Effect of Platelet-Rich Plasma on Fibrocartilage, Cartilage, and Bone Repair in Temporomandibular Joint

Effects of intra-articular injection of platelet-rich plasma on the inflammatory process and histopathological characteristics of cartilage and synovium in animals with osteoarthritis: a systematic review with meta-analysis

BACKGROUND

Osteoarthritis (OA) affects the entire joint, causing structural changes in articular cartilage, subchondral bone, ligaments, capsule, synovial membrane, and periarticular muscles that afflicts millions of people globally, leading to persistent pain and diminished quality of life. The intra-articular use of platelet-rich plasma (PRP) is gaining recognition as a secure therapeutic approach due to its potential regenerative capabilities. However, there is controversial clinical data regarding efficacy of PRP for OA treatment. In this context, gathering scientific evidence on the effects of PRP in treating OA in animal models could provide valuable insights into understanding its impact on aspects like cartilage health, synovial tissue integrity, and the inflammatory process in affected joints. Thus, the objective of this study was to assess the effects of PRP injections on inflammation and histopathological aspects of cartilage and synovium in animal models of OA through a comprehensive systematic review with meta-analysis.

METHODS

A electronic search was conducted on Medline, Embase, Web of Science, The Cochrane Library, LILACS, and SciELO databases for relevant articles published until June 2022. A random-effects meta-analysis was employed to synthesize evidence on the histological characteristics of cartilage and synovium, as well as the inflammatory process. The GRADE approach was utilized to categorize the quality of evidence, and methodological quality was assessed using SYRCLE's RoB tool.

RESULTS

Twenty-one studies were included in the review, with twelve of them incorporated into the meta-analysis. PRP treatment demonstrated superior outcomes compared to the control group in terms of cartilage histology (very low quality; p = 0.0002), synovium histology (very low quality; p < 0.0001), and reductions in proinflammatory markers, including IL-1 (low quality; p = 0.002), IL-6 (very low quality; p < 0.00001), and TNF-α (very low; p < 0.00001). However, PRP treatment did not yield a significant impact on PDGF-A levels (very low quality; p = 0.81).

CONCLUSION

PRP appears capable of reducing proinflammatory markers (IL-1, IL-6, TNF-α) and mitigating cartilage and synovium damage in animals with OA. However, the levels of evidence of these findings are low to very low. Therefore, more rigorous studies with larger samples are needed to improve the quality of evidence.

PROSPERO REGISTRATION

CRD42022250314.

Current Progress of Platelet-Rich Derivatives in Cartilage and Joint Repairs

In recent years, several types of platelet concentrates have been investigated and applied in many fields, particularly in the musculoskeletal system. Platelet-rich fibrin (PRF) is an autologous biomaterial, a second-generation platelet concentrate containing platelets and growth factors in the form of fibrin membranes prepared from the blood of patients without additives. During tissue regeneration, platelet concentrates contain a higher percentage of leukocytes and a flexible fibrin net as a scaffold to improve cell migration in angiogenic, osteogenic, and antibacterial capacities during tissue regeneration. PRF enables the release of molecules over a longer period, which promotes tissue healing and regeneration. The potential of PRF to simulate the physiology and immunology of wound healing is also due to the high concentrations of released growth factors and anti-inflammatory cytokines that stimulate vessel formation, cell proliferation, and differentiation. These products have been used safely in clinical applications because of their autologous origin and minimally invasive nature. We focused on a narrative review of PRF therapy and its effects on musculoskeletal, oral, and maxillofacial surgeries and dermatology. We explored the components leading to the biological activity and the published preclinical and clinical research that supports its application in musculoskeletal therapy. The research generally supports the use of PRF as an adjuvant for various chronic muscle, cartilage, and tendon injuries. Further clinical trials are needed to prove the benefits of utilizing the potential of PRF.

Hyaluronic Acid and Platelet-Rich Plasma Mixture Versus Hyaluronic Acid and Corticosteroid in the Treatment of Temporomandibular Joint Internal Derangement: A Comparative Randomized Study

Objectives

This study aimed to compare the effects of different intra-articular injections using a mixture of hyaluronic acid (HA) and platelet-rich plasma (PRP) versus hyaluronic acid and corticosteroid in the management of TMJ internal derangement with reduction.

Materials and Methods

Sixty patients were randomly divided into two equal groups. Group I was injected with hyaluronic acid and PRP, while group II was injected with hyaluronic acid and corticosteroid. Pain intensity according to the visual analogue scale, maximum inter-incisal opening (MIO), lateral movement, and joint sound were measured pre-operatively and at 1 week, 1 month, and 6 months post-operatively.

Results

MIO and lateral movements were improved in both groups, with a reduction in the number of patients suffering from clicking sounds along the follow-up periods with no significant difference between the studied groups. However, regarding pain, the group injected with HA and PRP achieved the best results after 6 months, while patients treated with HA and corticosteroids obtained the best results at the end of the 1st week.

Conclusion

Hyaluronic acid and platelet-rich plasma mixture performed better than hyaluronic acid and corticosteroid in the treatment of TMJ internal derangement with reduction at the long-term follow-up regarding pain intensity.

