RETRACTED: Inhibition of the p38-MAPK signaling pathway suppresses the apoptosis and expression of proinflammatory cytokines in human osteoarthritis chondrocytes

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Sections within Figures 2 and 6 appear similar to each other. Also, Figure 1B appears similar with a panel from Figure 1k of the article published by Lin Xiao, Dongping Gong, Loufeng Liang, Anwei Liang, Huaxin Liang, Xiayi Xu and Hongli Teng in Clinical Epigenetics 13 (2021) 53 https://doi.org/10.1186/s13148-021-01005-9, while Figure 4B appears similar with a panel from Figure 2A of the article published by Hongwei Chen, Shengdi Yang and Ruyi Shao in Arthritis Research & Therapy 21 (2019) 271 https://doi.org/10.1186/s13075-019-2033-5. Although this article was published earlier than the other articles, the Editor decided to retract this article given concerns about the reliability of the data. Following the release of the concerns in the public domain, the authors contacted the journal to report that some of the experiments in this article were executed in the laboratory of a third-party company. The authors reportedly found that the results of these experiments were unreliable in later validation experiments. The authors would like to apologize for the inconvenience caused.

Fibroblast growth factor-21 concentration in serum and synovial fluid is associated with radiographic bone loss of knee osteoarthritis

We aimed to evaluate whether FGF-21 concentration in serum and synovial fluid (SF) is associated with radiographic bone loss of knee osteoarthritis (OA). A total of 186 OA patients and 108 controls were recruited. The radiographic bone loss of knee OA was assessed by the Ahlbäck grading scale. FGF-21 concentration in serum and SF was measured by enzyme-linked immunosorbent assay (ELISA). We demonstrated that OA patients had significantly higher serum FGF-21 concentration compared with controls (204.30 [range 158.25-279.16] ng/L vs. 130.72 [range 94.93-218.03] ng/L, p < 0.01). FGF-21 concentration in serum was well correlated with that in paired SF samples (r = 0.668, p < 0.001). In OA patients, those with a higher Ahlbäck grade had significantly higher serum and SF FGF-21 concentration (p < 0.001 for both). FGF-21 concentration in serum and SF was significantly and independently associated with the Ahlbäck grade (r = 0.403, p < 0.001 and r = 0.410, p < 0.001; respectively). These findings indicated that FGF-21 might be a potential biomarker for predicting bone loss of OA. Therapeutic interventions by blocking FGF-21 signaling pathways to delay the degenerative process of OA warrants further investigations.

Serum fetuin-A levels are inversely associated with clinical severity in patients with primary knee osteoarthritis

The present study aimed to detect serum fetuin-A levels in knee osteoarthritis (OA) patients and to investigate their correlation with clinical severity. We enrolled 215 knee OA patients and 76 healthy controls. We measured serum fetuin-A levels by enzyme-linked immunosorbent assay and assessed the correlation between serum fetuin-A levels and Kellgren-Lawrence grades as well as Western Ontario and McMaster Universities Arthritis Index scores in OA patients. Our results demonstrated that serum fetuin-A levels were independently and negatively correlated with greater clinical severity in OA patients.

Correlation of synovial fluid HMGB-1 levels with radiographic severity of knee osteoarthritis

Purpose: This study measured high-mobility group box 1 (HMGB-1) levels in serum and synovial fluid (SF) in patients with primary knee osteoarthritis (OA) and correlated these levels with radiographic disease severity. Methods: Seventy-eight OA patients and 30 controls were enrolled in this study. All OA patients were scored according to the Kellgren-Lawrence (KL) grading system. HMGB-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Results: SF HMGB-1 levels were significantly higher in knee OA patients, compared with controls (P < 0.01). Moreover, SF HMGB-1 levels were positively associated with KL scores (P < 0.01). Multinomial logistic regression demonstrated that the SF HMGB-1 level was an independent factor for radiographic severity of OA (P=0.002); however, serum HMGB-1 levels did not differ significantly between OA patients and controls and did not correlate with KL scores (P > 0.05). Conclusion: These results demonstrate that HMGB-1 levels in SF of knee OA patients are independently associated with radiographic disease severity.

The contour of cementless femoral stem has minor effect on initial periprosthetic von Mises stress distribution. A 3-dimensional finite element analysis

OBJECTIVE

To evaluate periprosthetic von Mises stress distribution with cementless femoral stems of various contours.

METHODS

The study was carried out at the Department of Orthopaedics, Shanghai 6th Hospital, Shanghai, China between May 2008 and February 2009. Finite element models of proximal femoral replacement with 4 cementless stems (Alloclassic, Ribbed Anatomic, VerSys, and Securi-fit) of various contours were set up. Under the loading conditions of walking and stair climbing, 3-dimensional periprosthetic von Mises stresses were calculated, and the stress distribution patterns were compared.

RESULTS

Periprosthetic stresses were increased in level 1, 2, and 3 under the 2 loading conditions, and more considerably in level 2 and 3. The stresses were higher on the medial side in all cases. No remarkable difference was found in the patterns between the 4 stems.

CONCLUSION

The contour design of femoral stem has minor effect on initial periprosthetic von Mises stress distribution.