Does vitamin D deficiency influence the incidence and progression of knee osteoarthritis? - A literature review

Global Research on Osteoarthritis During 1994-2023: A Scientometric Assessment of Publications and Citations

Introduction

This study presents a global research scenario in the broad domain of osteoarthritis (OA) research, using quantitative and qualitative publication and citation indicators.

Methods

The study is based on 45,368 global publications, sourced from the Scopus bibliographical database, covering three decades (1994-2023). We studied the performance of the top 12 developed and top 12 developing countries. The key countries, organizations and authors at national and international levels were identified. The broad subject areas and key journals contributing to global OA research were delineated, besides identifying the broad characteristics of highly cited papers in the field.

Results

The United States and China were the most productive countries, while the Netherlands and Canada made the largest citation impact. Harvard Medical School and the University of Sydney made the most contribution, while Boston University and Pfizer Inc., USA registered the highest citation impact. Hunter DJ and Guermazi A were the most productive authors, while Lohmander LS, and Hochberg MC registered the highest citation impact. Osteoarthritis and Cartilage (n = 4879) and Annals of the Rheumatic Diseases (n = 786) published the maximum papers, while Arthritis and Rheumatism and Nature Reviews Rheumatology registered the largest citation impact. The highly cited papers with 100 or more citations constituted 6.25% of the total publications.

Conclusions

There has been a systematic growth of publications on OA. The research on OA was mainly done in developed countries, with the maximum publications coming from the United States of America, China and Canada. The most impactful publications on OA were from the Netherlands, Canada and the United States of America.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01111-9.

Effect of vitamin D supplementation on circulating level of autophagosome protein LC3A, inflammation, and physical performance in knee osteoarthritis

Aberrant autophagic activity is observed in osteoarthritic joints. Vitamin D was shown to alleviate not only osteoarthritis severity, but also autophagy process. However, the influence of vitamin D on autophagy in knee osteoarthritis (KOA) remains ambiguous. This study aimed to determine the effect of vitamin D2 on serum levels of autophagosome protein LC3A in patients with KOA and whether LC3A levels were correlated with serum 25-hydroxyvitamin D (25(OH)D) and clinical outcomes of patients with KOA. A total of 165 patients with KOA and 25 healthy controls were recruited. Vitamin D2 (ergocalciferol) was administered to patients with KOA at a weekly dosage of 40,000 IU. Serum LC3A, knee pain and functional scores, muscle strength, physical performance, and biochemical parameters were examined before and after 6 months of vitamin D2 supplementation. Serum LC3A levels were significantly higher in patients with KOA than healthy controls. In patients with KOA, vitamin D2 supplementation significantly decreased serum LC3A levels. Furthermore, baseline levels of serum LC3A were significantly associated with radiographic severity, pain and functional scores, total cholesterol, hs-CRP, IL-6, protein carbonyl, and serum 25(OH)D. After adjusting for established confounders, independent relationships among serum LC3A and radiographic severity, pain and functional scores, total cholesterol, hs-CRP, IL-6, protein carbonyl, and serum 25(OH)D were also observed. Vitamin D2 supplementation was shown to not only decrease serum levels of LC3A, inflammatory markers, as well as oxidative stress, but also improve muscle strength and physical performance in patients with KOA.

Investigation of Vitamin D Status, Age, and Body Mass Index as Determinants of Knee Osteoarthritis Severity Using the Kellgren-Lawrence Grading System in a Saudi Arabian Cohort: A Cross-Sectional Study

