Konstantinos Kazakos

The Influence of Platelet-Rich Plasma on Angiogenesis During the Early Phase of Tendon Healing

Background: The poor vascularity of tendons is a major factor in their limited healing capacity. The aim of this study was to assess the effect of Platelet Rich Plasma (PRP) on angiogenesis during tendon healing. Materials and Methods: Forty-eight skeletally mature New Zealand White rabbits were used. The Achilles tendon was transected transversely and 0.5 ml of PRP was injected into the tendon mass on each side of the incision on both limbs. The injection in the control group consisted of saline. Six animals from each group (12 tendons each) were sacrificed after 1, 2, 3, and 4 weeks following treatment. Three sections from each Achilles were stained with hematoxylinosin for microscopic examination. Further three sections were immunostained with a monoclonal antibody against CD31 (Daco Co), followed by image analysis to count new vessel numbers and statistical analysis was performed. Results: There was significantly more angiogenesis in the PRP group compared to the control group during the first two weeks of the healing process, i.e., inflammatory and proliferative phase (p < 0.0001). The orientation of collagen fibers in the PRP group was better organized. The number of the newly formed vessels in the PRP group were significantly reduced at 4 weeks compared to the controls (p < 0.0001) suggesting the healing process was shortened. Conclusion: PRP seems to enhance neovascularization which may accelerate the healing process and promote scar tissue of better histological quality. Clinical Relevance: Although these results need replication and further biomechanical research, PRP may promote tendon healing acceleration.

The use of autologous PRP gel as an aid in the management of acute trauma wounds

Autologous platelet-rich plasma (PRP) gel is increasingly used in the treatment of a variety of soft and bony tissue defects, such as accelerating bone formation and in the management of chronic non-healing wounds. We performed this study to assess the benefits of using autologous PRP gel in the treatment of acute limb soft tissue wounds. 59 patients with acute wounds (open fractures, closed fractures with skin necrosis and friction burns) were randomised into two groups. Group A (32 patients) were treated with conventional dressings and Group B (27 patients) were managed with local application of PRP gel. Gustillo grade IIIb or IIIc open fractures were not included in this study, as these injuries required coverage with flap. The clinical endpoints were the healing rate and/or the time required to bring about adequate tissue regeneration in order to undergo reconstructive plastic surgery. The rate of wound healing rate was significantly faster in Group B at week 1, 2 and 3 (p=0.003, p<0.001 and p<0.001, respectively). The mean time to plastic reconstruction in Group B was 21.26 days, S.D.=1.35 vs 40.6 days in Group A, S.D.=5.27 (p<0.001). This study has shown that PRP gel treatment can be a valuable and effective aid in the management of acute trauma wounds.

Safety and efficacy of commercially available demineralised bone matrix preparations: a critical review of clinical studies.

Demineralised bone matrix (DBM), a form of allograft, possesses the properties of osteoinductivity and osteoconductivity. A large body of data obtained from extensive preclinical studies have clearly supported the utility of DBM in human clinical settings. However, it is now recognized that various DBM configurations may differ considerably with regard to their bone inductive activity. Several factors could account for such variability, including the biologic properties of the graft, the host environment, and the methods of allograft preparation. The differing efficacy of DBM products may also depend on differences in particle size and shape, donor selection criteria, protocols for collection and storage, as well as DBM carrier materials. Several comparative studies have confirmed the differences in the osteoinductive potential of various DBM preparations. The purpose of the present review is to provide a critical overview of the current applications of DBM in a clinical setting.

