The efficacy of autologous platelet gel in pain control and blood loss in total knee arthroplasty. An analysis of the haemoglobin, narcotic requirement and range of motion

Treatment of dermal ulcer with autologous fibrin glue: Two case reports of an exploratory prospective pilot study

INTRODUCTION

The healing of recurrent and refractory skin ulcers requires a long time, during which there is risk of infection, and hospital admission is occasionally required for surgical or daily conservative treatment. Therefore, the development of promising treatments that promote faster, uneventful healing is a must. Composed of cryoprecipitate and thrombin, fibrin glue has a history of surgical use for preventing bleeding and spinal fluid leakage. Moreover, in-house cryoprecipitates contain higher concentrations of coagulation factors and cytokines that may enhance wound healing than commercially available products. However, the efficacy of completely autologous fibrin glue (AFG) in tissue repair has not yet been fully demonstrated.

PATIENT CONCERNS

This study aimed to evaluate the efficacy of AFG in the treatment of refractory skin ulcers in comparison with the conventional treatment.

DIAGNOSIS

Two patients with skin ulcer on their lower extremities due to trauma or scleroderma who showed resistance to conventional treatment were included in the study. Both study participants were diagnosed with refractory skin ulcer and were ineligible for autologous skin transplantation.

INTERVENTIONS

AFG was prepared following autologous blood donation using a Cryoseal® system. Subsequently, AFG was administered to 50% of the area of each ulcer and observed for 4 weeks in comparison with recombinant basic fibroblast growth factor with bucladesine sodium treatment that was administered to the rest of the ulcer.

OUTCOMES

The skin ulcer after trauma in participant 1 showed better improvement in the AFG-treated area. Although AFG did not show superiority regarding the ulcer area of a patient with scleroderma, it guarded the continuous exudation from the edge of the swollen skin surrounding the ulcer.

CONCLUSION

AFG showed effective and beneficial results for wound healing of refractory skin ulcer and prevented exudation without any severe adverse events.

The Role of Platelet-Rich Plasma Therapy in Joint Arthroplasty A Mini-Review

Orthobiologics are playing an increasingly large role in the clinical setting across multiple fields of surgery. Particularly, in the field of orthopedic surgery, the employment of platelet-rich plasma (PRP) therapy in total joint arthroscopy (TJA) has become popular for its prompted benefits of controlling pain, blood loss, and increased wound healing. PRP was originally used for thrombolytic conditions, however, the aforementioned potential benefits have led to its increased use across various fields of medicine including dermatology, neurosurgery, orthopedics, and sports medicine. Currently, there is a persisting gap in the literature surrounding the mechanism of action of PRP, as well as its true role in increasing positive patient outcomes in the context of TJA. Thus, this review aims to briefly highlight the physiological mechanisms underlining PRP therapy, evaluate recent preclinical and clinical data about its effects on TJA patient outcomes, and to describe its concomitant use in novel orthopedic-applications.

The Role of Platelet-Rich Plasma in Reducing Pain, Pruritis, and Improving Wound Healing of Skin Graft Donor Site

Background  Wound healing is a dynamic and complex process. Therefore, no single agent can efficiently mediate all aspects of the wound healing process. Split-thickness graft has become a workhorse of plastic surgery for wound or raw area cover. In this study, we evaluate the effectiveness of autologous platelet-rich plasma (PRP) on the donor site and its effect in pain, purities, and epithelization. Materials and Methods  This is a prospective study. A total of 15 patients were included who underwent split skin grafting for burns, trauma, or post-tumor excision raw area. PRP was prepared using standard described procedure. The donor site raw area after harvesting split-thickness graft was measured and the surface area was divided into two equal halves. One half was dressed using PRP and the other half was dressed using paraffin gauze piece only. The dressings were changed weekly for 3 weeks. Observation  We found significant reduction in severity of pain and pruritis in the PRP group as compared with control group. Epithelization was faster in the PRP group on day 7 and 14, but the overall healing time was nearly the same by day 21. The side-by-side dressing thus show a definite improvement in the post-split-thickness skin graft wound care and PRP as a good dressing alternative. Conclusion  Autologous PRP is very effective adjuvant in management of skin graft donor site. Its role in relieving pain and pruritis over donor site significantly improves patient's discomfort postoperatively. It helps in early and painless wound healing. However, we recommend for larger clinical study for better understanding of the efficacy of this blood product.

The Application of Platelet-Rich Plasma for Patients Following Total Joint Replacement: A Meta-Analysis of Randomized Controlled Trials and Systematic Review

Background

The clinical efficacy of platelet-rich plasma (PRP) in the treatment of total joint replacement (TJR) remains inconclusive. In this paper, systematic review and meta-analysis was adopted to assess the efficacy of using PRP for the treatment of TJR.

Methods

A comprehensive search of Medline, Embase, and Cochrane library databases for randomized controlled trial (RCT) articles recording data of PRP for TJR was conducted from inception to February 2022. Outcomes concerned were pain, range of motion (ROM), WOMAC score, length of hospital stay (LOS), hemoglobin (Hb) drop, total blood loss, wound healing rate, and wound infection. The methodological quality of the included RCTs was evaluated by using the Cochrane Risk of Bias Tool 2.0 (RoB 2.0). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was utilized to assess the level of evidence for the outcomes. Subgroup analysis was conducted according to the type of TJR.

Results

Ten RCTs were included in the meta-analysis. In the TKA subgroup, the available data demonstrated that there were significant differences in the outcomes of pain and Hb drop, while it was the opposite of ROM, WOMAC score, LOS, total blood loss, wound healing rate, and wound infection. In the THA subgroup, no significant differences could be seen between two groups in the outcomes of LOS and wound infection. However, the PRP group gained a higher wound healing rate in the THA subgroup.

Conclusion

The application of PRP did not reduce blood loss but improved the wound healing rate. However, more prospective and multicenter studies are warranted to confirm these results.

Combination of Platelet-Rich Plasma and Platelet Gel in Treatment of Resistance Androgenic Alopecia: a Case Series Study

BACKGROUND

Androgenic alopecia is a common genetic disorder that characterized by progressive hair follicles and hair atrophy. Despite of all available therapeutic techniques, there is low patient satisfaction rate. It seems finding new treatment options for androgenic alopecia is necessary. In the past decade Platelet-rich plasma (PRP), an autologous collection of concentrated platelets with haemostatic and tissue repairing effects has received developing attention for androgenetic alopecia treatment as a valuable therapeutic technique.

