Surgical reattachment of torn rotator cuff tendons can lead to satisfactory clinical outcome but failures remain common. Ortho-R product is a freeze-dried formulation of chitosan (CS) that is solubilized in platelet-rich plasma (PRP) to form injectable implants. The purpose of the current pilot study was to determine Ortho-R implant acute residency, test safety of different implant doses, and assess efficacy over standard of care in a sheep model. The infraspinatus tendon (ISP) was detached and immediately repaired in 22 skeletally mature ewes. Repair was done with four suture anchors in a suture bridge configuration (n = 6 controls). Freeze-dried formulations containing 1% w/v chitosan (number average molar mass 35 kDa and degree of deacetylation 83%) with 1% w/v trehalose (as lyoprotectant) and 42.2 mM calcium chloride (as clot activator) were solubilized with autologous leukocyte-rich PRP and injected at the tendon-bone interface and on top of the repaired site (n = 6 with a 1 mL dose and n = 6 with a 2 mL dose). Acute implant residency was assessed histologically at 1 day (n = 2 with a 1 mL dose and n = 2 with a 2 mL dose). Outcome measures included MRI assessment at baseline, 6 weeks and 12 weeks, histopathology at 12 weeks and clinical pathology. MRI images and histological slides were scored by 2 blinded readers (veterinarian and human radiologist, and veterinarian pathologist) and averaged. The Generalized Linear Model task (SAS Enterprise Guide 7.1 and SAS 9.4) was used to compare the different groups with post-hoc analysis to test for pairwise differences. Ortho-R implants were detected near the enthesis, near the top of the anchors holes and at the surface of ISP tendon and muscle at 1 day. Numerous polymorphonuclear cells were recruited to the implant in the case of ISP tendon and muscle. On MRI, all repair sites were hyperintense compared to normal tendon at 6 weeks and only 1 out 18 repair sites was isointense at 12 weeks. The tendon repair site gap seen on MRI, which is the length of the hyperintense region between the greater tuberosity and tendon with normal signal intensity, was decreased by treatment with the 2 mL dose when compared to control at 12 weeks (p = 0.01). Histologically, none of the repair sites were structurally normal. A trend of improved structural organization of the tendon (p = 0.06) and improved structural appearance of the enthesis (p = 0.1) with 2 mL dose treatment compared to control was seen at 12 weeks. There was no treatment-specific effect on all standard safety outcome measures, which suggests high safety. Ortho-R implants (2 mL dose) modulated the rotator cuff healing processes in this large animal model. The promising MRI and histological findings may translate into improved mechanical performance, which will be assessed in a future study with a larger number of animals. This study provides preliminary evidence on the safety and efficacy of Ortho-R implants in a large animal model that could potentially be translated to a clinical setting

Osteoarthritis (OA) is a debilitating disease characterised by degradation of articular cartilage and subchondral bone remodeling. Current therapies for early or midstage disease do not regenerate articular cartilage, or fail to integrate the repair tissue with host tissue, and therefore there is great interest in developing biological approaches to cartilage repair. We have shown previously that platelet-rich plasma (PRP) can enhance cartilage tissue formation. PRP is obtained from a patient's own blood, and is an autologous source of many growth factors and other molecules which may aid in healing. This raised the question as to whether PRP could enhance cartilage integration. We hypothesise that PRP will enhance integration of bioengineered cartilage with native cartilage. Chondrocytes were isolated from bovine metacarpal-phalangeal joints, seeded on a porous bone substitute (calcium polyphosphate) and grown in the presence of FBS to form an in vitro model of osteochondral-like tissue. After 7 days, the biphasic constructs were soaked in PRP for 30 minutes prior to implantation into the core of a ring-shaped biphasic explant of native bovine cartilage and bone. Controls were not soaked in PRP. The resulting implant-explant construct was cultured in a stirring bioreactor in serum free conditions for 2 weeks. The integration zone was visualised histologically. A push-out test was performed to assess the strength of integration. Matrix accumulation at the zone of integration was assessed biochemically and the gene expression of the cells in this region was assessed by RT-PCR. Significance (p<0.05) was assessed by a student's t-test or one-way ANOVA with tukey's post hoc. PRP soaked bioengineered implants, integrated with the host tissue in 73% of samples, whereas control bioengineered implants only integrated in 19% of samples based on macroscopic evaluation (p<0.05). The integration strength, as determined by the normalised maximum force to failure, was significantly increased in the PRP soaked implant group compared to controls (219 +/− 35.4 kPa and 72.0 +/− 28.5 kPa, respectively, p<0.05). This correlated with an increase in glycosaminoglycan and collagen accumulation in the region of integration in the PRP treated implant group, compared to untreated controls after 2 weeks (p<0.05). Immunohistochemical studies revealed that the integration zone was rich in collagen type II and aggrecan. The cells at the zone of integration in the PRP soaked group had a 2.5 fold increase in aggrecan gene expression (p=0.05) and a 3.5 fold increase in matrix metalloproteinase 13 expression (p<0.05) compared to controls. PRP soaked bio-engineered cartilage implants showed improved integration with native cartilage compared to non-treated implants, perhaps due to the increased matrix accumulation and remodeling at the interface. Further evaluation is required to determine if PRP improves integration in vivo

