Platelet-rich plasma versus hyaluronic acid in the treatment of knee osteoarthritis: a meta-analysis

Efficacy of multiple autologous apheresis platelet-rich plasma injections for treating knee osteoarthritis and its influencing factors: a retrospective cohort study

BACKGROUND

The lack of standardized Platelet-Rich Plasma (PRP) protocols for Knee Osteoarthritis (KOA), combined with significant patient variability, leads to inconsistent PRP effectiveness across studies. This study aims to assess the influence of PRP injection frequencies on KOA treatment and explore the role of patient characteristics and PRP properties in the treatment's effectiveness.

METHODS

A retrospective cohort study was conducted with KOA patients who received three PRP injections (4-week intervals) at a hospital in Chongqing. The Wilcoxon signed-rank test was used to analyze differences in self-reported recovery rates across different treatment time points, with Bonferroni correction applied for significance level adjustment (α). The Mann-Whitney U test, Kruskal-Wallis H test, Spearman correlation analysis, and restricted cubic spline models were used to assess the associations between sex, baseline Kellgren-Lawrence grade, age, PRP red blood cell (RBC) concentration, PRP white blood cell (WBC) concentration, PRP platelet concentration, the multiple of PRP platelet concentration relative to the baseline autologous level (Enrichment-PLT), and self-reported recovery rates.

RESULTS

The study included 28 KOA patients. Significant improvement in self-reported recovery rate was observed 4 weeks after the first treatment (median: 30.0%, P < 0.008) and after the second treatment (median: 45.0%, P < 0.008). However, no significant change was noted 4 weeks after the third treatment (median: 55.0%, P = 0.058), and recovery rates at 8, 12, and 24 weeks post-third treatment showed no significant differences compared to 4 weeks (all P > 0.008). Additionally, no correlations were found between sex, baseline Kellgren-Lawrence grade, age, PRP RBC concentration, PRP WBC concentration, PRP platelet concentration, or Enrichment-PLT and self-reported recovery rates.

CONCLUSION

At least two PRP injections are recommended, with effects lasting for at least 24 weeks. Factors such as sex, age, baseline Kellgren-Lawrence grade, and PRP properties (prepared by apheresis) do not significantly affect treatment outcomes.

Sodium hyaluronate and acupotomy bone decompression alleviates inflammatory responses in patients with knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (KOA), predominantly affecting middle-aged and elderly populations, induces localized joint pain and functional impairment. It was to evaluate the effectiveness of acupotomy bone decompression (ABD) combined with sodium hyaluronate (SH) intra-articular injection on inflammatory responses in treating KOA.

METHODS

Clinical data from 128 patients with KOA were retrospectively collected, categorized into SH group (n = 55) and ABD + SH group (n = 73). Pain was assessed using the visual analogue scale (VAS), knee joint function was evaluated, and knee joint balance and gait parameters were measured. The status of articular cartilage and bone marrow edema was evaluated using quantitative magnetic resonance imaging (MRI). Interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-3, MMP-9, and hypersensitive C-reactive protein (hs-CRP) were detected.

RESULTS

ABD + SH group showed drastic reductions in VAS scores, decreased indices of different axial balances, and increased stride length and walking speed versus the SH group (P < 0.05). Quantitative MRI examination revealed that relative to the SH group, ABD + SH group exhibited increased thickness of articular cartilage and reduced area of bone marrow edema post-treatment (P < 0.05). Post-treatment levels of hs-CRP, IL-6, IL-1β, TNF-α, MMP-3, and MMP-9 were markedly lower in the ABD + SH group versus SH group (P < 0.05). Moreover, the clinical effective rate in the ABD + SH group was drastically superior to the SH group (95.9% vs. 78.2%, P < 0.05).

CONCLUSION

Combining ABD with SH treatment for KOA effectively alleviates patient pain and inflammatory responses.

The efficacy and safety of intra-articular platelet-rich plasma versus sodium hyaluronate for the treatment of osteoarthritis: Meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is a common degenerative joint disease that primarily affects the elderly individuals. Traditional treatments include medications and physical therapy, but recent attention has turned to platelet-rich plasma (PRP) and hyaluronic acid (HA) injection therapies.

OBJECTIVE

This meta-analysis aimed to evaluate the efficacy and safety of PRP combined with HA versus PRP alone in the treatment of KOA.

METHODS

We conducted a comprehensive literature search of the PubMed, Embase, and Cochrane Library databases, which included covering publications from their inception to July 2024. Studies comparing PRP+HA with PRP alone were selected. Data on visual analog scale (VAS) scores, WOMAC total scores, Lequesne scores, and adverse events were extracted. Statistical analysis was performed via Review Manager 5.3.5.

RESULT

This meta-analysis included 16 studies involving a total of 1,384 patients. The VAS score comparison indicated that, in the long term, PRP combined with HA was more effective in reducing knee pain than PRP alone was (SMD: -0.30, 95% CI: -0.53 to -0.06, P =  0.01). The combined PRP and HA treatment achieved better results in terms of the WOMAC total score (MD =  -6.58, 95% CI: -10.65 to -2.52, P <  0.001). At the 6-month follow-up, the Lequesne index score comparison revealed that PRP combined with HA significantly improved knee pain scores compared with PRP alone (MD =  -1.38, 95% CI: -1.91 to -0.86, P <  0.001). In terms of adverse events, PRP+HA was associated with a lower risk of adverse events than PRP alone was (OR =  0.54, 95% CI: 0.33 to 0.85, P =  0.009).

CONCLUSION

PRP combined with HA offers significant long-term benefits in pain relief and functional improvement over PRP alone for knee osteoarthritis, with better safety. The sequence of injection may influence treatment outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024598691.

Corticosteroids, hyaluronic acid, platelet-rich plasma, and cell-based therapies for knee osteoarthritis - literature trends are shifting in the injectable treatments' evidence: a systematic review and expert opinion

INTRODUCTION

The aim of this systematic review was to quantify the data available on corticosteroids (CS), hyaluronic acid, (HA), platelet-rich plasma (PRP), and cell-based therapies for knee osteoarthritis (OA) treatment.

METHODS

A literature search was conducted on PubMed, Cochrane, WebofScience according to the PRISMA guidelines. Inclusion criteria: clinical studies of any level of evidence, written in English, evaluating the intra-articular use of CS, HA, PRP, or cell-based therapies for knee OA treatment.

RESULTS

The initial search identified 17,415 records. A total of 766 studies from 1959 were included. Of these, 401 were randomized controlled trials, 110 comparative studies, and 255 case series, for a total of 75,834 patients. (11,245 treated with CS 40,862 with HA 16,174 with PRP, 7,553 with cell-based therapies).

CONCLUSIONS

The evidence on injective knee OA treatments is increasing at different speeds with a more rapidly growing literature focusing on orthobiologics. Currently, HA has the largest evidence, followed by PRP that recently surpassed the number of studies evaluating CS. Cell-based therapies are also growing rapidly, although the number of studies is still lower. The rapid literature shift toward orthobiologics urges an update in societies' guidelines to align with the new body of evidence on knee OA treatments.

PROTOCOL REGISTRATION

www.crd.york.ac.uk/prospero identifier is CRD42024592972.

A Greater Platelet Dose May Yield Better Clinical Outcomes for Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review

PURPOSE

To determine whether the platelet dose administered during a platelet-rich plasma (PRP) injection for knee osteoarthritis (OA) affects clinical outcomes.

METHODS

A systematic review was performed by searching PubMed, Cochrane Library, and Embase for randomized controlled trials with at least 1 study arm using PRP for knee OA. Only studies that provided a platelet count, concentration, or dose with a minimum of 6-month outcome scores were included. Studies in which the PRP group had statistically significant positive outcomes were separated from those without statistical significance. The average platelet doses for studies with positive outcomes in the PRP group were compared with those without positive outcomes.

RESULTS

After exclusion criteria were applied, 29 studies were analyzed. Of the 29, there were 31 arms that used PRP as a treatment method, of which 28 had statistically significant positive outcomes at 6 months compared with the control group. The mean platelet dose in the 28 with a positive outcome was 5,500 ± 474 × 106, whereas the 3 that had no positive difference had a mean platelet dose of 2,302 ± 437 × 106 (P < .01). There were 18 studies with 12-month outcomes, with 16 of 18 having positive outcomes. The positive studies had an average platelet dose of 5,464 ± 511, whereas the studies that had no statistical difference had an average platelet dose of 2,253 ± 753 × 106 (P < .05).