METHODS

In this study 8 patients suffering from resistance androgenic alopecia were enrolled. The PRP and platelet gel was prepared and a total volume of 10 cc of the combination of PRP and platelet gel was injected in the scalp androgen-related areas using 23-gauge syringe. The treatment was performed one month, and 3 months after first injection (three times). The hair pull test was done before treatment. The outcome was evaluated 3, 6 and 9 months after treatment by hair pull test, dermoscopy, photography and patient's satisfaction.

RESULTS

A significant reduction in hair loss was observed before and after treatment. Hair count (density) increased from average number of 72 (hair/cm2) to 210 hair/cm2). Also the hair diameter was significantly increase before and after treatment for all patients (P<0.05). After the treatment, the pull test was significantly decrease in 8 patients (P<0.05).

CONCLUSION

This study supports the combination therapy of PRP and platelet gel for resistance androgenic alopecia treatment. This technique is an uncomplicated, feasible and cost effective treatment option for resistance androgenic alopecia, with high patient satisfaction.

Comparative efficacy and safety of topical hemostatic agents in primary total knee arthroplasty: A network meta-analysis of randomized controlled trials

BACKGROUND

Topical hemostatic agents are commonly used for reducing perioperative blood loss and transfusion requirement in primary total knee arthroplasty (TKA), although the optimal option has yet to be defined. This study aimed to evaluate the efficacy and safety of topical hemostatic agents and rank the best intervention using the network meta-analysis (NMA) method.

METHODS

We searched Web of science, PubMed, and Cochrane Library database up to April 2020, for randomized controlled trials (RCTs) on topical hemostatic agents in primary TKA. The quality of included studies was assessed using the Cochrane "risk of bias" tool. Direct and indirect comparisons were performed for the result of network meta-analysis followed by consistency test.

RESULTS

Thirty seven RCTs with 3792 patients were included in this NMA and the pooled results indicated that tranexamic acid plus diluted epinephrine (TXA+DEP) displayed the highest efficacy in reducing total blood loss, hemoglobin drop and transfusion requirement. None of the included treatments was found to increase risk of thromboembolic events compared to placebo. According to the results of ranking probabilities, TXA+DEP had the highest possibility to be the best topical hemostatic agent with regard to the greatest comparative efficacy and a relatively high safety level.

CONCLUSION

Current evidence supports that administration of TXA+DEP may be the optimal topical hemostatic agent to decrease blood loss and transfusion requirement in primary TKA. More direct studies that focused on the topical application of TXA+DEP versus other treatments are needed in the future.

Is Intra-Articular Administration of Fibrinogen Effective in Postoperative Total Knee Arthroplasty Blood Loss? A Randomized Clinical Trial

Objectives

The purpose of this study was to evaluate the effect of intra-articular injection of fibrinogen on postoperative bleeding following total knee arthroplasty.

Methods

A double-blind randomized clinical trial was conducted on 40 patients aged 40 - 70 years under spinal anesthesia candidate for total knee arthroplasty in Golestan hospital, Ahwaz, Iran, in 2017-2018. Patients were divided into fibrinogen intra-articular injection (n = 20) and control (n = 20) groups. The amounts of blood loss and blood transfusion requirement were recorded. Hemoglobin (Hb), hematocrit (HCT), international normalized ratio (INR), platelet (PLT), prothrombin time (PT), and partial thromboplastin time (PTT) were recorded before and after the surgery.

Results

There was no significant difference in the average amount of intraoperative blood loss between the groups (P > 0.05). The average amount of blood loss 24 hours after the surgery was significantly lower in the fibrinogen group than in the control group (fibrinogen group 350.61 ± 120.32 cc; control group 540.00 ± 170.21 cc; P = 0.0002). There were significant differences in transfusion between the groups (fibrinogen group 250 ± 20 cc; control group 350 ± 50 cc; P < 0.0001). There was a significant difference between the two groups in 24 h postoperative Hb and HCT (P < 0.001).

Conclusions

Intra-articular fibrinogen administration may reduce acute bleeding and can be used as an effective intervention to prevent further bleeding and the need for transfusion in patients undergoing total knee arthroplasty.

Efficacy of platelet-rich plasma in posterior lumbar interbody fusion: systematic review and meta-analysis

INTRODUCTION

We have conducted a systematic review and meta-analysis that aims to compare outcomes (pain VAS, fusion and adverse event) of PRP and placebo after posterolateral lumbar fusion (PLF) surgery.

MATERIALS AND METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies were identified from Medline and Scopus from inception to September 16, 2019 that reported visual analog scale back pain, postoperative complications and fusions of either group.

RESULTS

In a total of seven studies, two, two, three studies were RCT, prospective and retrospective studies, respectively. Overall, there were 270 patients (150 in the PRP group and 149 in the placebo group). Three, three, four, three, two, seven and four studies were reported for pain VAS back in 3 months, 6 months, 12 months, 24 months, period of fusion, postoperative fusion and adverse events, respectively. The unstandardized mean difference (UMD) VAS back in 3, 6, 6 and 24 months was - 0.41 (95% CI - 0.87, 0.05) score, - 0.97 (95% CI - 1.68, - 0.27) score, - 0.33 (95% CI - 0.61, - 0.59) score, - 0.19 (95% CI - 1.00, 0.62) scores lower than placebo after posterolateral lumbar fusion (PLF) patients. The UMD period of bone union were - 1.62 (95% CI - 1.85, - 1.39) months faster than placebo after PLF patients. A total of seven and four studies were reported fusion and adverse events between PRP and placebo group. No significant differences were noted for fusion and adverse events with the pooled RR of 1.03 (95% CI 0.48, 1.80) and 0.95 (95% CI 0.14, 6.56).

CONCLUSIONS

PRP with autologous bone graft had lower back pain and faster bone union time than bone graft alone. While, there have no difference in fusion rate and adverse events in both groups. Larger, prospective randomized controlled studies are needed to confirm these findings as the current literature is still insufficient. Further research including cost of operation, postoperative function and satisfaction, quality of life and cost-efficacy analysis is required to determine whether the PRP with autologous bone graft is superior to bone graft alone or not.

LEVEL OF EVIDENCE

Level II.

The Effect of Prosthesis Design on Blood Loss in Simultaneous Bilateral Total Knee Arthroplasty: Closed-Box versus Open-Box Prosthesis

Background

Various pre- and perioperative risk factors have been reported in association with blood loss in knee arthroplasty. However, the effect of the uncovered cancellous surface on blood loss in simultaneous bilateral total knee arthroplasty (SBTKA) by different prosthetic designs is not well elucidated. Therefore, this study aimed to compare the blood loss and transfusion rate between different knee prostheses in SBTKA and to identify risk factors that influence blood loss and transfusion after SBTKA.