The morphology and histology of the pectoral girdle of Hamipterus (Pterosauria), from the Early Cretaceous of Northwest China

As one of the mysteries volant vertebrates, pterosaurs were completely extinct in the K-Pg extinction event, which hampered our understanding of their flight. Recent studies on pterosaur flight usually use birds as analogies, since their shoulder girdle share many features. However, it was also proposed that these two groups may differ in some critical flight mechanisms, such as the primary muscles for the upstroke of the wings. Here, we describe and characterize the detail features of the pectoral girdle morphology and histology in Hamipterus from the Early Cretaceous of Northwest China for the first time. Our research reveals that the scapula and coracoid of Hamipterus form a synostosis joint, representing a distinct pectoral girdle adaption during pterosaur flight evolution, different from that of birds. The residual of the articular cartilage of the glenoid fossa supports the potential for cartilage tissue preservation in this location. The morphology of the acrocoracoid process of Hamipterus indicates it may work as a pulley for M. supracoracoideus as the main power of flight upstroke resembles that of birds. But the saddle type of the shoulder joint of the pterosaur may limit the rotation of the humerus head, suggesting a particular mechanism to control the angle of attack unlike birds. The presence of both the similarity and differences between the flight apparatus of pterosaurs and birds are highlighted in our research, which may be related to the flight mechanism and forelimb functional adaption. The distinctive feature of the flight apparatus of pterosaur should be treated with caution in future research, to better understand the life of this unique extinct volant vertebrate.

Medium-Term Effect of Treatment with Intra-Articular Injection of Sodium Hyaluronate, Betamethasone and Platelet-Rich Plasma in Patients with Temporomandibular Arthralgia: A Retrospective Cohort Study

Temporomandibular joint disorders are associated with pain and reduced jaw mobility. The aim of this study was to compare the long-term effect on pain of intra-articular TMJ injections of betamethasone, sodium hyaluronate and platelet-rich plasma. The sample was made up of 114 patients, who were randomly distributed into three groups at least three years ago and who achieved a total remission of pain after treatment. We found that the median number of months without pain was, according to each group, as follows: platelet-rich plasma: 33; sodium hyaluronate: 28; betamethasone: 19. Both platelet-rich plasma and sodium hyaluronate lead to significant pain-free time after treatment; when we compare bethametasone with the two other substances, it proved to be very ineffective.

Mesenchymal stem cells-derived microvesicles versus platelet-rich plasma in the treatment of monoiodoacetate-induced temporomandibular joint osteoarthritis in Albino rats

Temporomandibular joint osteoarthritis (TMJ-OA) is a serious disease, designated by severe joint pain and dysfunction. Limitations of current therapeutics have led to an increased interest in regenerative strategies. Recently, the non-surgical treatment of OA has seen increased use of biologic injectable therapies like mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Although these biotherapies represent an admirable effort, more studies are necessary to determine their efficacy. Thus, the aim of this study was to assess the curative potential of a single intra-articular injection of bone marrow MSCs-derived microvesicles (BM-MSCs-MVs) versus a single intra-articular injection of PRP in monoiodoacetate (MIA)-induced TMJ-OA model in Albino rats. Forty-eight male rats were used. A single intra-articular unilateral MIA injection was utilized to induce TMJ-OA. One week post induction, rats were sorted into 3 groups (16 rats each): group (I): received no treatment, groups (II) & (III): received BM-MSCs-MVs and PRP respectively. Scarification was done at 2 and 4 weeks from onset of treatment. Histological changes of the condylar TMJ were examined with H&E staining. Expression of IL-1β, TNF-α, NF-κB, MMP-13, MMP-3, and collagen ΙΙ markers was detected using real-time PCR. Histologically, the osteoarthritic group exhibited degenerated condylar tissues which were aggravated at 4 weeks. Oppositely, a marked improvement in the condylar TMJ histology was noticed in both the BM-MSCs-MVs-and PRP-treated groups at both time intervals. Additionally, the treated groups showed a decrease in IL-1β, TNF-α, NF-κB, MMP-13 and MMP-3 and an increase in collagen ΙΙ genes expression in contrast to the untreated group. Moreover, this difference was significant in the BM-MSCs-MVs group as compared to the PRP-treated group. Our results concluded that BM-MSCs-MVs as well as PRP treatments were able to target the key pathological features in OA, mainly inflammation and matrix degradation, and helped in restoring condylar structure in TMJ-OA rat model. However, BM-MSCs-MVs treatment exhibited more efficient therapeutic potential as compared to PRP treatment.

Advances in Tissue Engineering of the Temporomandibular Joint Disc: An Overview of Current Status and Future Directions

Advances in tissue engineering have progressed to potentially offer a solution to temporomandibular joint disc (TMJ) disorders not amenable to conservative therapies. Conclusive treatment options for patients with end-stage disc disorders requires discectomy and reconstruction of the articular disc with various materials. Tissue engineering TMJ disc is a promising alternative to the limited and sometimes inadequate clinical options in the management of such disorders. However, tissue engineering is far from completion for the TMJ disc regeneration. This review briefly discusses the properties of native disc, the mechanism by which TMJ disorders manifest, and how a tissue engineered disc could assuage the problems inherent in the management of such disorders. Furthermore, the review addresses and provides updates to relevant themes of tissue engineering in regards to the TMJ disc, namely, the scaffolds, cells and biomarkers, hurdles in tissue engineering of the disc, and its application in translation to the clinical practice and future directions.

Regeneration potential of bone marrow derived mesenchymal stem cells and platelet rich plasma (PRP) on irradiation-induced damage of submandibular salivary gland in albino rats

Radiation-induced damage to salivary glands (SG) is a consequence of radiotherapy for head and neck cancers. Recovery of the irradiated SG has been studied using various regenerative approaches. This study aims to compare the regenerative potentials of platelet-rich plasma (PRP) and bone marrow mononuclear cells (BMMCs) on irradiated rat submandibular salivary glands (SMD). 32 healthy male albino rats were irradiated with a single dose of 6 Gy then classified into four groups. Group A received no treatment while the other 3 groups were injected 24 h post-radiation with a single dose of either; BMMCs (Group B), PRP (Group C), or BMMCs suspended in PRP (Group D). SMD regeneration was assessed in terms of histological changes and TGF- β1 gene expression. The results showed that compared to the untreated group all groups showed successful regeneration with group D showing the best results. A statistically significant increase in the surface area of acini and TGF- β1 gene expression was observed in group D, followed by group C, then B. Our results prove that using PRP and BMMCs could be promising in decreasing irradiation side effects on SG. Moreover, combining PRP and BMMCs gives better effects compared to each therapy alone.

