Effect of serum and platelet-rich plasma on human early or advanced degenerative meniscus cells

Platelet-rich plasma for nonoperative management of degenerative meniscal tears: A systematic review

Background

Meniscus tears are a common cause of knee pain encountered in orthopedics and sports medicine. There are numerous management strategies, from physical therapy and oral medications to surgery. Recent evidence is more favorable for conservative management, as operative treatment has limited clinical benefits and is associated with an accelerated progression toward osteoarthritis. Injections with orthobiologic therapies, such as platelet-rich plasma (PRP), are emerging as an alternative therapeutic tool for degenerative tears. This study aims to evaluate the latest evidence regarding the efficacy of PRP injections for the nonoperative management of degenerative meniscal pathology.

Data sources

Articles were obtained from Embase, PubMed, World of Science, Cochrane, and Galileo databases after searching "Platelet-rich plasma" AND "Meniscus." Inclusion criteria consisted of original, human studies evaluating the use of platelet-rich plasma for nonoperative management of meniscus tears.

Main results

A total of 384 articles were screened, with ten studies selected for final inclusion. The pooled study population comprised 686 patients, with an average age ranging from 33 to 53 years, and a 38% female population. Three different injection approaches were utilized, categorized as intra-articular alone (IA), intra-meniscal alone (IM), or a combination of both. Most studies demonstrated improved pain and functionality by 3 months that persisted for at least one year. Within the IA and IM groups, the majority of patients were either radiographically stable (30-70%) or demonstrated interval healing (40-60%). Several studies within IM and combined treatment groups evaluated rates and time to arthroscopy, and found lower failure rates and greater arthroscopy-free survival time than control comparison groups.

Conclusion

PRP appears to be a safe and efficacious treatment strategy for degenerative meniscal pathology. However, due to diverse periprocedural techniques, PRP injectate characteristics, and a lack of high-quality studies, additional trials are needed to provide greater a degree of confidence in PRP's clinical impact on patients with meniscus tears.

Level of evidence

Systematic Review.

Platelet-rich plasma use in meniscus repair treatment: a systematic review and meta-analysis of clinical studies

Background

There is conflicting clinical evidence whether platelet-rich plasma (PRP) therapies could translate to an increased meniscus healing rate and improved functional outcomes. The objective of this systematic review and meta-analysis was to compare the failure rate and patient-reported functional outcomes in meniscus repair augmented with and without PRP.

Methods

We comprehensively searched the PubMed, Web of Science, Medline, Embase, and Cochrane Library databases to identify studies that compared the clinical efficacy of meniscus repair performed with PRP versus without PRP. The primary outcome was the meniscus repair failure rate, while the secondary outcomes were knee-specific patient-reported outcomes, including the International Knee Documentation Committee (IKDC) score, Lysholm knee scale, visual analog scale, Tegner activity level score, Western Ontario and McMaster Universities Osteoarthritis Index score, Single Assessment Numeric Evaluation score, and Knee injury and Osteoarthritis Outcome Score. Furthermore, subgroup analyses were performed by stratifying the studies according to the PRP preparation technique to investigate the potential sources of heterogeneity among studies.

Results

Our meta-analysis included nine studies (two RCTs and seven non-RCTs) with 1164 participants. The failure rate in the PRP group was significantly lower than that in the non-PRP group [odds ratio: 0.64, 95% confidence interval (CI) (0.42, 0.96), P = 0.03]. Furthermore, the PRP group was associated with a statistically significant improvement in the visual analog scale for pain [Mean difference (MD): − 0.76, 95% CI (− 1.32, − 0.21), P = 0.007] and Knee injury and Osteoarthritis Outcome Score-symptom [MD: 8.02, 95% CI (2.99, 13.05), P = 0.002] compared with the non-PRP group. However, neither the IKDC score nor the Lysholm knee scale showed any differences between the two groups. In addition, the results of subgroup analyses favored PRP over platelet-rich fibrin matrix (PRFM) regarding the IKDC score.

Conclusions

Although meniscus repairs augmented with PRP led to significantly lower failure rates and better postoperative pain control compared with those of the non-PRP group, there is insufficient RCT evidence to support PRP augmentation of meniscus repair improving functional outcomes. Moreover, PRP could be recommended in meniscus repair augmentation compared with PRFM. PRFM was shown to have no benefit in improving functional outcomes.