Methods

Demographic and perioperative data of patients who underwent SBTKA using either a closed-box or an open-box femoral component of posterior-stabilized fixed-bearing (PS FB) knee system were retrospectively reviewed. The calculated blood loss (CBL) and blood transfusion rate were compared by using Student t-test and confirmed with multivariate regression analysis.

Results

There was no significant difference in preoperative parameters between 54 closed-box and 56 open-box PS FB TKAs. The CBL of the closed-box TKA group was 135.23 mL less (95% confidence interval [CI], −215.30 to −55.16; p = 0.001) than that of the open-box TKA group. However, the blood transfusion rates of the closed- and open-box TKA groups were not significantly different (24.1% and 38.5%, p = 0.11). For each additional minute of total operative time, 3.75 mL (95% CI, 1.75 to 5.76; p < 0.001) of blood loss was anticipated. For each additional mg/dL of preoperative hemoglobin, 71% (p < 0.001) reduction of blood transfusion probability was predicted.

Conclusions

The use of closed- and open-box knee prostheses resulted in a significant difference in blood loss in SBTKA. Prolonged operative time also significantly increased CBL. Therefore, strategies to control the bleeding surface and shorten operative duration may be considered if blood loss is of special concern. The preoperative hemoglobin was the only factor that affects the probability of blood transfusion in SBTKA.

Blood management in fast-track orthopedic surgery: an evidence-based narrative review

BACKGROUND AND PURPOSE

Innovations able to maintain patient safety while reducing the amount of transfusion add value to orthopedic procedures. Opportunities for improvement arise especially in elective procedures, as long as room for planning is available. Although many strategies have been proposed, there is no consensus about the most successful combination. The purpose of this investigation is to identify information to support blood management strategies in fast-track total joint arthroplasty (TJA) pathway, to (i) support clinical decision making according to current evidence and best practices, and (ii) identify critical issues which need further research.

METHODS AND MATERIALS

We identified conventional blood management strategies in elective orthopedic procedures. We performed an electronic search about blood management strategies in fast-track TJA. We designed tables to match every step of the former with the latter. We submitted the findings to clinicians who operate using fast-track surgery protocols in TJA at our research hospital.

RESULTS

Preoperative anemia detection and treatment, blood anticoagulants/aggregants consumption, transfusion trigger, anesthetic technique, local infiltration analgesia, drainage clamping and removals, and postoperative multimodal thromboprophylaxis are the factors which can add best value to a fast-track pathway, since they provide significant room for planning and prediction.

CONCLUSION

The difference between conventional and fast-track pathways does not lie in the contents of blood management, which are related to surgeons/surgeries, materials used and patients, but in the way these contents are integrated into each other, since elective orthopedic procedures offer significant room for planning. Further studies are needed to identify optimal regimens.

Haemostasis and analgesia with autologous platelet-rich plasma in tonsillectomy

Objective

A single-centre, single-blinded prospective experimental study was conducted to determine the effectiveness of autologous platelet-rich plasma applied to the tonsillar bed post-operatively in reducing post-operative pain and haemorrhage.

Methods

Platelet-rich plasma, prepared prior to surgery, was applied with calcium gluconate to one randomly chosen tonsillar fossa. Pain and haemorrhage were analysed, using a visual analogue scale and a pre-defined grading scale respectively, four times on the day of surgery at 2-hourly intervals, and thrice on the following day.

Results

The pain score and haemorrhage grade on the test side were lower than on the control side. These findings were statistically significant.

Conclusion

This pilot study, conducted in India, revealed valid positive results for a promising new technology. The manual preparation of platelet-rich plasma could be automated in the future to allow a larger sample size.

Photopolymerizable Platelet Lysate Hydrogels for Customizable 3D Cell Culture Platforms

3D cell culture platforms have emerged as a setting that resembles in vivo environments replacing the traditional 2D platforms. Over the recent years, an extensive effort has been made on the development of more physiologically relevant 3D cell culture platforms. Extracellular matrix-based materials have been reported as a bioactive and biocompatible support for cell culture. For example, human plasma derivatives have been extensively used in cell culture. Despite all the promising results, in most cases these types of materials have poor mechanical properties and poor stability in vitro. Here plasma-based hydrogels with increased stability are proposed. Platelet lysates are modified by addition of methacryloyl groups (PLMA) that polymerize in controlled geometries upon UV light exposure. The hydrogels could also generate porous scaffolds after lyophilization. The results show that PLMA materials have increased mechanical properties that can be easily adjusted by changing PLMA concentration or modification degree. Cells readily adhere, proliferate, and migrate, exhibiting high viability when encapsulated in PLMA hydrogels. The innovation potential of PLMA materials is based on the fact that it is a complete xeno-free solution for human cell culture, thus an effective alternative to the current gold standards for 3D cell culture based on animal products.

Blood Plasma Derivatives for Tissue Engineering and Regenerative Medicine Therapies

Platelet-rich plasma (PRP) and its derivatives have been investigated and applied in regenerative medicine. The use of PRP as a supplement of cell culture media has consistently shown to potentiate stem cell proliferation, migration, and differentiation. In addition, the clinical utility of PRP is supported by evidence that PRP contains high concentrations of growth factors (GFs) and proteins which contribute to the regenerative process. PRP based therapies are cost effective and also benefit from the accessibility and safety of using the patient's own GFs. In the last years, a great development has been witnessed on PRP based biomaterials, with both structural and functional purposes. In this study we overview the most relevant PRP applications encompassing PRP based materials for tissue engineering and regenerative medicine. This review also summarizes the challenges in the fields of tissue engineering and regenerative medicine and provides a perspective on future directions.

Evaluation of the use of tranexamic acid in total knee arthroplasty

Objective

Evaluate the efficacy of tranexamic acid in reducing bleeding in patients undergoing total knee arthroplasty.

Methods

101 patients were randomized into two groups: the tranexamic acid group (n = 51) and the placebo group (n = 50). Patients were compared regarding the following parameters: reduction of hemoglobin, total estimated blood loss, drain output, and postoperative blood transfusion rate.

Results

Comparing the groups, there were statistically significant differences (p < 0.05) in the following parameters: reduction of hemoglobin, decreased hematocrit, estimated blood loss, and drain output. All values were lower in the tranexamic acid group. Only placebo group patients required blood transfusion.