Background:. Blood loss, pain and wound healing contribute significantly to the perioperative morbidity after total knee arthroplasty. Prospective randomized controlled studies are lacking, to our knowledge. The purpose of this study was to determine whether platelet rich plasma (PRP) might prevent blood loss and postoperative pain and expedite wound healing following TKA. Methods:. Forty consecutive age, sex and BMI-matched patients who had unilateral or bilateral arthritis of the knee with similar deformity and preoperative range of motion were enrolled for this prospective randomized controlled double blinded clinical trial. Preoperative haemoglobin, range of motion, WOMAC and KSS scores were noted. Platelet-rich plasma was applied over the wound including the capsule, medial and lateral recesses in seventeen patients. Twentythree served as controls. Postoperative haemoglobin, blood loss, blood transfusion, VAS score, Wound score, KSS and WOMAC score were recorded and evaluated. Results:. Autologous platelet gel (APG) group had a smaller decrease in haemoglobin (Preop Hb–POD3 Hb) compared to control (1.97/3.56; p = 0.00). Postoperative blood loss was 173.2 ml vs 220.4 ml (p = 0.02). Blood transfusion was significantly less in the APG group (0.59 units/1.43 units; p = 0.001). APG group experienced less pain immediately, at 6 weeks and 12 weeks postoperatively (VAS 6.5/7.39, 2.67/3.84, 1.61/2.31; p = 0.00, 0.00, 0.00) and required fewer narcotics than control (15.24/22.65; p = 0.00). There was statistically significant difference in ROM at 5. th. day, 6 weeks and 3 months (79.44°/74.22°, 96.11°/87°, 97.6°/93.9° respectively; p = 0.00, 0.00, 0.01). There was no significant difference in the wound scores of two groups (30.96/34.23; p = 0.311). Significant difference was observed in KSS and WOMAC scores at 6 weeks (158.96/148.77, 17.3/23; p = 0.00, 0.00) and 12 weeks (166.96/161.42, 10.86/14.61; p = 0.00, 0.00). However no significant difference was found at 6 months. Conclusions:. We found significant reduction in blood loss, postoperative pain and need for narcotics after the use of autologous platelet gel in patients of total knee arthroplasty. Quicker and better functional outcome was observed in the APG group. However, at six months and later follow up, both groups had similar functional scores. Its role on wound healing was statistically insignificant. Level of Evidence: Therapeutic Level II

