Juan Azofra

Comparison of Surgically Repaired Achilles Tendon Tears Using Platelet-Rich Fibrin Matrices

Background Platelet-rich fibrin matrices release a natural mixture of growth factors that play central roles in the complex processes of tendon healing. Hypothesis Application of autologous platelet-rich matrices during Achilles tendon surgery may promote healing and functional recovery. Study Design Case-control study and descriptive laboratory study; Level of evidence, 3. Methods Twelve athletes underwent open suture repair after complete Achilles tendon tear. Open suture repair in conjunction with a preparation rich in growth factors (PRGF) was performed in 6 athletes and retrospectively compared with a matched group that followed conventional surgical procedure. The outcomes were evaluated on the basis of range of motion, functional recovery, and complications. Achilles tendons were examined by ultrasound at 50 ± 11 months in retrospective controls and 32 ± 10 months in the PRGF group. In the laboratory portion of the study, PRGF treatment was characterized by the number of platelets and concentration of insulin (IGF-I), transformed (TGF-β1), platelet-derived (PDGF-AB), vascular endothelial (VEGF), hepatocyte (HGF), and epidermal (EGF) growth factors in patients affected by musculoskeletal traumatic injuries. Results Athletes receiving PRGF recovered their range of motion earlier (7 ± 2 weeks vs 11 ± 3 weeks, P = .025), showed no wound complication, and took less time to take up gentle running (11 ± 1 weeks vs 18 ± 3 weeks, P = .042) and to resume training activities (14 ± 0.8 weeks vs 21 ± 3 weeks, P = .004). The cross-sectional area of the PRGF-treated tendons increased less (t = 3.44, P = .009). TGF-β1 (74.99 ± 32.84 ng/mL), PDGF-AB (35.62 ± 14.57 ng/mL), VEGF (383.9 ± 374.9 pg/mL), EGF (481.5 ± 187.5 pg/mL), and HGF (593.87 ± 155.76 pg/mL) significantly correlated with the number of platelets (677 ± 217 platelets/μL, P < .05). Conclusion The operative management of tendons combined with the application of autologous PRGF may present new possibilities for enhanced healing and functional recovery. This needs to be evaluated in a randomized clinical trial.

Plasma Rich in Growth Factors to Treat an Articular Cartilage Avulsion: A Case Report

INTRODUCTION The application of an autologous plasma rich in growth factors is beneficial in restoring connective tissues, as shown by clinical evidence in oral surgery and more recently in arthroscopic anterior cruciate ligament reconstruction and two cases of ruptured Achilles tendon in professional athletes. This is attributed to the slow delivery of growth factors from harvested platelets that have been activated by endogenous thrombin promoted by the addition of calcium chloride. PURPOSE This case report describes a new application of this therapy in the arthroscopic treatment of a large, nontraumatic avulsion of articular cartilage in the knee of an adolescent soccer player. METHODS After arthroscopic reattachment of the large (>2 cm) loose chondral body in its crater in the medial femoral condyle, autologous plasma rich in growth factors was injected into the area between the crater and the fixed fragment. RESULTS AND CONCLUSION Despite the extremely poor prognosis of the case, complete articular cartilage healing was considerably accelerated, and the functional outcome was excellent, allowing a rapid resumption of symptom-free athletic activity. This technique opens new perspectives for human tissue regeneration.

A randomized clinical trial evaluating plasma rich in growth factors (PRGF-Endoret) versus hyaluronic acid in the short-term treatment of symptomatic knee osteoarthritis.

