Intra-Articular Platelet-Rich Plasma Injections in Knee Osteoarthritis: A Review of Their Current Molecular Mechanisms of Action and Their Degree of Efficacy

Effects of platelet-rich plasma combined with exercise therapy for one year on knee osteoarthritis: retrospective cohort study

BACKGROUND

Platelet-rich plasma (PRP) is a promising treatment for knee osteoarthritis (OA). However, exercise therapy and activities of daily living (ADL) guidance are recommended as core treatments in the Osteoarthritis Research Society International (OARSI) guidelines. However, the effects of PRP combined with exercise therapy are not fully understood. This study aimed to clarify the effectiveness of this treatment.

METHODS

We assigned patients diagnosed with knee OA and treated between January 2021 and December 2022 to groups who underwent PRP + exercise (PE), PRP (P), or exercise (E) therapy. Outcomes were evaluated using Knee Injury and Osteoarthritis Outcome Scores (KOOS) before, and 1, 3, and 12 months after treatment. Within-group comparisons according to the time of each score were statistically assessed using a one-way analysis of variance, then differences were analyzed using Bonferroni multiple comparisons p < 0.05). Treatment responses were determined using Outcome Measures in Rheumatology (OMERACT)-OARSI Responder criteria.

RESULTS

Pre-treatment KOOS did not significantly differ among the groups. Pain in the PE group improved within 1 month, symptoms, ADL, and quality of life (QOL) improved after 3, months and continued for 12 months. Pain and symptoms improved in the P group within 1 month, but ADLs and the QOL did not significantly change. Pain improved after 3 months in the E group and ADL, and QOL improved by 12 months. The response among the groups was the highest for the PE, with 50.0% at 1 and 3 months, and 65.0% at 12 months.

CONCLUSIONS

Therapy with PRP immediately relieved pain, whereas exercise conferred late, but enduring effects. Combining PRP with exercise conferred synergistic advantages that persisted for up to 12 months.

Semi-invasive therapies for pain in knee osteoarthritis: A systematic review and network meta-analysis

BACKGROUND

The increasing number of semi-invasive pain therapies in knee osteoarthritis poses challenges in decision-making. This review aimed to simultaneously compare established intra-articular therapies with newer peri-articular therapies and explore effect modifiers.

METHODS

Randomized controlled trials were searched from five electronic databases without date or language restrictions. Study selection and data extraction of reports, retrieved up to May 2024, were performed independently by paired assessors. The primary outcome was 6-month pain score. Nine treatments were included. The effect size (ES) for each treatment, relative to placebo, was estimated using standardized means difference and expressed with 95% confidence intervals (CI). The rigor of results was evaluated with subgroup/sensitivity analyses.

RESULTS

A total of 111 studies (14,695 participants) were included, with intra-articular hyaluronic acid having the greatest number of participants. Neuroablation demonstrated the greatest ES (1.08, 95% CI: 0.07, 2.10). While platelet-rich plasma (PRP) ranked second (ES: 0.75, 95% CI: 0.28, 1.22), it was the only intervention demonstrating statistically significant effect at 3, 6, and 12 months. However, this statistical significance was lost in some sensitivity analyses. Larger estimates for biologics and PRP compared with prolotherapy, steroid, and hyaluronic acid injections were consistently observed across different timepoints and in multiple sensitivity analyses. Generally, no statistically significant difference was found between the nine types of therapies.

CONCLUSION

Although there is robust evidence suggesting greater efficacy of PRP, potentially including biologics, over other interventions, future research is needed to identify the phenotype or patient subgroup that would benefit most from PRP.

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.

The combined application of pulsed electromagnetic fields and platelet-rich plasma in the treatment of early-stage knee osteoarthritis: A randomized clinical trial

BACKGROUND

This study aims to evaluate the therapeutic efficacy of combined treatment with pulsed electromagnetic fields (PEMFs) and platelet-rich plasma (PRP) injection in improving pain and functional mobility among patients with early-stage knee osteoarthritis (KOA). We hypothesize that this combined therapy can yield superior treatment outcomes.

