Platelet-rich plasma, especially when combined with a TGF-ß inhibitor promotes proliferation, viability and myogenic differentiation of myoblasts in vitro

Regeneration of skeletal muscle after injury is limited by scar formation, slow healing time and a high recurrence rate. A therapy based on platelet-rich plasma (PRP) has become a promising lead for tendon and ligament injuries in recent years, however concerns have been raised that PRP-derived TGF-β could contribute to fibrotic remodelling in skeletal muscle after injury. Due to the lack of scientific grounds for a PRP -based muscle regeneration therapy, we have designed a study using human myogenic progenitors and evaluated the potential of PRP alone and in combination with decorin (a TGF-β inhibitor), to alter myoblast proliferation, metabolic activity, cytokine profile and expression of myogenic regulatory factors (MRFs). Advanced imaging multicolor single-cell analysis enabled us to create a valuable picture on the ratio of quiescent, activated and terminally committed myoblasts in treated versus control cell populations. Finally high-resolution confocal microscopy validated the potential of PRP and decorin to stimulate the formation of polynucleated myotubules. PRP was shown to down-regulate fibrotic cytokines, increase cell viability and proliferation, enhance the expression of MRFs, and contribute to a significant myogenic shift during differentiation. When combined with decorin further synergistc effects were identified. These results suggest that PRP could not only prevent fibrosis but could also stimulate muscle commitment, especially when combined with a TGF-β inhibitor

THE PATHOGENETIC MECHANISM IN DELAYED ONSET MUSCLE SORENES

SAŽETAK Zakašnjela (odgođena) mišićna bol (DOMS, od. engl. delayed onset muscle soreness) sindrom je koji obuhvaća slabost mišića, bol, duboku osjetljivost u mišićima koja se javlja obično 24–48 sati nakon neuobičajene ili jako intenzivne tjelesne aktivnosti, a prolazi za 5–7 dana. Usprkos brojnim studijama koje se bave ovom problematikom, još nisu usuglašeni stavovi ni o mogućem patogenetskom mehanizmu DOMS-a niti o terapijskim ili preventivnim mogućnostima. Kao glavni uzročni čimbenik pojave DOMS-a navodi se ekscentrična kontrakcija u kojoj se mišić tijekom održavanja napetosti produžuje, ali mehanizam koji to objašnjava nije poznat. Ekscentrična aktivnost mišića može inducirati ozljedu mišićne stanice, koja se manifestira kao oštećenje miofibrilarnih i citoskeletnih struktura, gubitak mišićne snage i poremećaj slijeda aktiviranja motoričkih jedinica, promjena metaboličkih zbivanja u stanici i izlazak enzima u cirkulaciju. Novija istraživanja govore o mogućnosti da bol nije uzrokovana isključivo mehaničkim oštećenjima mišićne stanice i sekundarnim upalnim odgovorima koji podražuje nociceptore, već adaptacijskim procesima remodeliranja mišićne stanice, kojima se povećava snaga mišića dodavanjem novih sarkomera (sarkomerogeneza) i time štiti mišić od novih ozljeda. U ovom radu donosimo pregled dosadašnjih spoznaja o promjenama u mišićnoj stanici, za koje se misli da su uključene u patofiziološki mehanizam nastanka odgođene boli u DOMS sindromu, a čije bi razjašnjavanje moglo imati široku kliničku primjenu u sportskoj medicini.SUMMARY Delayed onset muscle soreness (DOMS) is the feeling of pain, tenderness, deep ache and stiffness that usually develops 24-48 hours after an unaccustomed or a high intensity exercise and subsides generally within 5 to 7 days. Despite numerous studies there is no general consensus on the underlying mechanisms of DOMS, treatment or prevention strategies. A major causative factor is eccentric muscle actions, i.e. active resistance to muscle lengthening. However, the cellular basis for this response remains unclear. Eccentric activities induce micro-injury of muscle cells resulting in myofibrillar disruption, prolonged loss of muscle strength, decrements in motor control, changes in energy substrate levels and presence of muscle proteins in the blood. Some recent research claims that DOMS is not caused by the pain from damaged muscle cells and secondary induced inflammatory processes, but from the reinforcement process. The biological response of muscle to eccentric contractions results in strengthening and protection from further injury. The muscle responds to training by reinforcing itself up to and above its previous strength by adding new sarcomeres, the segments in the muscle fibrils (sarcomerogenesis). In this review, we summarize the muscle cell disturbances and adaptation processes known to be involved in pathogenetic mechanisms of DOMS which could be of clinical importance in sports medicine

