Background and objectiveAn ultrasound-guided anesthetic technique targeting the interspace between the popliteal artery and capsule of the posterior knee (iPACK) can provide posterior knee analgesia with preserved motor function after total knee arthroplasty (TKA). This study compared the peroneal nerve motor-sparing effects of iPACK block and tibial nerve block (TNB) when combined with local infiltration analgesia (LIA) and continuous adductor canal block (CACB).MethodsIn this study, 105 patients scheduled for elective TKA were randomized to receive proximal iPACK block (iPACK1), distal iPACK block (iPACK2), or TNB, along with spinal anesthesia, modified LIA, and CACB. The primary outcome was the incidence of common peroneal nerve (CPN) motor blockade. Secondary outcomes included CPN sensory function, tibial sensorimotor function, posterior knee pain, pain score, intravenous morphine requirement, timed up-and-go test, quadriceps muscle strength, range of motion, length of hospital stay, patient satisfaction, and adverse events.ResultsThe incidence of CPN motor blockade was significantly higher in the TNB group than in the iPACK1 (p=0.001) and iPACK2 (p=0.001) groups, but was not significant between the iPACK1 and iPACK2 groups (p=0.76). Tibial nerve motor function was more preserved in the iPACK1 and iPACK2 groups than in the TNB group (p<0.001 and p<0.001, respectively). Complete CPN and tibial sensorimotor blockade were not observed in the iPACK2 group. Posterior knee pain score was significantly higher in the iPACK1 group than in other groups during the 24-hour postoperative period (p=0.001).ConclusionsCompared with TNB, iPACK1 and iPACK2 preserved CPN and tibial nerve motor function to a greater extent. However, iPACK2 did not demonstrate complete CPN and tibial nerve motor blockade while maintaining effective posterior knee pain relief.Trial registration numberTCTR20180206002.

BackgroundOsteoarthritis (OA) is a common degenerative joint disease causing pain, stiffness, reduced motion, swelling, crepitus, and disability. Dickkopf-1 (Dkk-1) is a critical mediator of osteoblastogenesis and regulates the joint remodeling. The aim of this study was to examine plasma and synovial fluid Dkk-1 levels of patients with primary knee OA and to investigate their relationship with disease severity.MethodsThirty-five patients aged 55-83 years with knee OA and 15 healthy individuals were recruited into this study. Disease severity was determined using weight-bearing anteroposterior radiographs of the affected knee. The radiological grading of OA in the knee was performed according to the Kellgren-Lawrence grading system. Dkk-1 levels in both plasma and synovial fluid were evaluated using enzyme-linked immunosorbent assay.ResultsThe average concentration of circulating Dkk-1 in the knee OA patients was remarkably lower than that of healthy controls (396.0 ± 258.8, 95%CI 307.1-484.9 vs 2348.8 ± 2051.5, 95%CI 1164.3-3533.3 pg/ml, p < 0.0001). Dkk-1 levels in synovial fluid were significantly lower than in paired plasma samples (58.6 ± 31.8, 95%CI 47.7-69.6 vs 396.0 ± 258.8, 95%CI 307.1-484.9 pg/ml, p < 0.001). Furthermore, both plasma and synovial fluid Dkk-1 levels were inversely correlated with radiographic severity (r = -0.78, p < 0.001 and r = -0.42, p = 0.01, respectively). Plasma Dkk-1 levels were also significantly correlated with synovial fluid Dkk-1 levels (r = 0.72, p < 0.001).ConclusionsDkk-1 levels in plasma and synovial fluid are inversely related to the severity of joint damage in knee OA. Dkk-1 could serve as a biochemical marker for determining disease severity and might play a potential role in the pathogenesis of the degenerative process of OA.

Background The objectives of this study were to delineate whether delirium in older adults is associated with activation of the immune-inflammatory response system (IRS) as indicated by activation of M1, T helper (Th)1, and Th17 profiles, and/or by reduced activities of the compensatory immunoregulatory system (CIRS), including Th2 and T regulatory profiles. Methods We recruited 65 older adult patients with a low energy impact hip fracture who underwent hip fracture operation. The CAM-ICU and the Delirium Rating Scale, Revised-98-Thai version (DRS-R-98) were assessed pre-operatively and 1, 2 and 3 days after surgery. Blood samples (day 1 and 2) post-surgery were assayed for cytokines/chemokines using a MultiPlex assay and the neutrophil/lymphocyte ratio. Results We found that delirium and/or the DRS-R-98 score were associated with IRS activation as indicated by activated M1, Th1, Th17 and T cell growth profiles and by attenuated CIRS functions. The most important IRS biomarkers were CXCL8, interleukin (IL)-6, and tumor necrosis factor-α, and the most important CIRS biomarkers were IL-4 and soluble IL-1 receptor antagonist. We found that 42.5% of the variance in the actual changes in the DRS-R-98 score (averaged from day 1 to day 3) was explained by T cell growth factors, baseline DRS-R-98 scores and age. An increase in the NLR reflects overall IRS, M1, Th1, Th17, and Th2 activation. Conclusions Post-hip surgery delirium is associated with activated IRS pathways and appears especially in patients with lowered CIRS functions.

The increased plasma levels of nitrite and MDA and the decreased plasma levels of vitamin E, TEAC, and FRAP indicated that oxidative stress was present in OA patients. These findings suggest that oxidative stress plays a potential role in pathophysiology of knee osteoarthritis.

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