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Objective The objective of this study was to assess the efficacy and safety of extracorporeal shockwave therapy (ESWT) for treatment of knee osteoarthritis (OA) using a systemic review and meta-analysis. Methods An extensive search of relevant articles from electronic databases Pubmed, Embase, and Cochrane Library from inception to March 2019 was conducted. The treatment outcomes (visual analog scale [VAS] and the Western Ontario and McMaster Universities Arthritis Index [WOMAC]) of the included articles were pooled to calculate effect sizes. The assessment of heterogeneity among articles was evaluated using I2. Statistical analyses were conducted using RevMan software. Results The results showed that the ESWT group had significant improvement in pain relief compared with the control group through 12 months based on WOMAC and VAS scores. Compared with the baseline level, the patients had significant improvement in pain relief at most follow-up points (one week to 12 months) based on WOMAC and VAS scores. The patients showed significant improvement in physical function at six- and 12-month follow-up when compared with the control group and for all follow-up (one to 12 months) when compared with the baseline level. Additionally, only minor complications were observed after ESWT treatment. Conclusions The use of ESWT for treatment of knee OA had a beneficial effect on pain relief and physical function improvement for up to 12 months, and only minor complications occurred after ESWT treatment. However, there remains a lack of clarity regarding the frequency and dosage levels of ESWT required to achieve the maximum improvement.

Aims Interleukin (IL)-1β is one of the major pathogenic regulators during the pathological development of intervertebral disc degeneration (IDD). However, effective treatment options for IDD are limited. Suramin is used to treat African sleeping sickness. This study aimed to investigate the pharmacological effects of suramin on mitigating IDD and to characterize the underlying mechanism. Methods Porcine nucleus pulposus (NP) cells were treated with vehicle, 10 ng/ml IL-1β, 10 μM suramin, or 10 μM suramin plus IL-1β. The expression levels of catabolic and anabolic proteins, proinflammatory cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB-related signalling molecules were assessed by Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence analysis. Flow cytometry was applied to detect apoptotic cells. The ex vivo effects of suramin were examined using IDD organ culture and differentiation was analyzed by Safranin O-Fast green and Alcian blue staining. Results Suramin inhibited IL-1β-induced apoptosis, downregulated matrix metalloproteinase (MMP)-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, and ADAMTS-5, and upregulated collagen 2A (Col2a1) and aggrecan in IL-1β-treated NP cells. IL-1β-induced inflammation, assessed by IL-1β, IL-8, and tumour necrosis factor α (TNF-α) upregulation, was alleviated by suramin treatment. Suramin suppressed IL-1β-mediated proteoglycan depletion and the induction of MMP-3, ADAMTS-4, and pro-inflammatory gene expression in ex vivo experiments. Conclusion Suramin administration represents a novel and effectively therapeutic approach, which could potentially alleviate IDD by reducing extracellular matrix (ECM) deposition and inhibiting apoptosis and inflammatory responses in the NP cells. Cite this article: Bone Joint Res 2021;10(8):498–513.

Cell-based therapy is an ideal way of repairing defective cartilage. At present, the articular chondrocytes (ACs) is the cell source for cartilage repair. Problematically, in serial culture, the dedifferentiation of ACs occurs, which may result in graft failure. In the present study, we examined chondrogenic capacity and physical characteristics of proliferating layer chondrocytes (PLCs) from the growth plate cartilage and evaluated its regenerative activity for cartilage repair. We found that PLCs preserved more chondrogenic phenotypes, such as polygonal appearances, whereas ACs appeared fibroblast-like after seventh passage. Profoundly, the ACs expressed higher apoptosis-related proteins, such as cleaved caspase-9 and cleaved caspase-3, than PLCs. Also, the PLCs have higher proliferation rate than ACs, and the cell doubling time is 20.9 h for PLCs and 29.5 h for ACs. Using flow cytometry, we demonstrated that 26.6% of PLCs entered the S-phase after 16 h serum re-addition to starved cells compared with 13.3% of ACs. Otherwise, col2a1, aggrecan, sox5, sox6, and sox9 mRNAs were significantly increased in PLCs compared with ACs; in contrast, the col1a and col10a1 mRNA expression level in PLCs was lower than that in ACs. The glycosaminoglycan content in PLCs was higher than that in ACs by the direct 1,9-dimethylmethylene blue assay. Histological and immunohistochemical evaluations have demonstrated that significantly more chondrogenic extracellular matrix was detected in the PLCs group compared with the ACs group after implantation in nude mice. Taken together, our data indicate the PLCs preserved much more chondrogenic phenotypes than ACs in vitro and in vivo. These results might imply that PLCs act as the better cell source for reapairing and regenerating growth plate and articular cartilage.