Chondrotoxic effects of intra-articular injection of local anaesthetics in the rabbit temporomandibular joint

The aim of this study was to investigate the chondrotoxic effects of a single-dose intra-articular injection of articaine, lidocaine, and bupivacaine on the rabbit temporomandibular joint (TMJ). Twenty-four rabbits were divided into four groups: control (group 1), articaine (group 2), lidocaine (group 3), and bupivacaine (group 4). Synovial fluid samples and venous blood were taken to evaluate matrix metalloproteinase 3 (MMP-3) levels. One millilitre of local anaesthetic solution was injected in the study groups and saline solution in the control group. The rabbits were euthanized after 4 weeks and the mandibular condyles and articular discs were evaluated. On histological examination, the study group samples had irregular joint surfaces, decreased collagen, and a thinner cartilage layer. Apoptotic cells were evaluated with the TUNEL method. TUNEL-positive apoptotic cell counts were higher in all study groups compared to the control group, and the difference was significant (P < 0.001). The mean preoperative serum MMP-3 level for all groups was 5.71 ± 3.33 ng/mL, while the mean postoperative level was 22.61 ± 6.36 ng/mL; this difference was significant (P < 0.001). A single-dose intra-articular injection of local anaesthetic had apoptotic effects on chondrocytes, leading to degenerative changes in the TMJ articular structures. Articaine was found to have less harmful effects than lidocaine and bupivacaine. Intra-articular injection of local anaesthetics should be limited in the TMJ because of the potential toxic effects.

A rabbit model to investigate temporomandibular joint osteochondral regeneration

OBJECTIVE

The objective of this study was 2-fold: (1) to describe the rabbit temporomandibular joint (TMJ) anatomy and (2) to provide a detailed, step-by-step description of a minimally invasive approach to perform a standard osteochondral TMJ defect that can be used to investigate the regenerative potential of biomaterials.

STUDY DESIGN

This study was performed in 2 steps. In the first, a total of 8 rabbit carcasses (n = 16 joints) were used to study the normal TMJ anatomy and histology to develop a minimally invasive approach to access the articulating surface of the condyle to perform a standard osteochondral defect. In the second, the surgical procedure was performed in 10 live animals to evaluate the feasibility of the model and to evaluate the regenerative potential of a biodegradable light-cured hydrogel seeded with stem cells (results not shown).

RESULTS

The cartilage of the mandibular condyle showed 4 layers: fibrous, proliferative, hypertrophic, and a zone of calcified cartilage. Positive safranin O staining was observed in the cartilage. The mean duration of the procedure (from incision to last stitch) was 35.5 (±9.21) minutes. All animals survived the procedures without any major complications.

CONCLUSIONS

This animal model represents an easy and nonmorbid surgical approach to rabbit TMJ.

Research progress on tissue engineering in repairing tempomandibular joint

Temporomandibular joint osteoarthritis (TMJOA) is mainly manifested as perforation of temporomandibular joint disc (TMJD) and destruction of condylar osteochondral complex (COCC). In recent years, tissue engineering technology has become one of the effective strategies in repairing this damage. With the development of scaffold material technology, composite scaffolds have become an important means to optimize the performance of scaffolds with the combined advantages of natural materials and synthetic materials. The gelling method with the minimally invasive concept can greatly solve the problems of surgical trauma and material anastomosis, which is beneficial to the clinical transformation of temporomandibular joint tissue engineering. Extracellular matrix scaffolds technology can solve the problem of scaffold source and maximize the simulation of the extracellular environment, which provides an important means for the transformation of temporo joint tissue engineering to animal level. Due to the limitation of the source and amplification of costal chondrocytes, the use of mesenchymal stem cells from different sources has been widely used for temporomandibular joint tissue engineering. The fibrochondral stem cells isolated from surface layer of articular cartilage may provide one more suitable cell source. Transforming growth factor β superfamily, due to its osteochondrogenesis activity has been widely used in tissue engineering, and platelet-rich derivative as a convenient preparation of compound biological factor, gradually get used in temporomandibular joint tissue engineering. With the deepening of research on extracellular microenvironment and mechanical stimulation, mesenchymal stem cells, exosomes and stress stimulation are increasingly being used to regulate the extracellular microenvironment. In the future, the combination of complex bioactive factors and certain stress stimulation may become a trend in the temporomandibular joint tissue engineering research. In this article, the progress on tissue engineering in repairing COCC and TMJD, especially in scaffold materials, seed cells and bioactive factors, are reviewed, so as to provide information for future research design and clinical intervention.

Therapy of antigen-induced arthritis of the temporomandibular joint via platelet-rich plasma injections in domestic pigs

The aim of this animal study was to investigate the effect of platelet-rich plasma (PRP) injections into the temporomandibular joint (TMJ) to treat antigen-induced arthritis AIA. AIA was induced via the application of bovine serum albumin (BSA) into the TMJ. Clear histological signs and protein analysis results indicating inflammation of the TMJ were observed. Afterwards, two PRP injections were performed over an interval of 2 weeks. Concentration levels of the proinflammatory cytokines IL-1β (PRP: 33.7 ± 5.6 pg/mg, untreated: 50.0 ± 2.9 pg/mg; p = 0.04) and TNF-α (PRP: 20.7 ± 2.5 pg/mg, untreated: 31.4 ± 2.7 pg/mg; p = 0.03) were significantly decreased in the PRP-treated joints. A significant reduction in signs of histological inflammation, such as hyperplasia of the synovial membrane, leucocyte infiltration, cartilage surface alterations, and an increase in cartilage-specific glycosaminoglycan content, was observed. This animal study supports the understanding of the underlying effects of PRP treatment in the TMJ, and may enhance novel PRP therapies in the future.

