Effects of platelet-rich plasma on subchondral bone marrow edema and biomarkers in synovial fluid of knee osteoarthritis

Complications of Platelet Rich Plasma Injection for Knee Osteoarthritis are Similar to Corticosteroids and Hyaluronic Acid, but are Significantly Greater than Placebo Injections: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

The purpose of this review was to investigate complications of platelet rich plasma (PRP) injections for knee osteoarthritis (OA) compared to other injected substances including hyaluronic acid (HA), corticosteroids, and placebo saline.

METHODS

PubMed, Embase, Web of Science, and Cochrane databases were searched to identify randomized control trials (RCTs) comparing PRP to another injectable treatment for knee osteoarthritis with documented complications. Studies not mentioning complications or utilizing PRP during surgery were excluded. Complications were pooled to determine overall complication rate and the number needed to harm (NNH). Subgroup analyses were performed for studies comparing PRP to hyaluronic acid, corticosteroids, and placebo saline using DerSimonian-Laird random-effects models displaying odds ratios (OR).

RESULTS

Twenty-four RCTs were identified with 2751 total patients, 1318 of whom received PRP injections. There was a total of 246 complications in the PRP group and 131 in the comparison cohort (18.66% vs. 9.14%, respectively p < 0.01). The NNH was 11. Subgroup analysis showed no difference in odds of complications when PRP was compared to HA and corticosteroids (OR 1.33, p = 0.22 I2 = 0.0% and OR 3.07, p = 0.35, I2 = 63.49%, respectively), but significantly more complications compared to placebo (OR 4.88, p < 0.01, I2 = 0.00%). Only one patient reported severe pain; however all other complications were described as moderate or mild and self-limiting.

CONCLUSION

The use of PRP for knee OA is not innocuous with a significantly higher rate of complications compared to placebo. However, most complications were reported as mild to moderate, and the odds of complications are similar to that of HA or corticosteroid injections. Compared to all other injectables, the NNH for PRP is 11, which is important for physicians to consider prior to PRP therapy.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II RCTs.

Platelet-rich plasma treatment for large joint osteoarthritis: retrospective study highlighting a possible treatment protocol with long-lasting stimulation of the joint with an adequate dose of platelets

Platelet-rich plasma (PRP) therapy has emerged as a potential treatment option for osteoarthritis (OA) due to its ability to promote tissue healing and anti-inflammatory effects. More evidences are needed to establish the optimal therapy protocol. We present here a retrospective analysis of 252 patients treated with PRP for big joints OA between 2020 and 2022. We aimed to evaluate the benefits of PRP combined with rehabilitation on pain and function as well as the potential prognosis factors. We observed clinically significant improvements in pain (VAS improvement 49% at 6 months, 45% at 12 months) and function (Single Assessment Numeric Evaluation i.e. SANE score improvement 44% at 6 months, 39% at 12 months). Multiple PRP shoots and high sports activity, especially competition level, were found as favorable prognosis factors. The authors would suggest offering systematically PRP therapy for competition sports practitioners. Moreover, authors suggest that multiple PRP shoots, spaced from 3 to 4 weeks, could be a viable treatment option for OA.

Most Publications Regarding Platelet-Rich Plasma Use in the Knee Are From Asia, Investigate Injection for Osteoarthritis, and Show Outcome Improvement: A Scoping Review

PURPOSE

To evaluate and synthesize the available literature related to platelet-rich plasma (PRP) treatment of knee pathologies and to provide recommendations to inform future research in the field.

METHODS

PubMed, CINAHL, and Scopus databases were queried on October 6, 2023. All identified citations were collated and uploaded into Covidence for screening and data extraction. Studies were included if they were human studies published in English with adult cohorts that received PRP as a procedural injection or surgical augmentation for knee pathologies with patient-reported outcome measures (PROMs) and level of evidence Levels I-IV.

RESULTS

Our search yielded 2,615 studies, of which 155 studies from 2006 to 2023 met the inclusion criteria. Median follow-up was 9 months (±11.2 months). Most studies (75.5%) characterized the leukocyte content of PRP, although most studies (86%) did not use a comprehensive classification scheme. In addition, most studies were from Asia (50%) and Europe (32%) and were from a single center (96%). In terms of treatment, 74% of studies examined PRP as a procedural injection, whereas 26% examined PRP as an augmentation. Most studies (68%) examined treatment of knee osteoarthritis. Many studies (83%) documented significant improvements in PROMs, including 93% of Level III/IV evidence studies and 72% of Level I/II evidence studies, although most studies (70%) failed to include minimal clinically important difference values. The visual analog scale was the most-used PROM (58% of studies), whereas the Short Form Health Survey 36-item was the least-used PROM (5% of studies).

CONCLUSIONS

Most published investigations of knee PRP are performed in Asia, investigate procedural injection for osteoarthritis, and show significant outcome improvements. In addition, this review highlights the need for better classification of PRP formulations.

LEVEL OF EVIDENCE

Level IV, scoping review of Level I-IV studies.

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.

Use of platelet-rich plasma in rheumatic diseases

Platelet-rich plasma (PRP) has gained increasing recognition as a promising therapeutic agent in managing rheumatic diseases. Conventional treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs), primarily act on reducing inflammation but fail to address the underlying mechanisms of connective tissue degradation. PRP, an autologous preparation enriched with growth factors and bioactive molecules, is pivotal in modulating inflammation and fostering tissue regeneration. This review overviews the therapeutic potential of PRP across a spectrum of rheumatic diseases, such as osteoarthritis (OA), rheumatoid arthritis (RA), systemic sclerosis (SSc), and osteonecrosis. The regenerative capacity of PRP, driven by vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor-beta (TGF-β), promotes tissue repair, reduces cartilage damage and improves joint function. Emerging evidence supports the efficacy of PRP in early-stage OA, demonstrating superior outcomes over traditional therapies like hyaluronic acid and glucocorticoids in terms of pain relief and functional improvement. Despite its benefits, PRP therapy is characterized by variability in treatment responses, with challenges in standardizing preparation protocols and treatment regimens. This review highlights the need for robust clinical trials to establish uniform treatment protocols, optimize patient selection, and evaluate the long-term clinical outcomes of PRP therapy in rheumatic diseases.