Objective Shockwave application is a potential treatment for osteoarthritis (OA), but the underlying mechanism remains unknown. Oxidative stress and a counterbalancing antioxidant system might be the key to understanding this mechanism. We hypothesized that reactive oxygen species (ROS) and the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2),which is an important regulator of cellular redox homeostasis, are plausible elements. Design Porcine chondrocytes were cultured in a 3-dimensional pellet model and subjected to shockwaves. The effects of shockwaves with various energy-flux densities on optimal extracellular matrix (ECM) synthesis were assessed. ROS, mitogen-activated protein kinase (MAPK) signaling, and the redox activity of Nrf2 were measured. To investigate the signaling mechanism involved in the shockwave treatment in chondrocytes, specific inhibitors of ROS, MAPK signaling, and Nrf2 activity were targeted. Results Shockwaves increased ECM synthesis without affecting cell viability or proliferation. Furthermore, they induced transient ROS production mainly through xanthine oxidase. The phosphorylation of ERK1/2 and p38 and the nuclear translocation of Nrf2 were activated by shockwaves. By contrast, suppression of ROS signaling mitigated shockwave-induced MAPK phosphorylation, Nrf2 nuclear translocation, and ECM synthesis. Pretreatment of chondrocytes with the specific inhibitors of MEK1/2 and p38, respectively, mitigated the shockwave-induced nuclear translocation of Nrf2 and ECM synthesis. Nrf2 inhibition by both small hairpin RNA knockdown and brusatol reduced the shockwave-enhanced ECM synthesis. Conclusions Shockwaves activated Nrf2 activity through the induction of transient ROS signaling and subsequently enhanced ECM synthesis in chondrocytes. This study provided fundamental evidence confirming the potential of shockwaves for OA management.

Radiofrequency ablation (RFA) was first introduced for treating knee osteoarthritis (OA) in 2010 and has emerged as a minimally invasive treatment option. Three RFA techniques have been adopted for treating knee OA, including conventional, pulsed, and cooled RFA. However, the efficacy among different RFA techniques in the treatment of knee OA is still unclear. Three electronic databases were systematically searched for relevant articles, including PubMed, Embase, and Cochrane Library. A meta-analysis of articles that investigated the use of RFA techniques in the treatment of knee OA was conducted to pool the effect size in pain before and after treatment. A total of 20 eligible articles (including 605 patients) were included for our meta-analysis. After treatment, the patients had significant improvements in pain for all three RFA techniques when compared with the baseline level for the 1, 3-, and 6-month follow-ups (p < 0.00001). However, there were no significant differences in the efficacy among the three RFA techniques for all follow-up visits (p > 0.05). The three RFA techniques demonstrated a significant improvement in pain for up to 6 months after treatment. Comparing the efficacy of the three RFA techniques in the treatment of knee OA, our results showed that no significant differences in pain relief among the three RFA techniques were observed at the 1-, 3-, 6, and 12-month follow-up visits.