METHODS

Based on the different treatment regimens, we divided 48 patients diagnosed with Kellgren-Lawrence grades I-III KOA into 3 groups: the PRP group, the PEMFs group, and the PRP + PEMFs group. Each subtype of KOA patients was randomly assigned to different treatment groups. In the PRP group, patients received intra-articular injections of leukocyte-rich platelet-rich plasma once a month for 3 consecutive months. In the PEMFs group, patients receive low-frequency PEMFs irradiation therapy with a frequency of 30 Hz and intensity of 1.5 mT, once daily, 5 times a week, for a consecutive treatment period of 12 weeks. In the PRP + PEMFs group, patients receive both of the aforementioned treatment protocol. The treatment effects on patients are evaluated at baseline and at weeks 4, 8, and 12 post-treatment. Assessment parameters include visual analog scale for pain, Western Ontario and McMaster Universities Osteoarthritis Index, Lequesne Index score, and knee joint range of motion.

RESULTS

From the 4th to the 12th week of treatment, the visual analog scale scores, Western Ontario and McMaster Universities Osteoarthritis Index scores, and Lequesne index scores of patients in all 3 groups gradually decreased, while knee joint mobility gradually increased (P < .05). At weeks 4, 8, and 12 after treatment, the PRP combined with PEMFs group showed significantly better scores compared to the PRP group and the PEMFs group, with statistically significant differences (P < .05). A total of 7 patients experienced adverse reactions such as knee joint swelling, low-grade fever, and worsening knee joint pain after treatment, all of which disappeared within 1 week after treatment. The incidence of complications did not differ significantly among the 3 groups (P = .67).

CONCLUSION

PRP, PEMFs, and the combination of PRP and PEMFs therapy all effectively alleviate knee joint pain and improve joint function. However, compared to single treatment modalities, the combined therapy of PRP and PEMFs demonstrates more pronounced efficacy.

Exploring the Efficacy of Biologics in Knee Osteoarthritis: Ultrasound Evaluation of Cartilage Regeneration Effects

Introduction

Biologics like growth factors, stem cells, and platelet-rich plasma show potential in stimulating cartilage regrowth and reducing inflammation. By synthesizing preclinical and clinical studies, this study offers insights into how these biologics work and their effectiveness in treating knee osteoarthritis.

Methods and Materials

Twenty-four participants with knee osteoarthritis (Kellgren - Lawrence grade II or III) were enrolled after obtaining consent. They received three doses of 2 ml intraarticular platelet-rich plasma at 1 month intervals. The clinical assessment involved the oxford knee score (OKS) and visual analogue scale (VAS) for pain on Days 0, 90, and 180. Ultrasound measured femoral and trochlear cartilage thickness pre- (Day 0) and post-PRP (Day 90-180).

Results

Before treatment, the average pain score was 7.2 (p = 1.03). On Day 90 post-PRP, it decreased to 5 (p = 0.81), and by Day 180, it further reduced to 4.5 (p = 0.97). The initial total OKS was 33.5 (p = 1.76), which increased to 36 (p = 1.71) on Day 90 and 38.5 (p = 1.89) on Day 180. The femoral and trochlear cartilage thickness also showed improvement from baseline (0.92) to Day 90 (0.96) and Day 180 (1.01), indicating significant cartilage healing post-PRP administration.

Conclusion

Our study highlights the probability of PRP in treating knee OA, highlighting their ability to alleviate symptoms, enhance joint function, and promote articular cartilage regeneration.

The varying clinical effectiveness of single, three and five intraarticular injections of platelet-rich plasma in knee osteoarthritis

OBJECTIVE

To investigate the variations in clinical effectiveness among patients diagnosed with knee osteoarthritis who underwent intra-articular administration of platelet-rich plasma using single, triple, or quintuple injections.

