Autologous Platelet-rich Fibrin Research Articles

Efficacy and safety of autologous platelet-rich fibrin for the treatment of infertility with intrauterine adhesions.

To evaluate the efficacy and safety of autologous platelet-rich fibrin (PRF) for the treatment of infertility with intrauterine adhesions. Forty patients who suffered from infertility with intrauterine adhesions (IUAs) were enrolled in this prospective trial from October 2018 to December 2019. They were randomly divided into a PRF group and a control group. Both groups underwent transcervical resection of adhesions (TCRA) during the follicular phase. PRF group: PRF prepared from autologous venous blood was placed in the uterine cavity after TCRA and after the first menstrual re-fluid; control group: no PRF insertion. After the second menstrual re-fluid, both groups underwent hysteroscopy to reevaluate adhesion severity. Pregnancy rate, intrauterine adhesion score, menstrual volume and duration, and endometrial thickness were assessed and adverse events were recorded. (1) PRF group pregnancy rate was significantly higher than the control group (55.0% vs. 20.0%). Mean follow-up time was (17.63 ± 2.33) months. All patients fell pregnant naturally. Four (PRF) and one (control) patients delivered live births without placental complications. (2) Intrauterine adhesion scores decreased compared with treatment-before. (3) In the pictorial blood loss assessment chart, score and menstrual duration during the 3rd menstrual cycle showed significant improvements for both groups. (4) Endometrial thickness also showed an increasing trend, and subendometrial bloodflow improved. (5) No treatment-related serious adverse events were noted. Placing PRF into the uterine cavity of infertility patients with IUAs following TCRA is a safe and effective therapeutic method.

Autologous platelet-rich fibrin (PRF) augmentation as an add-on therapy in deep surgical site infections (dSSIs) after instrumented spinal surgery: preliminary results of a single institution case series

BackgroundDeep surgical site infections (dSSIs) after instrumented spinal surgery pose major therapeutic challenges. Standard treatment involves surgical debridement, wound drainage, and long-term antibiotic administration. Autologous platelet-rich fibrin (PRF) constitutes a biomaterial obtained from patients’ own blood that contains leukocytes, chemokines and growth factors boosting cicatrization. Due to favorable results reported from other surgical disciplines such as dentistry, orthopedics, maxillofacial and plastic surgery using PRF, the authors hypothesized that PRF augmentation will promote wound healing in dSSIs.ObjectiveTo report our preliminary results on the safety and efficacy of autologous-PRF as an add-on therapy on a pilot case series of persistent dSSI after instrumented spinal surgery.MethodsAmong the 293 patients who underwent dorsal decompression and stabilization of the cervical, thoracic, and lumbar spine due to degenerative diseases in our department, 12 patients (4%) presented persisting dSSI after standard wound debridement and antibiotic treatment. PRF augmentation was used during a second surgical revision as an add-on therapy to standard debridement. In all cases, the wound was primarily closed without drains.ResultsWound healing was completed between 14 and 21 days after the second surgical revision in all patients. At a median follow-up of 8 months (range: 6 to 18 months), no recurrence of dSSI nor complications were encountered in any case.ConclusionsOur preliminary results suggest that PRF augmentation in persistent dSSI after instrumented spinal surgery appears to be a safe and effective strategy to promote wound healing. Prospective controlled studies are required to define the efficiency of PRF more clearly in both treating and preventing dSSI.

Management of Non-Healing Ulcers by Autologous Platelet Rich Fibrin (PRF)

Management of Non-Healing Ulcers by Autologous Platelet Rich Fibrin (PRF)

Analysis in efficacy of autologous platelet-rich fibrin in the treatment of infertility due to intrauterine adhesions

Objective To evaluate the efficacy of autologous platelet-rich fibrin (PRF) in the treatment of infertility due to intrauterine adhesion. Methods From October 2018 to October 2019, 40 patients diagnosed as intrauterine adhesion and excluded other infertility factors in Beijing Shijitan Hospital were randomly divided into PRF group and control group, with 20 cases in each group. The intervention lasted for 8 weeks. Patients in both groups underwent transcervical resection of adhesion (TCRA), and PRF was placed in the uterine cavity immediately after TCRA and 4 weeks later in the PRF group. After 8 weeks of TCRA, a second hysteroscopy was performed, and then follow-up was performed. Pregnancy rate, intrauterine adhesions score, menstruation, and endometrial thickness (EMT) were compared between two groups. Results The pregnancy rate of the PRF group was 70.00%, which was significantly higher than 20.00% of the control group (P 0.05). Conclusion The placement of PRF combined with the TCRA can improve the pregnancy rate of infertility due to intrauterine adhesion, reduce intrauterine adhesion scores, and improve clinical symptom.