The Effectiveness of Leukocyte-Poor Platelet-Rich Plasma Injections for Symptomatic Mild to Moderate Osteoarthritis of the Knee With Joint Effusion or Bone Marrow Lesions in a Japanese Population: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

BACKGROUND

Intra-articular platelet-rich plasma (PRP) injections have been proposed for the treatment of knee osteoarthritis (OA); however, their effectiveness in Japanese patients remains unclear.

PURPOSE

To investigate whether 3 intra-articular injections of leukocyte-poor PRP (LP-PRP) improve symptoms and joint function in symptomatic Japanese patients with mild to moderate knee OA.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Of 72 patients screened, 30 were included and randomized to receive LP-PRP (n = 15) or saline (placebo; n = 15) injections between March 2019 and February 2023. Patients attended a screening visit and 3 treatment visits at 1 week apart, followed by 3 follow-up visits (at 4, 12, and 24 weeks) after the initial treatment visit. The primary efficacy outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, whereas the secondary efficacy outcome measures were the proportion of patients showing a visual analog scale (VAS) improvement of ≥50%. Magnetic resonance imaging was performed to evaluate joint effusion and bone marrow lesions using the Whole-Organ Magnetic Resonance Imaging Score. Patients were followed for 24 weeks.

RESULTS

Patients in the PRP group (mean age, 65.9 years) had a mean hip-knee-ankle angle of 5.1°, with 7 and 8 patients demonstrating Kellgren-Lawrence grade 2 and 3 knee OA, respectively. Patients in the placebo group (mean age, 67.9 years) had a mean hip-knee-ankle angle of 3.8°, with 6 and 9 patients showing Kellgren-Lawrence grade 2 and 3 knee OA, respectively. No significant differences were identified in any baseline factors. The percentage change in Western Ontario and McMaster Universities Osteoarthritis Index scores from baseline to 24 weeks was significantly different (P= .032) between the PRP (median, 75.9%; quantile 1 [Q1], 49.6; quantile 3 [Q3], 94.1]) and placebo (median, 27.7%; Q1, -9.4; Q3, 80.9]) groups. Overall, 73.3% and 28.6% of the PRP group and placebo group, respectively, exhibited an improvement in visual analog scale scores of ≥50%, with a significant improvement observed in the PRP group (P = .027). Changes in bone marrow lesions from baseline to 24 weeks, as assessed on magnetic resonance imaging, significantly differed between groups (P = .017), with no significant differences in other secondary endpoints.

CONCLUSION

In Japanese patients with knee OA, 3 intra-articular LP-PRP injections led to clinical improvements at 24-week follow-up and significant functional improvements and pain relief after 24 weeks.

Automated system for classifying uni-bicompartmental knee osteoarthritis by using redefined residual learning with convolutional neural network

Knee Osteoarthritis (OA) is one of the most common joint diseases that may cause physical disability associated with a significant personal and socioeconomic burden. X-ray imaging is the cheapest and most common method to detect Knee (OA). Accurate classification of knee OA can help physicians manage treatment efficiently and slow knee OA progression. This study aims to classify knee OA X-ray images according to anatomical types, such as uni or bicompartmental. The study proposes a deep learning model for classifying uni or bicompartmental knee OA based on redefined residual learning with CNN. The proposed model was trained, validated, and tested on a dataset containing 733 knee X-ray images (331 normal Knee images, 205 unicompartmental, and 197 bicompartmental knee images). The results show 61.81 % and 68.33 % for accuracy and specificity, respectively. Then, the performance of the proposed model was compared with different pre-trained CNNs. The proposed model achieved better results than all pre-trained CNNs.

Bone marrow edema of the knee: a narrative review

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse.

Platelet-Rich Plasma for Knee Osteoarthritis: What Does the Evidence Say?

The utilization of platelet-rich-plasma as a therapeutic intervention for knee osteoarthritis has gained immense attention since 2008. The increase in the number of scientific publications dedicated to this area can be attributed to the majority of favorable results reported in clinical trials and basic science studies. However, despite the growing evidence, the use of platelet-rich plasma in clinical practice still poses controversial aspects. The potential mechanisms of action described for platelet-rich-plasma so far indicate that it could serve as a disease-modifying drug, acting to counteract important aspects of knee osteoarthritis pathophysiology (cartilage breakdown, inflammation, and bone remodeling). Nevertheless, its efficacy in slowing down the progression of knee osteoarthritis remains unproven. While inconsistencies have been noted, the majority of controlled clinical trials and meta-analyses advocate for the utilization of platelet-rich-plasma in treating knee osteoarthritis, as it has demonstrated greater efficacy than hyaluronic acid and placebo, with a follow-up of at least 1 year. Despite advancements made in certain areas, significant diversity persists regarding the formulations used, therapeutic regimen, extended follow-up periods, patient selection, and assessment of clinically relevant outcomes. Consequently, the leading clinical practice guidelines do not recommend its use. In light of the emerging evidence, this narrative review aims to provide an objective evaluation of the recent available scientific literature (last 5 years) focused on randomized clinical trials and meta-analyses to present a current overview of the topic.

Physical Exercise in Sports Sciences and Rehabilitation: Physiology, Clinical Applications and Real Practice

Physical exercise has long been recognized as a cornerstone of health promotion, disease prevention, and rehabilitation [...]