Finite element analysis of absorbable screws in Bernese periacetabular osteotomy / 中华骨科杂志

Objective:To investigate the stability and feasibility of using absorbable screws during Bernese periacetabular osteotomy.Methods:A retrospective analysis was conducted on a 36 year-old woman diagnosed with developmental dysplasia of the hip, who had undergone Bernese periacetabular osteotomy. Finite element analysis was used to simulate the stability of the acetabulum under loads of 10%, 20%, 50%, and 100% of the patient's weight. The structural stiffness of the pelvis and the maximum equivalent stress on the absorbable screws were observed under different conditions, including whether the acetabular bone block and the ilium were in contact, whether 3 or 4 screws were used, and whether a graft (including fibular cortical bone and PEEK grafts) was used.Results:The structural stiffness of the pelvis fixed with four screws increased by 67%-94% compared to that with three screws. After using a graft, the structural stiffness of the pelvis increased by 50%-83%. As the load increased, the maximum equivalent stress on the screws also increased. When the acetabular bone block and the ilium had no contact, no graft was used, and only three screws were used for fixation, the maximum equivalent stress could reach 518.9 MPa, while this value dropped to 61% when four screws were used (318.7 MPa). When the acetabular bone block and the ilium were in contact, the maximum equivalent stress was about 12% of that when there was no contact, regardless of the number of screws used. When a cortical bone graft or a PEEK graft was used, the maximum equivalent stress could drop to 21%-26% of that without a graft. When the screw strength was 130 MPa, a load of 20% of body weight was applied, and only three screws were used without a graft, the equivalent stress could exceed the strength of the screw; if four screws were used, the equivalent stress was slightly higher than the strength of the screw when a load of 50% of body weight was applied. However, when a graft was used (either cortical bone or PEEK), even when a load of 100% of body weight was applied, the equivalent stress was slightly lower than the strength of the screw.Conclusion:Absorbable screws can provide sufficient stability for Bernese periacetabular osteotomy. The contact between the acetabular bone block and the ilium, an increase in the number of screws, and the use of grafts (cortical bone and PEEK grafts) can further improve stability. Therefore, absorbable screws have broad application prospects in Bernese periacetabular osteotomy.

Metallic screw fixation versus absorbable screw fixation after open reduction in treatment of distal tibial epiphyseal fractures in adolescents / 中华创伤骨科杂志

Objective:To compare the efficacy between metallic screw fixation and absorbable screw fixation after open reduction in the treatment of adolescent distal tibial epiphyseal fractures.Methods:A retrospective study was conducted to analyze the data of 82 patients with closed distal tibial epiphyseal fracture who had been admitted to Department of Pediatric Orthopedics, Shengjing Hospital Affiliated to China Medical University from January 2013 to December 2020. There were 61 males and 21 females (aged from 8 to 15 years), and 39 left sides and 43 right sides. The Salter-Harris classification: type Ⅱ in 25 cases, type Ⅲ in 8 cases, and type Ⅳ in 49 cases. They were divided into 2 groups according to different internal fixation methods. Group A (42 cases) was subjected to open reduction and metallic screw fixation and group B (40 cases) to open reduction and absorbable screw fixation. Preoperative data, operation time, total treatment cost and complications during follow-up were recorded and compared between the 2 groups. In both groups at the last follow-up, anteroposterior and lateral ankle radiographs were taken for radiographic evaluation of the injury to the distal tibial epiphysis and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used to assess the ankle function.Results:The 2 groups were comparable because there were no significant differences in all their preoperative demographic data ( P>0.05). Group A was followed up for 18.0(16.0, 21.3) months while group B for 16.0(13.0, 20.0) months. The treatment cost for group A [27, 000 (25, 000, 33, 000) Yuan] was significantly higher than that for group B [23, 000 (19, 000, 27, 000) Yuan] ( P<0.05). The operation time was (112.4±34.3) min for group A and (101.0±41.1) min for group B, showing no significant difference ( P>0.05). The lateral distal tibial angle was 89.5 (88.0, 91.0)° on the affected side and 89.7°±1.8° on the unaffected sides in group A; it was 90.0 (88.3, 90.8)° on the affected side and 89.5°±1.8° on the unaffected side in group B. The anterior distal tibial angle was 81.9°±1.8° on the affected side and 81.8°±1.5° on the unaffected side in group A; it was 82.0 (81.0, 83.0)° on the affected side and 82.1°±2.2° on the unaffected side in group B. There was no significant difference in the above comparisons at the last follow-up in radiographic evaluation of the distal ankle joint between the affected and the unaffected sides in either group or between groups( P>0.05). There was a significant difference between the 2 groups in the rate of superficial skin infection [11.9% (5/42) versus 0% (0/40)] ( P<0.05), but there was no significant difference in the incidence of premature physeal closure between the 2 groups [11.9% (5/42) versus 5.0% (2/40)] ( P>0.05). The last follow-up revealed no significant difference in the AOFAS ankle-hindfoot score between group A [(90.6±4.9) points] and group B [(92.1±4.6) points] ( P>0.05). Conclusions:In the treatment of adolescent distal tibial epiphyseal fractures, compared with metallic screw fixation, absorbable screw fixation may lead to comparable efficacy in fixation, functional recovery and imaging evaluation, but no increased risk of premature physeal closure. Moreover, it spares the need for secondary surgical removal, and reduces operation time and treatment cost.