METHODS

One hundred twenty patients with grade I-III knee osteoarthritis were randomly assigned to three groups: PRP1 group, who received a single injection of platelet-rich plasma; PRP3 group, who received three PRP injections one week apart; PRP5 group, who received five PRP injections one week apart. The patients' conditions were evaluated using the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index-VA3.1 version (WOMAC-VA3.1) at baseline and 6, 12, 24, and 52 weeks 52 weeks follow up.

RESULTS

Out of the total participants, 106 patients (30 males and 76 females) completed the study. The primary outcome measure, WOMAC pain score, registered significant improvements across all groups when compared to pre-treatment levels. However, the application of 3 and 5 injections of platelet-rich plasma was substantially more effective than that of a single injection in reducing knee pain and stiffness, as well as enhancing physical function in patients with knee osteoarthritis. No statistically discernable difference was observed between PRP3 and PRP5 at all follow-up intervals, and there was no discernable difference between 3 and 5 PRP injections either. Mild side effects occurred in all three groups.

CONCLUSIONS

The administration of three or five injections of platelet-rich plasma is safe, substantially more effective than single injections, and leads to remarkable clinical improvement by significantly reducing knee pain, improving joint stiffness, and enhancing physical function in patients with grade I-III knee osteoarthritis. Furthermore, no significant difference was observed in the efficacy of three or five injections. Therefore, we recommend using three injections of PRP in the treatment of patients with knee osteoarthritis of grade I-III.

There Is Wide Variation in Platelet-rich Plasma Injection Pricing: A United States Nationwide Study of Top Orthopaedic Hospitals

BACKGROUND

Demand for platelet-rich plasma (PRP) injections for osteoarthritis has dramatically increased in recent years despite conflicting evidence regarding its efficacy and highly variable pricing in the top orthopaedic centers in the United States, because PRP is typically not covered by insurance. A previous study investigating the mean price of PRP injections obtained information only from centers advertising online the availability of PRP injections. Thus, there is a need for further clarification of the overall availability and variability in cost of PRP injections in the orthopaedic community as well as an analysis of relevant regional demographic and hospital characteristics that could be associated with PRP pricing.

QUESTIONS/PURPOSES

Our study purposes were to (1) report the availability and price variation of knee PRP injections at top-ranked United States orthopaedic centers, (2) characterize the availability of pricing information for a PRP injection over the telephone, (3) determine whether hospital characteristics (Orthopaedic Score [ U . S. News & World Report measure of hospital orthopaedic department performance], size, teaching status, and rural-urban status) were associated with PRP injection availability and pricing, and (4) characterize the price variation, if it exists, of PRP injections in three metropolitan areas and individual institutions.

METHODS

In this prospective study, a scripted telephone call to publicly listed clinic telephone numbers was used to determine the availability and price estimate (amount to be paid by the patient) of a PRP injection for knee osteoarthritis from the top 25 hospitals from each United States Census region selected from the U.S. News & World Report ranking of best hospitals for orthopaedics. Univariable analyses examined factors associated with PRP injection availability and willingness to disclose pricing, differences across regions, and the association between hospital characteristics (Orthopaedic Score, size, teaching status, and rural-urban status) and pricing. The Orthopaedic Score is a score assigned to each hospital by U . S. News & World Report as a measure of hospital performance based partly on patient outcomes, with higher scores indicating better outcomes.

RESULTS

Overall, 87% (87 of 100) of respondents stated they offered PRP injections. Pricing ranged from USD 350 to USD 2815 (median USD 800) per injection, with the highest prices in the Northeast. The largest price range was in the Midwest, where more than two-thirds of PRP injections given at hospitals that disclosed pricing cost USD 500 to USD 1000. Of the hospitals that offered PRP injections, 68% (59 of 87) were willing to disclose price information over the telephone. PRP injection pricing was inversely correlated with hospital Orthopaedic Score (-3% price change [95% CI -5% to -1%]; p = 0.01) and not associated with any of the other hospital characteristics that were studied, such as patient population median income and total hospital expenses. An intracity analysis revealed wide variations in PRP pricing in all metropolitan areas that were analyzed, ranging from a minimum of USD 300 within 10 miles of metropolitan area B to a maximum of USD 1269 within 20 miles of metropolitan area C.

