We investigated the effects of adipose-derived extract (AE) on cultured chondrocytes and in vivo cartilage destruction. AE was prepared from human adipose tissues using a nonenzymatic approach. Cultured human chondrocytes were stimulated with interleukin-1 beta (IL-1β) with or without different concentrations of AE. The effects of co-treatment with AE on intracellular signaling pathways and their downstream gene and protein expressions were examined using real-time PCR, Western blotting, and immunofluorescence staining. Rat AE prepared from inguinal adipose tissues was intra-articularly delivered to the knee joints of rats with experimental osteoarthritis (OA), and the effect of AE on cartilage destruction was evaluated histologically. In vitro, co-treatment with IL-1β combined with AE reduced activation of the p38 and ERK mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of the p65 subunit of nuclear factor-kappa B (NF-κB), and subsequently downregulated the expressions of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, IL-6, and IL-8, whereas it markedly upregulated the expression of IL-1 receptor type 2 (IL-1R2) in chondrocytes. Intra-articular injection of homologous AE significantly ameliorated cartilage destruction six weeks postoperatively in the rat OA model. These results suggested that AE may exert a chondroprotective effect, at least in part, through modulation of the IL-1β-induced inflammatory signaling pathway by upregulation of IL-1R2 expression.

Dorsal dislocation of metatarsophalangeal (MTP) joints of the lesser toe frequently occurs in patients with rheumatoid arthritis (RA), and may cause painful and uncomfortable plantar callosities and ulceration. The current study examined the reliability and clinical relevance of a novel radiographic parameter (the MTP overlap distance [MOD]) in evaluating the severity of MTP joint dislocation. The subjects of the current study were 147 RA patients (276 feet; 1104 toes). MOD, defined as the overlap distance of the metatarsal head and the proximal end of the phalanx, was measured on plain radiographs. The relationship between the MOD and clinical complaints (forefoot pain and/or callosity formation) was analyzed to create a severity grading system. As a result, toes with callosities had a significantly larger MOD. ROC analysis revealed that the MOD had a high AUC for predicting an asymptomatic foot (−0.70) and callosities (0.89). MOD grades were defined as follows: grade 1, 0 ≤ MOD < 5 mm; grade 2, 5 ≤ MOD < 10 mm; and grade 3, MOD ≥ 10 mm. The intra- and inter-observer reliability of the MOD grade had high reproducibility. Furthermore, the MOD and MOD grade improved significantly after joint-preserving surgeries for lesser toe deformities. Our results suggest that MOD and MOD grade might be useful tools for the evaluation of deformities of the lesser toe and the effect of surgical intervention for MTP joints in patients with RA.

We investigated the effects of a Tankyrase (TNKS-1/2) inhibitor on mechanical stress-induced gene expression in human chondrocytes and examined TNKS-1/2 expression in human osteoarthritis (OA) cartilage. Cells were seeded onto stretch chambers and incubated with or without a TNKS-1/2 inhibitor (XAV939) for 12 h. Uni-axial cyclic tensile strain (CTS) (0.5 Hz, 8% elongation, 30 min) was applied and the gene expression of type II collagen a1 chain (COL2A1), aggrecan (ACAN), SRY-box9 (SOX9), TNKS-1/2, a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), and matrix metalloproteinase-13 (MMP-13) were examined by real-time PCR. The expression of ADAMTS-5, MMP-13, nuclear translocation of nuclear factor-κB (NF-κB), and β-catenin were examined by immunocytochemistry and Western blotting. The concentration of IL-1β in the supernatant was examined by enzyme-linked immunosorbent assay (ELISA). TNKS-1/2 expression was assessed by immunohistochemistry in human OA cartilage obtained at the total knee arthroplasty. TNKS-1/2 expression was increased after CTS. The expression of anabolic factors were decreased by CTS, however, these declines were abrogated by XAV939. XAV939 suppressed the CTS-induced expression of catabolic factors, the release of IL-1β, as well as the nuclear translocation of NF-κB and β-catenin. TNKS-1/2 expression increased in mild and moderate OA cartilage. Our results demonstrated that XAV939 suppressed mechanical stress-induced expression of catabolic proteases by the inhibition of NF-κB and activation of β-catenin, indicating that TNKS-1/2 expression might be associated with OA pathogenesis.