Research progress of bioresorbable zinc alloy stent in the treatment of peripheral artery disease / 国际外科学杂志

With the development of percutaneous transluminal angioplasty, stent implantation has gradually become an important treatment for peripheral artery diseases, especially for arterial diseases of lower extremities. Due to the continuous exposure of the disadvantages of permanent metal stents and the continuous development of absorbable materials, researchers gradually pay attention to the bioresorbable stents with fewer long-term complications. At present, the application of bioresorbable stents in coronary artery disease has been relatively mature. This paper reviews the research progress of bioresorbable zinc alloy stents in peripheral artery disease.

Clinical courses and degradation patterns of absorbable plates in facial bone fracture patients

BACKGROUND: Absorbable plates are widely used in open reduction and internal fixation surgeries for facial bone fractures. Absorbable plates are made of polyglycolic acid (PGA), polylactic acid (PLA), polydioxane (PDS), or various combinations of these polymers. The degradation patterns of absorbable plates made from different polymers and clinical courses of patients treated with such plates have not been fully identified. This study aimed to confirm the clinical courses of facial bone fracture patients using absorbable plates and compare the degradation patterns of the plates. METHODS: A retrospective chart review was conducted for 47 cases in 46 patients who underwent open reduction and internal fixation surgery using absorbable plates to repair facial bone fractures. All surgeries used either PLA/PGA composite-based or poly-L-lactic acid (PLLA)/hydroxyapatite (HA) composite-based absorbable plates and screws. Clinical courses were confirmed and comparisons were conducted based on direct observation. RESULTS: There were no naturally occurring foreign body reactions. Post-traumatic inflammatory responses occurred in eight patients (nine cases), in which six recovered naturally with conservative treatment. The absorbable plates were removed from two patients. PLA/PGA composite-based absorbable plates degraded into fragments with non-uniform, sharp surfaces whereas PLLA/HA composite-based absorbable plates degraded into a soft powder. CONCLUSION: PLA/PGA composite-based and PLLA/HA composite-based absorbable plates showed no naturally occurring foreign body reactions and showed different degradation patterns. The absorbable plate used for facial bone fracture surgery needs to be selected in consideration of its degradation patterns.

Delay of neuropathic pain sensitization after application of dexamethasone-loaded implant in sciatic nerve-injured rats