CONCLUSION

We found that although PRP injections are widely available, pricing continues to be a substantial financial burden on patients, with large price variability among institutions. We also found that if patients are willing to shop around in a metropolitan area, there is potential to save a meaningful amount of money.

CLINICAL RELEVANCE

As public interest in biologics in orthopaedic surgery increases, knowledge of its pricing should be clarified to consumers. The debated efficacy of PRP injections, combined with our findings that it is an expensive out-of-pocket procedure, suggests that PRP has limited cost-effectiveness, with variable, discrete pricing. As such, the price of PRP injections should be clearly disclosed to patients so they can make informed healthcare decisions.

Navigating the Therapeutic Landscape: A Comprehensive Review of Platelet-Rich Plasma and Bone Marrow Aspirate Concentrate in Knee Osteoarthritis

This comprehensive review provides an in-depth analysis of platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) as potential treatments for knee osteoarthritis. It explores their mechanisms of action, clinical efficacy, safety considerations, and the importance of personalised treatment approaches. The review highlights promising findings regarding the ability of PRP and BMAC to alleviate symptoms, improve joint function, and potentially slow disease progression. It emphasises the need for further research into long-term outcomes, direct comparative studies, protocol standardisation, biomarker identification, and cost-effectiveness assessments to enhance clinical practice. While the review does not directly compare PRP and BMAC, it provides valuable insights into their respective roles in knee osteoarthritis management. The review aims to contribute to evidence-based advancements in regenerative therapies for knee osteoarthritis by addressing critical research priorities and refining treatment strategies.

Bibliometric analysis of the inflammatory mechanisms in knee osteoarthritis in recent 30 years

This study aimed to improve Knee Osteoarthritis (KOA) therapy by evaluating the knowledge framework and investigating research trends in inflammatory mechanisms. Conducting a thorough search on July 31, 2023, using the Science Citation Index Expanded of the Web of Science Core Collection, we identified 1,083 articles authored by 6,159 individuals from 3,610 institutions across 299 countries. China led in productivity with 377 papers, followed by the United States (253) and Japan (60). The University of California System (20 publications), Guangzhou University of Science and Technology (19), Duke University (18), and Shanghai Jiao Tong University (18) were the top institutions. Notably, the USA and Southern Medical University China held significant centrality in countries and institutions, respectively. Among 1,084 co-occurring keywords, "expression", "rheumatoid arthritis", "articular cartilage", "F kappa b", and "Synovial fluid" emerged as highly correlated topics. Analyzing inflammatory mechanisms in KOA through visualization tools offers insights into the knowledge framework, aiding in identifying future trends for better pain control. The study employed CiteSpace, VOS Viewer, and Tableau to analyze research hotspots and frontiers in inflammation mechanisms in KOA. It focused on essential signaling pathways in articular cartilage, synovial membrane, subchondral bone, and synovial fluids of OA patients and animal models, along with potential therapeutic reagents. Future exploration of the interaction between mechanisms can elucidate key factors in different pathways and the efficacy of injection therapy on inflammation.

The efficacy of platelet-rich plasma in treating osteoarthritis with an inflammatory phenotype: A 5-year follow up retrospective study

BACKGROUND

We aimed to explore whether platelet-rich plasma (PRP) can delay and reduce the incidence of total knee arthroplasty (TKA) and improve clinical symptoms in patients with inflammatory phenotype knee osteoarthritis (I-KOA).

METHODS

This was a retrospective cohort study with a 5-year follow up. We selected patients with I-KOA based on typical magnetic resonance imaging findings. Patients were divided into two groups: I-KOA and KOA. Subsequently, the patients underwent treatment for five consecutive years, receiving three fortnightly injections per year, totalling 15 injections per patient. The Kellgren-Lawrence (KL) grade and minimum joint space width (MJSW) were used to evaluate KOA progression. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society score (KSS), and the minimal clinically important difference were used to evaluate the improvement of KOA symptoms. The incidence and timing of TKA were statistically analysed.