Background. A cell-based tissue-engineered construct can be employed for treating meniscal lesions occurring in the non-vascularized inner two-thirds. The objective of this study was to test the hypothesis that both pre-differentiation of human bone marrow derived stromal cells (hBMSCs) into chondrogenic lineage before cell seeding and platelet-rich plasma (PRP) pretreatment on a PLGA mesh scaffold enhances the healing capacity of the meniscus with hBMSCs-seeded scaffolds in vivo. Methods. PRP of 5 donors was mixed and used for the experiments. The woven PLGA mesh scaffold (VicrylTM, Ethicon) measuring 20×8 mm (thickness, 0.2 mm) was prepared. The scaffolds were immersed into 1,000 μl of PRP and were centrifuged at 150g for 10 min. Then, the scaffold was flipped 180° and the same procedure was done for the other side. After washing, the scaffolds were soaked into 1,000 μl of DMEM media. hBMSCs from an iliac crest of 10 patients after informed consent and approval of our IRB were induced into chondrogenic differentiation with chondrogenic media containing 10 ng/ml rhTGF-ß3 in 1.2% alginate bead culture system for 7 days. Then, 2×10. 5. hBMSCs were recovered, seeded onto the scaffold, and cultured under dynamic condition. Based on the presence of pre-differentiation into chondrogenic lineage and the PRP pretreatment, 4 study groups were prepared. (no differentiation without PRP, no differentiation with PRP, chondrogenic differentiation without PRP, chondrogenic differentiation with PRP) Cell number for each cell-seeded scaffold was determined at 24 hours after seeding. Then, scaffolds were placed between human meniscal discs and were implanted subcutaneously in nude mice for 6 weeks (n=10 per group). Results. Cell attachment analysis revealed no significant difference among groups (p>0.05). The average cell number attached on the scaffold was ranged 1.1×10. 5. to 1.2×10. 5. among groups after 24 hours, so the initial cell seeding efficiency was ranged 55 to 60%. Histologic results from the 10 constructs containing hBMSCs undifferentiated and seeded onto non-PRP treated scaffolds revealed none had healed at all. Of the constructs containing hBMSCs undifferentiated and seeded onto PRP-pretreated scaffolds, three menisci healed and seven did not heal. Of the constructs containing hBMSCs pre-differentiated into chondrogenic lineage and seeded onto non-PRP treated scaffolds, six menisci healed and four did not heal. Of the constructs containing hBMSCs pre-differentiated into chondrogenic lineage and seeded onto PRP-pretreated scaffolds, seven menisci healed and three did not heal. Histological evaluation demonstrated a continuous hypercellular new fibrous tissue integrating into the native devitalized meniscus disc tissue in healed samples. The histological outcome between the groups was significant (p<0.05) (Table 1) (Figure 1). Conclusion. hBMSCs, which were differentiated into chondrogenic lineage before cell seeding and attached PRP-pretreated PLGA mesh scaffolds, demonstrated enhanced healing capacity of human meniscus in a meniscal repair mouse model. These findings demonstrate that both pre-differentiation of hBMSCs into chondogenesis and the PLGA scaffold modified by PRP pretreatment provides more biomimetic and biocompatible strategy for cell-mediated meniscal repair. Acknowledgements. This study was supported by Basic Science Research Program through the National Research Foundation of Korea (#2015-01004099)

Introduction

Collapse of femoral head associated with end-stage arthritis form hallmark of osteonecrosis of femoral head. Purpose was to assess efficacy of platelet rich plasma following core decompression in early stage of osteonecrosis of femoral head.

Rotator cuff disease encompasses a spectrum from partial to full thickness tears. Despite being 2–3 times more common than full–thickness tears, effective non-operative treatment for partial thickness tears has remained elusive. Platelet enriched plasma (PRP) has been proposed to enhance rotator cuff healing by enhancing the natural healing cascade. However, its utility in rotator cuff disease remains controversial. The purpose of this study was to compare the patient reported outcomes between PRP and corticosteroid injection in patients with symptomatic partial thickness tears.

This double blind randomized controlled trial enrolled patients with symptomatic, partial thickness rotator cuff tears or rotator cuff tendinopathy proven on ultrasound or MRI. Patients were randomized to either corticosteroid or PRP ultrasound-guided injection of the affected shoulder. Patients completed patient reported outcomes at 6 weeks and 12 weeks. The primary outcome was Visual Analog Scale (VAS) pain scores. Secondary outcomes included the Western Ontario Rotator Cuff (WORC) index, American Shoulder and Elbow Surgeons (ASES) score, and failure of non-operative management as determined by consent for surgery or progression to operative intervention.

Ninety-nine patients were enrolled in the study with equal demographics between the two groups. Taking into account pre-injection scores, patients with PRP injections demonstrated a statistically significant improvement in VAS scores compared to patients receiving corticosteroid injections at 12 weeks (p=0.045) but not at 6 weeks (p=0.704). There was no difference in other outcome measures or progression of the two groups to surgical intervention.

The use of PRP in the management of partial thickness rotator cuff tears demonstrates significant improvement of pain scores at 12 week follow up compared to corticosteroid injections. However, this did not affect the rate of progression to surgical intervention. Continued study is required to determine the utility of PRP in this patient population.