Conclusion

The use of intravenous tranexamic acid is effective to reduce bleeding in patients undergoing total knee arthroplasty.

Effect of Intraoperative Platelet-Rich Plasma Treatment on Postoperative Donor Site Knee Pain in Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction: A Double-Blind Randomized Controlled Trial

BACKGROUND

Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft anterior cruciate ligament (ACL) reconstruction. Hypothesis/Purpose: The purpose was to examine the effect of the intraoperative administration of platelet-rich plasma (PRP) on postoperative kneeling pain. It was hypothesized that PRP treatment would reduce knee pain.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Fifty patients (mean ± SD age, 30 ± 12 years) undergoing BPTB ACL autograft reconstruction were randomized to the PRP (n = 27) or sham (n = 23) treatment. In either case, 10 mL of venous blood was drawn before the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks, 6 months, 1 year, and 2 years after surgery, patients completed International Knee Documentation Committee (IKDC) forms and visual analog scale pain scores for activities of daily living and kneeling. Healing indices at the donor site were assessed by routine noncontrast magnetic resonance imaging (MRI) at 6 months. Mixed-model analysis of variance was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing, as measured by the width of the donor site defect.

RESULTS

Kneeling pain, pain with activities of daily living, and IKDC scores were not different between treatment groups at any of the time intervals ( P = .08-.83). Kneeling pain improved from 12 weeks to 6 months and from 1 to 2 years ( P < .05). IKDC scores improved substantially from 12 weeks to 6 months ( P < .001) and continued to improve to 2 years (PRP, 86 ± 19; sham, 89 ± 10). MRI indices of donor site healing were not different between treatment groups ( P = .53-.90).

CONCLUSION

Whether randomized to receive PRP in their patellar defect or not, patients continued to have similar levels of kneeling pain and patellar defect sizes after autograft BPTB ACL reconstruction. Registration: NCT01765712 ( ClinicalTrials.gov identifier).

Perioperative Blood Management Strategies for Total Knee Arthroplasty

Total knee arthroplasty (TKA) often causes a significant amount of blood loss with an accompanying decline in hemoglobin and may increase the frequency of allogeneic blood transfusion rates. Unfortunately, allogeneic blood transfusions have associated risks including postoperative confusion, infection, cardiac arrhythmia, fluid overload, increased length of hospital stay, and increased mortality. Other than reducing the need for blood transfusions, reducing perioperative blood loss in TKA may also minimize intra-articular hemorrhage, limb swelling, and postoperative pain, and increase the range of motion during the early postoperative period. These benefits improve rehabilitation success and increase patients' postoperative satisfaction. Preoperative anemia, coupled with intraoperative and postoperative blood loss, is a major factor associated with higher rates of blood transfusion in TKA. Thus, treatment of preoperative anemia and prevention of perioperative blood loss are the primary strategies for perioperative blood management in TKA. This review, combined with current evidence, analyzes various methods of blood conservation, including preoperative, intraoperative, and postoperative methods, in terms of their effectiveness, safety, and cost. Because many factors can be controlled to reduce blood loss and transfusion rates in TKA, a highly efficient, safe, and cost-effective blood management strategy can be constructed to eliminate the need for transfusions associated with TKA.

Efficacy of Early Fusion With Local Bone Graft and Platelet-Rich Plasma in Lumbar Spinal Fusion Surgery Followed Over 10 Years

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

Many oral surgeons use platelet-rich plasma (PRP) for bone defects, but the efficacy of PRP for spinal arthrodesis remains uncertain. The objective was to compare the efficacy of autologous local bone graft and PRP with local bone graft alone for promotion of bony union in posterolateral lumbar fusion (PLF) surgery, with investigation of the safety of PRP over 10 years.

METHODS

A prospective study was conducted in 29 consecutive patients who underwent one-level PLF at L4/5 for degenerative lumbar disease. Local bone on the left (control) side and local bone with PRP on the right side were grafted. The fusion area and absorption of grafted bone at 58 regions were determined using computed tomography at 2 weeks and 3, 6, and 12 months after surgery.

RESULTS

Average bone fusion areas on the PRP side were significantly wider at 3 and 6 months after surgery (P < .05). Average absorption values were significantly lower on the PRP side than on the control side at 3 and 6 months after surgery (P < .05). The PRP/control ratio was significantly different at 3 and 6 months compared to that at 2 weeks (P < .005). No adverse events related to PRP occurred with good clinical outcome over 10 years follow-up.

CONCLUSIONS

Local application of PRP combined with autologous local bone graft has a positive impact on early fusion for lumbar arthrodesis with no adverse events over 10 years, and thus is a safe and low cost autologous option in spinal fusion.

A systematic review of the effects of platelet rich plasma on outcomes for patients with knee osteoarthritis and following total knee arthroplasty

INTRODUCTION

Platelet rich plasma (PRP) has been suggested to be effective in the management of knee osteoarthritis. Review of current literature reveals conflicting evidence regarding the benefits of PRP in treating knee OA. Preclinical evidence supports the use of PRP injections to promote a favorable environment for joint tissue healing, targeting not only cartilage but also synovial and meniscal tissues which has a positive effect on delaying the progression of OA. Growth factors found in platelet granules are postulated to influence outcomes in knee OA and after total knee arthroplasty (TKA).

METHODOLOGY

A systematic review of studies investigating the use of PRP in knee osteoarthritis and following TKA, was performed by searching the following databases for randomised clinical trials and pseudo-randomised clinical and comparative trials comparing the use of PRP to treat knee osteoarthritis and following TKA: MedLine, EMBASE, Science Direct, PubMed, and the Cochrane Library. The primary outcomes were patient reported measures including pain (visual analog scale (VAS)), quality of life scores, and knee function.

RESULTS

A total of 2328 participants were analyzed across 17 included studies and pooled results showed a statistically significant reduction in pain in favor of PRP following TKA but not in non-surgical management of knee OA (P < 0.0001 and 0.13 respectively). No clinical benefit of PRP was found on quality of life and knee function (P = 0.07 and 0.05) following TKA, although a statistical improvement in knee function was demonstrated in patients with knee OA after PRP injection (P < 0.0001). There was no statistically significant clinical benefit of PRP on secondary outcomes including wound scores and length of hospital stay (p = 0.33 and 0.31, respectively). There was no statistically significant difference in respect to blood loss and overall symptoms in favor of PRP compared to control group following TKA (p = 0.37).