Randomised controlled trial of arthrocentesis with or without PRF for internal derangement of the TMJ

This prospective randomised clinical study aims to evaluate different treatments in patients with temporomandibular disorder. Control group (C) patients underwent arthrocentesis and experimental group (E) patients underwent injectable platelet-rich fibrin (İ-PRF) in addition to arthrocentesis. Helkimo Clinical Dysfunction Score (HCDS) examinations and VAS scores of the patients were recorded at the end of the 10th day, 1 month and 3 months. 36 patients (17 females, 19 males), 18 in the experimental and 18 in the control group, aged between 18 and 64 years and in groups 3, 4 and 5 according to Wilke's classification were included in this study. Improvement of VAS (E mean: 5,83, E standard deviation: 2,550, C mean: 2,94, C standard deviation: 2,043, p<0.001) and HCDS (E mean: 13,61, E standard deviation: 5,158, C mean: 9,22, C standard deviation: 6,916, p:0.039) of the experimental group patients was significantly higher than control group at the end of the third month. As a result of this study, the combination of i-PRF with arthrocentesis gave a much better outcome than arthrocentesis alone. Additional PRF injection should be preferred for severe dysfunction. Further studies with long-term follow-up are needed to better understand the effects of i-PRF.

Addition of platelet-rich plasma supports immune modulation and improved mechanical integrity in Alloderm mesh for ventral hernia repair in a rat model

The recurrence of ventral hernias continues to be a problem faced by surgeons, in spite of efforts toward implementing novel repair techniques and utilizing different materials to promote healing. Cadaveric acellular dermal matrices (Alloderm) have shown some promise in numerous surgical subspecialties, but these meshes still suffer from subsequent failure and necessitation of re-intervention. Here, it is demonstrated that the addition of platelet rich plasma to Alloderm meshes temporally modulates both the innate and cytotoxic inflammatory responses to the implanted material. This results in decreased inflammatory cytokine production at early time points, decreased matrix metalloproteinase expression, and decreased CD8+ T cell infiltration. Collectively, these immune effects result in a healing phenotype that is free from mesh thinning and characterized by increased material stiffness.

Comparison of Autologous Platelet-Rich Plasma and Chitosan in the Treatment of Temporomandibular Joint Osteoarthritis: A Retrospective Cohort Study

PURPOSE

The purpose of this article is to study the effect of autologous platelet-rich plasma (PRP) injected into the upper cavity of the temporomandibular joint (TMJ) on the treatment of TMJ osteoarthritis.

PATIENTS AND METHODS

We retrospectively analyzed the data of 27 patients with TMJ osteoarthritis treated at the China Medical University Hospital of Stomatology from September 2018 to September 2019. Maximal interincisal opening, pain intensity, and TMJ sounds were recorded and compared before treatment and at the 3rd and 6th months after the treatment. SPSS 24.0 software was used to analyze the data of each group, and the imaging changes in the condylar bone were compared before and 6 months after the treatment. The P-value was set at .05.

RESULTS

Better results were observed in the group treated with PRP on maximal interincisal opening and pain intensity than in the group receiving chitosan treatment. Regarding TMJ sounds, relief was observed in both groups, with no significant difference.

CONCLUSIONS

The effect of PRP on the improvement of the maximal interincisal opening and pain intensity of patients with TMJ osteoarthritis is better than that of chitosan. However, it should be noted that the incidence of complications associated with the injection of PRP may be higher than that with injection of chitosan.

The Application of Intra-Articulr Injections for Management of the Consequences of Disc Displacement without Reduction

The aim of the study was to make a comparative studies on the effectiveness of platelet rich plasma (PRP) and hyaluronic acid (HA) in intra-articular injections to the temporomandibular joints-in double blind studies application-based on the analysis of selected clinical parameters of functional efficiency and the mean value of joint's pain intensity before and after management. The study enrolled a group of 100 patients, aged 21 to 43 years, of both sexes, who came for the prosthodontic treatment. All patients had II b group of disorder according to the Research Diagnostic Criteria/Temporomandibular Disorder, and were consecutively, alternately assigned to the groups, 50 patients in each. Study group PRP was treated with intra-articular injection of platelet rich plasma and study group HA had injection with hyaluronic acid. The examination was double-blind, so that the injecting physician and the patient were not informed what kind of medicinal substance they received in the joint injection. The final selected clinical parameters did not differ statistically significantly between the groups, what means that both administered substances were effective in the repair of intra-articular structures. The results of research showed that the use of PRP and HA in intraarticular joint's injections positively affects in selected clinical parameters and decrease of the pain in temporomandibular joints in the case of disc displacement without reduction.

Autologous Freeze-Dried, Platelet-Rich Plasma Carrying Icariin Enhances Bone-Tendon Healing in a Rabbit Model

BACKGROUND

Tendon-bone interface (TBI) injuries are common in sports activities. Owing to the limited regenerative ability of the TBI, its functional healing remains a difficulty in clinical practice. Icariin (ICA) provides strong stimulation for osteogenesis. Platelet-rich plasma (PRP) can be used as a carrier for bioactive molecules, although its ability to provide sustained release for such molecules needs improvement.

HYPOTHESIS

Freeze-dried PRP (FD-PRP) as a carrier for ICA can provide sustained release of ICA into the tendon-bone (T-B) healing site, thus accelerating T-B healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 84 New Zealand rabbits with partial patellectomy in the hindlimb were randomly allocated into 3 different treatments: ICA incorporated with FD-PRP (ICA/FD-PRP), FD-PRP alone (FD-PRP), or saline control (CTL). The rabbit patella-patellar tendon (PP) interfaces were postoperatively harvested at postoperative week 8 or 16 for gross, radiological, histological, and mechanical evaluations.