Injured skeletal muscle repairs spontaneously via regeneration, however, this process is often incomplete because of fibrotic tissue formation. In our study we wanted to show improved efficiency of regeneration process induced by antifibrotic agent decorin in a combination with Platelet Rich Plasma (PRP)-derived growth factors. A novel human myoblast cell (hMC) culture, defined as CD56 (NCAM)+ developed in our laboratory, was used for evaluation of potential bioactivity of PRP and decorin. To determine the their effect on the viability of hMC we performed a MTT assay. To perform the cell proliferation assay, hMCs were separately seeded on plates at a concentration of 30 viable cells per well. Cell growth medium prepared with different concentrations of PRP exudates (5%, 10%, and 20%) and decorin (10 ng/mL, 25 ng/mL, and 50 ng/mL) were added and incubated for 7 days. After incubation we stained the cells with crystal-violet and measured the absorbance.

To study the expression of Transforming Growth Factor Beta (TGF-β) and myostatin (MSTN), two main fibrotic factors in the process of muscle regeneration we performed several ELISA assays in groups treated with all therapeutic agents (PRP, decorin and their combination). Further, we have studied the ability of these agents to influence the differential cascade of dormant myoblasts towards fully differentiated myotubes by monitoring step wise activation of single nuclear factors like MyoD and Myogenin via multicolor flow cytometry. We stained the cells simultaneously with antibodies against CD56, MyoD and myogenin. We acquired cell images of 5,000 events per sample at 40 x magnification using 488 nm and 658 nm lasers and fluorescence was collected using three spectral detection channels. We analysed the cells populations according to expression of single or multiple markers and their ratios.

Finally, we examined the treated cell populations using a multicolour laser microscope after staining for desmin (a key marker of myogenic differentiation of hMC), α-tubulin, and nuclei. Optical images were acquired at the center of chamber slides where the cell density is at its highest using a Leica TCS SP5 II confocal microscope and analysed using Photoshop CS6, where a “Color Range” tool was used in combination with a histogram palette to count the pixels that correspond to desmin-positive areas in an image.

The mitochondrial activity of cells, as determined by the MTT assay, was significantly increased (p < 0 .001) after exposure to tested concentrations of PRP exudate. Similarly, viability was elevated in all tested concentrations of decorin. PRP exudate enhanced the viability of cells to more than 400% when compared to the control (p < 0 .001). The viability of cells treated with PRP exudates was also significantly higher when compared to decorin (p < 0 .001). Decorin did not show a significant effect on cell proliferation compared to the control, however, cultivation with PRP exudate leads to a 5-fold increase in cell proliferation (p < 0 .001). Decorin was shown to down-regulate the expression of TGF-β when compared to the control by more than 15% (p < 0 .001) but significantly less than PRP exudate p < 0 .005). PRP significantly down-regulated TGF-β expression by more than 30% (p < 0 .001). Similarly, the MSTN expression levels were significantly down-regulated by decorin and PRP. MSTN levels of cells treated with decorin were decreased by 28.4% (p < 0 .001) and 23.1% by PRP (p < 0 .001) when compared to the control group.

Using flow cytometry we detected a 39.1% increase in count of myogenin positive cells in the PRP-treated group compared to the control. Moreover, there was a 3.09% increase in cells positive only for myogenin, whereas no such cells were found in the control cell population. The population of cells positive only for myogenin is considered as fully differentiated and capable of fusion into myotubes as well as future mucle fibers and is thus of great importance for muscle regeneration. At the same time 20.6% fewer cells remained quiescent (positive only for CD56). Cells positive for both MyoD and myogenin represent the population that shifted significantly towards mature myocites during myogenesis but are not yet fully committed.

Finally, a statistically significant up-regulation of desmin expression (p < 0 .01 for the PRP treated group, p < 0 .005 for the decorin and PRP + decorin treated groups) was present in all therapeutic groups when compared to the control. While no significant difference was found between the PRP and decorin-treated groups, their combination led to a more than 3-fold increase (p < 0 .005) of desmin expression when compared to single bioactives.

PRP can be a highly potential therapeutic agent for skeletal muscle regeneration and repair, especially if in combination with a TGF-β antagonis decorin. Achieving better healing could likely result in faster return to play and lower reinjury rate.

