PRP (platelet rich plasma) is a blood product derived from human plasma, the main component of which is enriched platelet cells, usually in concentrations more than five times the normal platelet concentration. Depending on the manufacturing process, PRP may contain different concentrations of leukocytes and red blood cells. Since the 1980s, PRP has been used in clinical treatment, and the production process of PRP has been greatly improved in the 1990s to produce PRP with a more homogeneous composition. PRP is used in a wide range of clinical applications, such as maxillofacial surgery, trauma surgery, etc., where trauma surgery focuses on acute and chronic tendon diseases, muscle fibrosis, joint capsule laxity, arthritis, synovitis, meniscal or articular cartilage injury, etc. The specific mechanism of action of PRP is still controversial, and it is generally believed that there are growth stimulating factors within RPR to promote tissue healing. PRP has many biological and chemical functions, such as biogel, coagulation, hemodynamic stabilization, and wound healing, in addition to promoting the accumulation of intra-articular hyaluronic acid and increasing the synthesis of aminoglycans and cartilage matrix. A large number of manufactured PRP products exist, but there are no clear comparative studies on the efficacy of various manufactured products. PRP in orthopedic practice Tendon Tendon disorders are more common in athletes and in the more active population. Tendon disorders are usually treated conservatively, and long-term regular conservative exercise can effectively improve the patient’s symptoms. Surgery is the last option, and the specific effectiveness of surgical treatment is questionable, so trauma surgeons are working to develop a more effective conservative treatment. Currently, conservative treatments are focused on PRP, but the results of clinically observed studies are more controversial. To avoid the trauma of surgical treatment and uncertainty of outcome, many scholars have investigated PRP for chronic tendon disease. edward et al. found that 2-3 PRP injections were effective in improving symptoms and prognosis and promoting healing in 28 patients with elbow tendon disease treated conservatively with PRP, but in a similar study with a sample size of 26 patients Connell et al. showed good clinical results in 35 patients treated with ultrasound-guided PRP injections for elbow tendon disease, and found that the thickness of the tendon was significantly thinner after 6 months of treatment than at the start of treatment. Suresh et al. reported that the combined use of empty needle puncture and autologous plasma injection technique for refractory medial humeral epicondylitis under ultrasound guidance was effective in reducing hypoechoic areas and neovascularization at the injection site during ultrasound exploration.Mishra et al. compared the therapeutic effects of PRP injection (15 cases) and bupivacaine + epinephrine injection (5 cases) in patients with elbow tendon disorders.The PRP group was found to be more effective in The PRP group was better than the bupivacaine group in terms of functional recovery, pain relief and satisfaction with efficacy. Peerbooms et al. compared the final outcome prognosis of 51 hormone-treated and 49 PRP-treated patients and found that the PRP group significantly reduced pain and improved function, with the hormone group improving function more significantly in the early stages but for a shorter duration; whereas the PRP group consistently improved the patients’ symptoms. Kon et al. performed three peritendinous PRP injections in 20 jumpers with knee pain and found that this method significantly improved the patients’ pain symptoms and knee function levels with a patient satisfaction rate of 80% (16/20). similar conclusions were reached by James et al. In these studies, it was also found that when the tendons at the injection sites were probed using ultrasound devices, the thickness and ultrasound hypoechoic areas of the tendons at these sites were significantly reduced compared to before the injection, but the neovascularized areas were not significantly changed or even increased compared to before. filardo et al. compared traditional physiological therapy (16 cases) and ultrasound-guided PRP injection method (15 cases) for patellar tendon disease and found that EQ -VAS, and pain levels were not significantly different when compared, but the PRP group was able to significantly improve the motor function of the patients at 6 months after the procedure. The efficacy of PRP injections in the treatment of plantar fasciitis has been studied extensively, and Kiter compared the efficacy of PRP, hormone and empty needle injections in 54 patients with plantar fasciitis and found no significant differences between groups on a 10-point VAS and AOFAS (American orhtopaedic foot and ankle society) scale. Lee et al. compared the efficacy of PRP and hormone therapy in 64 patients with plantar fasciitis and found that hormone therapy provided a longer treatment effect in terms of pain and functional prognosis, which was similar to the results of a randomized controlled study of 100 patients published by Kalaci et al. The results were similar to those of a randomized controlled study of 100 patients published by Kalaci et al. Another popular area of PRP application is the use of PRP after surgical repair of ruptured tendons, currently focused on the rotator cuff and Achilles tendon areas. Rotator cuff treatment: PRP has not shown much advantage over shoulder arthroscopy for rotator cuff injuries, and Maniscalco et al. reported a case of rotator cuff injury with a 10-mm tear treated with autologous PRP injection, which showed significant improvement in pain and joint motion during the 6-month postoperative follow-up, with healing of the rotator cuff tear on MRI. In a study of 53 patients conducted by Randelli et al. comparing the effects of PRP and arthroscopy, it was found that pain improved more significantly in the PRP group at 3 months postoperatively, while the remaining indices, such as the SST (simple shoulder test), University of California, UCLA, Constant- Castricini et al. did not find any significant difference in the treatment effect between PRP and shoulder arthroscopy in 88 patients at 