Utjecaj faktora rasta aktiviranih trombocita na uraštanje presatka, kod rekonstrukcije prednje ukrižene sveze koljenskog zgloba

Background. Long rehabilitation after arthroscopic anterior cruciate ligament (LCA) reconstruction still represents big problems for patients, especially in professional športsmen. The reason is slow graft healing in bone tunnels and a slow graft ligamentization process. Purpose: The purpose of this study was to determine if the use of platelet gel (PG) accelerates graft revascularisation after anterior cruciate ligament (LCA) reconstruction, and does it have any morphological and clinical relevance for outcome of the operation. Methods. Platelet gel was produced from the platelet rich plasma (PRP), prepared from a unit of whole blood in an Autologous Platelet Separator. PG was applied locally. Fifty patients were included, 25 in the platelet and 25 in a control group. We quantitatively evaluated the process of revascularization in the zone of the osteoligamentous interface in the bone tunnels and in the intraarticular part of the graft. Contrast enhanced magnetic resonance imaging (MRI) studies were carried out at 4-6, 10-12 and 25-27 weeks post surgery. We also evaluated extension of new sclerotic bone formation around tunnels and tunnels dilatation with MRI, knee stability with KT-2000 and functional outcomes of rehabilitation with functional scores. Results. At the first control (4-6 weeks), patients treated with PG demonstrated a significantly higher level of vascularization in the osteoligamentous interface (0.33±0.09), compared with the control group (0.16±0.09), p<0.001. In the intra-articular part of the graft we found no evidence of revascularization in either group. At the second control (10-12 W), the level of vascularisation decreased in the platelet group (0.20±0.13) and increased in the control group (0.17±0.10). In the intra-articular part of the graft we found minimal levels of revascularization but no differences among the groups. At third control (25-27 W) the level of vascularisation decreased in both group. The amount of new sclerotic bone formarion, was significantly higher in platelet group (68.57±14.2) in comparation with control group (54.50±16.6), p<0.0062, 6 months after surgery. The anteroposterior knee stability, was also significanty better in platelet (4.7±1.9) than in control (6.7±2.1) group, six months after sugery (p<0.003). Conclusion. The PG, applied locally, enhance early revascularization of the graft in the zone of the osteoligamentous interface in the bone tunnel, after anterior cruciate ligament reconstruction. Enhancement of this early postoperative biological process, is demonstrated in late morphological and clinical manifestations, as extensive new bone formation around bone tunnels, smaller enlargement of bone tunnels and more stable knee joint

New biological approaches in the reconstruction of anterior cruciate ligament (ACL)

