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See detailComparison of the platelet concentrations obtained in platelet-rich plasma (PRP) between the GPS™ II and GPS™ III systems
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Renouf, Julien et al

in Pathologie Biologie (2011), 59(5), 275-277

Introduction Platelet growth factors are known for their ability to speed up tissue healing (bone, skin, tendons, muscle). Various techniques make it possible to collect this platelet-rich plasma or PRP ... [more ▼]

Introduction Platelet growth factors are known for their ability to speed up tissue healing (bone, skin, tendons, muscle). Various techniques make it possible to collect this platelet-rich plasma or PRP. Methods This study compares the platelet concentrations obtained from five patients using GPS™ III, which has recently come onto the market, with those obtained using GPS™ II. Results and conclusion We obtain a platelet concentration that is six to nine times greater with GPS ™ II and GPS™ III, but there is no significant difference between the concentrations of PRP obtained with the two systems. [less ▲]

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See detailPlatelet-rich plasma (PRP) and tendon healing: animal model
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in British Journal of Sports Medicine (2011, February), 45(2), 1

Introduction: The tendon is a tissue which does not heal easily. Recently, several studies have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of ... [more ▼]

Introduction: The tendon is a tissue which does not heal easily. Recently, several studies have demonstrated the positive effects of platelets on the healing process of tendons. A local injection of platelet–rich plasma (PRP), which releases in situ many growth factors, has the potentiality to enhance the tendon healing process. The aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: A 5mm defect was surgically induced in 90 rats’ Achilles tendon. Rats were divided into 2 groups of 45: (A) control (no treatment) and (B) PRP treatment. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 traumatized Achilles tendons of each group were dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. After that, transcriptomic analyses were made on the tendon samples, to study the expression of type III collagen, matrix metalloproteases and tenomodulin. A hydroxyproline dosage was done to quantify the collagen in the tendon during its healing process. Tendons of the 15 remaining rats of each group were subjected to a histological study, respectively at day 5, 15 and 30 (5 rats for each time). Results: We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile test study was greater for tendons which had been submitted to an injection of PRP compared to the control group: +19% (day 5), +30% (day 15) and +43% (day 30). Histological study showed that PRP could enhance cells proliferation, angiogenesis and collagen organisation. Our biochemical analyses did not explain beneficial effects of PRP. Indeed, there was no significant difference neither between the expression of different studied genes, nor in the quantity of hydroxyproline between both groups. Conclusion: This experimentation has shown that a PRP injection could accelerate the tendons healing process and improve its quality. [less ▲]

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See detailTendon lesion and platelet-rich plasma (PRP) injection: rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in Annual Congress of the RBSPRM (2010, December 03)

Introduction: For a few years, the positive effect of platelets on the healing process of different tissues (skin, bones...) was demonstrated. In fact platelets contain lots of growth factors which can be ... [more ▼]

Introduction: For a few years, the positive effect of platelets on the healing process of different tissues (skin, bones...) was demonstrated. In fact platelets contain lots of growth factors which can be release locally and enhance the healing process. Thus the aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: Ninety rats’ Achilles tendons were sectioned. Forty-two rats beneficed of a PRP injection in situ. After 5, 15 and 30 days, 15 rats of both groups were euthanized after tendon sampling which were immediately submitted to a biomechanical tensile test until tendon rupture, using an original method of measurement (“cryo-jaw”). Histological and biochemical analyses were made as well as a quantification of collagen with an original procedure (quantification of the “greys” on histological cross-sections). Results: Tendons in the PRP group were more resistant to rupture than those in the control group. Histological findings showed in this group an increase of collagen proliferation and better collagen fibres reorganization. However, we did not find any biochemical difference neither in term of encoding gene expression for type III collagen, matrix metalloprotease 9 and tenomodulin. Conclusion: Our animal study demonstrated that an injection of PRP could accelerate the tendons healing process and improve its quality. [less ▲]

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See detailTendon lesion and platelet-rich plasma (PRP) injection
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

Poster (2010, November 25)

Introduction: For a few years, the positive effects of platelets on the healing process of different tissues (skin, bones...) were demonstrated. In fact platelets contain lots of growth factors which can ... [more ▼]