PURPOSE This multicenter, double-blind clinical trial evaluated and compared the efficacy and safety of PRGF-Endoret (BTI Biotechnology Institute, Vitoria-Gasteiz, Spain), an autologous biological therapy for regenerative purposes, versus hyaluronic acid (HA) as a short-term treatment for knee pain from osteoarthritis. METHODS We randomly assigned 176 patients with symptomatic knee osteoarthritis to receive infiltrations with PRGF-Endoret or with HA (3 injections on a weekly basis). The primary outcome measure was a 50% decrease in knee pain from baseline to week 24. As secondary outcomes, we also assessed pain, stiffness, and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index; the rate of response using the criteria of the Outcome Measures for Rheumatology Committee and Osteoarthritis Research Society International Standing Committee for Clinical Trials Response Criteria Initiative (OMERACT-OARSI); and safety. RESULTS The mean age of the patients was 59.8 years, and 52% were women. Compared with the rate of response to HA, the rate of response to PRGF-Endoret was 14.1 percentage points higher (95% confidence interval, 0.5 to 27.6; P = .044). Regarding the secondary outcome measures, the rate of response to PRGF-Endoret was higher in all cases, although no significant differences were reached. Adverse events were mild and evenly distributed between the groups. CONCLUSIONS Plasma rich in growth factors showed superior short-term results when compared with HA in a randomized controlled trial, with a comparable safety profile, in alleviating symptoms of mild to moderate osteoarthritis of the knee. LEVEL OF EVIDENCE Level I, randomized controlled multicenter trial.

Ligamentization of Tendon Grafts Treated With an Endogenous Preparation Rich in Growth Factors: Gross Morphology and Histology

PURPOSE To investigate whether the application of a particular platelet-rich plasma preparation rich in growth factors (PRGF) during anterior cruciate ligament (ACL) surgery gives a potential advantage for better tendon graft ligamentization. METHODS This study included 37 volunteers who underwent either conventional (control group, n = 15) or PRGF-assisted (n = 22) ACL reconstruction with an autogenous hamstring and required second-look arthroscopy to remove hardware or loose bodies, treat meniscal tears or plica syndrome, or resect cyclops lesions at 6 to 24 months after ACL surgery. The gross morphologies of the grafts were evaluated on second-look arthroscopy by use of the full arthroscopic score (0 to 4 points) to evaluate graft thickness and apparent tension (0 to 2 points) plus synovial coverage (0 to 2 points). At the same time, biopsy specimens were harvested uniformly from the grafted tendons. In these specimens the histologic transformation of the tendon graft to ACL-like tissue was evaluated by use of the Ligament Tissue Maturity Index, and a score to assess the progression of new connective tissue enveloping the graft was created by use of 3 criteria previously used to characterize changes during ligament healing: cellularity, vascularity, and collagen properties. RESULTS The overall arthroscopic evaluation of PRGF-treated grafts showed an excellent rating in 57.1% of the knees (score of 4) and a fair rating in 42.9% (score of 2 or 3). In contrast, evaluation of untreated grafts showed an excellent rating in 33.3% of the knees, a fair rating in 46.7%, and a poor rating in 20% (score of 0 or 1). Overall, arthroscopic evaluations were not statistically different between PRGF and control groups (P = .051). PRGF treatment influenced the histologic characteristics of the tendon graft, resulting in tissue that was more mature than in controls (P = .024). Histologically evident newly formed connective tissue enveloping the graft was present in 77.3% of PRGF-treated grafts and 40% of controls. The appearance of the connective tissue envelope changed with increasing time from surgery. On the basis of the histologic findings, we suggest that the remodeling of PRGF-treated grafts involves the formation of synovial-like tissue enveloping the graft. This tissue is eventually integrated in the remodeled tendon graft, conferring a similar appearance to the normal ACL. CONCLUSIONS The use of PRGF influenced the histologic characteristics of tendon grafts, resulting in more remodeling compared with untreated grafts. We have shown temporal histologic changes during the 6- to 24-month postoperative period of graft maturation, with newly formed connective tissue enveloping most grafts treated with PRGF. LEVEL OF EVIDENCE Level III, case-control study.

Reciprocal Actions of Platelet-secreted Tgf-β1 on the Production of Vegf and Hgf by Human Tendon Cells