Efficacy of Autologous Platelet-Rich Plasma Injections for Grade 3 Symptomatic Degenerative Meniscal Lesions: A 1-Year Follow-up Prospective Study

BACKGROUND

Platelet-rich plasma (PRP) injections have been proposed as a biologic option to provide symptomatic relief and delay surgery in patients with degenerative joint disease of osteoarthritis (OA). The efficacy of autologous PRP on symptomatic degenerative meniscal lesions (DMLs) has never been investigated.

HYPOTHESIS

We hypothesized that patients with symptomatic DMLs without OA undergoing autologous PRP injections experience a significant clinical improvement at 12 months.

STUDY DESIGN

Prospective case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 69 patients with symptomatic DMLs without radiographic evidence of knee OA (Kellgren-Lawrence radiographic grading scale 0-1) received 4 autologous PRP injections once a week. Patients were prospectively evaluated before the injection and then at 1, 3, 6, and 12 months. Evaluation was based on Lysholm knee scoring scale (primary outcome), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Tegner activity scale, and visual analogue scale scores.

RESULTS

Patients treated with PRP injections demonstrated an improving knee function and symptoms over the duration of the study. A significant improvement from baseline to 12 months was observed in all the outcome measures, and no patients experienced failure or required surgery during the follow-up. Patients younger than 50 years reported lower subjective level of pain and higher Tegner activity scale at baseline and had significantly better Lysholm knee scoring scale (P = 0.03) and WOMAC (P = 0.03) scores at 6 months, as well as better range of motion at 3, 6, and 12 months (P < 0.001). Thirty-three (47.8%) patients were very satisfied, 26 (37.7%) satisfied, 8 (11.6%) partially satisfied, and 2 (2.9 %) not satisfied, with 62 (89.8%) patients willing to repeat the same treatment. No patient was lost to follow-up and no patient experienced adverse reaction, infection, failure, recurrence or underwent further surgery.

CONCLUSION

PRP injections provide short-term benefits in symptomatic DMLs. Although promising results were evident at 12 months, this is a preliminary study and no definitive recommendation can be made based, for example, on longer follow-up.

CLINICAL RELEVANCE

This research supports the use of autologous PRP injections for symptomatic DMLs.

Platelet-Rich Plasma Augmentation for Isolated Arthroscopic Meniscal Repairs Leads to Significantly Lower Failure Rates: A Systematic Review of Comparative Studies

Background:

Studies have reported relatively high failure rates of isolated meniscal repairs. Platelet-rich plasma (PRP) has been suggested as a way to increase growth factors that enhance healing.

Purpose:

To compare (1) meniscal repair failures and (2) patient-reported outcomes after isolated arthroscopic meniscal repair augmented with and without PRP.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. Multiple databases were searched for studies that compared outcomes of isolated arthroscopic meniscal repair augmented with PRP versus without PRP in human patients. Failures and patient-reported outcome scores were reported for each study and compared between groups. Study heterogeneity was assessed using I² for each outcome measure before meta-analysis. Study methodological quality was analyzed. Continuous variable data were reported as mean and standard deviation from the mean. Categorical variable data were reported as frequency with percentage. All P values were reported with significance set at P < .05.

Results:

Five articles were analyzed (274 patients [110 with PRP and 164 without PRP]; 65.8% male; mean age, 29.1 ± 4.6 years; mean follow-up, 29.2 ± 22.1 months). The risk of meniscal repair failure ranged from 4.4% to 26.7% for PRP-augmented repairs and 13.3% to 50.0% for repairs without PRP. Meniscal repairs augmented with PRP had significantly lower failure rates than repairs without PRP (odds ratio, 0.32; 95% CI, 0.12-0.90; P = .03). One of the 5 studies reported significantly higher outcomes in the PRP-augmented group versus the no-PRP group for the International Knee Documentation Committee (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee injury and Osteoarthritis Outcome Score (KOOS) (P < .05 for all). The remaining 4 studies reported no significant difference between groups with regard to outcomes for the IKDC, Lysholm knee scale, visual analog scale for pain, or Tegner activity level.

Conclusion:

Although the studies were of mostly of low quality, isolated arthroscopic meniscal repairs augmented with PRP led to significantly lower failure rates (10.8% vs 27.0%; odds ratio, 0.32; P = .03) as compared with repairs without PRP. However, most studies reported no significant differences in patient-reported outcomes.

Augmentation of Meniscal Repair With Platelet-Rich Plasma: A Systematic Review of Comparative Studies

Background:

The effect of platelet-rich plasma (PRP) augmentation for meniscal repair (MR) is unclear, as current evidence is limited to small, mostly nonrandomized studies.

