"Pain without loosening"-revisions of knee arthroplasties in the Danish Knee Arthroplasty Register.

INTRODUCTION: We aimed to investigate "pain without loosening" as an indication for knee arthroplasty revisions and to screen for other indications potentially hidden in this category to improve future registration and enhance data quality in the Danish Knee Arthroplasty Register. METHODS: We included 104 patients undergoing revision knee arthroplasty for the indication "pain without loosening" from 1 January 2016 to 31 December 2018 at five Danish centres. Medical records, radiographs and computed tomographies were reviewed. RESULTS: In 103 of 104 cases, we confirmed "pain without loosening" as an indication for revision. We found hidden indications in 44 cases; malposition of components (n = 19), stiffness (n = 13), progression of arthrosis (n = 6), instability (n = 3), liner dislocation (n = 1), residual cement (n = 1) and aseptic loosening (n = 1). The Kellgren-Lawrence arthrosis grades prior to primary knee arthroplasty were 1-2 (31%) and 3-4 (69%). CONCLUSIONS: The indication "pain without loosening" covered patients revised due to pain, but other hidden indications were also present. Stiffness and malposition of components were hidden indications and these are not provided as indication options in the DKR and other registers. The relatively high frequency of arthrosis grade 1-2 prior to primary knee arthroplasty is concerning and may explain the occurrence of knee pain without any other pathology present. FUNDING: The Danish Rheumatism Association, the Region of Southern Denmark, the Research Fund of Region Zeeland and Region of Southern Denmark, and the University of Southern Denmark. TRIAL REGISTRATION: Not relevant.

The Danish Pain Research Biobank (DANPAIN-Biobank): a collection of blood, cerebrospinal fluid, and clinical data for the study of neuroimmune and glia-related biomarkers of chronic pain.

Background: Chronic pain is a major health problem worldwide but the limited knowledge of its underlying pathophysiology impairs the opportunities for diagnostics and treatment. Biomarkers of chronic pain are greatly needed to understand the disease and develop new targets for interventions and drug treatments, and potentially introduce more precise diagnostic procedures. Much evidence points to a neuroimmune pathology for many chronic pain conditions and that important neuroimmune biomarkers exist in the cerebrospinal fluid (CSF) of patients with chronic pain. Systematic collection of CSF in large cohorts of chronic pain patients and healthy volunteers has proven difficult, however. We established the Danish Pain Research Biobank (DANPAIN-Biobank) with the aim of studying potential neuroimmune and glia-related biomarkers of chronic pain. In this paper, we describe the methods and the study population of the DANPAIN-Biobank. Methods: In this cross-sectional study, we included (I) participants with high-impact (HI) chronic pain from a tertiary, interdisciplinary pain center; (II) participants with osteoarthritic pain scheduled for arthroplasty surgery of the hip or knee at a regional hospital; and (III) pain-free volunteers. All participants completed a questionnaire assessing pain, functional impairment, anxiety, depression, and insomnia before samples of blood and CSF were extracted. Quantitative sensory tests were performed on participants with HI chronic pain and pain-free volunteers, and postoperative outcome scores were available on participants with osteoarthritic pain. Results: Of the 352 participants included, 201 had HI chronic pain (of which 71% had chronic widespread pain), 81 had chronic osteoarthritic pain, and 70 were pain-free volunteers. Samples were handled uniformly, and CSF samples were frozen within 30 minutes. Conclusions: We describe the content of the DANPAIN-Biobank, which is unique in terms of the number of participants (including pain-free volunteers), extensive clinical data, and uniformity in sample handling. We believe it presents a promising new platform for the study of neuroimmune and glia-related biomarkers of chronic pain.

MRi of the knee compared to specialized radiography for measurements of articular cartilage height in knees with osteoarthritis.

This study aims to evaluate and compare extremity-MRi with specialized radiography by measuring articular cartilage height in patients with knee osteoarthritis. A prospective study, including sixty patients. Measurements on MRi images, Rosenberg view, and coronal stress radiographs were performed. MRI was compared to specialized radiography. Measurements in the medial compartment showed negligible/weak correlation between MRi and Rosenber/varus stress. In the lateral compartment, MRi and the Rosenberg/valgus stress view were strongly correlated. We conclude that MRi cannot replace radiographs for the measurement of articular cartilage thickness. MRi should, however, be reserved for more unusual cases of atypical clinical findings.