Background Knee osteoarthritis (OA) is a common and disabling condition affecting millions worldwide. This cross-sectional study endeavors to investigate the relationship between vitamin D status, age, body mass index (BMI), and knee OA in a cohort of individuals in Saudi Arabia. Methods In this cross-sectional study, we assessed vitamin D serum levels, conducted knee radiographs, and evaluated the severity of knee OA using the Kellgren-Lawrence grading system (KLGS). The analysis incorporated both descriptive and inferential statistics, including chi-square tests and a regression model to investigate the relationship between KLGS grades as indicators of knee OA severity and vitamin D levels, considering demographics as covariants. Results The study included 93 participants with suspected knee OA, of which a substantial portion of the sample population presented with knee OA (58 [62.4%]). Knee OA exhibited a higher prevalence among females, comprising 47 (50.54%) of the total, while 11 (11.83%) were male. The largest age group with knee OA was those older than 58 years, 27 (29.03%), followed by the age group of 48-58 years, 19 (20.43%). Obesity was a prevalent factor among knee OA patients (36 [38.7%]), with grade 2 (17 [18.3%]) and grade 3 (24 [25.8%]) being the most frequent. Vitamin D deficiency was prevalent in 54 (58%) of patients. Among knee OA cases, bilateral involvement was predominant in 46 (79%), with a substantial portion, 36 (62%), presenting deficient vitamin D levels. The regression model revealed that age (95% CI: 0.54-1.03, p < 0.001) and BMI (95% CI: 0.01-0.60, p = 0.04) significantly predict higher KLGS grades, indicating that increasing age and higher BMI are associated with higher KLGS grades. However, Vitamin D levels did not show a significant impact on the severity of knee OA. Conclusions The findings from this study highlight the importance of monitoring and maintaining adequate vitamin D levels to potentially reduce the risk of knee OA and the need for early detection and intervention to manage knee OA, particularly in females, older poplulation, and obese adults. They may guide healthcare providers in developing comprehensive approaches to reduce the risk of this condition.

Long-term effects of vitamin D supplementation and maintaining sufficient vitamin D on knee osteoarthritis over 5 years

OBJECTIVES

This study aimed to investigate the long-term effect of vitamin D supplementation compared to placebo over 5 years in participants with knee osteoarthritis (OA). We also aimed to describe the effect of maintaining sufficient serum vitamin D levels over five years in knee OA.

METHODS

Participants (n = 173) from the Hobart centre of the Vitamin D Effects on Osteoarthritis (VIDEO) trial were extensively followed up 3 years after the cessation of 2-year investigational treatment. Participants were classified as maintaining sufficient vitamin D (n = 79) and not maintaining sufficient vitamin D (n = 61) groups.

RESULTS

There was no significant difference in change in the knee symptoms, depression, and serum levels of IL6 and hs-CRP between both comparisons after 3 years of cessation of the clinical trial. However, among participants who reported no knee surgery (KS), there was a significant improvement in WOMAC function (β: - 83.7, 95% CI: - 167.3, 0) and depression scores (β: - 1.3, 95% CI: - 2.3, - 0.2) in vitamin D group compared to the placebo group. Similarly, those who maintained adequate vitamin D levels over 5 years had significantly less WOMAC knee pain (β: - 33.9, 95% CI: - 65.7, - 2) and physical dysfunction (β: - 105.5, 95% CI: - 198.2, - 12.8) than participants with vitamin D deficiency over 5 years.

CONCLUSION

Vitamin D supplementation over 2 years or maintaining vitamin D sufficiency for 5 years was not associated with statistically significant differences in change in knee symptom scores over 5 years. However, among participants who did not report KS, 2-year vitamin D supplementation and maintaining sufficient vitamin D was linked to modest improvements in knee symptoms and depression scores in knee OA.

Personalized Nutritional Strategies to Reduce Knee Osteoarthritis Severity and Ameliorate Sarcopenic Obesity Indices: A Practical Guide in an Orthopedic Setting

Knee osteoarthritis (KOA) is one of the most common joint diseases, especially in individuals with obesity. Another condition within this population, and which presents frequently, is sarcopenic obesity (SO), defined as an increase in body fat and a decrease in muscle mass and strength. The current paper aims to describe recent nutritional strategies which can generally improve KOA clinical severity and, at the same time, ameliorate SO indices. Searches were carried out in the PubMed and Science Direct databases and data were summarized using a narrative approach. Certain key findings have been revealed. Firstly, the screening and identification of SO in patients with KOA is important, and to this end, simple physical performance tests and anthropometric measures are available in the literature. Secondly, adherence to a Mediterranean diet and the achievement of significant body weight loss by means of low-calorie diets (LCDs) remain the cornerstone nutritional treatment in this population. Thirdly, supplementation with certain micronutrients such as vitamin D, essential and non-essential amino acids, as well as whey protein, also appear to be beneficial. In conclusion, in the current review, we presented a detailed flowchart of three different nutritional tracks that can be adopted to improve both KOA and SO based on joint disease clinical severity.