CONCLUSIONS

Improved clinical outcomes from PRP injections for knee OA may be related to a greater platelet dose.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Efficacy and Safety of Intra-Articular Therapy with Cross-Linked Hyaluronic Acid in Patients with Knee Osteoarthritis

Background/Objectives: Knee osteoarthritis (OA) is a degenerative chronic disease characterized by a reduction in articular cartilage, as well as pain and functional limitations. We evaluated both the efficacy and safety of cross-linked high-molecular-weight hyaluronic acid in patients with knee OA. Methods: In this observational prospective single-arm study, a cross-linked high-molecular-weight hyaluronic acid (DIART ONE 90 mg in 3 mL) was administered in single injections to 50 patients aged 18-65 years, with a follow-up at 3, 6, and 12 months. Several scores were evaluated, including the Knee Injury and Osteoarthritis Outcome Score as the primary outcome measure and the Visual Analogue Scale, Timed Up and Go Test, Six-Minute Walking Test, General Health Assessment with 36-Item Short Form Health Survey, Zung's Self-Rating Anxiety Scale, and Zung's Self-Rating Depression Scale as secondary outcome measures. Both physicians and patients knew the kind of treatment they received. Results: During the follow-ups, we observed a statistically significant improvement in clinical scores at 3 and 6 months, with a decrease in clinical benefit at 12 months. Functional and psychological benefits were significant at 3, 6, and 12 months. No side effects were described except pain associated with the site of injection. Conclusions: In conclusion, we documented that cross-linked high-molecular-weight hyaluronic acid (DIART ONE 90 mg in 3 mL) represents an effective option in the management of mild-moderate osteoarthritis.

Intra-Articular Hyaluronic Acid for Knee Osteoarthritis: A Systematic Umbrella Review

Objective: to evaluate the efficacy, safety, and cost-effectiveness of intra-articular hyaluronic acid (IAHA) in treating osteoarthritis (OA), considering innovations in formulations, comparative outcomes, and variability in guidelines. This review aims to synthesize evidence supporting the role of IAHA in multimodal treatment strategies. Materials and Methods: A general, narrative, umbrella review of systematic reviews and meta-analyses was conducted. Clinical practice recommendations and guidelines for IAHA use were also reviewed and evaluated. A comprehensive search was conducted across the main medical data sources. Inclusion criteria focused on studies evaluating the efficacy, safety, and impact of IAHA. Key outcomes included pain reduction (e.g., WOMAC, VAS), functional improvement, safety, and cost-effectiveness. Results: IAHA showed moderate efficacy in pain relief and functional improvement, especially in early-to-moderate OA. The results indicate that hybrid formulations and combination therapies show better clinical outcomes, with expanded efficacy and potential chondroprotection. However, heterogeneity between studies was noted, reflecting variability in patient populations and intervention protocols. International guidelines varied significantly, with some opposing routine use (e.g., AAOS, NICE) and others endorsing IAHA more or less conditionally (e.g., ESCEO, OARSI). Conclusions: IAHA remains a treatment modality in the arsenal of selected populations of people with OA, especially for early and moderate disease. High-quality, standardized studies are still needed to refine IAHA's role and establish personalized guidelines for individual patients. A concerted effort to harmonize global recommendations and economic strategies, such as tiered pricing, can increase equitable access and optimize IAHA's integration of multimodal treatment for OA.

Clinical efficacy of cell-free fat extract and its effects on bone marrow edema in patients with early to mid-stage knee osteoarthritis: a clinical trial in comparison with hyaluronic acid

BACKGROUND

Previous studies have shown that hyaluronic acid can delay the progression of knee osteoarthritis. Existing research has extracted a bright red fluid called cell-free fat extract from human adipose tissue, which may play an important role in delaying the progression of osteoarthritis. By comparing with intra-articular injection of hyaluronic acid, this study aimed to evaluate the effects of intra-articular injection of CEFFE on both clinical efficacy and the reduction of bone marrow edema in patients with early to mid-stage knee osteoarthritis.

METHODS

A total of 48 patients with KOA (Kellgren-Lawrence grade II-III) symptoms were randomly divided into CEFFE group (24 cases) and HA group (24 cases). The patients in the CEFFE group received five injections of CEFFE (2 ml, 1 time/week), and the patients in the HA group received five injections of HA (2 ml, 1 ml/10 mg, 1 time/week). All the patients underwent clinical assessments using rating scales, including VAS, WOMAC and Lysholm Knee Score. These assessments were conducted at pre-treatment and at 3-week, 6-week, 3-month, and 6-month follow-up timepoints post-treatment. The clinical efficacy was evaluated at the 6-month follow-up after the treatment. The changes in subchondral bone marrow edema before and 6 months after treatment were assessed by grading BME on MRI of the affected knees.

RESULTS

A total of 52 knees from 46 patients were included in the final analysis. Comparison of VAS score, WOMAC score, and Lysholm score between the two groups revealed that the differences between pre-treatment and 3 weeks post-treatment were not statistically significant (P > 0.05). For the VAS score and WOMAC score at 6 weeks, 3 months, and 6 months post-treatment, the CEFFE group was lower than the HA group (P < 0.05). For the Lysholm score, the CEFFE group was higher than the HA group (P < 0.05). Compared with pre-treatment, VAS scores and WOMAC scores were lower and Lysholm scores were higher at all post-treatment time points (P < 0.05). At 6 months post-treatment, the clinical efficacy of the CEFFE group was significantly better than that of the HA group (P < 0.05). At 6 months post-treatment, MRI grading showed that subchondral BME was reduced to different degrees in both groups, with the reduction being more pronounced in the CEFFE group (P < 0.05).

CONCLUSION

This study demonstrated that intra-articular injection of CEFFE into the knee joint could enhance the durability of tissue-specific cells (especially chondrocytes) and improve cellular metabolic processes, preventing the continued progression of osteoarthritis. Both CEFFE and HA were found to improve clinical symptoms and reduced subchondral bone marrow edema in the treatment of early to mid-stage knee osteoarthritis. However, CEFFE was more effective than HA in achieving these outcomes.

A critical overview of systematic reviews and meta-analyses of intra-articular injection of platelet rich plasma versus hyaluronic acid for knee osteoarthritis

This study is to summarize and evaluate the available evidence for the efficacy of platelet-rich plasma (PRP) and hyaluronic acid (HA) for knee osteoarthritis (KOA). Eight databases were searched from inception to September 15, 2024. All systematic reviews (SRs)/meta-analyses (MAs) treated with PRP versus HA for KOA were collected. Literature screening and data extraction were independently performed by two reviewers. The methodological quality, reporting quality, risk of bias, evidence quality, and evidence overlap rate of the included studies were evaluated by using AMSTAR 2, PRISMA 2020, ROBIS, GRADE, and GROOVE systems. Seventeen SRs were included. The results showed that the effectiveness and safety of PRP in the treatment of KOA may be superior to HA. The methodological quality of all 17 documents was extremely low quality. Sixteen of them had poor reporting quality, and there were relatively serious information deficiencies. All SRs were determined to be at high risk. Among the 221 outcome indicators, there were two medium-quality evidences, 30 low-quality evidences, and 189 extremely low-quality evidences. It was found that there was a very high overlap among the included articles. Currently, the quality of SRs on the treatment of KOA with PRP versus HA is relatively low. Future authors of SRs should adhere to quality assessment tool criteria, expand sample sizes to reduce overlap, and evaluate the quality of evidence for merged study results, in order to provide more reliable and rigorous evidence-based support for clinical practice.

Management of knee osteoarthritis using bone marrow aspirate concentrate: a systematic review

INTRODUCTION

Knee osteoarthritis (OA) is a common degenerative joint condition and a major cause of disability in the general population.

SOURCE OF DATA

Recent published literature identified from PubMed, EMBASE, Google Scholar, and Scopus.

AREAS OF AGREEMENT

Orthobiological therapies try to regenerate articular cartilage and stop the progression of the degenerative lesion. Intra-articular injections of biological derivates have been increasingly used in the last decade.

AREAS OF CONTROVERSY

The indications for the use of bone marrow aspirate concentrate (BMAC) are still unclear.

GROWING POINTS

We systematically reviewed the current literature on BMAC in the management of knee OA, giving an update on the current indications for the selection of the ideal patient and the preparations and efficacy of BMAC compared to other biological alternatives.

AREAS TIMELY FOR DEVELOPING RESEARCH

BMAC is a valuable source of mesenchymal stem cells, offering potential benefits in attenuating the inflammatory pathway associated with knee OA. Intra-articular injection of BMAC has shown effectiveness in clinical trials improving functional outcomes of knee OA patients. The superiority of BMAC over other orthobiological treatments cannot be assessed because of conflicting results.

Addressing Knee Osteoarthritis Pathology Through Platelet-Rich Plasma Treatment: A Comprehensive Review

Platelet-rich plasma (PRP) is gaining popularity across various medical fields, including orthopedics, for its potential in tissue regeneration and wound healing. As intra-articular treatments evolve, PRP has emerged as a promising option for managing knee osteoarthritis, meniscus, and ligament injuries. This review aims to provide an update on the current applications of PRP in treating knee osteoarthritis and its clinical implications in orthopedic and sports medicine. We reviewed 180 eligible studies, and our findings suggest that PRP injections significantly improve knee joint function compared to alternative treatments. The use of PRP across various medical fields has been growing in popularity recently. PRP is a biological product derived from the plasma portion of a patient's own blood, containing a higher concentration of platelets than normal. Its potential for tissue regeneration and wound healing has drawn significant attention from orthopedic surgeons, especially as intra-articular treatment options continue to evolve. The benefits of PRP in treating various osteoarticular conditions have sparked considerable interest within the orthopedic community, particularly for managing knee osteoarthritis, meniscus tears, and ligament injuries. This review aims to provide an updated overview of the current applications of PRP in the treatment of knee osteoarthritis and to offer clinical insights into its use in orthopedic and sports medicine practices. We reviewed 180 relevant titles and abstracts that met the inclusion criteria. Compared to other treatment options, PRP injections significantly enhance knee joint function.

