BackgroundDespite the success of total knee arthroplasty (TKA) in reducing knee pain and improving functional disability, the management of acute postoperative pain is still unsatisfactory. This study was aimed to quantitatively analyze the possible correlations between inflammatory cytokines, muscle damage markers and acute postoperative pain following primary TKA.MethodsPatients scheduled for unilateral primary TKA were consecutively included, the serial changes of the numerical rating scale (NRS) at rest (NRSR) and at walking (NRSW), serum inflammatory cytokines and muscle damage markers were assessed before surgery (T0) and at postoperative day 1, 2, 3 and 5 (T1-T4, respectively); while pain disability questionnaire (PDQ) and synovial fluid inflammatory cytokines were evaluated at T0. The correlations between inflammatory cytokines, muscle damage markers and pain scores were examined, and Bonferroni correction was applied for multiple comparisons.ResultsNinety six patients were included for serum markers and pain evaluations at T0-T4, while 54 (56.25%) for synovial fluid cytokines at T0. The NRSR at T1 and T2 were positively correlated with preoperative NRSW, while the NRSW at T1 to T4 were positively correlated with preoperative NRSR, NRSW and PDQ (all p < 0.05). The NRSR was positively correlated with serum PGE2, IL-6, and CK at T1; the NRSW was positively correlated with serum CRP at T1, with PGE2 and IL-6 at T1 to T3, with CK at T2 and T4, and with Mb and LDH at T1 to T4 (all p < 0.003). Meanwhile, positive correlations were observed between preoperative NRSW and synovial fluid PGE2, IL-6, IL-8, or TNF-α, as well as between PDQ and PGE2 (all p < 0.003), but no associations between postoperative pain scores and preoperative synovial fluid cytokines was found (all p ≥ 0.003). Additionally, the NRSR at T1 and T2, and NRSW at T1 to T4 were positively correlated with body mass index (all p < 0.05).ConclusionsSerum inflammatory cytokines and muscle damage markers are positively correlated with acute postoperative pain following primary TKA, and the key cytokines (CRP, PGE2, and IL-6) and markers (Mb, CK and LDH) may serve as the targets for developing novel analgesic strategies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-017-1597-y) contains supplementary material, which is available to authorized users.

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Osteoarthritis (OA) is a major cause of joint pain and disability, and chondrocyte senescence is a key pathological process in OA and may be a target of new therapeutics. MicroRNA-140 (miR-140) plays a protective role in OA, but little is known about its epigenetic effect on chondrocyte senescence. In this study, we first validated the features of chondrocyte senescence characterized by increased cell cycle arrest in the G0/G1 phase and the expression of senescence-associated β-galactosidase (SA-βGal), p16INK4a, p21, p53, and γH2AX in human knee OA. Then, we revealed in interleukin 1β (IL-1β)-induced OA chondrocytes in vitro that pretransfection with miR-140 effectively inhibited the expression of SA-βGal, p16INK4a, p21, p53, and γH2AX. Furthermore, in vivo results from trauma-induced early-stage OA rats showed that intra-articularly injected miR-140 could rapidly reach the chondrocyte cytoplasm and induce molecular changes similar to the in vitro results, resulting in a noticeable alleviation of OA progression. Finally, bioinformatics analysis predicted the potential targets of miR-140 and a mechanistic network by which miR-140 regulates chondrocyte senescence. Collectively, miR-140 can effectively attenuate the progression of early-stage OA by retarding chondrocyte senescence, contributing new evidence of the involvement of miR-mediated epigenetic regulation of chondrocyte senescence in OA pathogenesis.

BackgroundClosed drainage after primary total knee arthroplasty (TKA) has been used routinely for many decades, but controversies have arisen in recent years. The purposes of this study were to compare the clinical outcomes of closed drainage with nondrainage after primary TKA; and to assess the benefit and drawback of closed drainage.MethodsElectronic databases (PubMed/Medline, CENTRAL, Embase and Web of Science) were systematically searched for randomised controlled trials (RCTs) that investigated the efficacy and risks of closed drainage after primary TKA. Two investigators independently reviewed studies for eligibility, assessed the risk of bias and extracted the data. A meta-analysis was then performed using Review Manager Software.ResultsTwelve RCTs totalling 889 TKAs were identified. No significant differences in infection rate or blood loss were found between the closed drainage and nondrainage TKAs, and there was also no significant difference in haematoma formation, deep venous thrombosis, postoperative VAS score or range of motion between the two groups.ConclusionsThere appears to be no clear benefit or drawback to the use of closed drainage after primary TKA. Improving the use of closed drainage might provide better outcomes.

