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

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

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

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)

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.