The effect of pre-analytical handling on the stability of fractalkine, monocyte chemoattractant protein 1 (MCP1), interleukin 6 and interleukin 8 in samples of human cerebrospinal fluid.

Cytokine networks in cerebrospinal fluid (CSF) are important to our understanding of several neuroinflammatory diseases. Knowledge about optimal handling of samples is limited but important to minimize bias and reduce costs in CSF biomarker studies. The aim of this study was to examine the effect of storage temperature and time delay from CSF sample collection until freezing on the concentration of 11 different cytokines thought to be associated with chronic pain. CSF samples from 21 individuals undergoing hip or knee arthroplasty under spinal anesthesia were divided between two tubes. One tube was stored and centrifuged (within 30 min) at room temperature, and one tube was stored in ice water and centrifuged (within 30 min) at 4 °C. Each tube was split into six vials that were frozen at -80 °C, 0.5, 1, 2, 3, 4, or 5 h after collection. Cytokines were analyzed using a multiplex panel. A random effect panel data regression was conducted for each biomarker including the variables of storage temperature until freezing and time delay. Four cytokines had detectable levels: Fractalkine, monocyte chemoattractant protein 1(MCP-1), interleukine 6 (IL-6), and interleukine 8 (IL-8). There was no significant effect of storage temperature and time delay on MCP-1, IL-6, or IL-8 concentrations. Fractalkine concentration showed no clear trend. No concentration differences were observed between samples kept in ice water and those at room temperature except at the 3-h time point, and there was no overall significant effect of time delay on fractalkine concentration. We found no clear effect of storage temperature and time delay up to five hours from sample collection until freezing on the CSF concentrations of fractalkine, MCP-1, IL-6, or IL-8.

Randomized clinical trial of medial unicompartmentel versus total knee arthroplasty for anteromedial tibio-femoral osteoarthritis. The study-protocol.

BACKGROUND: In treatment of isolated medial unicondylar osteoarthritis of the knee, it is possible to choose between medial unicondylar knee arthroplasty (mUKA), or a total knee prosthesis (TKA). The demand for a blinded multicenter RCT with the comparison of mUKA and TKA has been increasing in recent years, to determine which prosthesis is better. Supporters of TKA suggest this treatment gives a more predictable and better result, whereas supporters of UKA suggest it is unnecessary to remove functional cartilage in other compartments. If the mUKA is worn or loosens, revision surgery will be relatively easy, whereas revision-surgery after a TKA can be more problematic. METHODS: A double-blinded multicenter Randomized Clinical Trial setup is the aim of the study. 6 hospitals throughout all 5 municipal regions of Denmark will be participating in the study. 350 patients will be included prospectively. Follow-up will be with PROM-questionnaires and clinical controls up to 20 years. DISCUSSION: Results will be assessed in terms of 1) PROM-questionnaires, 2) Clinical assessment of knee condition, 3) cost analysis. To avoid bias, all participants except the theatre-staff will be blinded. PROMS: OKS, KOOS, SF36, Forgotten Joint Score, EQ5D, UCLA activity scale, Copenhagen Knee ROM scale, and Anchor questions. Publications are planned at 2, 5 and 10 years after inclusion of the last patient. The development of variables over time will be analyzed by calculating the area under the curve (AUC) for the variable relative to the initial value, and comparisons of the between-group differences will be based on parametric statistics. In this study, we feel that we have designed a study that will address these concerns with a well-designed double-blinded multicentre RCT. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03396640 . Initial Release: 09/19/2017. Date of enrolment of first participant: 10/11/17.

[Fatal outcome for a patient in treatment with dabigatran suffering a subtrochanteric femoral fracture]. / Fatal blødning ved operation for hoftenær fraktur hos en patient i behandling med dabigatran

An 82-year-old woman in treatment with the thrombin inhibitor dabigatran etexilate (a new oral anticoagulant (NOAC)) was admitted with a subtrochanteric femoral fracture and surgery was initiated 15 hours after admittance. She had a blood loss of 6,000 ml and died the next morning from multi-organ failure. In 2013 1.8% of hip fracture patients in Funen received NOACs. Surgery is recommended within 24 hours for hip fracture patients to reduce mortality, but patients in treatment with NOACs should wait at least 48 hours before major surgery. Care should be taken when prescribing NOACs to patients with high risk of falling.