RESULTS

In total, 420 patients were included (I-KOA, n = 211; KOA, n = 209). No significant difference existed between both groups in the changes in the MJSW and KL grade at each time point. The I-KOA group exhibited significantly lower TKA incidence and delayed time to TKA. The WOMAC, KSS, and KSS function scores were significantly better in the I-KOA group than in the KOA group at each time point after treatment (P < 0.05).

CONCLUSION

The results of this retrospective study suggest that, compared with conventional KOA, intra-articular injection of PRP has better efficacy in patients with I-KOA but does not delay disease progression.

The Effects of the Combination of Rhein and Platelet-Rich Plasma on Human Articular Chondrocytes

BACKGROUND

The presence of side effects and low bioavailability of rhein has limited its use in the treatment of osteoarthritis. We aimed to evaluate the in vitro response of human articular chondrocytes to the presence of the combination of platelet-rich plasma (PRP) and rhein.

METHODS

Solutions of rhein were prepared to assess solubility and select a working concentration. A stimulus with interleukin-1β (IL-β, 10 ng/mL) was induced for 24 h on human chondrocytes. Five treatment groups were established: control, IL-β control, PRP, rhein, and PRP + rhein. Cell viability, cell migration, nitric oxide (NO) production, tumor necrosis factor-α (TNF-α), and gene expression analyses were carried out.

RESULTS

A concentration of 50 mg/L was selected after a dose-response curve assay. Both NO and tumor TNF-α production significantly decreased after PRP and PRP + rhein treatments at 24 and 48 h. The wound healing assay revealed a significant stimulation of migration after 72 h with the PRP and PRP + rhein treatments. Expression of IL-1β, IL-6, MMP-13, and ADAMTS-5 was significantly downregulated, particularly after treatment with the combination of PRP + rhein.

CONCLUSIONS

Much of the determinations denoted a better performance of the combination of PRP and rhein in decreasing the levels of the different targets evaluated; however, this was not great enough to detect a significant difference in comparison with the PRP treatment alone.

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.

Intra-articular injection of platelet-rich plasma in patients with hemophilia and painful knee joint cartilage degeneration

INTRODUCTION

Knee arthropathy causes pain to people with hemophilia (PWH). One of the current controversies is whether injections of intra-articular platelet-rich plasma (PRP) are effective in relieving the knee pain of PWH.

AREAS COVERED

A narrative literature review was conducted on the efficacy of PRP injections in the knees of PWH.

EXPERT OPINION

Intra-articular PRP knee injections are widely used in patients with knee osteoarthritis to relieve pain and delay total knee arthroplasty. Although numerous publications have supported the use of PRP in knee osteoarthritis, there is still major controversy regarding its true usefulness, given that a number of studies with a high degree of evidence have failed to show the efficacy of PRP. With respect to painful hemophilic arthropathy, the use of PRP injections is even more controversial, as there are only four publications on the subject supporting the use of PRP in hemophilia, all of them with a low degree of evidence. A publication with grade 1 evidence recommended against the use of PRP in hemophilic arthropathy because its efficacy has not been demonstrated. My opinion is that intra-articular PRP injections should not be used in hemophilia until there is more evidence of its benefits.

Intraarticular Injections of Mesenchymal Stem Cells in Knee Osteoarthritis: A Review of Their Current Molecular Mechanisms of Action and Their Efficacy