The association of vitamin D status with oxidative stress biomarkers and matrix metalloproteinases in patients with knee osteoarthritis

Objective

The association of vitamin D status with osteoarthritis (OA) has been demonstrated previously. The current study was performed to examine the association of vitamin D status with oxidative stress markers and matrix metalloproteinases (MMPs) in patients with knee OA.

Methods

This case-control study was conducted on 124 subjects with mild to moderate knee OA and 65 healthy controls. Demographic data was collected from all participants at baseline. Serum levels of vitamin D as well as markers of oxidative stress including malondialdehyde (MDA), total oxidant status (TOS), superoxide dismutase (SOD), oxidative stress index (OSI), paraoxonase-1 (PON-1), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant capacity (TAC) were evaluated for each participant. Furthermore, serum concentrations of MMP-1, MMP-3, MMP-13, and cartilage oligomeric matrix protein (COMP) were measured.

Results

The results of the present study indicated that individuals with vitamin D insufficiency had higher levels of MDA, TOS, SOD, and OSI as well as lower levels of PON-1 and TAC. Based on the linear regression analysis, serum vitamin D levels were inversely correlated with MDA, TOS, SOD, OSI, MMP-1, and MMP-13 and positively associated with TAC levels (p < 0.0001). Patients with sufficient vitamin D levels had lower MMP-1 and MMP-13 levels compared to patients with vitamin D insufficiency (p < 0.001 and p < 0.001, respectively).

Conclusion

Findings from this study showed a strong association between vitamin D deficiency and increased oxidative stress and MMPs activity in patients with knee OA.

No adverse effects on periarticular tissue by intra-articular vitamin D analogue calcipotriol in a reduced-dose zymosan-induced arthritis model in rats

Calcipotriol, a vitamin D analogue, is an antiproliferative and anti-inflammatory drug currently used in psoriasis. Here, our aim was to analyse the safety of calcipotriol for cartilage and bone in alleviated-dose (0.1 mg instead of usual ≥1mg dose) zymosan-induced arthritis in rats. Theoretically, high doses of vitamin D or analogues could have detrimental effects on bone or cartilage. The rats were divided into four groups: vehicle (n = 9), dexamethasone 0.1 mg/kg (n = 9), calcipotriol 0.1 mg/kg (n = 8) and negative control (n = 10) with no injections. Arthritic rats were given phosphate-buffered saline (PBS) injections to left knees as a control. After euthanasia on day 8, all knees were imaged with micro-computed tomography for surface lesions and decalcified for histological analyses. Contrary to our expectations, no significant changes could be observed in the tomography data and histological scores among the three treatment groups or between the vehicle-treated and non-arthritic group. Calcipotriol did not cause adverse effects on cartilage or subchondral bone within a week, suggesting that it could be safely used in local treatment of arthritis. The alleviated model caused synovitis with local and systemic inflammatory response without cartilage erosions, which might be useful in studying self-limiting synovitis where cartilage or bone effects are not of primary interest.

1,25-Dihydroxyvitamin D Deficiency Accelerates Aging-related Osteoarthritis via Downregulation of Sirt1 in Mice