RESULTS

Our results showed that FD-PRP can act as a carrier for sustained release of ICA into the T-B healing site. Macroscopically, no signs of infection or osteoarthritis were shown in the regenerated PP interfaces, and the area of cartilaginous metaplasia in the FD-PRP and ICA/FD-PRP groups at postoperative week 16 was significantly larger than that of the CTL group (P < .05 for all). Radiologically, micro-computed tomography showed that new bone which formed at the healing site in the ICA/FD-PRP group was significantly increased, remodeled, and mineralized in comparison with the CTL group (P < .05 for all). Histologically, the ICA/FD-PRP group exhibited a significant native PP interface, as shown by the enlargement and remodeling of new bone, well-organized collagen fibers, and robust production of proteoglycans in the regenerated fibrocartilage. The mechanical strength of the regenerated PP interface was significantly improved in the ICA/FD-PRP group. Significantly higher failure load and stiffness were shown in the ICA/FD-PRP group compared with the CTL and FD-PRP groups, respectively (P < .05 for all).

CONCLUSION

FD-PRP is a suitable sustained-release carrier for ICA, and ICA/FD-PRP can provide sustained release of ICA into the T-B healing site, thus effectively accelerating T-B healing.

CLINICAL RELEVANCE

Findings of this study demonstrate the feasibility of using FD-PRP as a carrier for ICA to improve T-B healing and provide a foundation for future clinical application.

Condylotomy to Reverse Temporomandibular Joint Osteoarthritis in Rabbits

PURPOSE

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is characterized by local tissue degeneration and pain. Treatments have been aimed at reducing symptoms, and only some can interfere with the progression of pathophysiologic changes caused by OA. Condylotomy is an alternative treatment for patients with OA refractory to conventional treatment. The aim of the present animal study was to investigate the influence of condylotomy on TMJ OA in New Zealand rabbits.

MATERIALS AND METHODS

The 36 rabbits were divided into 3 groups: the osteoarthritis group (OG; induced OA), treatment group (TG; induced OA plus condylotomy), and control group (CG; neither OA nor surgery). OA was induced using intra-articular monosodium iodoacetate injection for 40 days. The rabbits in the TG underwent condylotomy and were killed 20, 40, and 60 days after treatment. The rabbits in the CG and OG were killed at the same points.

RESULTS

The articular joint condition was better in the TG 60 days after surgery (P = .032). A direct comparison revealed regression of TMJ OA over time among the treated rabbits (P = .008). Surgical treatment promoted mandibular condylar remodeling in the TG, reversing the tissue degeneration caused by OA.

CONCLUSIONS

Our findings suggest that condylotomy could be an option for the treatment of OA and prevent damage to TMJ structures. This could be of particular importance for patients without satisfactory responses to more conservative treatment.

Combination of estrogen deficiency and excessive mechanical stress aggravates temporomandibular joint osteoarthritis in vivo

OBJECTIVE

It has been suggested that degenerative conditions of the temporomandibular joint (TMJ), such as osteoarthritis (OA) and progressive condylar resorption, are caused by multiple etiological factors, such as hormonal imbalance and excessive mechanical stress. However, it is unclear whether these factors interrelate in the degenerative process of the condyle. The aim of this study was to observe the effects of combined hormonal imbalance and excessive mechanical stress on the condyle using a mouse model.

MATERIALS AND METHODS

Ovariectomy (OVX) was performed in 8-week-old female mice. Three weeks after OVX, a build-up resin was bonded to the right maxillary molars to create imbalanced occlusion (increased occlusal vertical dimension, iOVD). Mice were divided into four groups: control, OVX, iOVD, and OVX + iOVD.

RESULTS

Histomorphometric analysis showed the lowest cartilage thickness and the highest TMJ-OA score in the OVX + iOVD group. Bone structural analysis showed significantly lower subchondral bone mass in all experimental groups. Additionally, the OVX + iOVD group showed up-regulated osteoclastic activity and increased apoptosis in the condyle. Gene expression analysis showed significantly elevated expression of pre-inflammatory cytokines in the OVX + iOVD group. These data showed that the OVX + iOVD group exhibited the most severe inflammatory TMJ-OA. Upregulation of ERα and activation of the ERK pathway was observed in the OVX + iOVD group.

CONCLUSIONS

Additive effects of estrogen deficiency and excessive mechanical stress on the condyle exacerbate TMJ-OA. Furthermore, estrogen deficiency and excessive mechanical stress combined may exacerbate TMJ-OA though activation of the ERK pathway.

The Role of Platelet-Rich Plasma in Cartilage Pathology: An Updated Systematic Review of the Basic Science Evidence

PURPOSE

To review the basic science studies on platelet-rich plasma (PRP) for cartilage and determine whether there has been an improvement in methodology and outcome reporting that would allow for a more meaningful analysis regarding the mechanism of action and efficacy of PRP for cartilage pathology.

METHODS

The PubMed/MEDLINE and EMBASE databases were screened in May 2017 with publication dates of January 2011 through May 2017 using the following key words: "platelet-rich plasma OR PRP OR autologous conditioned plasma (ACP) OR ACP AND cartilage OR chondrocytes OR chondrogenesis OR osteoarthritis OR arthritis." Two authors independently performed the search, determined study inclusion, and extracted data. Data extracted included cytology/description of PRP, study design, and results.

RESULTS

Twenty-seven studies (11 in vitro, 13 in vivo, 3 in vitro and in vivo) met the inclusion criteria and were included in the study. All of the studies (100%) reported the method by which PRP was prepared. Two studies reported basic cytologic analysis of PRP, including platelet, white blood cell, and red blood cell counts (6.7%). Nine studies reported both platelet count and white blood cell count (30.0%). Twelve studies reported platelet count alone (40.0%). Nine studies (30.0%) made no mention at all as to the composition of the PRP used. PRP was shown to increase cell viability, cell proliferation, cell migration, and differentiation. Several studies demonstrated increased proteoglycan and type II collagen content. PRP decreased inflammation in 75.0% of the in vitro studies reporting data and resulted in improved histologic quality of the cartilage tissue in 75.0% of the in vivo studies reporting data.