This meta-analysis suggests that mild- and high-flexion positions have similar efficacy in reducing total blood loss. In addition, subgroup analysis indicates that the mild-flexion position is superior in decreasing hidden blood loss compared with high-flexion; the high-flexion position is superior to mild-flexion in reducing transfusion requirements and improving postoperative ROM. Thus, the use of the high-flexion position is a viable option to reduce blood loss in patients following primary TKA without increasing the risk of wound-related infection, DVT or PE.

: The aim of this meta-analysis is to assess the effectiveness and safety of intravenous application tranexamic acid (TXA) in primary simultaneous bilateral total knee arthroplasty (TKA). We searched electronic databases including PubMed, Embase, the Web of Science, the Cochrane Library and the Google Scholar, for published studies involving the intravenous application TXA in primary simultaneous bilateral TKA. All randomized controlled trials were included. The focus of the meta-analysis was on the outcomes of total blood loss, drainage volume, transfusion requirements and deep venous thrombosis (DVT) and/or pulmonary embolism. The relevant data were analyzed using RevMan 5.2. Six high randomized controlled trials were included, with a total sample size of 394 patients. The intravenous application of TXA significantly reduced total blood loss [95% confidence interval (CI), -519.52 to -126.40; P = 0.001], drainage volume (95% CI, -551.76 to -138.57; P = 0.001) and transfusion requirements (risk ratio, 0.38; 95% CI, 0.21-0.68; P = 0.001) compared with the control group. In addition, there were no significant differences in the rate of DVT (P = 1.00) and/or pulmonary embolism between the two groups. Based on the current evidence, this meta-analysis showed that intravenous application of TXA is effective and a well tolerated treatment to reduce total blood loss, drainage volume and transfusion requirements without increasing the risk of DVT and/or pulmonary embolism in primary simultaneous bilateral TKA.

Background:Drainage and tranexamic acid (TXA) have been widely used in total knee arthroplasty (TKA). However, it remains unclear whether it is necessary to clamp the drain after minimally invasive TKA (MIS-TKA) when TXA is used. We therefore conducted a randomized controlled trial to compare the effects of clamping versus not clamping drainage following MIS-TKA in patients in whom TXA was used.Methods:From January 2015 to December 2015, 121 patients undergoing unilateral primary MIS-TKA were enrolled and randomly divided into 2 groups. In the clamping group (N = 60), drainage was clamped for the 1st 4 postoperative hours. In the nonclamping group (N = 61), drainage was not clamped. All patients underwent a minimidvastus approach and received 10 mg/kg TXA intravenously before tourniquet deflation. We recorded the total blood loss, drainage volume, and transfusion requirements in the postoperative period. We also measured the hemoglobin (Hb) and hematocrit (Hct) levels on postoperative days 1, 3, and 5. Other factors, including range of motion (ROM), visual analog scale (VAS), and occurrence of wound-related complications, deep vein thrombosis (DVT), and pulmonary embolism (PE) were recorded at the time of discharge and 1 and 6 months postoperatively. No statistically significant differences were found between the 2 groups with regard to age, gender, weight, BMI, preoperative Hb and Hct levels, preoperative ROM, VAS, duration of surgery, anesthesia method, and the American Society of Anesthesiologists classification.Results:The clamping group experienced better drainage volume results than the nonclamping group (P < 0.001). There were no statistically significant differences in TBL and transfusion requirements (P = 0.105 and 0.276, respectively); Hb and Hct levels on postoperative days 1, 3, and 5 were similar between the 2 groups. No significant differences were found for ROM, VAS, DVT, PE, wound-related complications, and hospital length of stay in the postoperative follow-up.Conclusion:Based on our findings, clamping drainage is unnecessary after routine MIS-TKA using TXA.

This study showed that administrating EPO + TXA in combination can increase haematological parameters and reduce the need for blood transfusion without increasing the risk of DVT or PE compared with TXA alone.