Effect of whole body vibration on HIF-2α expression in SD rats with early knee osteoarthritis

Cartilage Homeostasis under Physioxia

Articular cartilage receives nutrients and oxygen from the synovial fluid to maintain homeostasis. However, compared to tissues with abundant blood flow, articular cartilage is exposed to a hypoxic environment (i.e., physioxia) and has an enhanced hypoxic stress response. Hypoxia-inducible factors (HIFs) play a pivotal role in this physioxic environment. In normoxic conditions, HIFs are downregulated, whereas in physioxic conditions, they are upregulated. The HIF-α family comprises three members: HIF-1α, HIF-2α, and HIF-3α. Each member has a distinct function in articular cartilage. In osteoarthritis, which is primarily caused by degeneration of articular cartilage, HIF-1α is upregulated in chondrocytes and is believed to protect articular cartilage by acting anabolically on it. Conversely, in contrast to HIF-1α, HIF-2α exerts a catabolic influence on articular cartilage. It may therefore be possible to develop a new treatment for OA by controlling the expression of HIF-1α and HIF-2α with drugs or by altering the oxygen environment in the joints.

Efficacy of Combining Whole-body Vibration Training and Closed Kinetic Chain Exercises in Early Knee Osteoarthritis: A Preliminary Study

Objectives

We aimed to conduct a preliminary evaluation of the effectiveness of integrating whole-body vibration training (WBVT) into conventional closed kinetic chain (CKC) exercises as an intervention strategy for early knee osteoarthritis (KOA).

Methods

: This non-randomized comparative study conducted at an orthopedic clinic involved 53 patients (with Kellgren-Lawrence grades 1-2); 37 patients received only physical therapy (CKC group), and 16 patients received both physical therapy and WBVT (WBVT group). The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscale score for pain, and the secondary outcomes were the WOMAC subscale score for physical function and muscle-strength assessments [isometric knee extension strength and the 30-second chair-stand test (CS-30) score]. Propensity score matching (PSM) was used to adjust for bias between the control and intervention groups.

Results

: After PSM adjustment, 13 patients were selected from each group. The WBVT group showed a significant improvement in the WOMAC pain score (d=1.16, P=0.007) and a significant increase in the CS-30 score (d=0.81, P=0.049). However, for the WOMAC physical function score, the between-group difference remained statistically insignificant (d=0.59, P=0.146).

Conclusions

: WBVT may be effective in reducing the pain of early KOA. WBVT is a non-invasive and convenient method, underscoring its potential as a novel therapeutic option.

Mechanism of HIFs in osteoarthritis

Osteoarthritis (OA) is a common disabling disease which has a high incidence rate in the elderly. Studies have found that many factors are involved in the pathogenesis of OA. Hypoxia-inducible factors (HIFs) are core regulators that induce hypoxia genes, repair the cellular oxygen environment, and play an important role in the treatment of OA. For example, HIF-1α can maintain the stability of the articular cartilage matrix, HIF-2α is able to cause chondrocyte apoptosis and intensify in-flammatory response, and HIF-3α may be the target gene of HIF-1α and HIF-2α, thereby playing a negative regulatory role. This review examines the mechanism of HIFs in cartilage extracellular matrix degradation, apoptosis, inflammatory reaction, autophagy and then further expounds on the roles of HIFs in OA, consequently providing theoretical support for the pathogenesis of OA and a new target for OA treatment.

Physical Agent Modalities in Early Osteoarthritis: A Scoping Review

Early osteoarthritis (EOA) still represents a challenge for clinicians. Although there is no consensus on its definition and diagnosis, a prompt therapeutic intervention in the early stages can have a significant impact on function and quality of life. Exercise remains a core treatment for EOA; however, several physical modalities are commonly used in this population. The purpose of this paper is to investigate the role of physical agents in the treatment of EOA. A technical expert panel (TEP) of 8 medical specialists with expertise in physical agent modalities and musculoskeletal conditions performed the review following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) model. The TEP searched for evidence of the following physical modalities in the management of EOA: "Electric Stimulation Therapy", "Pulsed Electromagnetic field", "Low-Level Light Therapy", "Laser Therapy", "Magnetic Field Therapy", "Extracorporeal Shockwave Therapy", "Hyperthermia, Induced", "Cryotherapy", "Vibration therapy", "Whole Body Vibration", "Physical Therapy Modalities". We found preclinical and clinical data on transcutaneous electrical nerve stimulation (TENS), extracorporeal shockwave therapy (ESWT), low-intensity pulsed ultrasound (LIPUS), pulsed electromagnetic fields stimulation (PEMF), and whole-body vibration (WBV) for the treatment of knee EOA. We found two clinical studies about TENS and PEMF and six preclinical studies-three about ESWT, one about WBV, one about PEMF, and one about LIPUS. The preclinical studies demonstrated several biological effects on EOA of physical modalities, suggesting potential disease-modifying effects. However, this role should be better investigated in further clinical studies, considering the limited data on the use of these interventions for EOA patients.