Background: Autologous platelet-rich matrices can be an aid in surgery by promoting and accelerating tissue healing because of the release of growth factors including transforming growth factor (TGF)-&bgr;1 and platelet-derived growth factor (PDGF) from platelet &agr;-granules. Methods: PDGF and TGF-&bgr;1 were quantified in supernatants collected from platelet-rich matrices prepared in vitro (n = 45 donors) and they correlated with the number of platelets and showed a constant ratio (p < 0.05). Tendon cells in culture were exposed to the supernatants (n = 4 donors) from either platelet-rich or platelet-poor matrices, differing in their content of platelet-secreted molecules. These treatments were modified by either neutralizing or adding PDGF or TGF-&bgr;1. Effects were compared in terms of proliferation, procollagen I, vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) production. Results: PDGF was a partial contributor to cell proliferation, whereas exogenous TGF-&bgr;1 acted as a negative modulator (p < 0.05). The production of type I collagen was similar regardless of differences in the concentration of TGF-&bgr;1. Moreover, addition of exogenous TGF-&bgr;1 promoted a significant increase in collagen synthesis only in the absence of other platelet-released substances (p < 0.05). Exogenous TGF-&bgr;1 increased the synthesis of VEGF and simultaneously abolished the production of HGF. Furthermore, antibody-mediated neutralization of TGF-&bgr;1 induced a decrease in VEGF synthesis and concomitantly a substantial production of HGF (p < 0.05). Conclusion: The balance between TGF-&bgr;1 and the pools of platelet-secreted molecules may have important therapeutic implications in the control of angiogenesis and fibrosis.

Nonunions treated with autologous preparation rich in growth factors.

Objectives: To evaluate the clinical safety and efficacy of using a biologic technology known as preparation rich in growth factors (PRGF) for the treatment of nonhypertrophic nonunion. Design: The design of the study was a retrospective case series. Setting: The private practice was in 2 centers. Patients: There were 15 patients with a total of 16 aseptic nonunions, 12 diaphyseal and 4 supracondylar, diagnosed as nonhypertrophic. The mean time since prior surgical treatment was 21 months (9-46 months). Intervention: Supracondylar and diaphyseal nonunions followed surgical fixation with condylar plating or intramedullary nailing, whereas a composite biomaterial created by mixing PRGF with bone allograft was applied. The area was then covered with autologous fibrin membranes. Stable nonunions were treated with repeated percutaneous injections of PRGF; this minimally invasive procedure was also applied if delayed healing was suspected after surgical treatment. Main Outcome Measurements: Radiographic union using radiographic views was taken in 2 planes. Clinical outcome evaluated pain, motion at the fracture site upon manual stress testing, and recovery of range of motion. Results: All nonunions treated operatively healed after a single procedure, even though additional PRGF had to be injected in 2 patients. Two of 3 stable nonunions achieved healing only after repeated percutaneous PRGF injections. The mean time from surgery and/or PRGF application to union was 4.9 months (2-8 months). Complications associated with the described procedure were not observed. Conclusion: This study, although uncontrolled, shows that PRGF technology is clinically safe and can enhance the healing of nonhypertrophic nonunions.

Relationship between Investigative Biomarkers and Radiographic Grading in Patients with Knee Osteoarthritis

Objective. To examine new investigative biomarkers and their relevance for radiographic severity in knee osteoarthritis. Methods. The group comprised 63 patients with 73 knees examined. Patients were divided according to radiographic severity to allow for comparison of biomarker levels. Hyaluronic acid (HA), matrix metalloproteases (MMP-1, MMP-3 and MMP-13), tissue inhibitors of metalloproteases (TIMP-1 and TIMP-2), platelet-derived growth factor (PDGF-AB), transformed growth factor (TGF-β), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and insulin-like growth factor (IGF-I) were measured on synovial fluid and in plasma releasate at a single time point. Principal component analysis (PCA) followed by analysis of covariance were applied to evaluate data. Results. Four different groups of biomarker were identified in plasma releasates. The first (platelet number, PDGF-AB and TGF-β) and second groups (HA and IGF-I) were related to radiographic severity, P = .005 and P = .022, respectively. The third (MMP-1 and TIMP-2) and fourth groups (MMP-3 and TIMP-1) represented the catabolic balance, but were not associated to radiographic grading. Three different clusters of biomarkers were found in synovial fluid but did not show any significant association to radiographic grading. Conclusions. New imaging approaches to assess structural deterioration and correlation with biomarker levels are warranted to advance in OA research.

Ultrasound-guided plasma rich in growth factors injections and scaffolds hasten motor nerve functional recovery in an ovine model of nerve crush injury.