Gold-Induced Cytokine (GOLDIC) for the Management of Knee Osteoarthritis: A Systematic Review

Gold-induced cytokine (GOLDIC) is a novel orthobiologic approach utilizing gold particles to produce a serum rich in immunoregulating cytokines and growth factors, which is being explored for its potential in tissue regeneration and treating musculoskeletal issues like knee osteoarthritis (OA). This study aims to review its mechanism of action along with the outcomes of in vitro, preclinical, and clinical studies, with a secondary focus on documenting clinical trials related to its use in OA of the knee. A systematic search was conducted in four databases (Embase, Scopus, PubMed, Web of Science) for studies on GOLDIC therapy for knee OA, using specific keywords related to knee anatomy and OA. In vitro studies demonstrated that gold-containing compounds reduce nitric oxide production in chondrocytes, mitigating catabolic processes. Pre-clinical trials in horses with lameness showed significant symptom improvement. Clinical studies reported substantial improvements in pain, function, and joint homeostasis, with reduced synovial effusion and cytokine modulation following GOLDIC therapy. GOLDIC therapy, in addition to orthopedic indications such as for the management of OA of the knee, has also been investigated in non-orthopedic settings with early promising results. However, more research is needed to fully understand its mechanism of action and establish its clinical utility.

Leukocytes Do Not Influence the Safety and Efficacy of Platelet-Rich Plasma Injections for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Controlled Trial

BACKGROUND

Platelet-rich plasma (PRP) is increasingly used for the injection treatment of knee osteoarthritis (OA). However, the role of leukocytes contained in PRP is controversial, with some preclinical studies suggesting detrimental effects and others emphasizing their contribution in secreting bioactive molecules.

PURPOSE

To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.

HYPOTHESIS

That leukocytes could influence results both in terms of adverse events and clinical outcomes.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This double-blind randomized controlled trial included 132 patients with Kellgren-Lawrence grade 1-3 knee OA who were randomized to a 3-injection cycle of either LR-PRP or LP-PRP. Patients were prospectively assessed at baseline and at 2, 6, and 12 months with subjective evaluations comprising the International Knee Documentation Committee (IKDC) subjective score, the KOOS (Knee injury and Osteoarthritis Outcome Score), the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), the visual analog scale for pain, the EuroQol-visual analog scale, the EuroQol-5 dimensions, and the Tegner activity scale. Objective evaluations consisted of the IKDC objective score, active/passive range of motion, and circumference of the index and contralateral knees. Patient judgment of the treatment was recorded as well as adverse reactions and failures.

RESULTS

An overall improvement in subjective and objective outcomes was documented, with no differences between the 2 groups, except for the improvement in the IKDC subjective score at 2 months, which was greater for the LR-PRP group compared with the LP-PRP group (14.8 ± 14.8 vs 8.6 ± 13.3, respectively; P = .046), as well as for active (P = .021) and passive (P = .040) ROM of the index knee at 6 months, showing statistically significant higher values in the LP-PRP group; and for quadriceps circumference of the index (P = .042) and contralateral (P = .045) knees at 12 months, which were significantly greater in the LR-PRP group. The IKDC subjective score improved from 42.5 ± 17.6 at baseline to 55.6 ± 21.4 at 12 months for the LR-PRP group (P < .0005) and from 45.7 ± 16.4 to 55.3 ± 20.4 for the LP-PRP group (P = .001). No differences in terms of patient treatment judgment were observed at all follow-up time points. No severe adverse events related to the treatment were reported, but some mild adverse events related to the treatment were observed: 16 in the LR-PRP group and 17 in the LP-PRP group. Treatment failed in 5 patients in the LR-PRP group and 2 in the LP-PRP group.

CONCLUSION

This double-blind randomized controlled trial demonstrated that leukocytes did not affect the safety and efficacy of intra-articular PRP injections for the treatment of patients with knee OA. Both LR-PRP and LP-PRP demonstrated comparable clinical outcomes at all follow-up time points, without showing differences in subjective and objective outcomes or in adverse events and treatment failures.

REGISTRATION

NCT04187183 (ClinicalTrials.gov).

Evaluating the Efficacy of Platelet-Rich Plasma in Treating Primary Knee Osteoarthritis: A Prospective Interventional Study

INTRODUCTION

Knee osteoarthritis (OA) is a prevalent degenerative joint disorder causing pain, stiffness, and reduced function, significantly impacting the quality of life. Current treatments mainly provide symptomatic relief, with limited efficacy in halting disease progression. Platelet-rich plasma (PRP), a biological therapy rich in growth factors, has gained attention as a potential treatment for knee OA due to its regenerative properties. This study evaluates the efficacy of PRP in managing primary knee OA.

METHODOLOGY

This prospective interventional study included 100 patients diagnosed with primary knee OA, categorized using the Kellgren-Lawrence grading scale. Leukocyte-reduced PRP was prepared using the double-spin method and injected into the knee joint. The efficacy of PRP was assessed using the Western Ontario and McMaster Universities Arthritis (WOMAC) Index and Visual Analogue Scale (VAS) pain scores at six weeks, three months, and six months post-injection. Statistical analysis was performed using SPSS version 25.0, with significance set at p<0.05.

RESULTS

Significant improvements in the WOMAC and VAS scores were observed at all-time points post-PRP injection. The WOMAC score decreased from a baseline of 81.06 to 63.52 at six months (p < 0.001), and the VAS score reduced from 7.53 to 3.09 (p < 0.001). PRP was more effective in patients with lower body mass index (BMI) and less severe OA (Grades 1 and 2). Adverse events were mild, with 18% reporting mild pain or swelling.

CONCLUSION

PRP therapy significantly improves pain and function in patients with primary knee OA, particularly in early-stage disease. The treatment is generally safe, with minor adverse effects. PRP presents a promising non-surgical option, especially for those seeking to delay or avoid knee arthroplasty.

Infiltration therapy in the context of cartilage surgery

Guideline-based surgical cartilage therapy for focal cartilage damage offers highly effective possibilities to sustainably reduce patients' complaints and to prevent or at least delay the development of early osteoarthritis. In the knee joint, it has the potential to reduce almost a quarter of the arthroses requiring joint replacement caused by cartilage damage. Biologically effective injection therapies could further improve these results. Based on the currently available literature and preclinical studies, intra- and postoperative injectables may have a positive effect of platelet-rich plasma/fibrin (PRP/PRF) and hyaluronic acid (HA) on cartilage regeneration and, in the case of HA injections, also on the clinical outcome can be assumed. The role of a combination therapy with use of intra-articular corticosteroids is lacking in the absence of adequate study data and cannot be defined yet. With regard to adipose tissue-based cell therapy, the current scientific data do not yet justify any recommendation for its use. Further studies also regarding application intervals, timing and differences in different joints are required.

Effects of Photobiomodulation Associated with Platelet-Rich Plasma in Acute Rheumatoid Arthritis Induced in Female Wistar Rats' Knee

Objective: Rheumatoid arthritis causes inflammation, pain, and joint degradation, necessitating treatment with anti-inflammatory drugs and corticosteroids, posing various challenges. We aimed to evaluate the effects of photobiomodulation (PBM) at two different doses associated to platelet-rich plasma (PRP) in an in vivo model of induced acute arthritis in Wistar rats' knee. Methods: Eighty-four Wistar rats were assigned into seven groups, including animals treated with PBM and/or PRP. On day 0, arthritis was induced in sham and treated groups through the intra-articular injection of zymosan (200 μg). Twenty-four hours after induction, the PBM groups were treated with an AsGaAl laser, whereas the PRP-treated groups received intra-articular injections with a concentration of 8 × 105 platelets obtained from another four animals. After 3 days, the animals were euthanized, and the interleukin (IL)-6 and complement C3 gene and protein expression levels were analyzed. Statistical analysis was performed using the mean ± SD with analysis of variance and Tukey's posttest, with a significance level set at 5% (p < 0.05). Results: Synovial inflammation decreased in PBM-treated groups; however, PRP alone showed no significant difference. Gene expression analysis revealed a significant difference in IL-6 and C3 levels in the PBM and PBM+PRP-treated groups. Meanwhile, the PRP alone group exhibited significance for IL-6. Moreover, the PBM and PBM+PRP-treated groups showed a significant difference in C3 protein expression levels, whereas the PRP alone group showed no difference. Conclusion: The increase in cellular activity in the synovial membrane and the decrease protein expression levels are owing to the reduction in proinflammatory mediators following PBM therapy.