More than 10% of the world's population suffers from osteoarthritis (OA) of the knee, with a lifetime risk of 45%. Current treatments for knee OA pain are as follows: weight control; oral pharmacological treatment (non-steroidal anti-inflammatory drugs, paracetamol, opioids); mechanical aids (crutches, walkers, braces, orthotics); therapeutic physical exercise; and intraarticular injections of corticosteroids, hyaluronic acid, and platelet-rich plasma (PRP). The problem is that such treatments usually relieve joint pain for only a short period of time. With respect to intraarticular injections, corticosteroids relieve pain for several weeks, while hyaluronic acid and PRP relieve pain for several months. When the above treatments fail to control knee pain, total knee arthroplasty (TKA) is usually indicated; however, although a very effective surgical technique, it can be associated with medical and postoperative (surgery-related) complications. Therefore, it seems essential to look for safe and effective alternative treatments to TKA. Recently, there has been much research on intraarticular injections of mesenchymal stem cells (MSCs) for the management of OA of the knee joint. This article reviews the latest information on the molecular mechanisms of action of MSCs and their potential therapeutic benefit in clinical practice in patients with painful knee OA. Although most recent publications claim that intraarticular injections of MSCs relieve joint pain in the short term, their efficacy remains controversial given that the existing scientific information on MSCs is indecisive. Before recommending intraarticular MSCs injections routinely in patients with painful knee OA, more studies comparing MSCs with placebo are needed. Furthermore, a standard protocol for intraarticular injections of MSCs in knee OA is needed.

A comprehensive review of intraarticular knee injection therapy, geniculate injections, and peripheral nerve stimulation for knee pain in clinical practice

The knee is the most common joint in adults associated with morbidity. Many pathologies are associated with knee damage, such as gout or rheumathoid arthritis, but the primary condition is osteoarthritis (OA). Not only can osteoarthritis cause significant pain, but it also can result in signficant disability as well. Treatment for this condition varies, starting off with oral analgesics and physical therapy to surgical total knee replacmenet. In the gamut of this various treatments, a conservative approach has included intra articular steroid injections. With time, researchers and clinicians determined that other components injected to the knee may additionally provide relief of this condition. In this investigation, we describe different types of knee injections such as platelet-rich plasma (PRP), hyaluronic acid, stem cells, and prolotherapy. Additionally, we describe the role of geniculate knee injections, radiofrequency, and periopheral nerve stimulation. These treatments should be considered for patients with knee pain refractory to conservative therapies.

Platelet Rich Plasma Versus Autologous Conditioned Serum in Osteoarthritis of the Knee: Clinical Results of a Five-Year Retrospective Study

Objectives: There is no consensus on the effectiveness of platelet-rich plasma (PRP) and autologous conditioned serum (ACS) in the treatment of knee osteoarthritis (OA). Also, the group of patients who will benefit most from this treatment is not clear. This study aims to understand the effects of two treatment modalities: ACS and PRP on pain and clinical scores in the treatment of OA. For this reason, we compared the long-term (five-year follow up) clinical results of the patients to whom these two treatment methods were applied.

Materials and methods: Eighty-two knee osteoarthritis cases, selected from a database prospectively maintained in our tertiary university hospital after institutional ethics committee approval, examined between January 2013 and September 2020 and treated with ACS and PRP by the same orthobiological treatment team, were retrospectively analyzed. The clinical results of group A (n=40) treated with ACS and group B (n=42) treated with PRP were statistically analyzed. Clinical evaluations were made pre-injection and at one, six, 12, 24 and 60 months post-treatment, using the knee injury and osteoarthritis result score (KOOS) for the evaluation of function and a visual analog scale (VAS) for the evaluation of pain.

Results: Side effects were noted in two patients (5%) in group A and 16 patients (38.1%) in group B. More side effects were seen in group B compared to group A (p<0.001). The better VAS scores in both groups were detected in the sixth and 12th months. When VAS scores were examined, better results were obtained in group A in the 12th and 24th months (p<0.05). When KOOS scores were examined, the superiority of ACS to PRP at 12 and 24 months was shown in KOOS.S, KOOS.P and KOOS.ADL scores (p<0.05). There was no statistically significant difference between the two groups in terms of all scores and baseline scores at 60 months.

Conclusion: The effectiveness of ACS and PRP treatments can last up to two years. After two years, the effectiveness of both treatments decreases. Comparing the two treatments, ACS treatment showed better results on VAS and KOOS scores compared to PRP treatment.