In the present study we evaluated the motor recovery process of peripheral nerve injury (PNI), based on electrophysiological and histomorphometric criteria, after treatment with plasma rich in growth factors (PRGF) injections and scaffolds in an ovine model. Three groups of sheep underwent a nerve crush lesion: the first group (n = 3) was left to recover spontaneously (SR); the second group was administered saline injections (SI; n = 5) and a third group (n = 6) received PRGF injections and scaffolds immediately after the crush injury. At post‐intervention week 8, 70% of sheep in the PRGF group were CMAP‐positive, with no electrophysiological response in the rest of the groups. Histomorphometric analysis 12 weeks after the surgical intervention revealed that the average axonal density of the SR (1184 ± 864 axons/µm2) and SI (3109 ± 2450 axons/µm2) groups was significantly inferior to the control (8427 ± 2433 axons/µm2) and also inferior to the PRGF group (5276 ± 4148 axons/µm2), showing no significant differences between the control and PRGF groups. The axonal size of the SR and SI groups was significantly smaller compared with the control group (18 ± 4 µm2), whereas the axonal size of the PRGF group (6 ± 5 µm2) did not show statistical differences from the control. Morphometry of the target muscles indicated that the PRGF group had the lowest percentage volume reduction 12 weeks after the crush injury. The PRGF group had larger muscle fibre areas than the SI and SR groups, although the differences did not reach statistical significance. Overall, these data suggest that the PRGF injections and scaffolds hastened functional axon recovery and dampened atrophy of the target muscles in an ovine model. Copyright

Platelet rich plasma and knee surgery.

In orthopaedic surgery and sports medicine, the knee joint has traditionally been considered the workhorse. The reconstruction of every damaged element in this joint is crucial in achieving the surgeons goal to restore the knee function and prevent degeneration towards osteoarthritis. In the last fifteen years, the field of regenerative medicine is witnessing a boost of autologous blood-derived platelet rich plasma products (PRPs) application to effectively mimic and accelerate the tissue healing process. The scientific rationale behind PRPs is the delivery of growth factors, cytokines, and adhesive proteins present in platelets and plasma, as well as other biologically active proteins conveyed by the plasma such as fibrinogen, prothrombin, and fibronectin; with this biological engineering approach, new perspectives in knee surgery were opened. This work describes the use of PRP to construct and repair every single anatomical structure involved in knee surgery, detailing the process conducted in ligament, meniscal, and chondral surgery.

Combination of Intra-Articular and Intraosseous Injections of Platelet Rich Plasma for Severe Knee Osteoarthritis: A Pilot Study

The aim of this study was to assess a novel approach to treating severe knee osteoarthritis by targeting synovial membrane, superficial articular cartilage, synovial fluid, and subchondral bone by combining intra-articular injections and intraosseous infiltrations of platelet rich plasma. We explored a new strategy consisting of intraosseous infiltrations of platelet rich plasma into the subchondral bone in combination with the conventional intra-articular injection in order to tackle several knee joint tissues simultaneously. We assessed the clinical outcomes through osteoarthritis outcome score (KOOS) and the inflammatory response by quantifying mesenchymal stem cells in synovial fluid. There was a significant pain reduction in the KOOS from baseline (61.55 ± 14.11) to week 24 (74.60 ± 19.19), after treatment (p = 0.008), in the secondary outcomes (symptoms, p = 0.004; ADL, p = 0.022; sport/rec., p = 0.017; QOL, p = 0.012), as well as VAS score (p < 0.001) and Lequesne Index (p = 0.008). The presence of mesenchymal stem cells in synovial fluid and colony-forming cells one week after treatment decreased substantially from 7.98 ± 8.21 MSC/μL to 4.04 ± 5.36 MSC/μL (p = 0.019) and from 601.75 ± 312.30 to 139.19 ± 123.61  (p = 0.012), respectively. Intra-articular injections combined with intraosseous infiltrations of platelet rich plasma reduce pain and mesenchymal stem cells in synovial fluid, besides significantly improving knee joint function in patients with severe knee osteoarthritis. This trial is registered on EudraCT with the number 2013-003982-32.