Emerging observational data suggest that vitamin D deficiency is associated with the onset and progression of knee osteoarthritis (OA). However, the relationship between vitamin D level and OA and the role of vitamin D supplementation in the prevention of knee OA are controversial. To address these issues, we analyzed the articular cartilage phenotype of 6- and 12-month-old wild-type and 1α(OH)ase^-/- mice and found that 1,25(OH)₂D deficiency accelerated the development of age-related spontaneous knee OA, including cartilage surface destruction, cartilage erosion, proteoglycan loss and cytopenia, increased OARSI score, collagen X and Mmp13 positive chondrocytes, and increased chondrocyte senescence with senescence-associated secretory phenotype (SASP). 1,25(OH)₂D₃ supplementation rescued all knee OA phenotypes of 1α(OH)ase^-/- mice in vivo, and 1,25(OH)₂D₃ rescued IL-1β-induced chondrocyte OA phenotypes in vitro, including decreased chondrocyte proliferation and cartilage matrix protein synthesis, and increased oxidative stress and cell senescence. We also demonstrated that VDR was expressed in mouse articular chondrocytes, and that VDR knockout mice exhibited knee OA phenotypes. Furthermore, we demonstrated that the down-regulation of Sirt1 in articular chondrocytes of 1α(OH)ase^-/- mice was corrected by supplementing 1,25(OH)₂D₃ or overexpression of Sirt1 in mesenchymal stem cells (MSCs) and 1,25(OH)₂D₃ up-regulated Sirt1 through VDR mediated transcription. Finally, we demonstrated that overexpression of Sirt1 in MSCs rescued knee OA phenotypes in 1α(OH)ase^-/- mice. Thus, we conclude that 1,25(OH)₂D_3, via VDR-mediated gene transcription, plays a key role in preventing the onset of aging-related knee OA in mouse models by up-regulating Sirt1, an aging-related gene that promotes articular chondrocyte proliferation and extracellular matrix protein synthesis, and inhibits senescence and SASP.

Therapeutic applications of adipose-derived stromal vascular fractions in osteoarthritis

Osteoarthritis (OA) is considered to be a highly heterogeneous disease with progressive cartilage loss, subchondral bone remodeling, and low-grade inflammation. It is one of the world's leading causes of disability. Most conventional clinical treatments for OA are palliative drugs, which cannot fundamentally cure this disease. The stromal vascular fraction (SVF) from adipose tissues is a heterogeneous cell population. According to previous studies, it contains a large number of mesenchymal stem cells, which have been used to treat OA with good therapeutic results. This safe, simple, and effective therapy is expected to be applied and promoted in the future. In this paper, the detailed pathogenesis, diagnosis, and current clinical treatments for OA are introduced. Then, clinical studies and the therapeutic mechanism of SVF for the treatment of OA are summarized.

Predictive nomogram of cage nonunion after anterior cervical discectomy and fusion: A retrospective study in a spine surgery center

The cage nonunion may cause serious consequences, including recurrent pain, radiculopathy, and kyphotic deformity. The risk factors for nonunion following anterior cervical discectomy and fusion (ACDF) are controversial. The aim of the study is to investigate the risk factors for nonunion in cervical spondylotic cases after ACDF. We enrolled 58 and 692 cases in the nonunion and union group respectively and followed up the cases at least 6 months. Patient demographic information, surgical details, cervical sagittal parameters, and the serum vitamin D level were collected. A logistic regression was performed to determine the independent predictors for nonunion, which were used for establishing a nomogram. In order to estimate the reliability and the net benefit of nomogram, we applied a receiver operating characteristic curve analysis, calibration curves and plotted decision curves. Using the multivariate logistic regression, we found that age (odds ratio [OR] = 1.16, P < .001), smoking (OR = 3.41, P = .001), angle of C2 to C7 (OR = 1.53, P < .001), number of operated levels (2 levels, OR = 0.42, P = .04; 3 levels, OR = 1.32, P = .54), and serum vitamin D (OR = 0.81, P < .001) were all significant predictors of nonunion (Table 3). The area under the curve of the model training cohort and validation cohort was 0.89 and 0.87, respectively. The calibration curves showed that the predicted outcome fitted well to the observed outcome in the training cohort (P = .102,) and validation cohort (P = .125). The decision curves showed the nomogram had more benefits than the All or None scheme if the threshold probability is >10% and <100% in training cohort and validation cohort. We found that age, smoking, angle of C2 to C7, number of operated levels, and serum vitamin D were all significant predictors of nonunion.

Vitamin D status is associated with inflammatory biomarkers and clinical symptoms in patients with knee osteoarthritis

BACKGROUND AND AIM

The association between vitamin D status and osteoarthritis (OA) and bone remodeling has been shown previously. The present study was conducted to determine the association between vitamin D status and inflammatory biomarkers and clinical symptoms in patients with knee OA.