Platelet lysate for the treatment of osteoarthritis: a systematic review of preclinical and clinical studies

Intra-articular injection-based therapy is often used aside conservative treatment and lifestyle modifications to manage knee osteoarthritis (KO) patients. Conventional injections contain steroids and hyaluronic acid, while more recently multipotential adult stem cell, platelet-rich plasma (PRP), and platelet lysate (PL) injections have been used to promote cartilage regeneration or repair. The aim of the current study is to analyse current evidence on PL injections for the treatment of KO and to determine if these are effective and how these perform compared to other injection regimens. The databases of Scopus, Embase, PubMed, Web of Science, and Cochrane Library were searched on 30 June 2023. Risk of bias was assessed using the SYRCLE tool for animal studies and Cochrane RoB 2 as well as ROBINS-I tool for human studies. Studies were included if these were in English, any year, and regarded animals with osteoarthritis (OA) or human adult patients with OA. In vitro trials and non-adult human studies were excluded. Results on OA symptom stage and severity, and pain were recorded. The research retrieved three human studies (n = 48, n = 25, n = 58) and four animal studies: one rabbit, two studies, and one rat study. PL was found to decrease KO symptoms at follow-up ≤ 1 year with respect to baseline levels and when compared to hyaluronic acid or platelet-rich plasma. Symptoms returned 6 months-1 year after the final administration, with studies showing peak efficacy at approximately 6 months. Animal studies showed clinical improvements, reduction of lameness, and partial effect on the cartilage regeneration of the seven studies, two had a high risk of bias, four were associated to some concerns, and one had low risk. A major source of bias in these studies was the use of questionnaires and scoring that could be subject to interpretation. Overall, PL was well-tolerated and showed efficacy comparable to PRP; when pain control was assessed, it showed similar efficacy compared to hyaluronic acid. These findings may support its use in clinical trials to confirm these initial findings; future research should also focus on the comparison with other non-surgical treatments, on a more detail of the potential regenerative properties, and to optimise the treatment schedule.

Mechanisms and applications of the regenerative capacity of platelets-based therapy in knee osteoarthritis

Osteoarthritis (OA) is the most prevalent joint disease in the elderly population and its substantial morbidity and disability impose a heavy economic burden on patients and society. Knee osteoarthritis (KOA) is the most common subtype of OA, which is characterized by damage to progressive articular cartilage, synovitis, and subchondral bone sclerosis. Most current treatments for OA are palliative, primarily aim at symptom management, and do not prevent the progression of the disease or restore degraded cartilage. The activation of α-granules in platelets releases various growth factors that are involved in multiple stages of tissue repair, suggesting potential for disease modification. In recent years, platelet-based therapies, such as platelet-rich plasma, platelet-rich fibrin, and platelet lysates, have emerged as promising regenerative treatments for KOA, but their related effects and mechanisms are still unclear. Therefore, this review aims to summarize the biological characteristics and functions of platelets, classify the products of platelet-based therapy and related preparation methods. Moreover, we summarize the basic research of platelet-based regeneration strategies for KOA and discuss the cellular effects and molecular mechanisms. Further, we describe the general clinical application of platelet-based therapy in the treatment of KOA and the results of the meta-analysis of randomized controlled trials.

Efficacy of Platelet-Rich Plasma Intra-articular Injections in Hip and Knee Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative disorder that causes significant pain and functional limitations. Platelet-rich plasma (PRP) therapy has gained considerable attention in recent years in the treatment of musculoskeletal injuries. In this narrative review, we aim to investigate the role of intra-articular PRP injections in the treatment of knee and hip OA. The review also discusses different classifications of PRP based on composition. Furthermore, this narrative review also identified various limitations of PRP therapy in OA. PRP is classified into different types based on cell content and fibrin architecture, including pure platelet-rich plasma (P-PRP), leukocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and leukocyte- and platelet-rich fibrin (L-PRF). Various clinical trials have shown that PRP is an effective option for the treatment of knee and hip OA. However, the superiority of PRP over hyaluronic acid has been reported inconsistently. This variability can be attributed to PRP preparation techniques. The safety profiles of PRP are generally favorable and the adverse effects are generally mild in nature. Although there is sufficient evidence in support of PRP in the treatment of OA, the long-term effects of PRP have not been reported. Further studies should focus on longer follow-up periods to identify the efficacy and safety of PRP in treating knee OA. There is also a need for standardization of PRP preparations in OA management.

Platelet-Rich Plasma in Pediatric Surgery: A Comprehensive Review

Platelet-Rich Plasma (PRP) therapy has become a promising treatment option in pediatric surgery, offering a novel approach to tissue repair and regeneration. Obtained from the patient's own blood or umbilical cord blood (CB), PRP is a concentrated form of plasma enriched with platelets, growth factors, and cytokines essential for stimulating tissue healing. This systematic review explores the applications of PRP therapy in pediatric surgical procedures, focusing on its role in promoting wound healing, reducing postoperative complications, and enhancing patient outcomes. A systematic literature overview was conducted in accordance with PRISMA guidelines, encompassing studies published between 2004 and 2024. The research has identified different fields of application for PRP therapy in pediatric surgery, including treatment of pilonidal sinus and hypospadias repair. Key findings from clinical studies and randomized controlled trials are summarized, highlighting the efficacy of PRP therapy in accelerating wound healing, reducing pain, and improving patient recovery. Despite promising results, challenges and controversies surrounding PRP therapy persist, including variability in preparation protocols and optimal dosing regimens. The safety of PRP therapy in pediatric patients is also discussed, emphasizing its autologous nature and minimal risk of adverse reactions. In summary, this review highlights the role of PRP therapy as a safe and effective therapeutic approach in pediatric surgery, while further research to standardize protocols and elucidate optimal treatment strategies are still necessary.

Exploring Platelet-Rich Plasma Therapy for Knee Osteoarthritis: An In-Depth Analysis

The use of platelet-rich plasma (PRP) in all medical fields is currently gaining popularity (1). PRP is a biological product that can be defined as a segment of the plasma fraction of autologous blood with a platelet concentration level above the baseline (2). The fact that it has uses in tissue regeneration and wound healing has caught the eye of orthopedic surgeons as well, as intra-articular treatments have continued to evolve. Its benefits in the treatment of different osteoarticular pathologies are of great interest in the evolving orthopedic community, targeting mostly knee osteoarthritis, meniscus and ligament injuries (3). The purpose of this review is to update the reader on the current uses of platelet-rich plasma (PRP) in the treatment of knee osteoarthritis pathology and to provide clinical feedback on its uses in the fields of orthopedic and sports medicine practice (4). We proceeded in studying 180 titles and abstracts eligible for inclusion. Compared to alternative treatments, PRP injections greatly improve the function of the knee joint.

Adjunct treatment with ozone to enhance therapy of knee osteoarthritis: preliminary results

Knee osteoarthritis (knee OA), commonly known as gonarthrosis, is a chronic pathology involving knee at the joint level causing progressive pain, stiffness and difficulty in ambulation and leg movements. So far in situ infiltration therapies such as platelet rich plasma, conditioned autologous serum or hyaluronic acid, provided some encouraging though limited hopes for a routinely recommended therapy for knee OA. Recent clinical successful observations about the use of whole autologous blood ozonated with a calibrated mixture of oxygen and ozone, has promoted the present research study, in order to treat knee OA. A number of 250 patients suffering with knee OA of different Ahlback scores, were treated with infiltration of ozonated blood and evaluated for their WOMAC and Lequesne indexes, pre- and post-treatment, to evaluate pain, disability and stiffness. Patients recovered about 50% of their health status, reducing pain, stiffness and disability by only 5 sessions, one/week, with 20 μg/ml O3 ozonated autologous blood knee infiltrations. The evidence asks for further supporting results yet encourages our efforts to go ahead in this research issue. Key Points •The oxygen-ozone therapy via ozonated blood infiltration was used in this study. •Ozone reduced pain, disability, and stiffness in both female and male patients. •The treatment with ozone improved WOMAC both in type I and type II Ahlback knee OA. •The oxygen-ozone therapy via ozonated blood ameliorated Lequesne functional index.

Electrical Stimulation of Mesenchymal Stem Cells as a Tool for Proliferation and Differentiation in Cartilage Tissue Engineering: A Scaffold-Based Approach

Electrical stimulation (ES) is a widely discussed topic in the field of cartilage tissue engineering due to its ability to induce chondrogenic differentiation (CD) and proliferation. It shows promise as a potential therapy for osteoarthritis (OA). In this study, we stimulated mesenchymal stem cells (MSCs) incorporated into collagen hydrogel (CH) scaffolds, consisting of approximately 500,000 cells each, for 1 h per day using a 2.5 Vpp (119 mV/mm) 8 Hz sinusoidal signal. We compared the cell count, morphology, and CD on days 4, 7, and 10. The results indicate proliferation, with an increase ranging from 1.86 to 9.5-fold, particularly on day 7. Additionally, signs of CD were observed. The stimulated cells had a higher volume, while the stimulated scaffolds showed shrinkage. In the ES groups, up-regulation of collagen type 2 and aggrecan was found. In contrast, SOX9 was up-regulated in the control group, and MMP13 showed a strong up-regulation, indicating cell stress. In addition to lower stress levels, the control groups also showed a more spheroidic shape. Overall, scaffold-based ES has the potential to achieve multiple outcomes. However, finding the appropriate stimulation pattern is crucial for achieving successful chondrogenesis.