CONCLUSION

This systematic review demonstrated no long-term statistically significant improvement in patient validated outcomes and secondary outcomes both in patients with knee OA or following TKA for OA. However PRP has been shown to have short to medium-term benefits in pain control after TKA and activities of daily living in patients with OA.

Acne Scarring-Pathogenesis, Evaluation, and Treatment Options

Acne vulgaris is a ubiquitous problem affecting 80 percent of people ages 11 to 30 years, with many patients experiencing some degree of scarring. This review focuses on atrophic scars, the most common type of acne scar. We briefly address the cellular sequelae that lead to scar formation and the initial evaluation of patients with acne scars. We then discuss an algorithmic approach to the treatment of acne scarring based on the classification of scars into erythematous and atrophic types. Lastly, we discuss the future treatment of acne scars and ongoing clinical trials.

Perioperative blood management strategies for patients undergoing total knee replacement: Where do we stand now?

Total knee replacement (TKR) is one of the most common surgeries over the last decade. Patients undergoing TKR are at high risk for postoperative anemia and furthermore for allogeneic blood transfusions (ABT). Complications associated with ABT including chills, rigor, fever, dyspnea, light-headedness should be early recognized in order to lead to a better prognosis. Therefore, perioperative blood management program should be adopted with main aim to reduce the risk of blood transfusion while maximizing hemoglobin simultaneously. Many blood conservation strategies have been attempted including preoperative autologous blood donation, acute normovolemic haemodilution, autologous blood transfusion, intraoperative cell saver, drain clamping, pneumatic tourniquet application, and the use of tranexamic acid. For practical and clinical reasons we will try to classify these strategies in three main stages/pillars: Pre-operative optimization, intra-operative and post-operative protocols. The aim of this work is review the strategies currently in use and reports our experience regarding the perioperative blood management strategies in TKR.

The effect of platelet-rich plasma on reducing blood loss after total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Efficacy and safety of platelet-rich plasma (PRP) compared with control for preventing postoperative bleeding after total knee arthroplasty (TKA) is controversial. We performed a meta-analysis of randomized controlled trials (RCTs) to determine whether PRP might reduce blood loss and improve function following TKA.

METHODS

PubMed, Medline, Embase, Web of Science, and the Cochrane Library were searched to identify RCTs comparing PRP with control for patients undergoing unilateral TKA. The mean difference (MD) of total blood loss, hemoglobin (Hb) level, Hb drop, drain volume, range of motion (ROM), Western Ontario and McMaster Osteoarthritis Index (WOMAC) scores, length of hospital stay (LOS), and odds ratios of transfusion rate and postoperative complications in the PRP and control groups were pooled throughout the study. Relevant data were meta-analyzed using RevMan v5.3.

RESULTS

Six RCTs involving 529 patients were included (208 PRP vs. 321 controls). The application of PRP in TKA had a significantly less calculated total blood loss (MD = -98.11; 95% confidence interval [CI]: -153.63 to -42.59, P = .0005) and lower Hb drop (MD = -0.34; 95% CI: -0.59 to -0.09, P = .008) than the control in the early postoperative period while decreasing the LOS (MD = -2.12; 95% CI: -3.47 to -0.76, P = .002). No significant differences were seen in drain volume, Hb level, transfusion rate, ROM, WOMAC scores, and complications between the 2 groups (P > .05).

CONCLUSIONS

Our meta-analysis suggests that PRP appears to be effective in reducing postoperative blood loss and lowering Hb drop without increasing the risks of postoperative complications after TKA. However, owing to the variation of included studies, no firm conclusions can be drawn.

Topical use of platelet-rich plasma can improve the clinical outcomes after total knee arthroplasty: A systematic review and meta-analysis of 1316 patients

OBJECTIVE

Platelet-rich plasma (PRP) is extracted by centrifuging whole blood and characterized with a high concentration of platelets. The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) and non-RCTs is to evaluate the efficacy and safety of platelet-rich plasma (PRP) versus placebo after total knee arthroplasty (TKA).

METHODS

The Electronic databases of PubMed, Web of Science, Embase and Cochrane Database of Systematic Reviews were searched from inception to November 2016 and any studies involving PRP versus placebo for patients prepared for TKA were selected by two reviewers. The primary endpoint is the range of motion (ROM), which represents the function after TKA. The Western Ontario McMaster Universities Osteoarthritis Index Bellamy (WOMAC), pain at 24 h, 48 h and 7 day are also assessed the effect of PRP on the function and pain after TKA. The complications of infection is also compiled to assess the safety of PRP. Stata 12.0 was used to synthesis the final results.

RESULTS

Eleven clinical trials with 1316 patients are included in the meta-analysis. The pooled results indicate that administration PRP significantly increase ROM on the third day (MD = 4.72, 95% CI 2.74, 6.69; P = 0.000) and 3 month postoperatively (MD = 7.55, 95% CI 5.91, 9.19; P = 0.000). There is no statistical difference between the two groups in terms of WOMAC questionnaire score in 3 months (MD = -4.88, 95% CI -12.12, 2.41; P = 0.190). There were no statistical significance between the two groups in pain intensity at 24 h, 48 h and 7 day. There is no statistically significant difference between the PRP versus placebo in terms of the occurrence of infection (RR = 0.64, 95%CI: 0.19-2.14, P = 0.464).

CONCLUSION

Current meta-analysis indicates that PRP is associated with increasing the ROM after TKA in short term and long term. What's more, PRP can also decrease the WOMAC score and pain intensity without increasing the occurrence of infection.

Effects of heterologous platelet-rich plasma gel on standardized dermal wound healing in rabbits

PURPOSE

To evaluate the potential of heterologous platelet-rich plasma (PRP) gel for surgical skin wound healing in rabbits.

METHODS

Blood from a single healthy dog was used for PRP production, with calcium gluconate added to the PRP to form the gel. Two surgical excisions, one to the right and the other to the left of the dorsal midline, were made in six rabbits. One side was randomly allocated to topical application of a physiological solution, and the other was allocated to treatment with heterologous PRP gel. Clinical assessments (weight, pain sensitivity, coloring, edema, hyperemia, exudation, crust, and granulation) and morphometric evaluations were performed 0, 3, 7, 10, 14, and 17 days postoperatively. Histological analysis was performed on the 17th day.

RESULTS

With the exception of the presence of a crust at day 10, clinical variables did not differ significantly between the experimental groups. In both the control and PRP-treated groups, differences were identified when comparing time-points in terms of wound area reduction. Histological results indicated no significant differences between the control group and the PRP-treated group.