Treatment of Refractory Medicine Related Osteonecrosis of Jaw With Piezosurgical Debridement and Autologous Platelet Rich Fibrin: Feasibility Study.

Medicine related osteonecrosis of jaw (MRONJ) is incidental in patients receiving certain bone modifying agents in oncology. These lesions may not respond to conservative management and aggravate. Autologous platelet derivatives contain bone growth factors, which help in bone regeneration. The aim of this pilot study is to develop protocol for treatment of refractory MRONJ with pizosurgical debridement and advanced platelet rich fibrin.In this feasibility study, refractory MRONJ lesions were treated by piezosurgical debridement and insertion of autologous advanced platelet rich fibrin in 15 patients. One patient had 2 lesion sites, so in all 16 MRONJ sites were treated. These patients were evaluated at the end of 1 month and 4 months for healing of MRONJ lesion. Statistical analysis was done by using Fisher test for response assessment in relation to variable. Eight lesions (50%) showed complete healing at the end of 1 month. At the end of 4 months 13 lesions (81.50%) were completely healed, 2 lesions (12.5%) were downgrades, and 1 lesion (6.25%) did not respond to treatment. Number of doses of bone modifying agent was only factor found associated with nonhealing of MRONJ when treated with this protocol.In this pilot study, feasibility of use of piezosurgical debridement and platelet rich fibrin was evaluated. The results of the study suggest complete healing can be achieved with this treatment protocol. Further research with increased sample size is warranted to determine optimum use of autologous platelet concentrates in treatment of MRONJ.

An individual randomised efficacy trial of autologous blood products, leukocyte and platelet-rich fibrin (L-PRF), to promote ulcer healing in leprosy in Nepal: the TABLE trial protocol

BackgroundLeprosy is curable with multidrug therapy and treatment in the early stages can prevent disability. However, local nerve damage can lead to injury and consequently recurring and disfiguring ulcers. The aim of this study is to evaluate the treatment of leprosy ulcers using an autologous blood product; leukocyte and platelet-rich fibrin (L-PRF) to promote healing.MethodsThis is a single-centre study in the Anandaban Hospital, The Leprosy Mission Nepal, Kathmandu, Nepal. Consenting patients (n=130) will be individually randomised in a single-blinded, controlled trial. Participants will be 18 years of age or older, admitted to the hospital with a clean, dry and infection-free chronic foot ulcer between 2 and 20 cm2 in size. If the ulcer is infected, it will be treated before enrolment into the study. The intervention involves the application of leukocyte and platelet-rich fibrin (L-PRF) matrix on the ulcer beds during twice-weekly dressing changes. Controls receive usual care in the form of saline dressings only during their twice-weekly dressing changes. Primary outcomes are the rate of healing assessed using standardised photographs by observers blind to allocated treatment, and time to complete re-epithelialization. Follow-up is at 6 months from randomisation.DiscussionThis research will provide valuable information on the clinical and cost-effectiveness of L-PRF in the treatment of leprosy ulcers. An additional benefit is the evaluation of the effects of treatment on quality of life for people living with leprosy ulcers. The results will improve our understanding of the scalability of this treatment across low-income countries for ulcer healing in leprosy and potentially other conditions such as diabetic ulcers.Trial registrationISRCTN14933421. Registered on 16 June 2020

Development of Vancomycin Delivery Systems Based on Autologous 3D Platelet-Rich Fibrin Matrices for Bone Tissue Engineering.

Autologous platelet-rich fibrin (PRF) is derived from the blood and its use in the bone tissue engineering has emerged as an effective strategy for novel drug and growth factor delivery systems. Studies have approved that combined therapy with PRF ensures higher biological outcomes, but patients still undergo additional treatment with antibiotic drugs before, during, and even after the implantation of biomaterials with PRF. These systematically used drugs spread throughout the blood and lead not only to positive effects but may also induce adverse side effects on healthy tissues. Vancomycin hydrochloride (VANKA) is used to treat severe Staphylococcal infections but its absorption in the target tissue after oral administration is low; therefore, in this study, we have developed and analyzed two kinds of VANKA carriers—liposomes and microparticles in 3D PRF matrices. The adjustment, characterization, and analysis of VANKA carriers in 3D PRF scaffolds is carried out in terms of encapsulation efficiency, drug release kinetics and antibacterial activity; furthermore, we have studied the micro- and macrostructure of the scaffolds with microtomography.