Purpose:

To systematically review the literature to evaluate the efficacy and safety of MR with PRP augmentation.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify studies (level of evidence 1-3) that compared the clinical efficacy of MR performed with versus without PRP. The search phrase used was platelet-rich plasma meniscus. Patients were assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the visual analog scale (VAS) for pain, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score (KOOS), the subjective International Knee Documentation Committee (IKDC) score, and treatment failure.

Results:

We identified 6 studies (2 studies with level 1 evidence; 4 studies with level 3 evidence) that met inclusion criteria, for a total of 309 patients undergoing MR with PRP (mean age, 31.9 years) and 445 patients without PRP augmentation (mean age, 29.6 years). The mean follow-up was 32.8 months (range, 12-72 months). Overall, 17.0% of PRP patients experienced MR failure compared with 22.1% of non-PRP patients. No differences in VAS, Lysholm, or subjective IKDC scores were found between groups except in 1 study, in which postoperative subjective IKDC scores were significantly better in the PRP group (P < .01). Another study found significantly better postoperative WOMAC scores among PRP patients, and 2 studies found significantly better KOOS subscores among PRP patients.

Conclusion:

There are a limited number of high-quality studies comparing outcomes and healing rates between patients undergoing MR with versus without PRP augmentation. Based on the available evidence, patients undergoing MR with PRP augmentation experience similar clinical outcomes at midterm follow-up when compared with conventional MR, and additional studies are needed to determine the efficacy of MR augmented with PRP.

Identification of Pivotal Genes and Pathways in Osteoarthritic Degenerative Meniscal Lesions via Bioinformatics Analysis of the GSE52042 Dataset

Background

To better understand the process of osteoarthritic degenerative meniscal lesions (DMLs) formation, this study analyzed the dataset GSE52042 using bioinformatics methods to identify the pivotal genes and pathways related to osteoarthritic DMLs.

Material/Methods

The GSE52042 dataset, comprising diseased meniscus samples and healthier meniscus samples, was downloaded and the differentially-expressed genes (DEGs) were extracted. The reactome pathways assessment and functional analysis were performed using the “ClusterProfiler” package and “ReactomePA” package of Bioconductor. The protein–protein interaction network was constructed, followed by the extraction of hub genes and modules.

Results

A set of 154 common DEGs, including 64 upregulated DEGs and 90 downregulated DEGs, were obtained. GO analysis suggested that the DEGs primarily participated in positive regulation of the mitotic cell cycle and extracellular matrix organization. Reactome pathway analysis showed that the DEGs were predominantly enriched in TP53, which regulates transcription of genes involved in G2 cell cycle arrest and extracellular matrix organization. The top 10 hub genes were TYMS, AURKA, CENPN, NUSAP1, CENPM, TPX2, CDK1, UBE2C, BIRC5, and CCNB1. The genes in the 2 modules were primarily associated with M Phase and keratan sulfate degradation.

Conclusions

A series of pivotal genes and reactome pathways were identified elucidate the molecular mechanisms involved in the formation of osteoarthritic DMLs and to discover potential therapeutic targets.

Meniscus-shaped cell-free polyglycolic acid scaffold for meniscal repair in a sheep model

Since loss of meniscus is correlated with an increasing risk for osteoarthritis, meniscal scaffolds are proposed as new strategies. Development of a suitable scaffold has to take into account differing meniscus thickness, exposure to compressive and tensile forces combined with high porosity and biocompatibility of the material. After physical testing of three flat scaffolds composed of different modified polyglycolic acid (PGA) fibers, a three-dimensional meniscus-shaped PGA-hyaluronan implant was generated. Micro-computed tomography showed 90% porosity in the outer area with 50% in the inner area of the implant. Biocompatibility and expression of meniscus typical cartilaginous genes were shown for human meniscus cells cultivated in the implant with 10% human serum or 5% platelet-rich plasma for 14 days in vitro. The proof-of-concept study in sheep demonstrated proteoglycan- and collagen type I-rich repair tissue formation in partial meniscectomy combined with a meniscus-shaped PGA-hyaluronan implant after 6 months. In contrast, the control showed nearly no repair tissue formation. Thus, meniscus-shaped PGA-hyaluronan implants might be a suitable therapeutic approach to support repair tissue formation in partial meniscectomy.

Efficacy of platelet-rich plasma in arthroscopic repair for discoid lateral meniscus tears

Background

To evaluate the clinical results of arthroscopic repair with or without platelet-rich plasma (PRP) for tears of the discoid lateral meniscus (DLM).