Analogies Between Platelet-Rich Plasma Versus Hyaluronic Acid Intra-articular Injections in the Treatment of Advanced Knee Arthritis: A Single-Center Study

Background Knee osteoarthritis (KOA), a degenerative joint disease, is a common cause of chronic knee pain and disability in adults. Conservative management options are the first-line approach, but intra-articular injections, such as platelet-rich plasma (PRP) and hyaluronic acid (HA), are considered for advanced cases. This study aims to compare the efficacy of PRP versus HA injections in patients with advanced KOA. Methods A retrospective study was conducted on 145 patients with advanced KOA. Seventy patients received PRP injections, while 75 patients received HA injections. The Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and International Knee Documentation Committee (IKDC) score were employed to evaluate the treatment's efficacy. Adverse events associated with these injections were also recorded. Results Both PRP and HA injections significantly reduced pain and improved joint function in patients with advanced KOA. PRP injections were slightly more effective than HA injections in reducing pain scores. Both treatments showed similar improvements in functional outcomes. Adverse events were minimal and self-limiting for both treatments. Conclusions Both PRP and HA injections effectively ameliorate advanced KOA by reducing pain and improving function. PRP injections showed a slightly greater improvement in pain scores and functional outcomes. The choice between PRP and HA injections may depend on factors like cost, availability, and patient preference. Further research is needed to validate these findings and understand treatment suitability for different patient populations.

The Use of Platelet-Rich Plasma and Stem Cell Injections in Musculoskeletal Injuries

Injuries to the musculoskeletal (MSK) system can have a significant impact on an individual's activities of daily living, as this multifunctional unit is associated with physical movement. Treatment of MSK injuries often involves corticosteroid injections, supplements, pharmaceutical agents, and/or surgery. While these approaches have been shown to be effective for some patients over both the short and long term, they can be associated with limited relief, adverse effects, and/or decreases in activities of daily living. An unmet need exists to develop and/or implement more effective treatment approaches for MSK injuries. Treatment options being explored include platelet-rich plasma (PRP) and stem cell injections. This review outlines the current state of research evaluating PRP and stem cell injections in the treatment of various MSK injuries. A literature search was conducted using the PubMed database to identify the relevant published articles related to the use of PRP and/or stem cell injections for the treatment of MSK and cartilage injuries. PRP and stem cell injections have been shown to improve an individual's quality of life (QOL) and are associated with fewer side effects as compared to invasive standards of care in multiple MSK injuries such as plantar fasciitis, Achilles tendinopathy, acute muscle and tendon tears, ligament injuries, chondral and medial collateral ligament (MCL) knee injuries and arthritis, rotator cuff lesions, and avascular femoral necrosis. Specifically, these studies on PRP and stem cell injections suggest that both approaches are associated with a quicker return to activities of daily living while providing longer lasting relief without significant adverse events. The studies reviewed demonstrated PRP and stem cell approaches to be effective and safe for the treatment of certain MSK injuries, but as standardized protocols were not utilized across studies in the discussion of similar injuries, it was therefore difficult to compare their efficacy and safety. As such, further research is warranted to establish standardized research protocols across MSK injury studies to gain further insight into the efficacy, safety, and durability of PRP and stem cell injections.

Prognostic Factors in Intra-articular Platelet-Rich Plasma Treatment for Knee Osteoarthritis: A Comparative Analysis of Responders and Nonresponders

BACKGROUND

Knee osteoarthritis (KOA) is a chronic joint disease affecting activities of daily living (ADL) and quality of life due to pain and limited range of motion, afflicting a large number of patients worldwide. However, it is difficult to prevent the progression of the disease. Therapeutic strategies for KOA aim to maintain ADL and QOL by alleviating pain or managing locomotive function. Recently, intra-articular injection of platelet-rich plasma (PRP) has been gaining attention. In this study, the clinical results of PRP treatment in our institution were reported and compared between responders and non-responders using patient characteristics and imaging data assessed from plain X-rays and magnetic resonance imaging (MRI).

METHODS

Participants in the study were KOA patients with varus deformity assessed as grade 2 or higher in the Kellgren-Lawrence classification who received PRP treatment from January 2022 to November 2023 and were followed up for at least three months. PRP was prepared with 27 mL of blood collected from the patient, and 2.7 mL of PRP was prepared using the PEAK©︎PRP System from DePuy Synthes (Raynham, MA). Intra-articular injections of PRP were performed under echo-guided procedures, and responders or non-responders were determined using the Osteoarthritis Research Society International Standing Committee for Clinical Trials Response Criteria Initiative (OMERACT-OARSI) criteria evaluated by the Japanese Knee Injury and Osteoarthritis Outcome Score (J-KOOS) at three months after PRP injection. The clinical efficacy of PRP treatment for KOA was assessed in this study, and a dichotomous analysis was performed comparing the responder group and the non-responder group using patient characteristics and assessed data from plain X-ray images and MRI to determine prognostic factors for PRP treatment.

RESULTS

The study population included 36 knees with a mean age of 70.6. ± 9.2 years, comprising six knees in men and 30 knees in women. The responder group consisted of 16 knees (44.4%), and the non-responder group consisted of 20 knees (55.6%). J-KOOS subscores at pre-treatment elicited that each subscale in the R group was significantly lower than that in the NR group at pretreatment. A dichotomous analysis for the two groups revealed the distribution of sex and past medical history of hyperlipidemia to be significantly different between the two groups. Multivariable logistic regression analysis showed that the coexistence of hyperlipidemia was the main prognostic factor for the efficacy of PRP therapy.

DISCUSSION

In this study, comparisons were conducted between responders and non-responders to estimate prognostic factors for the efficacy of PRP therapy. Surprisingly, responders to the treatment tended to show lower J-KOOS scores and to have hyperlipidemia. A literature review revealed conflicting reports on prognostic factors for PRP therapy in KOA, highlighting the need for further research.

Long term improvement of knee osteoarthritis after injection of single high/very high volume of very pure PRP: A retrospective analysis of patients optimally managed in dedicated centers

Introduction

PRP is gaining increasing interest for pain relief and improvement of joint function in patients with knee osteoarthritis (KOA) but practices and results remain heterogeneous limiting its adoption as standard of care. Current international recommendations are to collect real-life evidence of efficacy with a systematic monitoring of PRP quality and patients' outcomes. We aimed to analyze the response of patients presenting KOA and treated with standardized PRP injection in routine care. We also investigated the potential contributing factors including patient's phenotype and PRP characteristics.

Methods

Patients with symptomatic KOA and that failed first-line therapy received a single injection of a qualified PRP prepared using medical devices allowing to recover a high/very high volume of very pure PRP. Visual analogue scale (VAS) and Western Ontario and McMaster Osteoarthritis Index (WOMAC) score were recorded at baseline and during 18 months follow-up.

Results

431 patients had available follow-up data at 3 months, 291 at 6 months, 137 at 12 months and 44 at 18 months. PRP induced a significant decrease of WOMAC score at all follow up endpoints (29.2 ± 19.2 at 3 months, p < 0.001 and 25.9 ± 19.7 at 12 months, p < 0.01, compared to 39.7 ± 18.9 at baseline). Similar results were observed for pain VAS (38.9 ± 23.3 at 3 months, p < 0.001 and 35.3 ± 24.1 at 12 months, p < 0.05, compared to 56.0 ± 20.7 at baseline). Changes at 12 months were correlated to baseline scores and to the level of improvement at 3 months. The proportion of OMERACT OARSI responders reached 56.2 % for the total cohort and 60.4 % for severe patients at 6 months. Treatment failure occurred for 8.4 % of patients. Age, BMI or Kellgren-Lawrence grade did not impact on efficacy.

Conclusion

This real-life study evidences the clinical benefit of a standardized high or very high-volume injection of very pure PRP in patients with KOA, including those with a severe grade. It opens perspectives in the positioning of such strategy to delay arthroplasty and provide insights on factors able to anticipate long term efficacy.

Medial or Lateral, That Is the Question: A Retrospective Study to Compare Two Injection Techniques in the Treatment of Knee Osteoarthritis Pain with Hyaluronic Acid

Background: Mild-to-moderate knee osteoarthritis (KOA) can be successfully treated using intra-articular hyaluronic acid (IA-HA). The medial infrapatellar (MIP) approach and lateral infrapatellar (LIP) approach are two of the most used techniques for performing IA-HA, but it is still not clear which one is preferable. Objectives: The study aims to find the best knee injection technique between MIP and LIP approaches. Methods: In total, 161 patients were enrolled, divided into two groups (MIP or LIP). Each technique was performed once a week for three weeks. Patients were evaluated using the Numeric Rating Scale (NRS), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Roles and Maudsley Score (RMS) at T0 (before the first injection), T1 (one week after the third injection) and T2 (six months after). Results: NRS, KOOS and RMS showed a statistically significant improvement in both groups at all the detection times, without significant differences. No differences were detected between the groups in terms of systemic effect effusions, while the MIP group presented a mildly higher number of bruises in comparison with the LIP group (p = 0.034). Conclusions: Both the IA-HA techniques are equally effective in measured outcomes. The MIP approach seems to produce some local and transient side effects. So, the choice of the LIP or MIP approach depends on the operator's skill and experience.