Platelet-rich plasma and fibrin glue for conjunctival autograft attachment in a recurrent neurotrophic sclero-conjunctival ulcer secondary to a chemical burn

A patient with recurrent neurotrophic sclero-conjunctival ulcer secondary to chemical injury with sodium hydroxide underwent three failed amniotic membrane transplants and a resection of the keratinized tissue plus oral mucosal graft. Despite this intensive treatment, the ulcer did not close completely. Thus, a conjunctival autograft from the contralateral eye was performed, together with autologous platelet-rich plasma (PRP) and fibrin glue (FG) to attach the graft. One year later, the eye was quiet, with no signs of sclero-conjunctival ulcer. The mixture of PRP and FG appears to be capable of attaching a conjunctival autograft and promoting the healing of sclero-conjuctival ulcers.

Obsidian ASG® Autologous Platelet-Rich Fibrin Matrix and Colorectal Anastomotic Healing: A Preliminary Study

Introduction: Anastomotic leakage (AL) following colorectal resection is a devastating complication affecting morbidity, mortality, and quality of life of patients in the long term. Different tissue sealants and biologic glues were tested showing conflicting results regarding their influence on anastomotic healing and leak prevention. Application of autologous platelet-rich fibrin (Vivostat A/S, Alleroed, Denmark), which acts as a source of angiogenic growth factors and cytokines, showed promising results in an in-vivo porcine model. Herein, we present the first human study of stapled colorectal anastomoses supplemented with an autologous-derived platelet-rich fibrin matrix (Obsidian ASG®, Rivolution GmbH, Rosenheim, Germany and Vivostat A/S, Alleroed, Denmark). Materials and Methods: A retrospective analysis of prospectively accumulated data was performed in two colorectal centers (Linz, Vienna) on patients undergoing left-sided colorectal or coloanal stapled anastomosis between October 2018 and December 2019. The Obsidian ASG® Matrix was applied to the rectal stump, and after closure with the circular stapling device, at the circumference of anastomosis in every single case. Anastomoses were supplemented with intra- and extra-anastomotic application (IAA—intra-anastomotic application developed by Rivolution GmbH, Rosenheim, Germany) of Obsidian ASG® Matrix. The primary endpoints were incidence of perioperative complications and anastomotic leak rate. Results: Two-hundred-sixty-one (138 female) patients underwent left-sided colonic (n=177) or rectal resection (n=84). In 253 (96.9%) cases, a laparoscopic or robotic-assisted approach was used. There were no complications attributable to the intraoperative application of the Obsidian ASG® Matrix. All intraoperative leak tests were negative. Overall, anastomotic leak rate accounted for 2.3% (6/261). AL following colonic and rectal resection was seen in 2.3% (4/177) and 2.4% (2/84), respectively. Complication and leak rate was similar in the two participating centers. Postoperative fever and elevated CRP levels were significantly correlated to AL. There was no significant risk factor for AL on multivariate analysis. Conclusion: Application of an autologous-derived platelet-rich fibrin matrix (Obsidian ASG®) at anastomotic site following colorectal resection is safe and associated with a low rate of anastomotic leakage.

Platelet Rich Fibrin in the Treatment of Localised Gingival Recession: A Case Report

Root recession presents a matter of aesthetic concern in every dental practice. Also it may illicit sensitivity and is more prone to caries than the covered root surfaces. Platelet- rich fibrin is a second generation platelet concentrate. It is basically autologous leukocyte and platelet-rich fibrin biomaterial. The use of PRF in combination with coronally advanced flap in the treatment of gingival recession has shown promising results and is gaining immense popularity among the dental practitioners. This case reports the use of PRF membrane in root coverage on the labial surface of maxillary canine. Keywords: Coronally advanced flap, platelet rich fibrin, gingival recession, growth factors.