CONCLUSIONS

Although the number of investigations on PRP for cartilage pathology has more than doubled since 2012, the quality of the literature remains limited by poor methodology and outcome reporting. A majority of basic science studies suggest that PRP has beneficial effects on cartilage pathology; however, the inability to compare across studies owing to a lack of standardization of study methodology, including characterizing the contents of PRP, remains a significant limitation. Future basic science and clinical studies must at a minimum report the contents of PRP to better understand the clinical role of PRP for cartilage pathology.

CLINICAL RELEVANCE

Establishing proof of concept for PRP to treat cartilage pathology is important so that high-quality clinical studies with appropriate indications can be performed.

The Effect of Platelet-Rich Plasma on the Temporomandibular Joint After Radiotherapy in Rabbits

OBJECTIVES

Platelet-rich plasma (PRP) was administered into the temporomandibular joint (TMJ) space, which had been exposed to radiotherapy (RT), in an attempt to prevent and/or treat the late-term complications associated with RT when used for the treatment of head and neck cancers (nasopharyngeal cancer in particular) on the musculoskeletal system.

METHODS

A total of 13 adult male New Zealand ( Oryctolagus cuniculus) rabbits were used in the study. The animals were classified into 3 groups: 6 in the RT group, 6 in the RT+PRP group, and 1 in the control group (exposed to neither). The TMJ space of each rabbit was exposed to 2240 cGy external RT in total, and PRP was administered into the TMJ space 1 month later. The joints were surgically removed 1 month later and examined histopathologically.

RESULTS

In the group given RT+PRP, the level of inflammation, amount of muscle fibrosis, vascular wall fibrosis, synovial membrane and condyle cartilage thickness, temporal extrabone fibrous cell layer count, and intramuscular changes were similar to those recorded in the control group, although the positive effects of PRP were not found to be statistically significant.

CONCLUSIONS

The findings of the present study demonstrate that injections of PRP may increase joint inflammation and therefore enhance blood supply, resulting in the onset of regeneration. These favorable effects of PRP may be helpful in the fight against late-term musculoskeletal complications of RT and may minimize such side effects as sore jaw, malnutrition, and weight loss.

Platelet-Rich Plasma in Treatment of Temporomandibular Joint Dysfunctions: Narrative Review

Background: The aims of this narrative review were to examine up-to-date literature in order to evaluate the effectiveness of arthrocentesis or injections with platelet-rich plasma in temporomandibular affections and to compare them to arthrocentesis alone or with hyaluronic acid (HA) or to hyaluronic acid injections. Methods: The search of international literature was made on the PMC, PubMed and Cochrane databases, including all full-length text of studies on humans focused on osteoarthritis and disc displacements and their treatment with platelet-rich plasma arthrocentesis or injections. All design studies were included in the review and they were examined for three different outcomes: pain, joint sound and mandibular motion. English papers were only selected. Results: Even though the low number of studies in this field, arthrocentesis with platelet-rich plasma and platelet-rich plasma injections in temporomandibular disorders’ management were found to be effective in reducing pain and joint sound as well as in improving mandibular motion in a maximum follow-up of 24 months. Conclusion: Comparison to arthrocentesis alone or to HA use in arthrocentesis or by injections provided encouraging results in terms of the effectiveness of platelet-rich plasma use.

Effect of platelet-rich plasma on temporomandibular joint cartilage wound healing: Experimental study in rabbits

PURPOSE

The aim of the study is to evaluate the effect of platelet-rich plasma (PRP) injection on temporomandibular joint (TMJ) cartilage and subchondral bone healing.

MATERIALS AND METHODS

Sixteen New Zealand rabbits were divided into two groups, including single PRP and multiple PRP injection groups. Sodium mono-iodoacetate (MIA) was injected bilaterally into the TMJ of all rabbits to create osteoarthritis (OA). PRP was injected once into the right TMJ in the single PRP group and was injected three times (once a week) into the right TMJ in the multiple injection group 4 weeks after injection of MIA. At the time of each PRP injection, isotonic NaCl solution was injected into the left TMJ in the control groups. All animals were sacrificed 30 days after the first PRP injection.

RESULTS

As a result of the histological evaluation, there was no statistically significant difference in cartilage and subchondral bone regeneration between the groups (p > 0.05).

CONCLUSIONS

Although there was no statistically significant difference between PRP and control groups, it was seen that improvement were better in PRP groups. According to the Results of our study, it seems that different methods should be tried to investigate the efficacy of PRP on the TMJ healing.

Effectiveness of platelet-rich plasma injection in patients with temporomandibular joint osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this study was to investigate the effectiveness of platelet-rich plasma (PRP) injection after arthrocentesis or arthroscopy in patients with temporomandibular joint osteoarthritis.

STUDY DESIGN

Electronic databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched for reports up to July 30, 2018. We included all published or unpublished randomized controlled trials (RCTs). The primary outcome was pain reduction, and the secondary outcome was the improvement of maximal mouth opening. Weighted mean differences were utilized for random-effect meta-analysis.

RESULTS

Five RCTs were enrolled in the meta-analysis, comparing PRP injection to placebo (hyaluronic acid [HA] injection, saline injection, or no injection). The results revealed that PRP injection was more effective than placebo in pain reduction, but no in the improvement of maximal mouth opening, in the long term. In the subgroup analysis, PRP injection yielded better outcome only in pain reduction comparing to HA injection (Weighted mean difference 1.34, 95% confidence interval [CI] 0.95-1.73).