We investigated the roles of low-density lipoprotein receptor-related protein (LRP) 4 and its ligand Agrin in the pathophysiology of cartilage degeneration. Immunohistochemical analysis of human normal articular cartilage and cartilage tissues from patients with osteoarthritis (OA) obtained during surgery of the knee joint showed marked LRP4 expression in the early stages of OA, which then decreased with cartilage degeneration, whereas Agrin was consistently increased with cartilage degeneration. In normal human articular chondrocytes (NHACs), mild cyclic tensile strain (CTS) (0.5 Hz, 5% elongation, 2 h) increased the expression of LRP4 and aggrecan (ACAN), while intense CTS (0.5 Hz, 10% elongation, 6 h) increased the expression of Agrin without affecting LRP4 expression. Treatment with recombinant human (rh) Agrin downregulated the mRNA expression of LRP4 and ACAN, but upregulated the expression of LRP5/6, SRY-box transcription factor 9 (SOX9), Runt-related transcription factor 2 (RUNX2), and a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4). Immunocytochemistry and Western blot analysis showed that rhAgrin treatment upregulated the expression of β-catenin and SOX9. Agrin knockdown by siAGRN transfection partially reduced the nuclear protein expression of β-catenin, which was increased with intense CTS. LRP4 knockdown by siLRP4 transfection increased the expression of LRP5/6, SOX9, RUNX2, ADAMTS-4, and Agrin. These results suggested that intense CTS increases the expression of Agrin, which might interfere with the role of LRP4 in the inhibition of LRP5/6 and their downstream β-catenin signaling, leading to cartilage degeneration.

Background/Objectives: Launched in Japan in 2022, ozoralizumab (OZR) is a novel, anti-tumour necrosis factor (TNF)-α inhibitor for treating rheumatoid arthritis (RA) that is refractory to conventional therapies. However, there is a lack of evidence regarding its perioperative management. Methods: This retrospective case series included nine patients with RA who underwent a total of 12 either RA-related (n = 9) or unrelated (n = 3) orthopaedic procedures. We reviewed patient demographics, surgical procedures, perioperative OZR discontinuation periods, and postoperative complications. Results: The mean preoperative OZR discontinuation period was 15.8 days (range, 2–25 days). Sutures were removed at a mean of 12.8 days postoperatively (range, 11–14 days) after adequate wound healing had been confirmed. The mean total discontinuation period was 34.9 days (range, 27–43 days). No cases of surgical site infection (SSI) or delayed wound healing (DWH) were observed during a minimum follow-up period of three months. One patient experienced a disease flare before OZR was restarted. Conclusions: Preoperative OZR discontinuation for up to four weeks appeared to be safe in this cohort. These findings may assist orthopaedic surgeons in determining an appropriate perioperative discontinuation strategy for OZR that minimises SSI and DWH risk while reducing the likelihood of RA flare.

Total wrist arthroplasty is a challenging procedure for wrist joints severely destroyed by rheumatoid arthritis. The most common postoperative complication of total wrist arthroplasty is the loosening of the carpal component. Revision surgeries for failed total wrist arthroplasties can be complicated owing to severe bone loss and concomitant soft-tissue problems. Here we report a case (68-year-old woman with a history of rheumatoid arthritis for 24 years) of severe aseptic loosening of semi-constrained total wrist arthroplasty and its salvage surgery. During the primary arthroplasty procedure, severe instability at the second through fifth carpometacarpal joints was observed, and arthrodesis of these joints was required. The radiographs obtained nine months after surgery showed loosening of the carpal component. Subsequently, she suffered a stroke, resulting in a loss of follow-up, and higher stress was loaded on her upper extremities during standing and walking. In the radiograph taken at her revisit 25 months after the primary surgery, the subsidence of the carpal component progressed, and loosening of the radial component was observed. Total wrist arthrodesis was performed using a bulk bone allograft of the femoral head, combined with a penetrating Wrist Fusion Rod^®. Rapid bone union was achieved without soft tissue irritation. We conclude that wrist arthrodesis with a bulk bone allograft combined with an intramedullary nail is a reasonable option for failed total wrist arthroplasty.