Autologous Platelet-Rich Fibrin Membrane to Augment Healing of Microfracture Has Better Macroscopic and Histologic Grades Compared With Microfracture Alone on Chondral Defects in a Rabbit Model

To determine the invivo effectiveness of a single-stage surgical procedure that combines microfracture and an autologous platelet-rich fibrin (PRF) membrane for cartilage repair in a rabbit model. Cartilage defects were created in the trochlear groove of the knees of adult white rabbits. Defects were divided into 2 treatment groups: microfracture only (control group) and microfracture covered by a PRF membrane (PRF group). To evaluate the repair cartilage, assessments were performed at 4, 12, and 24 weeks postoperatively using the International Cartilage Repair Society (ICRS) macroscopic scoring system and modified Wakitani histologic grading system. The mean ICRS macroscopic scores in the control and PRF groups were 4.1 and 5.8, respectively, at 4 weeks (P= .0623); 6.3 and 9.8, respectively, at 12 weeks (P= .006); and 6.5 and 10.3, respectively, at 24 weeks (P= .010). The mean modified Wakitani scores in the control and PRF groups were 4.0 and 3.9, respectively, at 4 weeks (P > .999); 5.3 and 10.4, respectively, at 12 weeks (P= .006); and 2.6 and 7.4, respectively, at 24 weeks (P= .012). The ICRS macroscopic scores and modified Wakitani scores showed that a single-stage surgical procedure combining microfracture and a PRF membrane was more effective than surgery with only microfracture for promoting cartilage repair. A single-stage surgical procedure combining microfracture and an autologous PRF membrane is a potentially beneficial treatment method for cartilage defects that does not require using any xenocollagen membrane.

Effectiveness of Silicon Platelet-Rich Fibrin and Autologous Bone on Bone Regeneration in Rabbit Calvarian Defects: A Radiological and Histological Study

Repairing bone defects in oral surgery often requires the use of bone regeneration techniques. Silicon is an element that has been employed as regeneration material in several studies. In our study, silicon was combined with autologous bone and platelet-rich fibrin (PRF) membranes to analyse the behaviour of this element in bone regeneration. Four circumferential defects were created in the cranial vault of five New Zealand rabbits. The following elements were applied to the regeneration of the defects: (P): PRF; (S): silicon and (B): autologous bone, with the following distribution of study groups: Group 1 (PSB); Group 2 (PS); Group 3 (SB) and Group 4 (CONTROL): unregenerate group. The animals were sacrificed after 3 weeks. Computed microtomography studies (μ-CT) were carried out, as well as histomorphometric ones. The ANOVA statistical test was used with a Bonferroni post-hoc test to compare the results (p ≤ 0.05). Radiologically, groups PSB and SB were better as far as quantity and percentage of healthy bone observed, but not significantly compared to the control group. The PS group was significantly worse. The histological test revealed that the PSB group was the one to present the largest area, percentage and perimeter of mineralised bone. On evaluating the forming bone (osteoid), no difference was observed across the groups with the exception of the bone perimeter, where the SB group was significantly better. The bone height variable showed no significant differences. In conclusion we can state that the combination of PRF, autologous bone and silicon provides good results at 3 weeks whilst the PS group shows the worst results. This highlights the importance of autologous bone forming part of the graft material in order for the bone to mineralise.

Autologous Platelet-Rich Fibrin (PRF) as an Adjunct in the Management of Osteoradionecrosis and Medication-Related Osteonecrosis of Jaws. Case Series in A Single Centre

Osteoradionecrosis (ORN) of the jaws and medication-related osteonecrosis of the jaws (MRONJ) are uncommon but serious diseases affecting the oral and maxillofacial region with clinically similar appearance but distinct pathophysiology. Management of ORN and MRONJ is inherently challenging and the treatment outcomes are unpredictable. The use of autologous platelet concentrates (APCs) to promote hard and soft tissue healing is well described in the literature, and the efficacy of leucocyte and platelet-rich fibrin (L-PRF) has been well documented in a number of clinical studies. The aim of this study was to present our treatment strategy and the outcomes of incorporating L-PRF as a surgical adjunct in management of ORN and MRONJ in our centre. Methods: eight cases of ORN and MRONJ were treated with a combination of sequestrectomy and L-PRF as a surgical adjunct. Results: the overall success was 87.5%. Using L-PRF as an adjunct, we were able to predictably manage ORN and MRONJ without causing significant morbidity. Conclusion: our experience shows that L-PRF may be used as a valuable and cost-effective adjunct to surgical management of ORN and MRONJ. However, due to a limited number of patients, and a short period of review, the true effectiveness of the method is yet to be demonstrated in a longer follow-up study including a greater number of patients, besides the inclusion of a control group.

