured value from predefined mean values. T-Score ≤ -1 = osteopenia; T-Score ≤ -2,5 = osteoporosis.
Time frame: preoperative (approx. 1Day)
Dual-Energy X-Ray Absorptiometry
Body composition in relation to the lean mass. Fat Mass and Lean mass (gram).
Time frame: preoperative (approx. 1Day)
Dual-Energy X-Ray Absorptiometry
Fat Mass in percent.
Time frame: preoperative (approx. 1Day)
Joint examination (HJHS)
The hemophilia joint health score is a combined test of questioning and clinical examination with a goniometer and examines both elbow, knee and ankle joints using a goniometer for range of motion and axial alignment (0-3 points), pain numerical rating scale (0-10 points), swelling (0-3 points), crepitation (0-2 points) and gait abnormalities (0-4 points). A "total score" of 0 to 124 points is achievable. A higher score means a worse joint status.
Time frame: preoperative (approx. 1Day)
Hip examination (Harris Hip Score)
The Harris Hip Score is is a combined test of questioning and clinical examination with a goniometer to assess hip complaints. The perceived pain, the function of the joint, existing deformities and the range of motion are assessed or queried with a total score of 0-100 points, with a low score indicating a functionally poorer hip joint.
Time frame: preoperative (approx. 1Day), postoperative (approx. 7 Days), 6-8 weeks postoperative
Knee examination (Knee Society Score)
The Knee Society Score is a combined test of questioning and clinical examination with a goniometer and evaluates the functional ability of the knee joint after total or partial knee arthroplasty. This includes objective (knee alignment, knee instability, range of motion), functional (standard and advanced activities) and subjective (patient expectations and satisfaction, symptoms) components. A total of 0-100 points can be achieved, with a lower value signaling a poorer assessment of the knee joint.
Time frame: preoperative (approx. 1Day), postoperative (approx. 7 Days), 6-8 weeks postoperative
Blood samples
The blood samples of all patients are collected in the clinical routine in preparation for surgery and during the inpatient stay. As part of the study, the parameters vitamin D3 (nmol/l), calcium (nmol/l), creatine kinase (U/l), TSH (µu/ml), C-reactive protein (mg/l), leukocytes (G/l), hemoglobin (%) are used for statistical analyses.
Time frame: preoperative (approx. 1Day), postoperative (approx. 7 Days), 6-8 weeks postoperative
Biomaterial
Biomaterial that is obtained/discarded as standard during the surgical procedure (Bone, cartilage, synovial fluid, synovial mucosa, Hoffa fat bodies). After preparation, the samples are stored at -80°C or -150°C until the measurements. Once the sample collection is complete, the stored samples are further processed for the measurements according to the manufacturer's instructions in order to determine and quantify inflammatory mediators or cell populations from the blood and tissue samples using an immunoassay (e.g. ELISA, multiplex approach, flow cytometry, proteomics, RNAseq, in vitro functional assay). The inflammatory mediators/cell populations are then analysed pseudonymously on the basis of the clinical course and in the context of the microbiological, histological, laboratory chemical and imaging findings from the patient file, which were routinely collected during the inpatient stay.
Time frame: during operation
Plan to share: No — The publication of anonymous patient data is not allowed by informed consent.
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