Osteoarthritis (OA) is the most common type of arthritis, characterized by pain and physical disability. More than 10% of persons \> 55 years have symptomatic OA, primarily involving the knees. Knee arthroplasty is considered a successful orthopaedic procedure in progressed knee OA (KOA) with severe pain and disability where non-surgical treatments have been tried. It has long been recognized that injury to the body, either from trauma or surgery causes an inflammatory response. As TKA is considered a more invasive procedure compared with UKA, TKA and UKA may not trigger inflammatory reactions of the same magnitude. Differences in inflammatory response between TKA and UKA could help explain why differences in outcome are present, despite both procedures being technically successful. Even though knee arthroplasty is a very common and successful procedure, there are no existing studies comparing the invasiveness of TKA and UKA. As morbidity and mortality rates differ between the groups, the aim of this prospective cohort study is to investigate whether the post-operative inflammatory responses differ between TKA and UKA, and secondarily whether this difference can explain the difference in outcome between the two procedures. The investigators hypothesize that TKA generates a larger postoperative systemic inflammatory response compared with UKA due to more extensive periarticular soft tissue and bone trauma. The study's primary outcome is C-reactive Protein (CRP) measured in blood 24 hours after surgery (22-26 hours after surgery \~ day 1). Participants which are candidates for either a TKA or a UKA will through serial blood test measurement have their postoperative systemic inflammatory response measured. This further will be correlated to the clinical and functional outcomes over a 2-years postoperative follow-up period.
Study Type
OBSERVATIONAL
Enrollment
29
The choice between TKA and UKA is based on the radiological presentation of the knee KOA on an x-ray. A surgery with TKA involves the replacement of both the medial and lateral compartments of the knee.
The choice between TKA and UKA is based on the radiological presentation of the knee KOA on an x-ray. A surgery with UKA involves the replacement of one compartment.
Department of Orthopaedic Surgery, Amager Hvidovre Hospital
Hvidovre, Denmark
C-reactive protein (CRP)
Marker of systemic inflammation and soft tissue injury
Time frame: Day 1 (24 hours after surgery)
Interleukin-1-beta (IL1-beta)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Interleukin-6 (IL6)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Interleukin-8 (IL8)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Tumor necrosis factor alfa (TNF-alfa)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Metalloproteinases (MMP3, MMP9, MMP13)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Calprotectin - S100 calcium binding protein A8/A9 (S100A8/S100A9)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
S100 calcium-binding protein B (S100B)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
C-Reactive Protein (CRP)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Haemoglobin (Hb)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Erythrocyte Sedimentation Rate (ESR)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
White cell count (L+D)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Platelets
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Myoglobin
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Lactate dehydrogenase (LDH)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Creatine Kinase (CK)
Marker of systemic inflammation and soft tissue injury
Time frame: Baseline, 2 hours, 1 day, 7 days, and 21 days (after surgery)
Duration of surgery in minutes
The time from when the surgeon of record starts the procedure until he/she leaves the procedure. This information will be collected from the patient's medical record.
Time frame: Within the first week after surgery
Postoperative x-rays
Postoperative x-rays of the knee are performed routinely in order to evaluate whether implants are placed in accordance with recommendations.
Time frame: On day of surgery, or postoperative day 1, or postoperative day 2
Knee pain (VAS)
Pain assessed using the visual analogue score (VAS) following surgery. The Scores go from 0-10. 0 = no pain. 10 = the most pain. The patients indicate how their pain during the last 24 hours fit in to the scale.
Time frame: Day 1, day 7, day 21, 3 months, 6 months, 12 months, 24 months (after surgery)
Analgesia requirements after surgery
Both preoperative and postoperative requirement of analgesia will be noted. Analgesia requirement will include Paracetamol, NSAID, Acetylic Acids and Opioids. Type of anaesthesia/sedation used during surgery will in addition be recorded. The above information will be collected from the patient's medical record.
Time frame: Day 1, day 7, day 21, 3 months (after surgery)
Perioperative complications
Complications which happens during surgery.
Time frame: 1 day During admission (after surgery)
Length of stay/ Re-admissions within the first 90 days
The patients are expected to be discharged on day 1 post-surgery after a blood sample is taken at 24 hours post-surgery. It will be recorded if a patient is not able to be discharged at this time and for how many days the admission will last. The number of readmissions within 90 days of surgery and the reason for re-admission will also be recorded. This information will be collected from the patient's medical journal.