The Use of Autologous Platelet Rich Fibrin Membrane as a Second Layer in Snodgrass Repair of Distal Hypospadias

Background: Hypospadias is a common pediatric health problem. Snodgrass [Tubularized Incised Plate Urethroplasty]surgical repair was adopted as the standard technique, although different techniques had been described. However, higher complication rate continues to be a problem. The aim of the work: To evaluate the use of platelet rich fibrin membrane as an intermediate layer in the Snodgrass repair of distal hypospadias. Patients and Methods: Thirty children were included. All were evaluated preoperatively by full history taking, clinical examination and laboratory investigations. Then all were treated by Tubularized Incised Plate Urethroplasty with the use of platelet rich fibrin membrane as an intermediate layer. They then followed up and any early or late complications were registered. Results: Hypospadias was recurrent among 83.3%. Patient age ranged between one and six years and the mean operative time was 67±5.4 minutes; the mean hospital stay duration was 7.0±1.2 days. The success rate was 93.3% and complication rate was 6.7%. Complications were edema in 6.7%, urethro-cutaneous fistula [UCF] in 6.7% and skin infection among 3.3%. Conclusion: The use of a platelet rich fibrin membrane is a feasible and safe intermediate layer for hypospadias surgery in Tubularized Incised Plate Urethroplasty. The procedure is quick and straightforward and has a low postoperative complication.

Bone regeneration with platelet-rich fibrin and autologous bone graft after extracting impacted canine. Case report

The objective of this case report is to assess the use of autologous bone graft and platelet-rich fibrin (FRP), as guided bone regeneration, after the extraction of a retained canine. A 42-year-old female patient, with a history of controlled hypertension, attended the SERODU dental clinic (Ecuador), due to the presence of prominence in the left nasolabial region. A Computerized Axial Tomography (CT) was performed, in which tooth 1.3 included in the maxilla was observed, in a horizontal position, the crown mesially and the root distally. It was decided to carry out the extraction of the retained canine and the placement of regenerative biomaterials based on FRP and an autologous bone graft, obtained from the right maxillary tuberosity. Clinical and radiographic controls were carried out after surgery. Six months later, adequate healing and images compatible with bone regeneration were observed in the intervened area.

Management of Maxillary Radicular Cyst by Using the Titanium-Prepared Platelet-Rich Fibrin (T-PRF): A Case Report

Radicular cysts are the most common inflammatory cysts of the jaws. Surgical intervention aims to eliminate periapical pathology in order to allow bone regeneration and healing of periapical tissues. Autologous platelet-rich fibrin is a healing biomaterial in oral surgical defects with the new perspective of accelerated healing. Titanium-prepared platelet rich fibrin (T-PRF) is a third-generation platelet concentrate developed to overcome the harmful effects of silica in glass tubes and also has a longer resorption rate. The purpose of this case report is to present the effects of T-PRF applied to the bone defect that occurs after the enucleation of the radicular cyst. A significant increase in bone density was observed after eight months of follow-up. T-PRF has been shown to be effective in the treatment of bone defects. Therefore, it is thought that it can be used as the only regenerative material in the treatment of bone defects.

Treatment Modalities for Multiple Gingival Recession– A New Prospects

This case series reports the various treatment modalities to treat the multiple recessions. Gingival recession is a widespread clinical manifestation affecting single or multiple root surfaces at all teeth types. Periodontal reconstructive surgery consists of various mucogingival procedures. The primary goal of these procedures is to benefit periodontal health through the reconstruction of lost hard and soft tissues, or by preventing its additional loss, and also enhancing the esthetic appearance. Platelet-rich fibrin is a second generation platelet concentrate and is defined as an autologous leukocyte and platelet-rich fibrin biomaterial. Care was taken not to extend the incisions till the tip of the interdental papilla. A full thickness mucoperiosteal flap was reflected, extending beyond the mucogingival junction. A wide range of surgical techniques has been proposed for the treatment of the gingival recessions, each with its advantages and disadvantages. To provide predictable and long-term results, it is of paramount importance that the surgical technique is individually selected, taking into account several crucial factors such as the size of the defect, the width of the keratinised gingiva apical to the defect and the thickness of the flap.