Introduction: For a few years, the positive effects of platelets on the healing process of different tissues (skin, bones...) were demonstrated. In fact platelets contain lots of growth factors which can be release locally and enhance the healing process. Thus the aim of our experiment was to ascertain by an original mechanical measure whether the use of PRP was of interest for accelerating the healing process of rats’ Achilles tendons after surgical induced lesion. Methods: A 5mm defect was surgically induced in 90 rats’ Achilles tendon. Rats were divided into 2 groups of 45: (A) control (no treatment) and (B) PRP treatment. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 traumatized Achilles tendons of each group were dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. After that, transcriptomic analyses were made on the tendon samples, to study the expression of type III collagen, matrix metalloproteases and tenomodulin. A hydroxyproline dosage was finally realised to quantify the collagen in the tendon during its healing process. Tendons of the 15 remaining rats of each group were subjected to a histological study, respectively at day 5, 15 and 30 (5 rats for each time). Results: We demonstrated that (1) the stress (F) during biomechanical tensile test up to tendon rupture was significantly greater for tendons which had been submitted to an injection of PRP compared to the control group; (2) the surface (S) area of the section of the tendon was greater in the PRP group during the 15 first days, but this section was similar after 30 days in the 2 groups; (3) the ration F/weight of the rat was significantly greater in the PRP group at each time; (4) constrain was similar after the 15 first days but was significantly greater in the PRP group after 30 days. Histological study showed that PRP could enhance cells proliferation, angiogenesis and collagen organisation. Our biochemical analyses did not explain beneficial effects of PRP. Indeed, there was no significant difference between the expressions of different studied genes. Conclusion: Our animal study demonstrated that an injection of PRP could accelerate the tendons healing process and improve its quality. [less ▲]

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See detailInjection de concentrés plaquettaires et régénération tendineuse : modèle animal
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in 3ème Congrès Commun SFMS - SFTS (2010, October 01)

Introduction : La régénération tendineuse en traumatologie du sport demeure un processus actuellement difficile à gérer et de nouvelles voies thérapeutiques sont en cours d’exploration. La littérature ... [more ▼]

Introduction : La régénération tendineuse en traumatologie du sport demeure un processus actuellement difficile à gérer et de nouvelles voies thérapeutiques sont en cours d’exploration. La littérature récente fait état d’effets bénéfiques sur la régénération tendineuse de concentrés plaquettaires (platelet-rich plasma ou PRP), administrés in situ, dus au relargage de facteurs de croissance par activation des plaquettes et à leur activité stimulante au cours de la cicatrisation. Dès lors, nous avons souhaité tester l’effet bénéfique de ce traitement sur des rats préalablement lésés au niveau de leur tendon d’Achille. Matériel et Méthode : Une section unilatérale du tendon d’Achille a été réalisée chez 60 rats Sprague Dawley adultes. De ces 60 rats, 30 ont subi une cicatrisation naturelle (rats contrôles) et 30 rats ont bénéficié d’une injection in situ de PRP le jour de la lésion. Diverses études biomécaniques, biochimiques et histologiques ont été réalisées sur ces tendons d’Achille en cours de cicatrisation à respectivement J5, J15 et J30 après lésion. Dix rats supplémentaires ont servi de témoins sains (sans lésion tendineuse). L’étude biomécanique appréciait la résistance maximale des tendons à la traction à l’aide de mors type « cryo-jaws ». L’étude histologique évaluait l’évolution cellulaire pendant la phase de cicatrisation. L’analyse transcriptomique étudiait l’expression de gènes codant pour le collagène de type III, les métalloprotéases matricielles (MMP-9) et la ténomoduline (TNMD), ainsi qu’un dosage d’hydroxyproline permettant d’évaluer la quantité de collagène présente dans le tendon au cours de la cicatrisation. Résultats : L’étude biomécanique démontre la meilleure résistance des tendons traités avec du PRP par rapport aux tendons contrôles à J5 (+19%), J15 (+30%) et significativement à J30 (+43%). L’étude histologique suggère qu’une injection de PRP stimule la prolifération cellulaire, favorise l’organisation tissulaire, stimule l’angiogenèse et la réorganisation architectural du collagène. L’étude biochimique ne permet pas d’expliquer les effets bénéfiques puisqu’il n’y a pas de différence dans l’expression des gènes des différentes molécules matricielles (collagène de type III, MMP-9 et TNMD) ni dans la quantité d’hydroxyproline qui s’accroit au cours du temps de la cicatrisation de façon similaire dans les deux groupes. Conclusion : L’injection de PRP améliore et accélère la cicatrisation tendineuse et augmente la résistance aux contraintes mécaniques du tendon en cours de cicatrisation. [less ▲]