Neuroimmune interactions underlying the development of pain sensitization in models of neuropathic pain have been widely studied. In this study, we evaluated the development of allodynia and its reduction associated with peripheral antineuroinflammatory effects induced by a dexamethasone-loaded biodegradable implant. Chronic constriction injury (CCI) of the sciatic nerve was performed in Wistar rats. The electronic von Frey test was applied to assess mechanical allodynia. The dexamethasone-loaded implant was placed perineurally at the moment of CCI or 12 days after surgery. Dorsal root ganglia (DRG; L4-L5) were harvested and nuclear extracts were assayed by Western blot for detection of nuclear factor (NF)-κB p65/RelA translocation. Dexamethasone delivered from the implant delayed the development of allodynia for approximately three weeks in CCI rats when the implantation was performed at day 0, but allodynia was not reversed when the implantation was performed at day 12. NF-κB was activated in CCI rat DRG compared with naïve or sham animals (day 15), and dexamethasone implant inhibited p65/RelA translocation in CCI rats compared with control. This study demonstrated that the dexamethasone-loaded implant suppresses allodynia development and peripheral neuroinflammation. This device can reduce the potential side effects associated with oral anti-inflammatory drugs.

Rib's strapping-traction technology combined with memory-alloy ribs embracing fixator for multiple rib fractures under video-assisted thoracoscope / 中华创伤杂志

Objective To investigate the clinical efficacy of rib's strapping-traction technology using absorbable implants combined with memory-alloy ribs embracing fixator in treating multiple rib fractures under video-assisted thoracoscope.Methods A retrospective case control study was performed to analyze 178 patients with multiple rib fractures treated from January 2015 to June 2017.According to the operation method,all patients were divided into observation group (91 patients) and control group (87 patients).The observation group including 59 males and 32 females aged (39.7 ± 7.8)years adopted internal fixation by rib's strapping-traction technology using absorbable implants combined with memory alloy ribs embracing fixator under video-assisted thoracoscopic surgery.The control group including 56 males and 31 females aged (40.2 ± 6.9) years adopted internal fixation by conventional rib's clamping-traction technology using towel forcep combined with memory-alloy ribs embracing fixator under video-assisted thoracoscopic surgery.The incision length,single rib internal fixation time,number of internal fixation rib fractures,visual analogue scale (VAS) score on postoperative 1 d,postoperative chest drainage,postoperative hospital stay,and postoperative fracture healing were compared between the two groups.Results All patients were followed up for 3-30 months (mean,16.7 months).All operations were successful,with no case of thoracotomy.The observation group had shorter incision length [(4.3 ± 1.2) cm vs.(6.2 ± 1.7) cm] and single rib internal fixation time [(10.3±2.9)min vs.(14.1 ±2.3)min] than the control group (P＜0.05).There were no significant differences (P ＞ 0.05) between the two groups in number of internal fixation rib fractures [(5.7±.3.6) vs.(5.9±3.3)],postoperative chest drainage [(668.3 ±131.4)ml vs.(703.7±116.2)ml],postoperative hospital stay [(6.4 ± 1.8) d vs.(6.8 ± 1.7) d],the VAS score on postoperative 1 d [0-3 point,62％ vs.61％;4-6 point,38％ vs.39％],postoperative osteophyte formation rate [postoperative 1 month,97％ vs.95％;postoperative 3 months,100％ vs.100％].Stable chest walls and thoracic deformity recovery were seen in all patients,with no significant complications occurred.Conclusion Rib's strapping-traction technology using absorbable implants combined with memory-alloy ribs embracing fixator under video-assisted thoracoscope is convenient and has exact efficacy for multiple rib fractures,with advantage of shorter incision length and operation time over conventional thoracoscopic surgery,and thus is worthy of clinical application.

Early experience and favorable clinical outcomes of everolimus-eluting bioresorbable scaffolds for coronary artery disease in Korea