Chronic plantar fasciitis is a common condition but can be difficult to successfully treat. Platelet rich plasma (PRP), a concentrated bioactive component of autologous blood rich in cytokines and other growth factors, was compared with cortisone injection in the treatment of severe cases of plantar fasciitis resistant to traditional non-operative paradigms. Thirty-six patients (16 males 20 females) were prospectively randomized into two study groups. All patients had pre-treatment MRI and ultrasound studies consistent with plantar fasciitis. The first group was treated with a single ultrasound guided injection of 40 mg Depo-Medrol at the injury site and the second group was treated with a single ultrasound guided injection of un-buffered autologous PRP at the injury site. The cortisone group had an average age of 59 (24–74) and had failed 4 months (3–24) of standard non-operative management (rest, heel lifts, PT, NSAIDS, cam walker immobilization, night splinting, local modalities) and had pre-treatment AOFAS scores of 52 (24–60). The PRP group had an average age of 51 (21–67) and had failed 5 months (3–26) of standard non-operative management (rest, heel lifts, PT, NSAIDS, cam walker immobilization, night splinting, local modalities) and had pre-treatment AOFAS scores of 37 (30–56). All patients were then immobilized fully weight bearing in a cam walker for 2 weeks, started on eccentric home exercises and allowed to return to normal activities as tolerated and without brace support. Post-treatment AOFAS scores were PRP 95 (84–100) and cortisone 81(60–90) at 3 months (CI 95% p< .0001), PRP 95 (86–100) and cortisone 81 (60–90) at 6 months (CI 95% p< .0001), and PRP 94 (86–100) and cortisone 58 (45–77) at 12 months (CI 95% p< .0001). Platelet rich plasma injection is more effective and durable than cortisone injection for the treatment of severe chronic plantar fasciitis refractory to traditional non-operative management.

Autologous injection of platelet rich plasma (PRP) stimulates healing process in degenerated tendons. The purpose of this study is to compare the functional outcome of lateral epicondylitis treated with PRP and steroid injection.

Tennis elbow patients who failed conservative medical therapy were included and were allocated randomly steroid group (n=70) and PRP group (n=63). Data were collected before procedure, at 4, 8, 12 weeks, 1 year and 2 years after procedure. The main outcome measures were visual analogue score, Mayo elbow performance score, DASH score and hand grip strength.

Successful treatment was defined as more than a 25% reduction in visual analogue score or DASH score and more than 75 score in Mayo elbow performance score. We observed that 35 of the 70 patients (50%) in corticosteroid group and 47 of the 63 patients (75%) in PRP group were successful, which was significantly different (p<.001), according to DASH score 37 of the 70 patients (53%) and 47 of the 63 patients (75%) in the PRP group were successful which was also significantly different (P = .005), Mayo elbow performance score was successful in 36 of the 70 patients (51%) in corticosteroid group and 49 of the 63 patients (78%) in PRP group. The improvement in hand grip strength of hand from 24.7kg (mean) 26kg in corticosteroid group and 23.5kg (mean) to 32.9kg (mean) in PRP group.

PRP injection for chronic lateral epicondylitis reduces pain, improve functionality and hand grip strength when compared to steroid injection.

Post-traumatic osteonecrosis of the femoral head (ONFH) is a major complication of femoral neck fractures that require numerous solutions. The purpose of the current study is to investigate the effects of platelet-rich plasma (PRP) incorporated autologous granular bones graft for the treatment of pre-collapse stages (ARCO stage II-III) of post-traumatic ONFH. A total of 46 patients were eligible and enrolled into the study. 24 patients were treated with core decompression and PRP incorporated autologous granular bones graft (treatment group: 9 females and 15 males, age range, 16–39 years), and 22 patients with core decompression and autologous granular bones graft (control group: 6 females and 16 males, age range, 18–42 years. During a minimum duration of follow-up of 36 months, multiple imaging techniques including X-ray and computed tomography (CT) scanning were used to evaluate the radiological results, and Harris hip score (HHS) and the visual analogue scale (VAS) were chosen to assess the clinical results. Both treatment group and control group had a significant improved HHS (P < 0.001). The minimum clinically important difference (MCID) for HHS was reached in 91.7% of treatment group and 68.2% of control group (P = 0.0449). HHS in treatment group was significantly higher than control group at the last follow-up (P = 0.0254). VAS score was significantly declined in treatment group when compared with control group (P = 0.0125). Successful clinical results were achieved in 21 of 24 patients (87.5%) in treatment group compared with 13 of 22 patients (59.1%) in control group (P = 0.0284). Successful radiological results were achieved in 19 of 24 patients (79.2%) in treatment group compared with 11 of 22 patients (50%) in control group (P = 0.0380). The survival rates using requirement for further hip surgery as an endpoint were higher in treatment group in comparison to control group (P = 0.0260). The PRP incorporated autologous granular bones graft is a safe and effective procedure for the treatment of pre-collapse stages (ARCO stage II-III) of post-traumatic ONFH