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See detailPlatelet-Rich Plasma injection to improve tendon healing process
Kaux, Jean-François ULg; Drion, Pierre ULg; Renouf, Julien et al

in Osteoarthritis and Cartilage (2010, September), 18(Supplement 2), 221

Introduction It is well known that injured tendons do not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or late management. Recently, several studies ... [more ▼]

Introduction It is well known that injured tendons do not heal easily. For example, tendinopathy is a condition which often becomes chronic in the case of bad or late management. Recently, several studies, essentially in vitro and, more recently, a few in clinical practice, have demonstrated the positive effects of platelets on the healing process of different tissues. In fact, platelets contain lots of growth factors which can be released after a local injection. These growth factors have the potentiality to enhance the tendon healing process, for example after rupture or tendinopathy. The aim of our experiment was to ascertain whether the use of Platelet-Rich Plasma (PRP) was of interest for accelerating the healing process of Achilles tendon after surgical induced lesion. Methods All experimental procedures and protocols used in this investigation / were reviewed and approved by the Institutional Animal Care and Use Committee of the University of Liège. 60 rats were divided into 2 groups: A: control (no injection) and B: PRP injection. A 5mm defect was surgically induced in the rats’ Achilles tendon after resection of plantaris tendon. Rats of group B received a PRP injection in situ after the surgery. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, the traumatized Achilles tendons of 10 rats of both groups were removed and dissected during their healing process. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a “Cryo-jaw”. Rats were then euthanized. Statistical analyses were made with an ANOVA. Values are significant when p-value is below 0.05. Results We observed that the force necessary to induce tendon rupture during biomechanical tensile testing increased with time in both groups; that this force was greater for tendons which had been submitted to an injection of PRP. The ratio between force and weight increased with time in both groups; that this ratio was greater for tendons which had been submitted to an injection of PRP too. There is also a significant interaction between time and the group. The surface area of the section of the tendons increased between 5 and 15 days followed by a stabilization. After 30 days, sections in both groups were similar. Thus, the constraint was similar after 5 and 15 days but is significantly better for PRP group after one month. Discussion – Conclusion We demonstrated that the force necessary to induce tendon rupture during biomechanical tensile testing was greater for tendons which had been submitted to an injection of PRP. These results were observed and significant (p<0.05) from day 5 onwards. We observed too that the section of the tendon was the same in both groups after 30 days. Thus the quality of the healing tendon is better with an injection of PRP, as shown with the increase of the constraint until rupture. Acknowledgement This experimentation was partially financed by “Standard de Liège 2007” and “Lejeune-Lechien 2008” grants. [less ▲]

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See detailGPS™ II and GPS™ III: comparison of obtained platelets concentrations
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Renouf, Julien et al

Poster (2010, March 20)

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study ... [more ▼]

Introduction: Recently, several researches, essentially in vitro, demonstrated the positive effects of platelets on healing process of different tissues: bones, muscles and tendons. The aim of this study is to compare the obtained platelets concentration between the new GPS™ III and GPS™ II. Methods: Two blood samples of 52 mL were taken in 5 volunteers and transferred respectively in both GPS™ II and GPS™ III. These devices were centrifuged at 3200 RPM during 15 min. The platelet-rich plasma (PRP) was thus collected and transferred in 6 mL test tubes. Cells count was done using an analyser ABX Micros 60. Results and conclusion: Platelets concentrations were more important from 6.2 up to 9.2 times with GPS™ II and from 7.3 up to 8.3 times with GPS™ III compared to blood samples. Efficiency of the collected platelets was around 92% for GPS™ II and 96% for GPS™ III. Both techniques made it possible to collect platelets but, unfortunately, also a lot of red and white blood cells. None of these parameters showed any significant difference (p>0.05). Conflicts of interests: The 10 devices GPS™ II and GPS™ III were provided gracefully by the firm Biomet Biologics TTC. [less ▲]

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