Aims Autologous chondrocyte implantation (ACI) is a promising treatment for articular cartilage degeneration and injury; however, it requires a large number of human hyaline chondrocytes, which often undergo dedifferentiation during in vitro expansion. This study aimed to investigate the effect of suramin on chondrocyte differentiation and its underlying mechanism. Methods Porcine chondrocytes were treated with vehicle or various doses of suramin. The expression of collagen, type II, alpha 1 (COL2A1), aggrecan (ACAN); COL1A1; COL10A1; SRY-box transcription factor 9 (SOX9); nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX); interleukin (IL)-1β; tumour necrosis factor alpha (TNFα); IL-8; and matrix metallopeptidase 13 (MMP-13) in chondrocytes at both messenger RNA (mRNA) and protein levels was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot. In addition, the supplementation of suramin to redifferentiation medium for the culture of expanded chondrocytes in 3D pellets was evaluated. Glycosaminoglycan (GAG) and collagen production were evaluated by biochemical analyses and immunofluorescence, as well as by immunohistochemistry. The expression of reactive oxygen species (ROS) and NOX activity were assessed by luciferase reporter gene assay, immunofluorescence analysis, and flow cytometry. Mutagenesis analysis, Alcian blue staining, reverse transcriptase polymerase chain reaction (RT-PCR), and western blot assay were used to determine whether p67phox was involved in suramin-enhanced chondrocyte phenotype maintenance. Results Suramin enhanced the COL2A1 and ACAN expression and lowered COL1A1 synthesis. Also, in 3D pellet culture GAG and COL2A1 production was significantly higher in pellets consisting of chondrocytes expanded with suramin compared to controls. Surprisingly, suramin also increased ROS generation, which is largely caused by enhanced NOX (p67phox) activity and membrane translocation. Overexpression of p67phox but not p67phoxAD (deleting amino acid (a.a) 199 to 212) mutant, which does not support ROS production in chondrocytes, significantly enhanced chondrocyte phenotype maintenance, SOX9 expression, and AKT (S473) phosphorylation. Knockdown of p67phox with its specific short hairpin (sh) RNA (shRNA) abolished the suramin-induced effects. Moreover, when these cells were treated with the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) inhibitor LY294002 or shRNA of AKT1, p67phox-induced COL2A1 and ACAN expression was significantly inhibited. Conclusion Suramin could redifferentiate dedifferentiated chondrocytes dependent on p67phox activation, which is mediated by the PI3K/AKT/SOX9 signalling pathway. Cite this article: Bone Joint Res 2022;11(10):693–708.

Study Design: This was a single-center, retrospective study. Objective: The objective of this study was to assess the risk factors for deformity progression after scoliosis correction surgery in spinal muscular atrophy (SMA) patients. Summary of Background Data: Moderate residual postoperative scoliosis curve is common in SMA populations; however, the acceptable postoperative scoliosis curve for preventing deformity progression remains uncertain. Materials and Methods: Twenty-nine SMA patients undergoing scoliosis correction surgery were included. Scoliosis progression was defined as an increase of 10 degrees in the major curve of Cobb angle (MCCA); pelvic obliquity (PO) or concave-side hip progression was arbitrarily defined as an increase of ≥1 grade after surgery. Risk factors for deformity progression were examined using Cox proportional hazard models. The cumulative incidence rate of deformity progression was performed by the Kaplan-Meier survival analysis Results: The mean age at surgery was 13.3 years (range: 8–25 y) and the mean follow-up time was 7 years (range: 2–22.9 y). The mean MCCA was corrected from 69 to 34.6 degrees at initial follow-up and 42.2 degrees at the final follow-up. Postoperative MCCA ( P =0.002) and PO ( P =0.004) at initial follow-up were the risk factors for scoliosis progression. Postoperative MCCA at initial follow-up ( P =0.007) and age at the time of surgery ( P =0.017) were the risk factors for PO progression. Different cutoff points of postoperative MCCA at initial follow-up were compared for predicting deformity progression. We found the patient with postoperative MCCA of <30 degrees at initial follow-up had a significantly less cumulative incidence rate of progression than their counterparts for scoliosis ( P =0.005), PO ( P =0.023), and concave-side hip progressions ( P =0.008). Conclusions: We recommended that MCCA should be corrected to <30 degrees to prevent postoperative scoliosis, PO, and concave-side femoral head coverage percentage progressions. Patients receiving surgery earlier had less postoperative MCCA at initial follow-up but with no increase in the risk of postoperative scoliosis progression.