Izhodišča: Ruptura sprednje križne vezi (ACL) je ena pogostejših poškodb kolena. Pri zdravljenju igra ključno vlogo uspešna rekonstrukcija ACL z vstavitvijo presadka. Uspešnost operativnega postopka je 73-95 %, vrnitev na predoperatvno stopnjo dejavnosti pa 37-75 %. Glavna težava po rekonstrukciji je zelo dolga rehabilitacija. Bolniki ne smejo polno obremeniti kolena najmanj 6 mesecev po poškodbi. Uspešnost rekonstrukcije ACL je odvisna od vraščanja presadka v kostnem tunelu in od ligamentizacije, t.j. procesa, pri katerem pridobi lastnosti nativnega ACL. Pri tem igrajo pomembno vlogo biomehanski dejavniki (pravilni položaj kostnih tunelov -anatomska lega presadka, pričvrstitev in ustreznost presadka ter pooperativna rehabilitacija) in biološki odziv presadka po rekonstrukciji (stopnja revaskularizacije in nastajanje kolagenskih vlaken), ki ga lahko pospešimo z dodajanjem rastnih faktorjev (RF), periosta in uporabo mezenhimskih zarodnih celic. Ti pristopi so novost v rekonstrukciji ligamentnih struktur, saj posegajo v biologijo celjenja med kostjo in presadkom. Danes uporabljamo tehniko za pridobivanje s trombociti bogate plazme (PRP) iz avtologne krvi, ki jo damo na mesto vstavitve presadka in tako pospešimo vraščanje in proces ligamentizacije presadka. Zaključki: Pregledni članek obravnava dejavnike, ki vplivajo na uspešnost zdravljenja po rekonstrukciji ACL. Poznavanje in modulacija biološkega odziva presadka je nov pristop k zdravljenju pretrgane ACL, bolnikom in športnikom pa omogoča hitrejšo vrnitev k vsakodnevnim in drugim telesnim dejavnostim.Background: Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. The operative reconstruction is usually performed as the standard treatment. The success of the operative technique is between 73-95 %, and 37-75 % of patients return to the preoperative physical activity. The main problem after surgical reconstruction is the long rehabilitation period. Patients are not allowed to perform sports activities for 6 months after surgery. The outcome after ACL reconstruction depends upon the healing of the graft in the bone tunnel and upon the ligamentization of the intraarticular part of the graftthis is a process during which the graft attains the features of a native ACL. The biomechanical factors (anatomical tunnel position, fixation, adequacy of the graft and postoperative rehabilitation) and biological response (revascularization and the number of collagen fibers) seem to play a crucial role after surgery. The biological response can be accelerated with the use of growth factors (GF), periosteum and mesenchymal stem cells (MSCs). Nowadays platelet-rich plasma (PRP) from autologous blood is applied at the graft insertion site to promote healing and ligamentization of the graft. Conclusion: The review focuses on the factors that influence the outcome of ACL reconstruction. A better understanding of the graft\u27s biological response and its modulation is the basis of new approach in the treatment of ACL rupture, which enables the patient and athlete to quicker resume their everyday and sports activities

Artroskopska anatomija in patoanatomija raztrganine sprednje križne vezi

Purpose: To arthroscopically evaluate the size variability of the Anterior cruciate ligament (ACL) insertion sites and to determine whether there are variations in rupture patterns of the two ACL bundles. Material and Methods: Ninetyfour patients undergoing ACL reconstruction between June 2008 and June 2009 were included in our study. The average age of the patients was 26.7 +/- 8.3 years (range, 1648 years). Only patients with an ACL rupture less than 120 days old were included as unpublished data revealed difficulty in distinguishing between AM and PL bundles in older ACL ruptures.Results: The femoral ACL insertion site length ranged from 11 to 20 mm (15.9 +/- 2.2). On the tibial side, the length of the tibial ACL insertion site ranged from 9 to 20 mm (16.0 +/- 2.1). On the femoral side, the width of the ACL insertion site ranged from 6 to 11 mm (8.3 +/- 1.2). On the tibial side, the width of the entire ACL insertion site ranged from 6 to 12 mm (8.7 +/- 1.1). The most frequent injury pattern was found to be the proximal rupture of both bundlesseen in 74 patients (78.7%). Conclusion: Both hypotheses were confirmed, and this may be clinically relevant in anatomic ACL reconstruction.Cilji: Artroskopsko smo želeli določiti variacijo velikosti narastišča sprednje križne vezi (SKV) ter ugotoviti, ali ima raztrganina sprednje križne vezi različne vzorce glede na dejstvo, da je sestavljena iz dveh snopov. Material in metode: V raziskavo je bilo vključenih 94 operiranih bolnikov s pretrgano sprednjo križno vezjo v obdobju od junija 2008 do junija 2009. Povprečna starost bolnikov je bila 26.7 +/- 8.3 (od 16 do 48 let). Vključitvena kriterija sta bila dva: pretrganje sprednje križne vezi in čas med poškodbo in operacijo , krajši od 120 dni. Ta kriterij je bil določen, ker se je pri prejšnji neobjavljeni raziskavi pokazalo, da je 120 dni po poškodbi težko ločiti oba snopa. Rezultati: Ugotovili smo, da je dolžina narastišča sprednje križne vezi na femur od 11 do 20 mm (15.9 +/- 2.2). Na tibiji je dolžina od 9 do 20 mm (16.0 +/- 2.1). Širina narastišča sprednje križne vezi na femur je od 6 do 11 mm (8.3 +/- 1.2). Širina narastišča sprednje križne vezi na tibijo je med 6 in 12 mm (8.7 +/- 1.1). Najpogostejši vzorec poškodbe sprednje križne vezi je bila raztrganina obeh snopov proksimalno, in sicer kar pri 74 bolnikih (78.7 %). Zaključek: Obe hipotezi sta bili potrjeni, kar je morda klinično pomembno pri rekonstrukciji sprednje križne vezi