Ten years of injectable platelet-rich fibrin

The use of platelet-rich fibrin (PRF) has seen widespread advantages over platelet-rich plasma (PRP) in many fields of medicine. However, until 2014, PRF remained clinically available only in its solid clotted form. Modifications to centrifugation protocols and tube technology have led to the development of a liquid injectable version of PRF (i-PRF). This narrative review takes a look back at the technological developments made throughout the past decade and further elaborates on their future clinical applications. Topics covered include improvements in isolation techniques and protocols, ways to further concentrate i-PRF, and the clinical impact and relevance of cooling i-PRF. Next, various uses of i-PRF are discussed, including its use in regenerative periodontology, implantology, endodontics, temporomandibular joint injections, and orthodontic tooth movement. Furthermore, various indications in medicine are also covered, including its use in sports injuries and osteoarthritis of various joints, treatment of diabetic ulcers/wound care, and facial esthetics and hair regrowth. Finally, future applications are discussed, mainly its use as a drug delivery vehicle for small biomolecules, such as growth factors, antibiotics, exosomes, and other medications that may benefit from the controlled and gradual release of biomolecules over time.

The Oxygen-Ozone Adjunct Medical Treatment According to the Protocols from the Italian Scientific Society of Oxygen-Ozone Therapy: How Ozone Applications in the Blood Can Influence Clinical Therapy Success via the Modulation of Cell Biology and Immunity

BACKGROUND

Ozone is an allotrope of oxygen whose use in medicine has rapidly grown in recent years. Ozonated blood allows for the use of ozone in a safe modality, as plasma and blood cells are endowed with an antioxidant system able to quench ozone's pro-oxidant property and to elicit the Nrf2/Kwap1/ARE pathway.

METHODS

We present two clinical studies, a case-series (six patients) observational study adopting ozone as a major autohemotherapy and topical ozone to address infected post-surgical wounds with multi-drug resistant bacteria and an observational study (250 patients) using ozonated blood for treating knee osteoarthritis.

RESULTS

Ozonated blood via major autohemotherapy reduced the extent of infections in wounds, reduced the inflammatory biomarkers by more than 75% and improved patients' QoL, whereas ozonated blood via minor autohemotherapy improved significantly (p < 0.001) WOMAC and Lequesne's parameters in knee osteoarthritis.

CONCLUSIONS

The models described, i.e., ozone autohemotherapy in wound antimicrobial treatment and ozonated blood in knee osteoarthrosis, following our protocols, share the outstanding ability of ozone to modulate the innate immune response and address bacterial clearance as well as inflammation and pain.

Umbilical Cord Mesenchymal Stem Cell Secretome Improves Clinical Outcomes and Changes Biomarkers in Knee Osteoarthritis

(1) Background: The current treatment for osteoarthritis is ineffective due to its focus on pain relief and lack of cartilage repair. Viscosupplementation such as hyaluronic acid improves symptoms but remains unnoticed for several months. Researchers are exploring cell-based therapies such as mesenchymal stem cells secretome and mesenchymal stem cells, which can repair cartilage damage. The objective of the research is to evaluate and compare the effectiveness of the secretome derived from umbilical cord mesenchymal stem cells (UC-MSCs) with hyaluronic acid (HA). (2) Methods: An open-label clinical trial involving 30 knee osteoarthritis patients divided into two groups received UC-MSC secretome and hyaluronic acid doses. The study assessed clinical outcomes using VAS and WOMAC and measured MMP-3 and TGF-β1 levels before and after treatment. (3) Results: A study of 30 subjects found that the UC-MSC secretome group showed a decrease in pain in the OA knee compared to the HA group. The therapy was most effective after the third injection, and the group showed a decrease in the MMP-3 ratio and an increase in TGF-β1 compared to the hyaluronic acid group. (4) Conclusions: UC-MSC secretome intra-articular injections showed superior clinical improvement, biomarker changes, and no side effects compared to hyaluronic acid over a 5-week interval.

Intra-articular injections in sport-active patients with degenerative cartilage lesions or osteoarthritis of the knee: a systematic review

PURPOSE

The aim of this systematic review was to analyse the available clinical evidence on intra-articular knee injections for the treatment of degenerative cartilage lesions and osteoarthritis (OA) in sport-active patients.

METHODS

A literature search was performed in July 2023 according to the PRISMA guidelines on three electronic databases (PubMed, Cochrane, Web of Science). Studies addressing intra-articular injections for degenerative knee cartilage lesions or knee OA in sport-active patients were included. The Downs and Black's "checklist for measuring quality" was used to evaluate risk of bias and quality of the included studies.

RESULTS

Only 10 clinical studies for a total of 296 sport-active patients were included, with a publication trend increasing over time. The studies were 9 case series and 1 RCT; 7 studies focused on hyaluronic acid (HA), 2 studies focused on platelet-rich plasma (PRP), while 1 study compared HA and PRP. Overall, safety and positive clinical findings were for both HA and PRP, although not always with satisfactory results in terms of return to sport. The Downs and Black evaluation showed an overall poor quality of the included studies, with an average score of 21.1 points (range 19-25).

CONCLUSIONS

The available clinical evidence is still limited, with only a few studies published and an overall low-quality of evidence, suggesting a potential role of HA and PRP injections to treat these patients. However, further high-level trials are needed to confirm the real benefits of these treatments for the management of sport-active patients affected by degenerative cartilage lesions or OA of the knee.

Multifactorial Comparative Analysis of Platelet-Rich Plasma and Serum Prepared Using a Commercially Available Centrifugation Kit

Background Platelet-rich plasma (PRP) is an autologous product prepared by centrifuging whole blood. PRP is reported to have high tissue repair potential and anti-inflammatory properties. Recently, PRP has become a potential treatment option for osteoarthritis, contributing to pain relief and locomotive improvement. However, the underlying therapeutic mechanisms and key biochemical factors in PRP remain unclear. This study aimed to estimate the major factors for tissue repair involved in PRP treatment by comparing between serum and PRP prepared from the same patients using the Luminex assay. Methodology Blood samples were collected from nine healthy volunteers, and serum and PRP were prepared. PRP was prepared using a PEAK©︎ PRP SYSTEM kit of DePuy Synthes Mitek Sports Medicine (Raynham, Massachusetts, USA), which is a commercially available PRP preparation kit. The white blood cell count, hemoglobin level, and platelet count were automatically measured for both whole blood and PRP in the hospital's clinical laboratory using the XE-5000™ Automated Hematology System (Sysmex, Kobe, Japan). Comparative analysis of biological factors was then performed using the Luminex assay on serum and PRP. Results PRP was found to have significantly higher white blood cell and platelet counts and lower hemoglobin levels than whole blood. Furthermore, PRP contained significantly higher levels of various factors, including interleukin (IL)-1ra, IL-10, IL-13, C-C motif chemokine ligand (CCL)-2, CCL3, CCL4, CCL8, CCL13, CCL21, C-X-C motif chemokine ligand (CXCL)-10, matrix metalloproteinase (MMP)-3, MMP-9, cluster of differentiation (CD) 40 ligand, vascular endothelial growth factor (VEGF), VEGF-C, platelet-derived growth factor (PDGF)-AB, PDGF-BB, and bone morphogenic protein (BMP)-2. Additionally, IL-1ra and IL-4 showed significant correlations with white blood cell counts in PRP, whereas VEGF had a significant correlation with platelet counts. Conclusions PRP contains various factors in higher quantities than serum. Specifically, the notable increase in the anti-inflammatory cytokine IL-1ra is suggested to play a key role as a major therapeutic mechanism of PRP.

The management of osteoarthritis symptomatology through nanotechnology: a patent review

Osteoarthritis is considered a degenerative joint disease that is characterised by inflammation, chronic pain, and functional limitation. The increasing development of nanotechnology in drug delivery systems has provided new ideas and methods for osteoarthritis therapy. This review aimed to evaluate patents that have developed innovations, therapeutic strategies, and alternatives using nanotechnology in osteoarthritis treatment. The results show patents deposited from 2015 to November 2021 in the online databases European Patent Office and World Intellectual Property Organisation. A total of 651 patents were identified for preliminary assessment and 16 were selected for full reading and discussion. The evaluated patents are focused on the intraarticular route, oral route, and topical route for osteoarthritis treatment. The intraarticular route presented a higher patent number, followed by the oral and topical routes, respectively. The development of new technologies allows us to envision a promising and positive future in osteoarthritis treatment.

Meta-analysis of the efficacy and safety of arthroscopic surgery associated with platelet-rich plasma infusion when treating knee osteoarthritis

OBJECTIVE

To assess the efficacy and safety of arthroscopic surgery associated with platelet-rich plasma (PRP) infusion in treating knee osteoarthritis (KOA).

METHODS

PubMed, EMBASE, ScienceDirect, Cochrane Library, China Knowledge Network Database, China VIP Database, Wanfang Database, and China Biomedical Literature Database online database were searched for the case-control trial of arthroscopic surgery associated with PRP infusion in patients with KOA. During the search period of January 2010 through May 2022, two researchers independently extracted the data. With RevMan5.3, we performed a meta-analysis on the collected data.