CONCLUSIONS

This meta-analysis demonstrated that PRP injection provided adjuvant efficacy to arthrocentesis or arthroscopy in pain reduction for temporomandibular joint osteoarthritis in the long term. Furthermore, PRP injection significantly reduced pain better compared with HA injection, saline injection, or no injection.

Effect of arthrocentesis plus platelet-rich plasma and platelet-rich plasma alone in the treatment of temporomandibular joint osteoarthritis: A retrospective matched cohort study (A STROBE-compliant article)

Although the research on using platelet-rich plasma (PRP) for temporomandibular joint osteoarthritis (TMJ-OA) has advanced, no unified standards exist for determining the joint use of arthrocentesis and the injection dose and frequency of PRP. This study aimed to compare the efficacy of 2 TMJ-OA treatment approaches, arthrocentesis plus platelet-rich plasma (A+PRP) and PRP alone, and attempted to provide another potential treatment option with a single injection of 2 mL of high-concentration and high-purity PRP.This retrospective matched cohort study enrolled 208 patients who were treated for temporomandibular disorders (TMDs) in the Department of Oral and Maxillofacial Surgery of Tainan Sin-Lau Hospital between August of 2013 and January of 2016, from which 90 patients were selected for the final analysis. The predictor variables were treatment outcome indicators, including joint crepitus sounds, TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, temporomandibular joint (TMJ) arthralgia, pain when chewing most foods, and maximum assisted opening (MAO). The data were analyzed using χ tests, t tests, and multiple regression analyses.Among the 90 patients, 30 were assigned into the A+PRP group, and 60 were included in the PRP group. A matching method was used to ensure no statistically significant differences in the categorical and continuous variables between the 2 groups. After treatment, both the A+PRP and PRP groups showed improvements in TMJ-OA. The 2 treatment groups did not show statistically significant differences in the symptom improvement rates of joint crepitus sounds, reparative remodeling, and TMJ arthralgia. However, compared with PRP alone, the A+PRP treatment demonstrated superior performance in improving TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, and pain when chewing most foods.Both A+PRP and PRP treatments can effectively improve multiple symptoms of TMJ-OA. Based on the results from this study, we recommend a single injection with 2 mL of high-concentration and high-purity PRP for TMJ-OA treatment. For patients with TMJ-OA accompanied by other clinical symptoms, including TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, and pain when chewing most foods, a treatment approach using arthrocentesis prior to a PRP injection can achieve a higher efficacy.

Platelet-rich plasma for the therapeutic management of temporomandibular joint disorders: a systematic review

This systematic review aimed to investigate whether intra-articular injections of platelet-rich plasma (PRP) are beneficial for the treatment of degenerative temporomandibular disorders, such as temporomandibular joint osteoarthritis (TMJ-OA) and disc displacement with osteoarthritic lesions, when compared to other treatments, such as injections of hyaluronic acid (HA) or saline. An electronic search of the MEDLINE and Scopus databases was performed using combinations of the terms "temporomandibular" and "platelet rich plasma", to identify studies reported in English and published up until May 2017. A hand-search of relevant journals and the reference lists of selected articles was also performed. The initial screening identified 153 records, of which only six fulfilled the inclusion criteria and were included in this review. Of these studies, three compared PRP with HA, while three compared PRP with Ringer's lactate or saline. Four of the studies found PRP injections to be superior in terms of improvements in mandibular range of motion and pain intensity up to 12 months after treatment, while the remaining two studies found similar results for the different treatments. There is slight evidence for the potential benefits of intra-articular injections of PRP in patients with TMJ-OA. However, a standardized protocol for PRP preparation and application needs to be established.

Histological and Immunohistochemical Analyses of Repair of the Disc in the Rabbit Temporomandibular Joint Using a Collagen Template

A previous study demonstrated that the reconstituted type I collagen matrix extracted from rabbit tendons enabled the TMJ disc to regenerate in the rabbit. The aim of this study was to investigate changes in the extracellular matrix (ECM) and mechanisms of regeneration in the TMJ disc. In 36 New Zealand rabbits that underwent a partial discectomy, discs were replaced with reconstituted collagen templates for 3 months. A histological analysis showed that moderate to severe degeneration appeared in partially discectomized joints without implantation. In contrast, discs experienced regeneration of reconstituted collagen template implantation and the joint returned to normal function. Cells in the regenerative tissue expressed ECM, and fibers became regular and compact due to tissue remodeling over time. Reparative cells differentiated into chondroblasts, and showed highly dense pericellular fibers. The morphology and collagen composition of the disc and condyle in the 3-month experimental group were similar to those of normal tissues. In conclusion, the reconstituted collagen template facilitated the regeneration of surgically discectomized discs. Type I and type II collagens play a crucial role in the regeneration of articular discs.

The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Methods

Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.

Results

Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs.

Conclusions

Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively.

Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1.

Clinical efficacy of a centric relation occlusal splint and intra-articular liquid phase concentrated growth factor injection for the treatment of temporomandibular disorders

The agony that accompanies the incidence and symptoms of temporomandibular disorders (TMDs) is an important concern in the oral and maxillofacial region. The objective of this study was to explore the clinical findings after centric relation occlusal splint (CROS) treatment and intra-articular injection treatment with liquid phase concentrated growth factors (LPCGFs) in patients with disc displacement without reduction (DDWOR).The group under investigation of this retrospective cohort study included patients with DDWOR who received treatment from April 2014 until March 2016. The predictor variable was the therapeutic method. The outcome variables included joint crepitus sound, visual analog scale (VAS) of temporomandibular joint (TMJ) arthralgia, TMD-associated headache, myofascial pain with referral, deviation of the mandible during opening (DoM), and maximal interincisal opening (MIO). At the stage of CROS treatment, evaluation of all variables adopted the individual as the unit; at the stage after LPCGF injection, the evaluation of joint sound adopted the joint as the unit, whereas the other variables adopted the individual as the unit.Among the 29 patients, 6 (20.68%) were males and 23 (79.31%) were females. Distribution by age ranged from 15 to 84 years (mean age 39.55 ± 15.49 years). After CROS treatment, except for the joint crepitus sound, which failed to achieve significant improvement (P > 0.05), other symptoms, such as DOM, TMD-associated headache, myofascial pain with referral, TMJ arthralgia, and MIO, all achieved statistically significant improvements (P < 0.05). After 2 mL of LPCGF was injected once after CROS treatment, 26 joint crepitus sound symptoms were relieved (P < 0.001) after an average of 48.5 ± 64.1 days.CROS alone can alleviate TMD clinical symptoms, except for the joint crepitus sound. Approximately 72.2% of joint crepitus sounds could be improved within 48 days, on average, once 2 mL of LPCGF was injected. Comparisons were still required in the future, with the effects of other therapeutic methods.