Time frame: 90 days (after surgery)
90 days complications (medical, surgical)
Complications (both medical and surgical) arising within 90 days of surgery will be recorded. The information will be collected from the patient's medical records. Complications includes myocardial infarction/cardiac events, cerebrovascular events, venous thromboembolism, deep infection, reoperation, revision, and death.
Time frame: 90 days (after surgery)
Data on any revisions performed on includes patient within 24 months
Any revisions in patients within 24 months will be recorded. The reason for revision and the type of revision will be noted. The information will be collected from the patient's medical records.
Time frame: 24 months (after surgery)
Pain Catastrophizing Scale (PCS)
The Pain Catastrophizing Scale (PCS) is a 13-item patient reported outcome measure developed to evaluate catastrophic thinking related to pain. Standardized answer options are given through a 5-point Likert scales, from 0 (not at all) to 4 (all the time). Higher scores indicate higher level of catastrophizing. A total score yielding (ranging from 0-52), along with three subscale scores assessing rumination, magnification, and helplessness.
Time frame: Baseline
Pain Detect Questionnaire (PDQ)
The PDQ is a patient administered questionnaire used to assess the likelihood of a pain experience being of neuropathic origin.
Time frame: Baseline
Oxford Knee Score (OKS)
The Oxford Knee Score (OKS) is a 12-item patient reported outcome questionnaire developed specifically to assess the patient's perspective on the outcomes of knee arthroplasty with respect to combined pain and physical function. Standardized answer options are given (5 Likert boxes) and each question is assigned a score from 0 to 4. Thus, a total score is calculated from 0 to 48, with 48 indication the best outcome. The OKS is short, practical, reliable, valid, and sensitive to clinically important changes over time18.
Time frame: Baseline, 3 months, 6 months, 12 months, 24 months (after surgery)
The Forgotten Joint Score
The Forgotten Joint Score was designed to assess patient outcome in patients undergoing conservative or operative treatment of the knee, and it analyses patient's ability to forget about a joint as a result of successful treatment. The questionnaire consists of 12 questions that are equally weighted and measure patient satisfaction. Standardized answer options are given (6 Likert boxes). Scores are summed to create a composite score that is converted to a 100-point scale. Higher scores indicate greater satisfaction.
Time frame: Baseline, 3 months, 6 months, 12 months, 24 months (after surgery)
European Quality of Life questionnaire with 5 dimensions for adults (EQ-5D)
EQ-5D-5L is a standardized patient-reported instrument for measurement of health outcome and quality of life. EQ-5D-5L is designed for self-completion by respondents and is ideally suited for use in surveys. The EQ-5D-5L consists of 2 pages - the EQ-5D-5L description system and the EQ Visual Analogue Scale (EQ VAS). The descriptive system comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). Standardized answer options are given (5 22.12.2022 Page 17 of 30 Likert boxes) and each question is assigned a score from 1 to 5. Instructions to respondents are included in the questionnaire. The EQ VAS records the respondent's self-rated health on a 20 visual analogue scale with endpoints labelled "the best health you can imagine" and "the worst health you can imagine". This information can be used as a quantitative measure of health judged by the individual respondents.
Time frame: Baseline, 3 months, 6 months, 12 months, 24 months (after surgery)
Patient acceptable Symptom States (PASS)
One question regarding PASS will be used to assess how many patients consider themselves well after surgery (as opposed to feeling better). PASS is assessed as a dichotomous outcome (yes/no) to the question:"Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?". The actual question asked will be in Danish (Appendix G).
Time frame: 3 months, 6 months, 12 months, 24 months (after surgery)
Treatment failure (TF)
We will define treatment failure in two ways: 1. Patients replying 'no' to the PASS question (above) will be asked to answer (yes/no) the following question: "Would you consider your current state as being so unsatisfactory that you think the treatment has failed?" Patients replying, 'yes' to this second question will be defined as experiencing 'treatment failure' (TF). 2. Patients who during the observation period undergo revision surgery are defined as TF. We will seek information about the reason for revision surgery (e.g. infection, malalignment, loosening/lysis, implant wear, dislocation/instability, stiffness, pain, and other reasons) in the medical records.
Time frame: 3 months, 6 months, 12 months, 24 months (after surgery)
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