16 months postoperative follow-up. Achilles tendon treatment: Approximately 25-45% of patients with Achilles tendon injuries have poor results with conservative treatment and may eventually require surgical treatment. The efficacy of conservative versus surgical treatment in improving patient symptoms is controversial, and Devos et al. reported that the 24-month postoperative follow-up of 54 patients with Achilles tendon injuries with PRP injection + rehabilitation exercises (treatment group) or saline injection + rehabilitation exercises (control group) showed no significant difference in pain and functional improvement in the PRP group compared to the control group. Schepull et al. compared the functional recovery of 14 patients treated with surgery and 16 patients treated with surgery + PRP and found no significant differences in the elastic modulus, heel raise index, but in the significant index of Achilles tendon rupture score ( Achilles tendon total rupture score, detrimental effect, determinant) was slightly lower in the PRP+surgery group than in the surgery-only group, leading the authors to conclude that the additional PRP treatment did not provide greater benefit to the patients, but Sanchez et al. reached inconsistent conclusions in their study, in which PRP + surgical treatment group could start functional recovery and rehabilitation exercises earlier after surgery, and pathological analysis of cross-sections of the repaired Achilles tendon at the PRP injection site revealed a structure that more closely resembled a normal Achilles tendon. Ligament Approximately 60,000-75,000 ACL injuries occur each year in the United States, with approximately half requiring surgical intervention. The most widely used ligament repairs are the autogenous bone-patellar tendon, femoral cord tendon and quadriceps tendon, and good ligament repair is critical for early knee motion. The most widely used material is the bone-patellar tendon repair, but this technique can lead to donor site dysfunction. The femoral cord tendon does not suffer from donor site dysfunction, but there are difficulties in integrating the bone surface and tendon graft during surgical repair. The complete ligament grafting process consists of three steps: incorporation, neoligament formation and remodeling, and growth factors play an important role in driving these processes. Orrego et al. compared standard ligament reconstruction techniques + three different intraoperative management measures: group 1, standard reconstruction + bone plug in tunnel; group 2, standard reconstruction + PRP injection; group 3, standard reconstruction + PRP injection + bone plug in tunnel, with results at 6-month postoperative follow-up Hint: Only 78% of the ligaments in the control group showed low signal, while this percentage was 100% in the PRP group, and no signal changes at the bone-ligament interface were found in the different groups. This suggests that platelets may promote the maturation process of bone graft without significant effect on the bone-ligament interface. a comparative study by Radice et al. of standard and PRP+standard reconstruction techniques found that the time to achieve complete homogeneity of the grafted ligaments on MRI was halved by the PRP+standard reconstruction technique compared to the standard reconstruction technique (179 days vs. 369 days). In contrast, Silva et al. came to the opposite conclusion with a four-group comparative study, in which they concluded that the PRP group was not significantly effective in promoting ligament healing. In conclusion: Platelet-derived growth factors are widely used in many areas of medicine and are now widely used in dermatology, ophthalmology, dentistry, aesthetic surgery, maxillofacial surgery and sports medicine. Although there are numerous studies on the clinical efficacy and basic applications of PRP, the specific mechanism of action of PRP is not yet clear to investigators. There is no widely accepted standard for PRP concentration. Conventional platelet concentrations in blood range from 150,000 to 350,000/ul, with an average concentration of 200,000/ul. 5 ml of PRP preparation has a platelet concentration of 1,000,000/ul, which is more than five times the normal plasma platelet concentration. Low concentrations of platelets do not achieve the same therapeutic effect, while high concentrations of platelets and standard concentrations of platelets have a similar therapeutic effect and are even harmful in some cases, probably because of the excess toxicity of growth factors. The second point of inconsistency is the technology of production of PRP preparations. Depending on the technology used for PRP production, PRP preparations may contain large amounts of highly concentrated platelets and other types of cells, such as white blood cells, red blood cells, and other plasma components, which may have an impact on the therapeutic effect of PRP. The understanding of how to activate PRP is not well understood. Thrombin and calcium ions are platelet activators, along with the presence of other platelet activators. cacl activates thrombin, which mimics the blood coagulation process and is an effective pathway for PRP activation. The time point and time course of PRP therapy is unclear. Given the multiple uncertainties mentioned above, it is difficult to make an assessment of the specific efficacy of PRP and its mechanism of action. From the information that currently exists, it appears that PRP can be used as a treatment for some diseases, but does not address all problems. It is important to clarify which diseases PRP is therapeutically effective for. Certain non-randomized controlled findings suggest a better role for PRP in the treatment of tendon disorders, but the opposite conclusion is often true when randomized controlled studies are performed. Surgery for tendon and ligament disorders is difficult to conclude with certainty because of the influence of many factors. Most of the current clinical studies are too short to draw definitive conclusions because of the lack of standard controls and the short follow-up period. More rigorous basic science studies are needed to determine the exact effect of PRP treatment, as well as scientifically designed randomized controlled clinical studies with long follow-up periods.