CONCLUSION

Heterologous platelet-rich plasma gel promoted dermal wound healing in rabbits with no adverse effects.

Platelet-rich plasma does not decrease blood loss in total knee arthroplasty

This study was designed to assess the use of platelet-rich plasma (PRP) during primary total knee arthroplasty (TKA). The authors hypothesized that this would result in less blood loss and greater hemoglobin and hematocrit levels at discharge and would potentially decrease the length of hospital stay. Leukocyte rich PRP was used during the procedure and at wound closure. Two surgeons performed all procedures in a similar fashion. Two different TKA implants were used. Each surgeon used the same implant throughout the study. A limited medial parapatellar approach was used and drains were used at closure. No tranexamic acid preparations were used. Continuous passive motion machines were used in all patients during their hospital stay. A total of 102 consecutive TKAs were performed. The study group (n=46) consecutively received the PRP injections during the TKA, whereas the control group (n=47) did not. Hemoglobin and hematocrit levels were obtained pre- and postoperatively. Estimated blood loss was recorded during surgery, and the auto-collection reinfusion drain system output was measured. The length of hospital stay was collected and recorded. The study showed that hemoglobin and hematocrit levels were not different when comparing study and control groups. Age and sex differences were insignificant. Finally, no statistical difference was seen for the estimated blood loss and hospital stay between the 2 groups. Platelet-rich plasma use during TKA does not decrease hospital stay or reduce estimated blood loss in the perioperative period.

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions

BACKGROUND

This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included independently of their design. Experimental studies relevant to the clarification of PRP's effects and mechanisms of action in tissues of interest, conducted in any animal species, were selected.

RESULTS

This review included 123 studies. PRP's beneficial effects were observed in 46.7% of the clinical studies, while the absence of positive effects was observed in 43.3%. Among experimental studies, 73% yielded positive results, and 7.9% yielded negative results. The most frequent flaws in the clinical trials' designs were the lack of a true placebo group, poor product characterization, insufficient blinding, small sampling, short follow-up periods, and adoption of poor outcome measures. The methods employed for PRP preparation and administration and the selected outcome measures varied greatly. Poor study design was a common feature of equine clinical trials. From studies in which PRP had beneficial effects, 67.8% had an overall high risk of bias. From the studies in which PRP failed to exhibit beneficial effects, 67.8% had an overall low risk of bias.

CONCLUSIONS

Most experimental studies revealed positive effects of PRP. Although the majority of equine clinical studies yielded positive results, the human clinical trials' results failed to corroborate these findings. In both species, beneficial results were more frequently observed in studies with a high risk of bias. The use of PRP in musculoskeletal lesions, although safe and promising, has still not shown strong evidence in clinical scenarios.

The clinical efficacy of using autologous platelet rich plasma in hip arthroplasty: A retrospective comparative study

BACKGROUND

Platelet rich plasma (PRP) is a blood derivative concentrate of platelets, fibrin and growth factors obtained through withdrawal and centrifugation of autologous blood and use for its inherent hemostatic and adhesive properties to promote wound healing. Hip arthroplasty is often associated with significant perioperative complications including blood loss necessitating blood transfusions, which can lead to multiple adverse reactions, infection transmission, and longer hospital stay.

MATERIALS AND METHODS

We conducted this retrospective comparative study to determine whether the use of PRP can reduce the bleeding complications in hip replacement surgeries and therefore decrease analgesic requirements and shorten the hospital stay.

RESULTS

Sixty patients had consecutive hip replacement surgeries. The study group (n=23) received PRP applications while the control group (n=37) were operated without PRP applications. Postoperative drop of hemoglobin, number of red blood cell (RBC) transfusions, analgesic requirements, and duration of hospital stay were recorded. There was no significant difference in the drop of hemoglobin preoperatively and postoperatively comparing study and control groups (P=0.75). There was no difference in transfusion requirements between the two groups (P=0.16) but there was trend toward less transfusion in the PRP-treated group. There were also no statistical differences in analgesic use (P=0.83) and lengths of hospitalization (P=0.68) between the two groups.

CONCLUSION

We concluded that there is no clinical efficacy in using PRP in hip replacement surgeries. We recommend a larger prospective study be conducted to determine its clinical utility as an optimization strategy to improve outcome after hip arthroplasty.

Platelet-rich plasma (PRP) applied during total knee arthroplasty

Objective

To evaluate the efficacy of platelet-rich plasma regarding healing, pain and hemostasis after total knee arthroplasty, by means of a blinded randomized controlled and blinded clinical study.

Methods

Forty patients who were going to undergo implantation of a total knee prosthesis were selected and randomized. In 20 of these patients, platelet-rich plasma was applied before the joint capsule was closed. The hemoglobin (mg/dL) and hematocrit (%) levels were assayed before the operation and 24 and 48 h afterwards. The Womac questionnaire and a verbal pain scale were applied and knee range of motion measurements were made up to the second postoperative month. The statistical analysis compared the results with the aim of determining whether there were any differences between the groups at each of the evaluation times.

Results

The hemoglobin (mg/dL) and hematocrit (%) measurements made before the operation and 24 and 48 h afterwards did not show any significant differences between the groups (p > 0.05). The Womac questionnaire and the range of motion measured before the operation and up to the first two months also did not show any statistical differences between the groups (p > 0.05). The pain evaluation using the verbal scale showed that there was an advantage for the group that received platelet-rich plasma, 24 h, 48 h, one week, three weeks and two months after the operation (p < 0.05).

Conclusions

In the manner in which the platelet-rich plasma was used, it was not shown to be effective for reducing bleeding or improving knee function after arthroplasty, in comparison with the controls. There was an advantage on the postoperative verbal pain scale.

Reduction of pain via platelet-rich plasma in split-thickness skin graft donor sites: a series of matched pairs

In the past decade, autologous platelet-rich plasma (PRP) therapy has seen increasingly widespread integration into medical specialties. PRP application is known to accelerate wound epithelialization rates, and may also reduce postoperative wound site pain. Recently, we observed an increase in patient satisfaction following PRP gel (Angel, Cytomedix, Rockville, MD) application to split-thickness skin graft (STSG) donor sites. We assessed all patients known to our university-based hospital service who underwent multiple STSGs up to the year 2014, with at least one treated with topical PRP. Based on these criteria, five patients aged 48.4±17.6 (80% male) were identified who could serve as their own control, with mean time of 4.4±5.1 years between operations. In both therapies, initial dressing changes occurred on postoperative day (POD) 7, with donor site pain measured by Likert visual pain scale. Paired t-tests compared the size and thickness of harvested skin graft and patient pain level, and STSG thickness and surface area were comparable between control and PRP interventions (p>0.05 for all). Donor site pain was reduced from an average of 7.2 (±2.6) to 3 (±3.7), an average reduction in pain of 4.2 (standard error 1.1, p=0.0098) following PRP use. Based on these results, the authors suggest PRP as a beneficial adjunct for reducing donor site pain following STSG harvest.