During the therapy of infected pseudarthrosis and arthrodesis in which multiple autologous bone grafts did not result in osseous consolidation and in delayed osseous healing of transport stretches after completion of segmental transport in osteomyelitis patients without acute infection symptoms, mesenchymal stem cells were added to the treatment. This study demonstrates the mid- and long-term results in different application possibilities with good and poor results. The aim is to develop an algorithm in treating bone defects regarding the different biomaterials and implants that exist on the market. The indication to apply mesenchymal stem cells was the reconstruction of osseous lesions after chronic osteomyelitis, the treatment of pseudarthrosis and the support of osseous growth in segmental transports. Further indications were the absence of adequate amounts of autologous spongiosa, multiple previous operations, risk factors (diabetes, peripheral vascular disease, alcohol and nicotine abuse, etc.) as well as chronic wound healing failure. To obtain the mesenchymal stem cells, we employed two different systems from two companies. Both systems concentrate the mesenchymal stem cells after puncture and aspiration from the pelvic crest. The concentrated stem cells were either mixed with platelet-rich plasma and added to the autologous spongiosa or injected into the area of osseous regeneration after completion of segment transport. Since 2009, we have applied mesenchymal stem cells to 87patients. The treatment was performed in 73 cases of persisting pseudarthrosis after multiple bone grafts and in 14 cases of delayed osseous healing after segmental transport. The results were evaluated by continuous clinical and radiological examinations in our outpatient clinic. We found a great variety in our results with a mainly high rate of survival and healing in the autologous bone grafts with mesenchymal stem cells, resulting predominantly in stabilization of the pseudarthrosis. Furthermore a good osseous consolidation was documented in several cases with transport stretches of segmental transports. However we also had some frustrating results with all the well-known complications of septic surgery. Our experiences so far, have led to a distinguished therapy-algorithm including all the biomaterials and additives that are used in our hospital. Overall, the results demonstrate an advantage in the treatment with mesenchymal stem cells, espe-cially in problematic and difficult cases in combination with multiple pre-existing conditions. The use of mesenchymal stemcells must be included in a general concept regarding all treatment possibilities, it is, however, not a guarantee for successful therapy of osseous lesions after chronic osteomyelitis especially as a single toll mechanism

Purpose:. To examine the performance of a novel blood plasma-based bone putty for augmenting the treatment of open tibia fractures. The putty was manufactured from pooled blood plasma and contains a concentration of both plasma and platelet-derived regenerative factors. Based on clinical reports of the use of autologous platelet-rich plasma to treat injuries, we hypothesized that the putty would accelerate healing of fractures and surrounding soft tissues. Methods:. Two-arm, randomized controlled study including 20 treatment patients and 10 controls. Follow-up examinations occurred at 14, 30, 60, 90, 180, and 365 days. The product was provided in a syringe containing 3 cc of putty in a double-pouched, sterile box. The putty was placed at the fracture site during open fracture reduction and mechanical stabilization. Results:. Both treatment and control groups were well balanced with a mean age of 35. Seventy percent were Gustillo IIIA and IIIB injuries, 67% were active smokers, and 70% received external fixation. No adverse events related to the use of the putty were noted. The use of the putty significantly reduced infections at 90 days (p = 0.002), accelerated bone bridging at 90 and 180 days, and provided more rapid wound closure at 30 days. In the subset of patients with IIIA/IIIB injuries, the putty group demonstrated more significantly reduced infections (p = 0.0007), with accelerated bone healing and wound closure approaching statistical significance. There were statistically fewer adverse events with the putty (42.1%) compared to controls (80.0%). Conclusions:. The potential for using a concentration of natural plasma and platelet-derived regenerative factors to augment the healing of traumatic injuries makes this first-in-man study relevant and exciting. The putty performed as expected, promoting more rapid healing of both fractures and wounds. The dramatic reduction in infections was unanticipated and is likely related to antimicrobial peptides in plasma and platelets