The Application of Whole-Body Vibration Training in Knee Osteoarthritis

With the gradual increase of the aging population in Chinese society, the incidence of knee osteoarthritis showed an increasing trend. However, there are very few practical solutions for it. As a novel neuromuscular training technique, whole-body vibration training has become a candidate for treating knee osteoarthritis. In this review, we firstly elaborated on the mode of action and influence factors of the whole-body vibration training. Next, we summarized its effects in knee osteoarthritis, including improving knee function and some uncertain muscle function and proprioception effects. Next, we also summarized its possible mechanisms, including improving bone microstructure, delaying articular cartilage degeneration, modulating inflammatory cells and inflammatory factors. Then, we summarized the clinical effectiveness of whole-body vibration training by analyzing some clinical randomized controlled trials. Finally, based on the above summary, we analyzed and listed the limitations of whole-body vibration training in treating knee osteoarthritis and found the shortcomings in the existing studies. This review provides ideas for the future application of whole-body vibration training in the treatment of knee osteoarthritis.

Effects of whole-body vibration plus hip-knee muscle strengthening training on adult patellofemoral pain syndrome: a randomized controlled trial

PURPOSE

To investigate whether whole-body vibration (WBV) plus hip-knee muscle strengthening is more efficient in relieving pain and improving function than hip-knee strengthening alone.

METHODS

Thirty-six participants with patellofemoral pain syndrome (PFPS) were recruited and randomly allocated to either the (1) hip-knee strengthening only (HK group, n = 18) or (2) WBV plus hip-knee strengthening group (WHK group, n = 18). All participants attended 18 physiotherapy sessions (3 sessions/week, 40 min/session) over 6 weeks. Data on symptoms, function, surface electromyography (sEMG) signals from the vastus medialis and gluteus medius, and quality of life were evaluated at baseline (T₀), 6 weeks after (T₆), and the 12-week follow-up (T₁₈).

RESULTS

Significant group × time interactions were found for the VAS score (p < 0.001) and vastus medialis performance (p ≤ 0.015). The WHK group exhibited a greater pain relief than did the HK group at T₁₈ (p ≤ 0.014). The WHK group exhibited significantly larger improvements in the RMS value than did the HK group at T₆ (p ≤ 0.011).

CONCLUSIONS

The present study shows that 6 weeks of WBV plus hip-knee strengthening can improve vastus medialis performance and maintain long-term pain relief to a significantly greater extent than can hip-knee strengthening alone.IMPLICATIONS FOR REHABILITATIONThe present study shows that 6 weeks of WBV plus hip-knee strengthening can improve vastus medialis performance and maintain long-term pain relief to a significantly greater extent than can hip-knee strengthening alone.

Long-term Effects of Mechanical Vibration Stimulus on the Bone Formation of Wistar Rats: An Assessment Method Based on X-rays Images

BACKGROUND

Bone is a complex living tissue that adapts itself to the demands of mechanical stimuli such as physical activity and exercise. Whole-body vibration (WBV) is a type of exercise characterized by the transmission of mechanical vibration stimuli produced by a vibrating platform. This study aimed to investigated, in experimental model, the effect of WBV exercise on the bone in different frequencies through X-ray analysis.

MATERIALS AND METHODS

Wistar rats were divided in three groups: control, exposed to WBV of 10 Hz and exposed to WBV of 20 Hz, during 8-weeks. All procedures to obtain the radiographic images were carried out before and after the experiments. The femur linear size and bone density measurements through radiographic images were performed in all animals. A factor of increase for bone density (FIBD) was determined.

RESULTS

No differences were observed in the qualitative comparison between the groups, as well as radiographic bone density before the experiment. However, after the experiment the bone density increased in the rats exposed to WBV of 10 Hz and 20 Hz compared to control group. Also, the FIBD was higher in the groups exposed to WBV in comparison with control.

CONCLUSION

These findings indicate an increase of the bone density dependent of the vibration stimulus frequency. In addition, this increase suggests a possible osteogenic effect to the mechanical vibrations of 10 and 20 Hz.

Effects of Catalpa Alcohol From Rehmannia glutinosa on Calcium-Binding Protein, Interleukin-1β, and Galectin-3 in Synovial Tissues of Rats With Knee Osteoarthritis

Objectives

We aimed to evaluate the effects of catalpa alcohol from Rehmannia glutinosa on the expressions of calcium-binding protein (S100A12), interleukin-1β (IL-1β), and galectin-3 in the synovium of rats with early knee osteoarthritis (KOA).

Methods

Fifty-two adult male Wistar rats aged 3 to 8 weeks were divided into normal control (n = 16), model (n = 12), low-dose (n = 12), and high-dose groups (n = 12). On the 10th day after modeling, 6 rats in normal control group and 6 in the other 3 groups were randomly selected. X-ray and 3-dimensional computed tomography (3D CT) images of the left knee joint were taken under live anesthesia. The joint cavity of sacrificed rats was opened to observe cartilage surface. After 28 consecutive days of administration, the synovial tissue of left knee joint was collected.

Results

The S100A12, IL-1β, and galectin-3 levels in synovial tissue were detected by immunohistochemistry and ELISA. There were articular cartilage defects in left knees. Radiologic examination showed significant joint space narrowing and hyperplasia, and 3D CT joint space value decreased (P &lt; 0.05). The Mankins and OARSI scores of synovial histopathology were significantly different (P &lt; 0.05). The S100A12, IL-1β, and galectin-3 levels in synovial tissue of the model group significantly exceeded those of the normal control group (P &lt; 0.01). Compared with the model group, such levels of low-dose (P &lt; 0.05) and high-dose groups (P &lt; 0.01) were significantly lower.

Conclusions

The S100A12, IL-1β and galectin-3 levels in synovium tissue decreased with rising concentration of catalpa alcohol from R. glutinosa. Therefore, this drug is potentially suitable for inhibiting an inflammatory response to delay the progression of KOA.