Systematic effects of surgical treatment of hip fractures: Gliding screw-plating vs intramedullary nailing

AIM Numerous studies have been published regarding the comparison between intramedullary nail and the dynamic hip screw and plate for the fixation of intertrochanteric fractures in elderly patients. In this paper we present a comparative study of these two methods regarding their systemic effects on this group of patients. MATERIALS-METHODS This is a randomized trial of 120 consecutive patients with an intertrochanteric fracture treated with either extramedullary fixation (dynamic hip screw and plate; DHS, Synthes-Stratec, Oberdorf, Switzerland) or intramedullary nail (Gamma nail, Stryker Howmedica, Freiburg, Germany and Endovis BA, Citieffe, Bologna, Italy). The parameters that we assessed pre-operatively, in addition to their demographics, included their mental state (MMSE), their nutritional and immune state and their pulmonary function. Intra-operatively we calculated the amount of radiation exposure, the amount of blood loss and the length of operative time for each procedure. Postoperatively we repeated the calculation of the mental and pulmonary state and the blood loss, during days 1, 3, and 10 and related them to the ease of the patients mobilization. RESULTS Decreased bleeding and post-operative pain, reduced post-operative morbidity and faster recovery of function were better but not significant in the group of intramedullary fixation (all p>0.05). However, in the same group there were slightly more patients in whom the MMSE was falling, together with their pulmonary function, suggesting that this method probably predisposes to higher chances of pulmonary dysfunction and the possibility of pulmonary embolism. CONCLUSION We found no significant differences between the two methods of stabilization of these fractures regarding their systemic effects perioperatively. The classic dynamic hip screw can preserve its position as a safe and effective solution for these already vulnerable patients having sustained a trochanteric fracture against the novel intramedullary techniques.

Does a Single Application of PRP Alter the Expression of IGF-I in the Early Phase of Tendon Healing?

The purpose of this study was to determine whether or not a single application of platelet-rich plasma (PRP) in a ruptured tendon alters the expression of IGF-I in the early phase of healing in an animal wound model. We performed an Achilles tendon rupture model on 48 New Zealand white rabbits, by transecting the tendon transversely and then injecting 0.5 mL of PRP into the tendon mass on one side, and injecting saline on the contralateral, control side. Twenty-four animals received PRP (PRP group), and 24 animals served as untreated controls (control group). Six animals (12 limbs) were killed from each group at 1, 2, 3, and 4 weeks postoperatively. After the animals were killed, 6 paraffin sections were made from each Achilles tendon, 3 of which were stained with hematoxylin and eosin and subjected to microscopic examination, and 3 of which were immunostained with an anti-IGF-I primary antibody. Density of brown diaminobenzidine (DAB) staining was evaluated to quantitatively analyze the results. IGF-I was expressed intracellularly in various cell types throughout the entire healing phase. The growth factor was localized in the epitenon and the endotenon, with an overexpression in the epitenon in the PRP group by the fourth week in comparison with the controls. Furthermore, the tendons treated with PRP healed more rapidly. Based on these findings, PRP could be useful to surgeons treating ruptured tendon.

Application of PRP gel alone or in combination with guided bone regeneration does not enhance bone healing process: An experimental study in rabbits

INTRODUCTION The aim of this study was to assess the hypothesis that application of platelet-rich plasma (PRP) gel in mandibular defects in rabbits, alone or in combination with guided bone regeneration (GBR) techniques, could enhance the bone healing process. MATERIALS AND METHODS Thirty New Zealand white rabbits were used. Three groups of 10 animals each were assigned, and the animals were sacrificed after 12 weeks. During the operation, a rotating trephine bur was used to create circular defects 10-mm in diameter in the region anterior to the jaw angles. In group human fascia lata (HFL), a human fascia lata membrane was used. In group PRP, PRP gel was used to fill the defect, and in group HFL+PRP, PRP was used to fill the defect which after that was covered with a human fascia lata membrane. RESULTS In general, none of the control sides and the PRP treated sides had full development of bone or filling of the defect through bone bridging. Conversely, the sides on which the fascia lata membrane or the combination of membrane and PRP had been applied were characterized mostly by development of newly formed bone that bridged the gap. CONCLUSIONS Our results suggest that the application of PRP gel alone or in combination with GBR does not enhance bone healing process.