BACKGROUND/AIMS: Compared with metallic drug-eluting stents (DES), bioresorbable vascular scaffolds (BVS) may further improve long-term outcomes of percutaneous coronary intervention (PCI) in patients with coronary artery disease. We report our early experience with BVS in Korea. METHODS: We evaluated 105 consecutive patients with BVS implanted at Asan Medical Center, Korea between October 21, 2015 and June 3, 2016. Angiographic results, and in-hospital and 6-month clinical outcomes were assessed. RESULTS: A total of 134 BVS were implanted to treat 115 lesions. The mean age was 62 ± 10.5 years; 85 patients (81%) were males, 26 patients (25%) were presented with acute coronary syndrome. Among 115 lesions treated with BVS, 76 (66.1%) were B2/C type, 27 (23.5%) were bifurcation lesions, and four (3.5%) were chronic total occlusion. Pre-dilation and post-dilation using high-pressure non-compliant balloon was performed in 104 lesions (90.4%) and 113 lesions (98.2%), respectively. During the procedure, intravascular imaging was used for all patients (100%; intravascular ultrasound 89 and optical coherence tomography 40 patients). Device success rate was 100%. In-segment and in-scaffold acute again were 1.1 ± 0.6 and 1.3 ± 0.5 mm, respectively. Periprocedural myocardial infraction occurred in four patients (3.8%). No deaths, stent thrombosis, or urgent revascularizations occurred either during hospitalization or the follow-up period. CONCLUSIONS: In this single-center experience, implantation of BVS with intravascular imaging support was feasible and early clinical outcomes were excellent. Evaluation of long-term efficacy and safety of BVS and its feasibility in clinical use for a broader range of lesions is warranted.

Biomechanical Analysis of Biodegradable Cervical Plates Developed for Anterior Cervical Discectomy and Fusion

STUDY DESIGN: In-vitro biomechanical investigation. PURPOSE: To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. OVERVIEW OF LITERATURE: Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. METHODS: A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4–C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5–C6 segment) and adjacent (C4–C5 segment) levels. RESULTS: The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. CONCLUSIONS: The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period.

Long-Term Follow-Up of Patients after Percutaneous Coronary Intervention with Everolimus-Eluting Bioresorbable Vascular Scaffold / Seguimento Muito Tardio de Pacientes após Intervenção Coronária Percutânea com Suporte Vascular Bioabsorvível Eluidor de Everolimus

Abstract Background: Bioresorbable vascular scaffolds (BVS) were developed to improve the long-term results of percutaneous coronary intervention, restoring vasomotion. Objectives: To report very late follow-up of everolimus-eluting Absorb BVS (Abbott Vascular, Santa Clara, USA) in our center. Methods: Observational retrospective study, in a single Brazilian center, from August 2011 to October 2013, including 49 patients submitted to Absorb BVS implantation. Safety and efficacy outcomes were analyzed in the in-hospital and very late follow-up phases (> 2 years). Results: All 49 patients underwent a minimum follow-up of 2.5 years and a maximum of 4.6 years. Mean age was 56.8 ± 7.6 years, 71.4% of the patients were men, and 26.5% were diabetic. Regarding clinical presentation, the majority (94%) had stable angina or silent ischemia. Device success was achieved in 100% of cases with 96% overall procedure success rate. Major adverse cardiovascular events rate was 4% at 30 days, 8.2% at 1 year, and 12.2% at 2 years, and there were no more events until 4.6 years. There were 2 cases of thrombosis (1 subacute and 1 late). Conclusions: In this preliminary analysis, Absorb BVS showed to be a safe and effective device in the very late follow-up. Establishing the efficacy and safety profiles of these devices in more complex scenarios is necessary.

Resumo Fundamento: Os suportes vasculares bioabsorvíveis (SVB) foram desenvolvidos com o intuito de melhorar os resultados da intervenção coronária percutânea a longo prazo, restabelecendo-se a vasomotricidade. Objetivos: Reportar o seguimento muito tardio do implante do SVB eluidor de everolimus Absorb® (Abbot Vascular, Santa Clara, EUA) em nosso centro. Métodos: Estudo observacional, retrospectivo, em um único centro brasileiro, que incluiu 49 pacientes submetidos ao implante do SVB Absorb® entre agosto/2011 e outubro/2013. Foram analisados os desfechos de segurança e eficácia na fase hospitalar e bastante tardia (> 2 anos). Resultados: Todos os 49 pacientes completaram um seguimento mínimo de 2,5 anos, sendo o máximo de 4,6 anos. A média de idade foi 56,8 ± 7,6 anos, sendo 71,4% da população estudada do sexo masculino e 26,5% composta por diabéticos. Considerando a apresentação clínica, a grande maioria (94%) tinha angina estável ou isquemia silenciosa. Obteve-se sucesso do dispositivo em 100% dos casos e do procedimento, em 96%. A taxa de eventos cardiovasculares maiores foi de 4% aos 30 dias, de 8,2% em 1 ano, e de 12,2% em 2 anos, sem mais eventos até 4,6 anos. Houve 2 casos de trombose (1 subaguda e 1 tardia) até o último seguimento. Conclusões: Nesta análise preliminar, o uso do SVB Absorb® mostrou-se seguro e eficaz no seguimento bastante tardio. Faz-se necessário estabelecer o perfil de eficácia e segurança destes dispositivos em cenários de maior complexidade.