METHODS

This case-control study was performed on 124 subjects with mild to moderate knee OA and 65 healthy controls. Demographic data was collected from all participants at baseline. We used Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC Index) for evaluating the severity of clinical symptoms in these patients. Serum levels of vitamin D as well as markers of inflammation including interleukin 1-β (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-alpha (TNF-α), high-sensitivity C-reactive protein (hs-CRP), and nuclear factor k-B (NF-κB) p65 were evaluated for each participant.

RESULTS

The results of the present study showed that patients with knee OA had lower levels of vitamin D and higher levels of IL-1β, TNF-α, hs-CRP, and NF-кB p65 compared with healthy controls (P < 0.0001). The levels of IL-1β, TNF-α, and NF-кB p65 in knee OA patients with vitamin D insufficiency were significantly higher compared with the knee OA patients with sufficient vitamin D (P < 0.05). Based on the linear regression analysis, serum vitamin D levels were inversely correlated with IL-1β, TNF-α, hs-CRP, and NF-кB p65 levels (P < 0.0001). Patients with sufficient vitamin D levels had lower total and physical function WOMAC scores compared with patients with vitamin D insufficiency (P = 0.011 and P = 0.010, respectively).

CONCLUSION

The results suggest a strong link between vitamin D deficiency and increased inflammatory biomarkers as well as increased severity of clinical symptoms in knee OA patients.

Epidemiology of osteoarthritis

OBJECTIVE

To summarize the current state of the evidence regarding osteoarthritis (OA) prevalence, incidence and risk factors at the person-level and joint-level.

DESIGN

This was a narrative review that took a comprehensive approach regarding inclusion of potential risk factors. The review complements prior reviews of OA epidemiology, with a focus on new research and emerging topics since 2017, as well as seminal studies.

RESULTS

Studies continue to illustrate the high prevalence of OA worldwide, with a greater burden among older individuals, women, some racial and ethnic groups, and individuals with lower socioeconomic status. Modifiable risk factors for OA with the strongest evidence are obesity and joint injury. Topics of high interest or emerging evidence for a potential association with OA risk or progression include specific vitamins and diets, high blood pressure, genetic factors, metformin use, bone mineral density, abnormal joint shape and malalignment, and lower muscle strength/quality. Studies also continue to highlight the heterogenous nature of OA, with strong interest in understanding and defining OA phenotypes.

CONCLUSIONS

OA is an increasingly prevalent condition with worldwide impacts on many health outcomes. The strong evidence for obesity and joint injury as OA risk factors calls for heightened efforts to mitigate these risks at clinical and public health levels. There is also a need for continued research regarding how potential person- and joint-level risk factors may interact to influence the development and progression of OA.

Vitamin D Receptor Gene Polymorphisms and Risk of Knee Osteoarthritis: Possible Correlations with TNF-α, Macrophage Migration Inhibitory Factor, and 25-Hydroxycholecalciferol Status

Osteoarthritis (OA) etiology and pathogenesis not yet fully understood. We studied the role of vitamin D receptor single-nucleotide polymorphisms (VDR-SNPs), vitamin D3, serum and synovial macrophage migration inhibitory factor (MIF), and tumor necrosis factor-α (TNF-α) in the development and progression of knee OA (KOA). This study included 205 Egyptian subjects (105 patients with KOA and 100 unrelated, healthy matched subjects selected as controls). The patient group was divided into three groups according to KOA severity (mild, moderate, and severe), with 35 patients in each group. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used for the ApaI and TaqI SNPs. Vitamin D, serum and synovial TNF-α, and MIF assays were performed using ELISA kits. There were significantly lower serum levels of 25-hydroxycholecalciferol with significant increasing TNF-α and MIF levels in relation to disease severity among the cases (all: p˂0.05).Wild homozygous and heterozygous mutant genotypes (GG+GT) and G allele of ApaI demonstrated risk for KOA development, with odds ratio OR = 6.313 (95% confidence interval (CI) 2.074-19.210) and OR = 1.532 (95%CI 1.013-2.317), respectively. Homozygous mutant CC genotype and C allele of TaqI could be considered a risk factor associated with KOA development, with OR = 2.667 (95%CI 1.270-5.601) and OR = 0.737 (95%CI 0.496-1.095), respectively. VDR-SNPs, vitamin D3, TNF-α, and MIF could play an essential role in the pathogenesis and progression of KOA with mechanistic associations.