Use of rapid prototyping drill guide template for pedicle screw placement

Izhodišča: Postavitev pedikularnih vijakov s prostoročno tehniko je povezana z znatnim odstotkom predrtja pedikla. To tveganje lahko zmanjšamo z uporabo medoperativne diaskopije ali z navigacijo, ki imata določene pomembne pomanjkljivosti. Obetaven princip, s katerim bi lahko odpravili večino težav, je metoda hitre izdelave prototipov, s katero lahko izdelamo bolniku prilagojene vodilne šablone, ki omogočajo optimalno pozicioniranje vijakov. V zadnjem desetletju je bilo izvedenih nekaj študij, v katerih so predvsem na kadavrih z uporabo šablon relativno uspešno vsadili pedikularne vijake. Pri nas smo izvedli klinično študijo in izdelali šablone, ki omogočajo hkratno vsaditev vijakov na več ravneh. V raziskavo smo prvič vključili tudi križnično hrbtenico. Metode: V prospektivno klinično raziskavo primerov s kontrolami je bilo vključenih 15 oseb. V ledveno in križnično hrbtenico smo vstavili 30 pedikularnih vijakov z uporabo vodilnih šablon, 36 vijakov pa smo vstavili prostoročno pod nadzorom RTG. Na podlagi preoperativnih CT-posnetkov smo s postopkom selektivnega laserskega sintranja izdelali vodilne šablone. V obeh skupinah smo opravili analizo predrtja pediklov glede na pooperativni izvid CT. Rezultati: Incidenca predrtja pedikla je pri uporabi vodilne šablone statistično značilno manjša kot pri kontroli. Zaključki: Uporaba večnivojskih vodilnih šablon se je izkazala kot zanesljiva metoda, ki pomembno zmanjša verjetnost za poškodbo pedikla in s tem povezane zaplete. Kljub temu ima določene pomanjkljivosti, ki so povezane z relativno dolgim časom izdelave vodilnih šablon, z napakami pri izdelavi ali s pozicioniranjem med operacijo. Zaradi omenjenih lastnosti metoda ni nadomestila prostoročne tehnike ali navigacije, vendar je pomembna alternativa v izbranih primerih.Background: Pedicle screw placement using free hand technique has high incidence of pedicle perforation. The said risk can be reduced with intra-operative fluoroscopy or navigation, which have some disadvantages. A promising principle for solving most of the issues is the rapid prototyping technology. By this technique it is possible to manufacture patient specific drill guide templates that enable optimal pedicle screw placement. In the last decade, many studies have featured relatively successful implantations of pedicle screws through the use of drill guide templates, though mostly on cadavers. We performed a similar clinical study involving the manufacture of templates for the lumbar and sacral regions that enable simultaneous multiple-level screw implanting. Methods: A randomized clinical trial was performed in 15 patients. In the lumbar and sacral spine 30 screws were implanted using drill guide template and 36 screws using free hand technique under fluoroscopy supervision. Preoperative CT-scans were taken for drill guide template design and manufacture using selective laser sintering method. According to postoperative CT-scan analysis, pedicle perforation incidence was estimated. Results: The incidence of cortex perforation was significantly reduced in the drill guide template group. Conclusions: Drill guide templates have turned out to be a reliable solution that importantly reduces pedicle perforation incidence and complications related to it. However, there are shortcomings: a relatively lengthy manufacturing process, possible manufacturing faults and incorrect positioning during the operation. Owing to mentioned disadvantages, templates have not replaced free hand and navigation technique yet, but could represent a useful tool in some selected cases