Platelet derivatives in regenerative medicine: an update

Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

The role of platelet gel in osteoarticular injuries of young and old patients

BACKGROUND

The use of autologous platelet gel in orthopedics is effective in accelerating the healing process of osteochondral, muscle, tendon and ligament lesions. The aim of our study was to verify whether the variability in response to infiltration with platelet gel was dependent on the underlying disease treated, sex and age of the patients. During four years, 140 patients have been treated for musculoskeletal injuries by infiltration of gel platelet and lysate platelet obtained from autologous thrombin, with echo-ultrasound guided. The response to treatment was assessed at different time points T0, T1, T2 with respect to pain estimation (VAS), joint mobility (ROM scale) and echo-ultrasound evaluation. This data collection has allowed classifying the response to treated lesions in three categories: NR (no response), PR (partial response), CR (complete response).

RESULTS

The data here reported showed that the ability to physical recovery response is evident in tendon injuries, while the large joints injuries gave a poor response. Almost all patients showed a significant pain relief after the first infiltration, but in terms of echo-ultrasound evaluation and tissue repair, only the muscle and tendon injuries showed hyperechoic areas, signs or evidences of repair. Concerning the correlation between response to infiltration with platelet gel and gender/age of the patients, the clinical results appear not influenced by the age and the gender of the patient.

DISCUSSION

Our data indicate that, pain relief and ability to physical recovery of muscles, tendons and ligaments depend on tissue repair clearly visible by echo ultrasound evaluation. On the other hand tissue repair seems not occur in the large joints (hip and knee) where arthritis and /or corrosion of articular cartilage cannot be repaired and the only relief is exclusively linked to the reduction of periarticular inflammation (reduction of the inflammatory leakage and signs).

Intraoperative platelet-rich plasma does not improve outcomes of total knee arthroplasty

This randomized controlled study was conducted to assess the effects of platelet-rich plasma (PRP) on outcomes of total knee arthroplasty (TKA). Forty patients who underwent unilateral TKA were evaluated prospectively; 20 received intraoperative PRP and 20 served as control subjects. The results showed no significant differences in reduction of bleeding, range of motion, swelling around the knee joint, muscle power recovery, pain, Knee Society Scores, and Knee Injury and Osteoarthritis Outcome Score between the 2 groups. Additionally, no distinct clinical characteristics were found in patients who received intraoperative PRP. Therefore, we conclude that intraoperative PRP does not improve outcomes of TKA.

Mean platelet volume (MPV) predicts middle distance running performance

BACKGROUND

Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners.

METHODS

The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75-85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection.

RESULTS

The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly associated with running performance.

CONCLUSION

The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance.

Platelet rich concentrate promotes early cellular proliferation and multiple lineage differentiation of human mesenchymal stromal cells in vitro

Platelet rich concentrate (PRC) is a natural adjuvant that aids in human mesenchymal stromal cell (hMSC) proliferation in vitro; however, its role requires further exploration. This study was conducted to determine the optimal concentration of PRC required for achieving the maximal proliferation, and the need for activating the platelets to achieve this effect, and if PRC could independently induce early differentiation of hMSC. The gene expression of markers for osteocytes (ALP, RUNX2), chondrocytes (SOX9, COL2A1), and adipocytes (PPAR-γ) was determined at each time point in hMSC treated with 15% activated and nonactivated PRC since maximal proliferative effect was achieved at this concentration. The isolated PRC had approximately fourfold higher platelet count than whole blood. There was no significant difference in hMSC proliferation between the activated and nonactivated PRC. Only RUNX2 and SOX9 genes were upregulated throughout the 8 days. However, protein expression study showed formation of oil globules from day 4, significant increase in ALP at days 6 and 8 (P ≤ 0.05), and increased glycosaminoglycan levels at all time points (P < 0.05), suggesting the early differentiation of hMSC into osteogenic and adipogenic lineages. This study demonstrates that the use of PRC increased hMSC proliferation and induced early differentiation of hMSC into multiple mesenchymal lineages, without preactivation or addition of differentiation medium.

Prospective, randomized trial to evaluate efficacy of a thrombin-based hemostatic agent in total knee arthroplasty

Total knee arthroplasty (TKA) can be associated with substantial blood loss, leading to increased morbidity and transfusion rates. The study objective was to evaluate routine use of a thrombin-based topical hemostatic matrix in reducing blood loss and transfusion requirements in primary TKA. 108 patients were enrolled in a prospective, randomized, single-center trial. Patients receiving the hemostatic agent demonstrated a lower mean calculated blood loss (1325.2±464.8mL vs. control, 1509.3±432.8mL; P=0.02), drain output (415.6±202.0mL vs. control, 579.9±306.7mL; P=0.008), and length of stay (3.3±0.8days vs. control, 3.7±1.1days; P=0.03), without a statistically significant difference in mean hemoglobin loss or transfusion requirements. The clinical utility of this hemostatic agent to reduce transfusions after uncomplicated, primary TKA continues to remain unclear.

The effect of platelet-rich plasma on the differentiation of synovium-derived mesenchymal stem cells

Platelet-rich plasma (PRP), the plasma portion of blood with a high platelet concentration, has been reported to be helpful in stem cell chondrogenesis due to large amount of growth factors it contains. Here, we examined the influence of PRP on the differentiation of synovium-derived stem cells (SDSCs) and also evaluated if PRP alone was sufficient to induce SDSCs differentiation. First, the cell proliferation in various differentiation media was analyzed using the MTT assay and it was significantly higher in groups cultured with media that contained PRP. Then, We performed Safranin-O staining and type I, II, and X collagen immunohistochemistry (chondrogenesis), von Kossa staining (osteogenesis), and Oil Red O staining (adipogenesis). The staining was most prominent in groups cultured with optimized differentiation media without PRP in all three lineages of differentiation. The mRNA expression levels of typical differentiation markers were also analyzed using reverse transcription quantitative polymerase chain reaction. Although, culture in optimized differentiation media increased the mRNA expression of the typical differentiation marker genes, they were significantly reduced when cultured in the media supplemented with PRP. PRP has negative effects on SDSC differentiation in all three differentiation lineages and PRP alone does not induce SDSC differentiation.