Methods

Twenty-nine patients with DLM tears within a stable knee were arthroscopically treated with meniscal suture repair. Of those, 14 were augmented with platelet-rich plasma (PRP), and 15 were performed without PRP augmentation. Patients were evaluated at baseline (the day before surgery) and then 12 and 24 months after the last injection. Evaluation included the Lysholm score, and Ikeuchi grade, Visual analogue score (VAS) for pain and failure rate. Failure was defined by patients developing symptoms of joint line pain, locking, swelling or requiring repeat arthroscopy.

Results

There was no difference in the failure rate in the PRP group (1 of 14) compared with the non-PRP group (2 of 15) (P = 0.58). Statistically significant improvement in Lysholm score, Ikeuchi grade and VAS for pain was documented at the last follow-up compared with baseline in both PRP and non-PRP group. No significantly difference was found between the PRP group and non-PRP group on Lysholm score, Ikeuchi grade and VAS for pain at the last follow-up. In the univariate analysis of each variable, younger age (P = 0.036) and longer follow-up duration (P = 0.043) were statistically associated with a better function improvement. Whereas in multivariate analysis, only younger age (P = 0.004) was significantly associated with a better function improvement.

Conclusion

With regard to clinical evaluations in arthroscopic repair for DLM tears, PRP group had similar effect in pain relief and functional improvement to non-PRP group at mid-term follow-up. Future larger prospective studies with a longer follow-up are needed to determine whether PRP should be used with DLM repair.

Effects of storage culture media, temperature and duration on human adipose‑derived stem cell viability for clinical use

Adipose-derived stem cells (ADSCs) are mesenchymal stem cells that are often used in regenerative medicine. Maintaining ADSC viability is important, as this optimizes the curative effects of cell therapy. However, the optimal conditions for cell viability preservation remain unknown. The present study aimed to acquire a better protocol for ADSC storage by comparing the effects of various solutions and temperatures for ADSC preservation, in order to suggest the most effective methods of short-term ADSC preservation for clinical use. ADSCs from passage 2 were suspended in solutions comprising 0.9% NaCl, 10% human serum (HS) or 10% platelet-rich plasma (PRP). Suspended cells were maintained at 4°C or room temperature (~26°C) for 2, 4 and 6 h. The differentiation capacity, apoptosis and proliferation of ADSCs were determined by oil red O/alizarin red S staining, flow cytometry, and a cell counting kit-8 cell proliferation assay, respectively. In addition, reverse transcription-quantitative polymerase chain reaction and western blot analysis was performed. The results revealed that proliferation of ADSCs decreased with time. The optimal time for ADSC use was ~2 h, and 4 h was determined to be the latest time that ADSCs should be used. The 10% HS group had the highest survival rate, followed by the 10% PRP group; these two groups had higher survival rates than the 0.9% NaCl group (P<0.05). HS and PRP at 4°C enhanced the ADSC proliferation rate (P<0.05), although the difference between these two groups was insignificant (P>0.05). In conclusion, the optimal time to use ADSCs was <2 h, and should not exceed 4 h. It was recommended that, for the transportation and short-term storage of ADSCs during clinical use, they should be stored with 10% HS at 4°C to maintain ADSC viability. In addition, this was a cost-effective and safe method.

Cell-Free Strategies for Repair and Regeneration of Meniscus Injuries through the Recruitment of Endogenous Stem/Progenitor Cells

The meniscus plays a vital role in protecting the articular cartilage of the knee joint. The inner two-thirds of the meniscus are avascular, and injuries to this region often fail to heal without intervention. The use of tissue engineering and regenerative medicine techniques may offer novel and effective approaches to repairing meniscal injuries. Meniscal tissue engineering and regenerative medicine typically use one of two techniques, cell-based or cell-free. While numerous cell-based strategies have been applied to repair and regenerate meniscal defects, these techniques possess certain limitations including cellular contamination and an increased risk of disease transmission. Cell-free strategies attempt to repair and regenerate the injured tissues by recruiting endogenous stem/progenitor cells. Cell-free strategies avoid several of the disadvantages of cell-based techniques and, therefore, may have a wider clinical application. This review first compares cell-based to cell-free techniques. Next, it summarizes potential sources for endogenous stem/progenitor cells. Finally, it discusses important recruitment factors for meniscal repair and regeneration. In conclusion, cell-free techniques, which focus on the recruitment of endogenous stem and progenitor cells, are growing in efficacy and may play a critical role in the future of meniscal repair and regeneration.