RESULTS

A total of six clinical controlled studies were included, including 333 individuals. Compared with the control group treated only by arthroscopic surgery, the results showed that the visual analogue scores of patients in the arthroscopic surgery and PRP infusion group were significantly lower at 3, 6 and 12 months after operation, and the Western Ontario and McMaster Universities Osteoarthritis Index were significantly lower at 3, 6 and 12 months after operation (p < .05). The meta-analysis of Hospital for Special Surgery (HSS) knee score and Lisum knee score (LKSS) showed that postoperative HSS score, LKSS score at 3, 6, and 12 months after operation, and SF-36 quality of life score at 6 and 12 months after operation were higher (p < .05).

CONCLUSION

Arthroscopic debridement associated with PRP is more successful in relieving knee pain and enhancing knee joint function than arthroscopic debridement in treating KOA. The treatment scheme deserves to be popularized in clinical practice, but further research and longer interventions will be needed to validate it, using high-quality methods.

Non-operative Management and Outcomes of Femoroacetabular Impingement Syndrome

PURPOSE

To serve as a guide for non-operative physicians in the management of femoroacetabular impingement syndrome and provide an algorithm as to when to refer patients for potential surgical management.

RECENT FINDINGS

Supervised physical therapy programs that focus on active strengthening and core strengthening are more effective than unsupervised, passive, and non-core-focused programs. There is promising evidence for the use of intra-articular hyaluronic acid and PRP as adjunct treatment options. Recent systematic reviews and meta-analyses have found that in young active patients, hip arthroscopy demonstrates improved short-term outcomes over physical therapy. The decision for the management of FAIS is complex and should be specific to each patient. Consideration of the patient's age, timing to return to sport, longevity of treatment, hip morphology, and degree of cartilage degeneration is required to make an informed decision in the treatment of these patients.

Efficacy and Safety of Hyaluronic Acid and Platelet-Rich Plasma Combination Therapy Versus Platelet-Rich Plasma Alone in Treating Knee Osteoarthritis: A Systematic Review

Knee osteoarthritis (KOA) is a chronic degenerative disease of the joint characterized by biochemical and biomechanical alterations of articular cartilage, degradation of the joint edge, and subchondral bone hyperplasia. Nowadays, intra-articular hyaluronic acid (HA) or platelet-rich plasma (PRP) has become a popular treatment modality for treating KOA. Each treatment can be used independently or in combination. However, the efficacy and safety of combination treatment are still inconclusive, and there is a lack of high-quality level 1 studies that support using combination therapy over PRP alone. Consequently, we conducted a systematic review to examine the effectiveness and safety of combining HA and PRP therapy versus using PRP therapy alone in KOA patients. Based on the most up-to-date evidence, the dual approach of PRP and HA therapy yields outcomes similar to PRP therapy alone in the short term, up to 12 months. Nonetheless, when considering longer-term results, particularly in the 24-month follow-up, dual therapy holds the potential to produce superior outcomes compared to PRP alone therapy. Additionally, in terms of safety, dual therapy has been associated with slightly fewer adverse events.

Italian Orthopaedic and Traumatology Society (SIOT) position statement on the non-surgical management of knee osteoarthritis

BACKGROUND

Knee osteoarthritis (OA) is a chronic disease associated with a severe impact on quality of life. However, unfortunately, there are no evidence-based guidelines for the non-surgical management of this disease. While recognising the gap between scientific evidence and clinical practice, this position statement aims to present recommendations for the non-surgical management of knee OA, considering the available evidence and the clinical knowledge of experienced surgeons. The overall goal is to offer an evidenced-based expert opinion, aiding clinicians in the management of knee OA while considering the condition, values, needs and preferences of individual patients.

METHODS

The study design for this position statement involved a preliminary search of PubMed, Google Scholar, Medline and Cochrane databases for literature spanning the period between January 2021 and April 2023, followed by screening of relevant articles (systematic reviews and meta-analyses). A Società Italiana Ortopedia e Traumatologia (SIOT) multidisciplinary task force (composed of four orthopaedic surgeons and a rheumatologist) subsequently formulated the recommendations.

RESULTS

Evidence-based recommendations for the non-surgical management of knee OA were developed, covering assessment, general approach, patient information and education, lifestyle changes and physical therapy, walking aids, balneotherapy, transcutaneous electrical nerve stimulation, pulsed electromagnetic field therapy, pharmacological interventions and injections.

CONCLUSIONS

For non-surgical management of knee OA, the recommended first step is to bring about lifestyle changes, particularly management of body weight combined with physical exercise and/or hydrotherapy. For acute symptoms, non-steroidal anti-inflammatory drugs (NSAIDs), topic or oral, can be used. Opioids can only be used as third-line pharmacological treatment. Glucosamine and chondroitin are also suggested as chronic pharmacological treatment. Regarding intra-articular infiltrative therapy, the use of hyaluronic acid is recommended in cases of chronic knee OA [platelet-rich plasma (PRP) as second line), in the absence of active acute disease, while the use of intra-articular injections of cortisone is effective and preferred for severe acute symptoms.

Retrospective Analysis of Responders and Impaired Patients with Knee Osteoarthritis Treated with Two Consecutive Injections of Very Pure Platelet-Rich Plasma (PRP)

OBJECTIVES

To assess the effectiveness of two consecutive intraarticular injections of PRP to treat knee osteoarthritis (KOA), discriminating between responders and impaired patients.

METHODS

This retrospective study included 73 consecutive patients who were referred for two intra-articular PRP injections (one week apart) for treating symptomatic moderate/severe KOA. Biological characterization of the PRP, including platelets, leukocytes and erythrocytes, was evaluated. Patient's subjective symptoms were recorded before the treatment and 1 year after the second injection using pain VAS and WOMAC scores. Responders were defined by an improvement of 10 points on WOMAC.

RESULTS

At a 1-year follow up, we found 36 (49.3%) patients who fulfilled the criteria of responders, and 21 (28.8%) patients were impaired. A statistically and clinically significant global improvement of -29.2 ± 14.3 (p < 0.001) points in WOMAC score was observed 1 year after treatment in the responder group, with a higher response rate in patients with KL 2 (57.7%) compared to KL IV (28.6%). The percentage of patients with KL IV was higher in the impaired group (48.0%) compared to the responders (16.6%). As expected, the evaluation of the functionality of the knee in the impaired group indicates that it significantly worsened after one year from treatment (p = 0.027). However, the average pain score remained stable with no significant differences after 1 year (p = 0.843). No clinical complications or severe adverse events after the PRP injections were reported.

CONCLUSION

The present study suggests that two intra-articular injections of 10 mL of very pure PRP provide pain and functional improvement in symptomatic KOA.

The Use of Intra-articular Platelet-Rich Plasma as a Therapeutic Intervention for Hip Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

There is a cohort of patients in whom hip preservation surgery is not indicated, because they have developed signs of early osteoarthritis (OA), and nor can they have a hip replacement, as they are too early in the disease process. Management of this cohort of patients is not standardised and both pharmacological and nonpharmacological measures are utilised to reduce pain. Interventions available for early OA include intra-articular injections of steroids, viscosupplementation and more recently platelet-rich plasma (PRP). However, the use of PRP in hip OA has not yet been studied systematically.

PURPOSE

To assess intra-articular PRP as a therapeutic intervention for hip OA, including the duration of efficacy, influence of dose and composition of PRP, and the incidence of adverse effects.

STUDY DESIGN

A systematic review and meta-analysis; Level of evidence, 4.

METHODS

We performed literature searches on the MEDLINE, EMBASE, CINAHL, WEB OF SCIENCE, COCHRANE, and SCOPUS databases, and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Data were pooled using random-effects meta-analysis. We assessed the quality of the included studies using the methodological index for non-randomized studies instrument, with an additional assessment for randomized controlled trials with the revised Cochrane risk of bias tool for randomized trials. This is the first study to concisely collate the available data on the use of PRP in hip OA.

RESULTS

Eight studies were included in the analysis, with data from a total of 331 patients. PRP significantly reduced pain compared with the baseline at multiple time points, with the greatest effect at the 1- to 2-month follow-up, but PRP significantly improved function only at the 1- to 2-month follow-up. A significantly larger reduction in pain was achieved with a single injection of PRP compared with multiple injections, a total injected dose of PRP <15 mL compared with ≥15 mL, and use of a leukocyte-poor PRP preparation compared with leukocyte-rich PRP. There were no lasting adverse effects.

CONCLUSION

Low- and moderate-quality evidence suggests that PRP reduces pain and improves function at the end-point follow-up of studies compared with the baseline. Moderate-quality evidence suggests that a larger reduction in pain is achieved with a single injection of PRP compared with multiple injections, and low-quality evidence attributes a larger reduction of pain with a total injected dose of PRP <15 mL compared with ≥15 mL and using leukocyte-poor PRP compared with leukocyte-rich PRP.

[Treatment of unicompartmental osteoarthritis of the knee]

Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.