The Development of Disease-Modifying Therapies for Osteoarthritis (DMOADs): The Evidence to Date

Osteoarthritis (OA) is a complex heterogeneous articular disease with multiple joint tissue involvement of varying severity and no regulatory-agency-approved disease-modifying drugs (DMOADs). In this review, we discuss the reasons necessitating the development of DMOADs for OA management, the classifications of clinical phenotypes or molecular/mechanistic endotypes from the viewpoint of targeted drug discovery, and then summarize the efficacy and safety profile of a range of targeted drugs in Phase 2 and 3 clinical trials directed to cartilage-driven, bone-driven, and inflammation-driven endotypes. Finally, we briefly put forward the reasons for failures in OA clinical trials and possible steps to overcome these barriers.

Nociception: the roles of vitamin D

Objective: to carry out a systematic computer-assisted analysis of scientific literature on on the relationships between the effects of vitamin and nociception (including the impact of vitamin D deficiency on the development of pain syndrome.

Material and methods. For the query “(pain OR nociception) AND (vitamin D OR cholecalciferol OR VITD OR CALCITRIOL OR HYDROXYVITAMIN OR DIHYDROXYVITAMIN OR ALPHACALCIDOL)", 2318 references, including 77 references on alpha-calcidol, were found in the biomedical publications database PubMed. The computer-assisted analysis of this array of publications was carried out using the current big data analysis methods developed within the topological and metric approaches to recognition/classification problems.

Result and discussion. A systematic computer-assisted text analysis of 2318 studies on the relationships between nociception and vitamin D showed that the analgesic effects of the vitamin are by anti-inflammatory action and the regulation of serotonergic, dopaminergic, and opioidergic neurotransmission. The lower blood levels of the major vitamin D metabolite 25 (OH)D is a risk factor for decreased pain threshold in myalgia, fibromyalgia, arthralgia, dorsalgia, and a number of neuralgias.

Conclusion. In patients with impaired renal conversion of active vitamin D metabolites (especially in the elderly), the efficacy of cholecalciferol-based drugs is reduced, which makes it necessary to use the active forms of vitamin D.

Association of vitamin D and knee osteoarthritis in younger individuals

BACKGROUND

The incidence of primary osteoarthritis knee is gradually increasing among young individuals. The increasing prevalence of obesity, sedentary lifestyle, sporting activity, and vitamin D deficiency (VDD) has been hypothesized for this shifting disease trend. This study was designed to look for the association of serum vitamin D among these young arthritic patients.

AIM

To look for the association of serum vitamin D in younger knee osteoarthritis (KOA) patients.

METHODS

In a 2-year observational study, 146 non-obese KOA patients of 35-60 years were evaluated clinically (Knee injury and Osteoarthritis Outcome Score, KOOS) and radiologically (Kellegren-Lawrence stage, KL). The serum 25(OH)D level of these patients and 146 normal healthy individuals of same age group were estimated.

RESULTS

Both the groups were comparable in terms of age and sex. The average serum 25(OH)D level in healthy individuals and KOA patients was 45.83 ng/mL and 34.58 ng/mL, respectively (P < 0.001). Inadequate serum 25(OH)D level (< 30 ng/mL) was found in 46.57% of KOA patients and 24% of normal healthy participants indicating a significant positive association (odds ratio 2.77, 95%CI: 1.67-4.54, P < 0.001). The 25(OH)D level in KL grade I, II, III and IV was 43.40, 30.59, 31.56 and 33.93 ng/mL respectively (no difference, P = 0.47). Similarly, the KOOS score in sufficient, insufficient and deficient groups were 65.31, 60.36 and 65.31, respectively (no difference, P = 0.051).

CONCLUSION

The serum 25(OH)D level is significantly low in younger KOA patients. However, the clinical and radiological severities have no association with serum vitamin D level.