Temporal and spatial expression of TGF-β1 in an Achilles tendon section model after application of platelet-rich plasma

BACKGROUND To investigate the effect of platelet-rich plasma (PRP) on TGF-beta1 expression during tendon healing. METHODS We used 48 skeletally mature New Zealand White rabbits. 24 rabbits received the PRP, and 24 rabbits served as an untreated control group. Equal numbers of animals were sacrificed at 1st, 2nd, 3rd, and 4th week. The surgical procedure involved a transverse incision to transect the Achilles tendon. A volume of 1ml of PRP was then injected into the tendon mass in the PRP group. Histological and immunohistochemical evaluations with an anti-TGF-beta primary antibody were performed. RESULTS The pattern of expression of TGF-beta1 in the PRP group was characterized by a significant upregulation during the first 2 weeks and subsequently significant downregulation in the 3rd and 4th week in comparison with the controls. CONCLUSIONS Our results suggest that PRP may affect the tendon healing process by altering the expression of TGF-beta1.

Use of demineralized bone matrix in the extremities

Autologous bone graft is considered as the gold standard for all indications for bone grafting procedures but the limited availability and complications in donor site resulted in seeking other options like allografts and bone graft substitutes. Demineralized bone matrix (DBM) is an allograft product with no quantity limitation. It is an osteoconductive material with osteoinductive capabilities, which vary among different products, depending on donor characteristics and differences in processing of the bone. The purpose of the present review is to provide a critical review of the existing literature concerning the use of DBM products in various procedures in the extremities. Clinical studies describing the use of DBM alone or in combination with other grafting material are available for only a few commercial products. The Level of Evidence of these studies and the resulting Grades of Recommendation are very low. In conclusion, further clinical studies of higher quality are required in order to improve the Recommendation Grades for or against the use of DBM products in bone grafting procedures.

Simultaneous bilateral tibial tubercle avulsion fracture in an adolescent: a case report and review of the literature

Avulsion fractures of the tibial tubercle are uncommon. Bilateral tibial tubercle avulsion fractures are extremely rare. In this article, we describe Watson-Jones type III simultaneous bilateral tibial tubercle avulsion fractures in a 17-year-old boy who fell on the ground while taking off in high jump in sport. An open anatomic reduction and internal fixation was performed. We report here on the successful surgical treatment of a simultaneous bilateral fracture of the tibial tuberosity in an adolescent. These types of fractures involve a growth plate, extend through the articular surface and appear to do well with open reduction and secure internal fixation despite their bilateral nature, with recovery and functional outcome comparable to results from unilateral tibial tubercle avulsion fractures.

Intravenous vs Topical Tranexamic Acid in Total Knee Arthroplasty Without Tourniquet Application: A Randomized Controlled Study.

BACKGROUND Use of tranexamic acid (TXA) is effective and safe in reducing the blood loss in total knee arthroplasty (TKR) performed using a tourniquet, but, data in TKR performed without tourniquet are limited, and there is no study comparing the topical (T) with intravenous (IV) TXA administration. Our aim was to compare the topical (T) with intravenous (IV) TXA administration in TKR performed without tourniquet. MATERIAL AND METHODS A total of 120 patients undergoing unilateral TKR for knee osteoarthritis were included in a prospective randomized study. Operations were performed under spinal anesthesia, no tourniquet was used, and the postoperative regime was the same for all patients. Patients were divided into 3 groups; in group C (control), 40 patients received no TXA, in group IV, 40 patients received 1 g of TXA intravenously, and in group L, 1 g of TXA was applied locally to 40 patients. The primary outcome measures included the calculated blood loss, the transfusion rate, and quantity of allogeneic blood units, whereas secondary outcome measures were complications. RESULTS There was no statistically significant difference in patients demographics and perioperative results. Calculated blood loss, allogeneic blood transfusion rate, and quantity in group C were significantly higher compared with those of TXA groups (P < .001). There was no significant difference in complications rate between the 3 groups. CONCLUSIONS According to the results of this study, IV or T administration of 1-g TXA significantly reduced the blood loss and the need for allogeneic blood transfusion in patients undergoing TKR without a tourniquet (with no significant difference between the 2 routes of administration).