Application of platelet-rich plasma with stem cells in bone and periodontal tissue engineering

Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone loss. Autogenous bone is the present gold standard of bone regeneration. However, disadvantages like donor site morbidity and its decreased availability limit its use. Even allografts and synthetic grafting materials have their own limitations. As certain specific stem cells can be directed to differentiate into an osteoblastic lineage in the presence of growth factors (GFs), it makes stem cells the ideal agents for bone regeneration. Furthermore, platelet-rich plasma (PRP), which can be easily isolated from whole blood, is often used for bone regeneration, wound healing and bone defect repair. When stem cells are combined with PRP in the presence of GFs, they are able to promote osteogenesis. This review provides in-depth knowledge regarding the use of stem cells and PRP in vitro, in vivo and their application in clinical studies in the future.

Temporomandibular joint disorders treated with articular injection: the effectiveness of plasma rich in growth factors-Endoret

The objective of this study was to evaluate the effectiveness of the temporomandibular joint (TMJ) osteoarthritis treatment through articular injections of plasma rich in growth factors (PGRF)-Endoret. Thirteen patients (median age, 47.64 y; SD, 7.51; range, 40-64 y; male-female ratio, 2:11) with osteoarthritis of TMJ associated to chronic pain have been selected. They were treated with articular injections of PRGF-Endoret, measuring the maximum mouth opening and pain level before the first injection (t0), 30 days after just before the second (t1), and after 6 months (t2). Data were analyzed using the paired Student's t-test data. The visual analogue scale score at t0 is 7.69 (range, 4-10; SD, 1.9), whereas that at t1 is 1.54 (range, 0-5; SD, 1.74) and that at t2 is 0.23 (range, 0-2; SD, 0.65). These differences in the results are statistically highly significant (P < 0.0001 comparison t0-t1 and t0-t2 and P < 0.01 comparison t1-t2). In terms of maximum mouth opening, it reduced from 30.15 mm at t0 (range, 26-40 mm; SD, 4.44) to 37.54 mm at t1 (range, 31-51 mm; SD, 5.10), with an increase of 7.38 mm (range, 4-11 mm; SD, 2.02) and a highly significant difference (P < 0.0001). At t2, it was 39.54 mm (range, 34-51; SD, 4.55) with an increase of 9.38 mm (range, 5-12 mm; SD, 2.21) compared with t0 and that of 2.00 mm compared with t1. Both differences in the results are statistically significant (P < 0.0001 and P < 0.01, respectively). The articular injections of PRGF-Endoret represent a very efficient method to control pain and to improve the TMJ mobility.

Current understanding of pathogenesis and treatment of TMJ osteoarthritis

Osteoarthritis is a common disease that can cause severe pain and dysfunction in any joint, including the temporomandibular joint (TMJ). TMJ osteoarthritis (TMJOA) is an important subtype in the classification of temporomandibular disorders. TMJOA pathology is characterized by progressive cartilage degradation, subchondral bone remodeling, and chronic inflammation in the synovial tissue. However, the exact pathogenesis and process of TMJOA remain to be understood. An increasing number of studies have recently focused on inflammation and remodeling of subchondral bone during the early stage of TMJOA, which may elucidate the possible mechanism of initiation and progression of TMJOA. The treatment strategy for TMJOA aims at relieving pain, preventing the progression of cartilage and subchondral bone destruction, and restoring joint function. Conservative therapy with nonsteroidal anti-inflammatory drugs, splint, and physical therapy, such as low-energy laser and arthrocentesis, are the most common treatments for TMJOA. These therapies are effective in most cases in relieving the signs and symptoms, but their long-term therapeutic effect on the pathologic articular structure is unsatisfactory. A treatment that can reverse the damage of TMJOA remains unavailable to date. Treatments that prevent the progression of cartilage degradation and subchondral bone damage should be explored, and regeneration for the TMJ may provide the ideal long-term solution. This review summarizes the current understanding of mechanisms underlying the pathogenesis and treatment of TMJOA.

Platelet-rich plasma in bone regeneration: engineering the delivery for improved clinical efficacy

Human bone is a tissue with a fairly remarkable inherent capacity for regeneration; however, this regenerative capacity has its limitations, and defects larger than a critical size lack the ability to spontaneously heal. As such, the development and clinical translation of effective bone regeneration modalities are paramount. One regenerative medicine approach that is beginning to gain momentum in the clinical setting is the use of platelet-rich plasma (PRP). PRP therapy is essentially a method for concentrating platelets and their intrinsic growth factors to stimulate and accelerate a healing response. While PRP has shown some efficacy in both in vitro and in vivo scenarios, to date its use and delivery have not been optimized for bone regeneration. Issues remain with the effective delivery of the platelet-derived growth factors to a localized site of injury, the activation and temporal release of the growth factors, and the rate of growth factor clearance. This review will briefly describe the physiological principles behind PRP use and then discuss how engineering its method of delivery may ultimately impact its ability to successfully translate to widespread clinical use.