Future of Chondroprotectors in the Treatment of Degenerative Processes of Connective Tissue

Osteoarthritis is one of the most common diseases of the connective tissue of the elderly. It was found that most epidemiological studies used the Kellgren and Lawrence system for classification of osteoarthritis, which indicates one of the 5 degrees (0-4) of osteoarthritis in various joints according to the radiographic atlas. It has been proven that chondroprotectors are represented by the following active substances: chondroitin sulfate, glucosamine sulfate or hydrochloride, hyaluronic acid, glycosaminoglycans, extraction preparations from animal or plant raw materials. The sources of raw materials for the manufacture of combined chondroprotectors are known, methods for their preparation and use are described. The main drugs on the chondroprotective market are presented. The effectiveness of their use for the treatment of osteoarthritis has been proven. It was found that preparations containing chondroitin sulfate have anti-inflammatory activity, affecting mainly the cellular component of inflammation, stimulate the synthesis of hyaluronic acid and proteoglycans. Methods of treating osteoarthritis using cell therapy (the use of readily available, highly proliferative, and multipotent mesenchymal stromal cells) are presented.

Alternative and complementary therapies in osteoarthritis and cartilage repair

Osteoarthritis (OA) is the most common joint condition and, with a burgeoning ageing population, is due to increase in prevalence. Beyond conventional medical and surgical interventions, there are an increasing number of ‘alternative’ therapies. These alternative therapies may have a limited evidence base and, for this reason, are often only afforded brief reference (or completely excluded) from current OA guidelines. Thus, the aim of this review was to synthesize the current evidence regarding autologous chondrocyte implantation (ACI), mesenchymal stem cell (MSC) therapy, platelet-rich plasma (PRP), vitamin D and other alternative therapies. The majority of studies were in knee OA or chondral defects. Matrix-assisted ACI has demonstrated exceedingly limited, symptomatic improvements in the treatment of cartilage defects of the knee and is not supported for the treatment of knee OA. There is some evidence to suggest symptomatic improvement with MSC injection in knee OA, with the suggestion of minimal structural improvement demonstrated on MRI and there are positive signals that PRP may also lead to symptomatic improvement, though variation in preparation makes inter-study comparison difficult. There is variability in findings with vitamin D supplementation in OA, and the only recommendation which can be made, at this time, is for replacement when vitamin D is deplete. Other alternative therapies reviewed have some evidence (though from small, poor-quality studies) to support improvement in symptoms and again there is often a wide variation in dosage and regimens. For all these therapeutic modalities, although controlled studies have been undertaken to evaluate effectiveness in OA, these have often been of small size, limited statistical power, uncertain blindness and using various methodologies. These deficiencies must leave the question as to whether they have been validated as effective therapies in OA (or chondral defects). The conclusions of this review are that all alternative interventions definitely require clinical trials with robust methodology, to assess their efficacy and safety in the treatment of OA beyond contextual and placebo effects.

Therapeutic and Preventive Potential of Vitamin D Supplementation in Knee Osteoarthritis

Objective

Vitamin D deficiency is linked with pain, function, and radiographic progression of knee osteoarthritis (KOA), but the results of studies addressing the association and effect of vitamin D supplementation for pain, function, quality of life, radiographic disease, and progression are inconsistent. The aim of this review is to determine the therapeutic and preventive potential of vitamin D supplementation in KOA.

Method

Eligible pertinent English language studies published in 2000 and thereafter in Medline/PubMed, Scopus, and Google Scholar were selected by using keywords that include “knee osteoarthritis,” “vitamin D supplementation,” “pain,” “structural abnormalities,” “treatment,” and “progression.”

Results

The results of a few studies showed a preventive potential for vitamin D in KOA, but most of the randomized clinical trials that assessed the therapeutic efficacy of vitamin D supplementation in KOA found no clear therapeutic effect, with the exception of one study that found a small but significant effect of vitamin D on pain and knee function. Nonetheless, the results of a few longitudinal studies as well as systematic reviews are promising and thus encourage further studies. Inconsistent results on the effect of vitamin D on KOA may be attributed to factors such as severity of KOA, baseline level of serum vitamin D, duration of treatment, and vitamin D dosages.

Conclusion

Given the multiple skeletal and extraskeletal benefits of vitamin D supplementation in elderly people, the issue of vitamin D supplementation in KOA requires further study to elucidate the dosage and duration of treatment that provides the most effective therapeutic effect.