Effectiveness of Autologous Tissue Grafts on Soft Tissue Ingrowth in Patients Following Partial Root Extraction with Socket Shield: A Retrospective Analysis of a Case Series.

There is little knowledge about healing patterns for the socket with an intentionally retained root fragment: a socket shield. The clinical observation is soft tissue ingrowth next to the socket shield. The aim of this study was to evaluate the effectiveness of autologous grafting matrices in preventing soft tissue ingrowth. Patient data from a private clinic were searched for sockets with a socket shield left to heal with blood clot or grafted with autologous materials: autologous platelet-rich fibrin (PRF), scraped particulate bone, cortical tuberosity bone plate, or particulate dentin and covered with PRF membranes. The included sites were exposed by the flap 4 months after the first surgery, and soft tissue ingrowth depth and width next to the root fragment were measured by a scaled probe and documented. Evaluation of 34 sites showed the greatest depth of soft tissue ingrowth in the nongrafted sockets (6.0 ± 0.0 mm). Grafting with PRF plugs (depth of 2.3 ± 0.2 mm) or particulate bone (depth of 2.7 ± 0.6 mm) decreased soft tissue ingrowth. Grafting with particulate dentin or cortical tuberosity bone plate resulted in a soft tissue ingrowth depth of only 1 mm, yielding the best clinical outcome. Radiography confirmed those findings. Autologous dentin particulate or tuberosity cortical bone plate is most effective for preventing soft tissue ingrowth.

Effect of addition of platelet-rich fibrin to tragal perichondrium graft in the endoscopic trans-canal myringoplasty

BackgroundMyringoplasty operation is the reconstruction of the tympanic membrane (TM) which is performed to prevent recurrent discharge of the ear and to improve the hearing impairment which is caused by TM perforation. Platelets are the key factors in tissue repair mechanisms. They provide essential growth factors, which stimulate fibroblasts to create extracellular matrix deposition and neovascularization. The aim of this study is the assessment of the topical use of autologous platelet-rich fibrin (PRF) in the improvement of myringoplasty success rate.ResultsPatients were divided to two groups, group A included 20 patients who were submitted to myringoplasty operation with adding of PRF from the same patient, and group B included 20 patients who were submitted to myringoplasty operation without adding of PRF. At 6 months postoperatively, the success rate (graft taking) in case group A (95%) was significantly higher than in the control group (70%) (P value = 0.037). Success in terms of hearing gain of the air-bone gap was more than 10 dB achieved in 19 patients (95%) in case group A, and 14 patients (70%) in control group B were with a statistically non-significant difference (P value = 0.079). There was no effect of PRF use on hearing gain in graft-taken cases because hearing gain is related to the closure of TM.ConclusionTopical PRF application over tragal perichondreal graft during myringoplasty is successful, safe, and highly efficient with no complications. PRF improves healing of chronic TM perforations and prevents postoperative infection.

Is percutaneous injection of bone marrow concentrate, demineralized bone matrix and PRF an alternative to curettage and bone grafting for treating aneurysmal bone cyst?

To determine the efficacy and safety of a single injection with autologous bone marrow concentrate (BMC) combined with demineralized bone matrix (DBM) and platelet-rich fibrin (PRF) compared to curettage and bone grafting for treating aneurysmal bone cysts (ABC). Two hundred thirty-nine patients were treated with curettage and bone grafting (Curettage Group), and 21 with percutaneous injection of DBM associated with autologous BMC and PRF (DBM + BMC + PRF Group). All patients attended the outpatient clinic to assess ABC healing and clinical results at the first 3, 6, 9 and 18 months after surgery and then annually in the absence of symptoms. The mean follow-up was 42 months for the Curettage Group (range 6-180 months) and 28 months for the DBM + BMC + PRF Group (range, 6-85 months). Out of the 21 patients who had injection with BMC, DBM, and PRF, 17 (80%) require no additional treatment and they were considered healed. Of the 239 patients treated with curettage and bone grafting after core needle or open biopsy, 177 (74%) were considered healed after the first treatment. Injection in comparison with curettage presented the same risk for local recurrence. The overall rate of local recurrence for all patients was 25%. Univariate and multivariate analyses showed a significant difference in local recurrence rates in patients younger than 15 years, and for the cyst located in the long bones of the lower limbs than the cyst located in the long bones of the upper limbs.