The role of WNT and IL-1 signaling in osteoarthritis: therapeutic implications for platelet-rich plasma therapy

Different from inflammatory arthritis, where biologicals and targeted synthetic molecules have revolutionized the disease course, no drug has demonstrated a disease modifying activity in osteoarthritis, which remains one of the most common causes of disability and chronic pain worldwide. The pharmacological therapy of osteoarthritis is mainly directed towards symptom and pain relief, and joint replacement is still the only curative strategy. Elucidating the disease pathophysiology is essential to understand which mechanisms can be targeted by innovative therapies. It has extensively been demonstrated that aberrant WNT and IL-1 signaling pathways are responsible for cartilage degeneration, impaired chondrocyte metabolism and differentiation, increased extracellular matrix degradation, and altered subchondral bone homeostasis. Platelet-rich plasma is an autologous blood derivative containing a concentration of platelets that is much higher than the whole blood counterpart and has shown promising results in the treatment of early knee osteoarthritis. Among the proposed mechanisms, the modulation of WNT and IL-1 pathways is of paramount importance and is herein reviewed in light of the proposed regenerative approaches.

Chondroprotective Effects of Chondrogenic Differentiated Adipose-Derived Mesenchymal Stem Cells Sheet on Degenerated Articular Cartilage in an Experimental Rabbit Model

Adipose-derived stem cells (ADSCs) have been studied for many years as a therapeutic option for osteoarthritis (OA); however, their efficacy remains insufficient. Since platelet-rich plasma (PRP) induces chondrogenic differentiation in ADSCs and the formation of a sheet structure by ascorbic acid can increase the number of viable cells, we hypothesized that the injection of chondrogenic cell sheets combined with the effects of PRP and ascorbic acid may hinder the progression of OA. The effects of induction of differentiation by PRP and formation of sheet structure by ascorbic acid on changes in chondrocyte markers (collagen II, aggrecan, Sox9) in ADSCs were evaluated. Changes in mucopolysaccharide and VEGF-A secretion from cells injected intra-articularly in a rabbit OA model were also evaluated. ADSCs treated by PRP strongly chondrocyte markers, including type II collagen, Sox9, and aggrecan, and their gene expression was maintained even after sheet-like structure formation induced by ascorbic acid. In this rabbit OA model study, the inhibition of OA progression by intra-articular injection was improved by inducing chondrocyte differentiation with PRP and sheet structure formation with ascorbic acid in ADSCs.

A Randomized Trial of Intra-articular Injection Therapy for Knee Osteoarthritis

BACKGROUND

Intra-articular injections are widely used for conservative treatment of knee osteoarthritis (OA). However, rigorous data are lacking regarding the comparative therapeutic effectiveness of these injections.

PURPOSE

The aim of this study was to compare clinical outcomes after intra-articular injections of glucocorticoid, hyaluronic acid, platelet-rich plasma (PRP), or placebo in patients with mild or moderate OA of the knee.

MATERIALS AND METHODS

In a double-blinded, placebo-controlled, single-center trial, we randomly assigned knees with early- to middle-stage knee OA (Kellgren-Lawrence grade 1-3) to an intra-articular injection with one of these substances: glucocorticoid, hyaluronic acid, PRP, or placebo. Primary outcome was pain reduction within 6 months after the injection, assessed with the numeric rating scale (NRS; range, 0-100). Secondary outcome parameters included WOMAC scores, Tegner Activity Scale, knee mobility, and adverse events. Finally, a linear mixed-effects model was calculated and corrected for possible patient and covariate effects.

RESULTS

One hundred twenty knees (30 knees per treatment group) in 95 patients (41 female) were included in the final analysis. The median age of patients was 60 years (interquartile range, 54.0-68.0). There was no evidence that the drug effects of primary and secondary outcome parameters differed over time. The median pain at baseline was 32.5 (interquartile range, 15.00-50.00) on NRS. The changes in pain level during the first 6 months compared with baseline were small (within ±5 points on NRS), whereas the intrapatient variability was large between -20 and +20 points. Secondary outcome parameters did not differ significantly among the groups. Kellgren-Lawrence grade did not have a statistically significant effect on pain reduction ( P = 0.61).

CONCLUSIONS

There is no evidence that knee injections with glucocorticoid, PRP, or hyaluronic acid have superior short- or long-term effects in patients with low pain level at baseline and early- to middle-stage knee OA when compared with placebo.

The value of injectable viscoelastic supplements for joints

Intra-articular viscoelastic supplements are commonly administered by musculoskeletal radiologists for the treatment of symptomatic osteoarthritis (OA). This article provides an overview of the putative mechanism of action of the agents, a brief review of the evidence base underlying the practice, a commentary on some of the major society guidelines regarding the treatment, and a description of the adverse events that are associated with intra-articular hyaluronic acid administration.

Potential applications of drug delivery technologies against radiation enteritis

INTRODUCTION

The incidence of abdominal tumors, such as colorectal and prostate cancers, continually increases. Radiation therapy is widely applied in the clinical treatment of patients with abdominal/pelvic cancers, but it often unfortunately causes radiation enteritis (RE) involving the intestine, colon, and rectum. However, there is a lack of suitable treatment options for effective prevention and treatment of RE.

AREAS COVERED

Conventional clinical drugs for preventing and treating RE are usually applied by enemas and oral administration. Innovative gut-targeted drug delivery systems including hydrogels, microspheres, and nanoparticles are proposed to improve the prevention and curation of RE.

EXPERT OPINION

The prevention and treatment of RE have not attracted sufficient attention in the clinical practice, especially compared to the treatment of tumors, although RE takes patients great pains. Drug delivery to the pathological sites of RE is a huge challenge. The short retention and weak targeting of conventional drug delivery systems affect the therapeutic efficiency of anti-RE drugs. Novel drug delivery systems including hydrogels, microspheres, and nanoparticles can allow drugs long-term retention in the gut and targeting the inflammation sites to alleviate radiation-induced injury.

Osteoarthritis: pathogenic signaling pathways and therapeutic targets

Osteoarthritis (OA) is a chronic degenerative joint disorder that leads to disability and affects more than 500 million population worldwide. OA was believed to be caused by the wearing and tearing of articular cartilage, but it is now more commonly referred to as a chronic whole-joint disorder that is initiated with biochemical and cellular alterations in the synovial joint tissues, which leads to the histological and structural changes of the joint and ends up with the whole tissue dysfunction. Currently, there is no cure for OA, partly due to a lack of comprehensive understanding of the pathological mechanism of the initiation and progression of the disease. Therefore, a better understanding of pathological signaling pathways and key molecules involved in OA pathogenesis is crucial for therapeutic target design and drug development. In this review, we first summarize the epidemiology of OA, including its prevalence, incidence and burdens, and OA risk factors. We then focus on the roles and regulation of the pathological signaling pathways, such as Wnt/β-catenin, NF-κB, focal adhesion, HIFs, TGFβ/ΒΜP and FGF signaling pathways, and key regulators AMPK, mTOR, and RUNX2 in the onset and development of OA. In addition, the roles of factors associated with OA, including MMPs, ADAMTS/ADAMs, and PRG4, are discussed in detail. Finally, we provide updates on the current clinical therapies and clinical trials of biological treatments and drugs for OA. Research advances in basic knowledge of articular cartilage biology and OA pathogenesis will have a significant impact and translational value in developing OA therapeutic strategies.

Clinical Efficacy of Intra-Articular Injection with P-PRP Versus that of L-PRP in Treating Knee Cartilage Lesion: A Randomized Controlled Trial

OBJECTIVE

Platelet-rich plasma（PRP), with different concentration of leukocytes, may lead to varying effects in the treatment of cartilage lesions. So far, current research has not shown enough evidence on this. To evaluate the clinical efficacy and safety of intra-articular injection with pure platelet-rich plasma (P-PRP) versus those of leukocyte platelet-rich plasma (L-PRP) in treating knee cartilage lesions, we conducted a double-blind, randomized controlled clinical trial with a larger sample and longer follow-up period.

METHODS

From October 2019 to October 2020, 95 patients were invited to participate in our study, and 60 (63.2%) were randomized to P-PRP (n = 30) or L-PRP (n = 30) groups. Patients from the two groups were treated with knee intra-articular injections of P-PRP or L-PRP. Visual analog scale (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were assessed using an unpaired t-test for independent samples preoperatively and at 6 weeks, 12 weeks, 6 months, and 12 months after intervention.

RESULTS

We followed up 27 cases in the P-PRP group and 26 cases in the L-PRP group. No significant differences in VAS and WOMAC scores were found between the two groups before the intervention (p > 0.05). The WOMAC Pain and VAS-Motions scores of the P-PRP group were significantly lower than those of the L-PRP group at 6 weeks after the intervention (p < 0.05). While the long-term clinical efficacy of both injections was similar and weakened after 12 months, more adverse events were found in the L-PRP group.

CONCLUSIONS

The short-term results demonstrate a positive effect in reducing pain and improving function in patients with knee cartilage lesions in the two groups. While the P-PRP injection showed better clinical efficacy in the early phase of postoperative rehabilitation and resulted in fewer adverse events, long-term follow-up showed similar and weakened efficacy after 12 months.

TRIAL REGISTRATION

ChiCTR1900026365. Registered on October 3, 2019, http://www.chictr.org.cn/showproj.aspx?proj=43911.