Platelet-rich plasma in androgenic alopecia: myth or an effective tool

Platelet-rich plasma (PRP) has become a newer method for the treatment of various types of alopecia. In this prospective study, safety, efficacy and feasibility of PRP injections in treating androgenic alopecia were assessed. Eleven patients suffering from hair loss due to androgenic alopecia and not responding to 6 months treatment with minoxidil and finasteride were included in this study. The hair pull test was performed before every treatment session. A total volume of 2-3 cc PRP was injected in the scalp by using an insulin syringe. The treatment was repeated every two weeks, for a total of four times. The outcome was assessed after 3 months by clinical examination, macroscopic photos, hair pull test and patient's overall satisfaction.

The use of PRP in ligament and meniscal healing

Platelet-rich plasma (PRP) has become a popular treatment for acute and chronic soft tissue injuries. Although the majority of research has focused on its use in tendinopathy, PRP may have potential in meniscus and ligament healing. Some level II studies support a possible benefit for anterior cruciate ligament (ACL) allograft maturation, and preliminary animal studies point to a potential role for PRP in primary ACL repair. However, randomized controlled trials have not demonstrated a benefit of PRP for ACL tendon allograft-tunnel integration. To date, 2 studies document the use of PRP for meniscal applications, but this field is largely unexplored. With respect to ligament and meniscal applications, the current literature suggests PRP may be promising for primary ACL repair in skeletally immature patients, ACL graft maturation, and repair of meniscal tears in the avascular zone.

Platelet-rich plasma: underlying biology and clinical correlates

Platelet-rich plasma (PRP) has recently become the focus of intensive interest and discussion, in part because of the expanding understanding of platelet function. Anucleate platelets within PRP release a myriad of growth factors and cytokines while contributing to plasma coagulation and fibrin development; the latter acts as vehicle for the local delivery. The biological effects of PRP are largely attributed to the platelet secretome and plasma signaling proteins. Clinical data suggest that PRPs may exploit different regenerative mechanisms under diverse disease conditions, including hemostasis, inflammation, angiogenesis and the synthesis of extracellular matrix. The success of PRP therapies depends on current tissue healing research and the translation of this knowledge into clinical developments.

The effect of platelet-rich plasma formulations and blood products on human synoviocytes: implications for intra-articular injury and therapy

BACKGROUND

The effect of platelet-rich plasma (PRP) on chondrocytes has been studied in cell and tissue culture, but considerably less attention has been given to the effect of PRP on synoviocytes. Fibroblast-like synoviocytes (FLS) compose 80% of the normal human synovium and produce cytokines and matrix metalloproteinases that can mediate cartilage catabolism.

PURPOSE

To compare the effects of leukocyte-rich PRP (LR-PRP), leukocyte-poor PRP (LP-PRP), red blood cell (RBC) concentrate, and platelet-poor plasma (PPP) on human FLS to determine whether leukocyte and erythrocyte concentrations of PRP formulations differentially affect the production of inflammatory mediators.

STUDY DESIGN

Controlled laboratory study.

METHODS

Peripheral blood was obtained from 4 donors and processed to create LR-PRP, LP-PRP, RBCs, and PPP. Human synoviocytes were cultured for 96 hours with the respective experimental conditions using standard laboratory conditions. Cell viability and inflammatory mediator production were then evaluated.

RESULTS

Treatment with LR-PRP resulted in significantly greater synoviocyte death (4.9% ± 3.1%) compared with LP-PRP (0.72% ± 0.70%; P = .035), phosphate-buffered saline (PBS) (0.39% ± 0.27%; P = .018), and PPP (0.26% ± 0.30%; P = .013). Synoviocytes treated with RBC concentrate demonstrated significantly greater cell death (12.5% ± 6.9%) compared with PBS (P < .001), PPP (P < .001), LP-PRP (P < .001), and LR-PRP (4.9% ± 3.1%; P < .001). Interleukin (IL)-1β content was significantly higher in cultures treated with LR-PRP (1.53 ± 0.86 pg/mL) compared with those treated with PBS (0.22 ± 0.295 pg/mL; P < .001), PPP (0.11 ± 0.179 pg/mL; P < .001), and RBCs (0.64 ± 0.58 pg/mL; P = .001). IL-6 content was also higher with LR-PRP (32,097.82 ± 22,844.300 pg/mL) treatment in all other groups (P < .001). Tumor necrosis factor-α levels were greatest in LP-PRP (9.97 ± 3.110 pg/mL), and this was significantly greater compared with all other culture conditions (P < .001). Interferon-γ levels were greatest in RBCs (64.34 ± 22.987 pg/mL) and significantly greater than all other culture conditions (P < .001).

CONCLUSION

Treatment of synovial cells with LR-PRP and RBCs resulted in significant cell death and proinflammatory mediator production.

CLINICAL RELEVANCE

Clinicians should consider using leukocyte-poor, RBC-free formulations of PRP when administering intra-articularly.

Variance of matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) concentrations in activated, concentrated platelets from healthy male donors

BACKGROUND

The use of autologous blood concentrates, such as activated, concentrated platelets, in orthopaedic clinical applications has had mixed results. Research on this topic has focused on growth factors and cytokines, with little directed towards matrix metalloproteinases (MMPs) which are involved in post-wound tissue remodeling.

METHODS

In this study, the authors measured the levels of MMP-2, MMP-9 and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), in activated platelets derived from blood of healthy, male volunteers (n = 92), 19 to 60 years old. The levels of the natural inhibitors of these proteases, tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2 and TIMP-4 were also assessed.

RESULTS

Notably, there was no significant change in concentration with age in four of six targets tested. However, TIMP-2 and TIMP-4 demonstrated a statistically significant increase in concentration for subjects older than 30 years of age compared to those 30 years and younger (P = 0.04 and P = 0.04, respectively).

CONCLUSION

TIMP-2 and TIMP-4 are global inhibitors of MMPs, including MMP-2 (Gelatinase A). MMP-2 targets native collagens, gelatin and elastin to remodel the extracellular matrix during wound healing. A decreased availability of pharmacologically active MMP-2 may diminish the effectiveness of the use of activated, concentrated platelets from older patients, and may also contribute to longer healing times in this population.