Risk factors for the long-term incidence and progression of knee osteoarthritis in older adults: role of nonsurgical injury

Complement 3 and 4 impact in osteoarthritis

Aim: To investigate the association between serum complement 3 and 4 (C3 and C4) levels and clinical characteristics in osteoarthritis (OA) patients.Methods: This retrospective study included 361 OA patients divided into groups based on complement levels. Clinical data and laboratory test results, including C3, C4, ESR and CRP levels, were analyzed using non-parametric tests, Spearman correlation and multivariate regression.Results: The AC-OA group had lower PA, C3, C4, ESR, CRP and IgA levels compared with controls. C3 levels were positively correlated with ESR (r = 0.260, p < 0.001) and CRP (r = 0.243, p < 0.001). C4 levels also correlated with ESR (r = 0.175, p = 0.001) and CRP (r = 0.263, p < 0.001) and were significantly associated with the number of affected joints.Conclusion: Serum C4 levels are effective indicators of disease activity in OA, particularly in terms of joint involvement and CRP levels, while C3 levels showed no significant association. These findings suggest a potential role for C4 in predicting OA activity.

Medial meniscus posterior root tears with advanced osteoarthritis or subchondral insufficiency fracture are good indications for unicompartmental knee arthroplasty at a minimum 2-year follow-up

INTRODUCTION

The outcomes of unicompartmental knee arthroplasty (UKA) in the presence and absence of medial meniscus posterior root tears (MMPRTs) have not been compared. This study compared the characteristics and clinical outcomes of patients undergoing UKA with and without MMPRTs.

MATERIALS AND METHODS

This study analyzed 68 patients. The presence or absence of MMPRTs was evaluated using preoperative magnetic resonance imaging. Patient characteristics, clinical scores before surgery and at the final evaluation, and imaging findings were compared between patients with and without MMPRTs. Multiple regression analysis was conducted on postoperative visual analog scale (VAS)-pain scores.

RESULTS

MMPRTs were present in 64.7% (44/68) of patients. Patients with MMPRTs were significantly younger (67.8 ± 8.2 vs. 75.0 ± 7.1 years, p < 0.001) and had a shorter duration from the development of symptoms to the time of surgery than those without (6.8 ± 8.4 vs. 36.1 ± 38.9 months, p < 0.001). Component placement or lower-limb alignment did not significantly differ between the groups. Preoperative clinical scores were not significantly different between the groups; however, patients with MMPRTs showed significantly better postoperative VAS-pain scores than those without (10.0 ± 9.0 vs. 28.2 ± 26.0 points, p = 0.026). Multiple regression analysis of postoperative VAS-pain scores revealed the significant effect of duration from the development of symptoms to the time of surgery (p = 0.038).

CONCLUSIONS

Patients undergoing UKA with MMPRTs were younger with less radiographic osteoarthritic changes compared to those without MMPRTs, and their postoperative VAS-pain scores were significantly superior. The duration from the development of symptoms to the time of surgery significantly influenced postoperative pain in patients undergoing UKA.

Methylation Regulation of LPCAT3 Improves Osteoarthritis by Regulating ACSL4 to Inhibit Chondrocyte Ferroptosis

With the increasing aging population in China, the incidence rate of knee osteoarthritis is expected to rise annually. Therefore, we conducted a study to investigate the crucial role of LPCAT3 in osteoarthritis and its underlying mechanisms. We collected samples from normal volunteers (n = 12) and patients with osteoarthritis (n = 12) at our hospital. It was observed that LPCAT3 mRNA expression was reduced and positively correlated with IL-1β mRNA expression in patients with osteoarthritis. In a mouse model, LPCAT3 mRNA and protein expression were found to be suppressed. Furthermore, in an in vitro model, the enrichment level of LPCAT3 mRNA was inhibited by a specific m6A antibody through si-METTL3. Si-METTL3 also reduced the stability of LPCAT3 mRNA in the in vitro model. The inhibition of LPCAT3 was found to exacerbate osteoarthritis in the mouse model. Additionally, LPCAT3 was shown to reduce inflammation in the in vitro model. It was also observed that LPCAT3 reduced chondrocyte ferroptosis by inhibiting mitochondrial damage. LPCAT3 protein was found to interact with ACSL4 protein, and its up-regulation suppressed ACSL4 expression in the in vitro model. ACSL4 was identified as a target of LPCAT3 for suppressing mitochondrial damage in the in vitro model. In conclusion, this study demonstrates that LPCAT3 improves osteoarthritis by regulating ACSL4 to inhibit chondrocyte ferroptosis, thus providing a novel target for the treatment of osteoarthritis.