The cause of elbow tendinosis is most likely a combination of mechanical overloading and abnormal microvascular responses. Numerous methods of treatment have been advocated. In this study, we evaluated the use of platelet-rich plasma (PRP) as a treatment for resistant epicondylitis. The rationale for using platelets is that they participate predominantly in the early inflammation phases and degranulation. They constitute a reservoir of critical growth factors and cytokines which when placed directly into the damaged tissue, may govern and regulate the tissue healing process. We looked at 25 patients (19 with lateral and 6 with medial) who failed to improve after physiotherapy, cortisone injections and application of epicondylar clasps and assessed the efficacy of platelet-rich plasma injections using Gravitational platelet separation system (GPS). The cohort of patients included over a period of three years had physiotherapy, stretches, epicondylar clasp and an average of 2.9steroid injections (1–6) before having a PRP injection. The mean patient age was 43 years ranging between 24 and 54. There were 11 men and 14 women. The study included 19 patients with lateral epicondylitis and 6 patients with symptoms on the medial side. The ratio between dominant and nondominant side was according to the literature: 76%. The quick DASH scores imroved by 14% on an average in the first 3 months and further 26% in the following 9 months. 4 patients needed reintervention, 3 lateral and 1 medial and had surgical release between 6 and 12 months. 2 of them had reinjections before surgery. No local infections except mild inflammation and no systemic effects were noted. Within the limitations of being a case series and limited follow-up PRP injections provided a safe and progressive benefit over a period of 1 year in refractory cases, providing a good nonoperative alternative

Purpose. Platelet-Rich Plasma (PRP), an autologous derivative of whole blood that contains a supraphysiological concentration of platelets and growth factors. Most published studies have investigated the effect of PRP-conditioned media on cell cultures. We are not aware of any study that has investigated whole PRP with its cellular components on human tissue cultures. This study aims to investigate the effect of PRP on cell migration from human Achilles tendon explants, and the subsequent cellular proliferative effects in culture. Methods. This is an in-vitro study on tendon explants obtained from Achilles tendon rupture patients. The samples were collected in sterile DMEM F12 solution then carefully cut into approximately 1–3mm. 3. sections. Tendon explants were cultured in three media types: 1. 100% PRP; 2. 50% PRP; and 3. 50% fetal calf serum (FCS). 1 and 2 were made up using DMEM F12 media (standard culture medium). Explants and cells were incubated at 37°c in 5% CO. 2. for 48 hours. Results. Images of the explanted tissue were taken using a Nikon TE300 microscope with Retiga CCD camera and cells around each explant were counted. Kruskal-Wallis statistical test showed that 100%PRP and 50%PRP cultured explants have significantly higher number of cells (p ≤0.002 and 0.028 respectively) when compared with 50%FCS cultured explants. Ziva ultrasensitive proliferation assay revealed that 100%PRP significantly increased cell proliferation. In addition, PicoGreen assay showed that DNA content of 100% PRP cultured cells were significantly higher than the control. The concentration of TGF-b1, VEGF, PDGF-AB and IGF-1 growth factors were significantly higher in PRP comparing to 50% FCS medium. Conclusion. Our findings show that whole PRP strongly affect the behaviour of human tenocytes, indicating that PRP may have potential role as an orthobiological agent in ruptured tendon treatments

Tendinopathy is a debilitating musculoskeletal condition which can cause significant pain and lead to complete rupture of the tendon, which often requires surgical repair. Due in part to the large spectrum of tendon pathologies, these disorders continue to be a clinical challenge. Animal models are often used in this field of research as they offer an attractive framework to examine the cascade of processes that occur throughout both tendon pathology and repair. This review discusses the structural, mechanical, and biological changes that occur throughout tendon pathology in animal models, as well as strategies for the improvement of tendon healing.

Cite this article: Bone Joint Res 2014;3:193–202.

We present seven patients with recurrent haemarthroses after total knee arthroplasty, caused by an inherent platelet function defect. These patients developed painful knee swelling, persistent bleeding and/or wound breakdown, a platelet factor 3 availability defect being identified in all cases. Surgical exploration, with joint debridement, lavage and synovectomy, was performed in four patients who did not improve with conservative therapy. Histopathological examination of synovium revealed a focal synovial reaction with histiocytic infiltration, and occasional foreign-body giant cells. One patient required an early revision because of aseptic loosening of their tibial component. The condition was treated by single-donor platelet transfusions with good results. The diagnosis, management, and relevance of this disorder are discussed.