Clinical Study on Percutaneous Intramedullary Bioresorbable Pin Fixation for Fourth and Fifth Metacarpal Bone Fracture

PURPOSE: Metacarpal fracture of a ring and little finger occurs frequently. Percutaneous intramedullary fixation is a simple and effective method with a low incidence of complications. To date, Kirschner wire (K-wire) fixation has been widely used, but this has problems such as pin infection. Moreover it is difficult to start early active motion exercise. So, we replaced the K-wire with a bioresorbable implant and evaluated the results. METHODS: This study was conducted from 2014 to 2016 and involved 10 consecutive patients with 10 metacarpal neck fractures. All cases underwent percutaneous intramedullary fixation using the ActivaPin (Bioretec Ltd.) within 7 days after injury, and the average follow-up period was 13 months. At the final follow-up, all cases were assessed in terms of total active motion (TAM), bony union and angular deformity based on plain radiographs. RESULTS: The patients started active motion exercise within 1 week and regained a full range of motion after average 4 weeks. The TAM results were excellent at 250° to 270° in all cases. Regarding radiographic findings, fractures united in all cases and there were no malunion and knuckle deformity. CONCLUSION: Replacement of a K-wire with a bioresorbable pin prevented soft tissue damage and dorsal scarring. And our percutaneous intramedullary bioresorbable pin fixation technique resulted in early recovery of range of motion and correction of deformity. The patients regained range of motion and returned to daily life early.

Development of absorbable transthoracic left atrial appendage reverse occluder and in vitro animal experiment / 第二军医大学学报

Objective To design and prepare an absorbable transthoracic left atrial appendage (LAA) reverse occluder and delivery system and to evaluate the feasibility of absorbable transthoracic LAA reverse occlusion by in vitro experiment. Methods A double-disk-shaped absorbable transthoracic LAA occluder was designed using polydioxanone (PDO), poly-L-lactic acid (PLA), and polyglycolic acid (PGA). Compression properties, elastic recovery properties and ultimate sustainable effective delivery times of the tail thread riveting were tested by in vitro water bath. Six isolated dog hearts were punctured at the center of the upper 1/3 axis of left atrial appendage under direct vision,and 14F sheath with scale was used to complete the in vitro experiment of occlusion. The location and effect of the occluder were observed by anatomizing the hearts after closure. Results Absorbable LAA occluder was smoothly delivered by 14F sheath, and instantly released and restored to 96% of original size after placed for 15 min in the sheath. Tail thread riveting could tolerate (5.20±0.75) times effective delivery. Six heart specimens successfully underwent the occluding tests in vitro. We found that the occluder was well located, with the opening disk of the left atrial appendage porting into the opening a little, and the opening was in an over distraction state. There was no influence on blood flow of pulmonary vein and function of the mitral valve. Conclusion The absorbable transthoracic LAA reverse occluder is well-designed and matches the anatomy of the left atrial appendage of canine. Further animal experiment is needed to evaluate the feasibility, safety and efficacy of the absorbable transthoracic LAA reverse occluder.

Bone healing after biodegradable mini-plate fixation

ABSTRACT PURPOSE: To compare bone healing in mandibular vertical body osteotomies (MVBO) after fixation with a resorbable 2.0mm-profile fixation system in the first and third postoperative months in rabbits. METHODS: Twenty hemimandibles of ten rabbits were divided into two groups according to duration of resorbable fixation-one or three months. The MVBOs were performed and one four-hole, resorbable, 2.0mm mini-plate fixation system was used on each side. The computed tomography (CT) scans, scanning electron microscopy (SEM), and histomorphometric outcomes of groups I and II were compared. RESULTS: Significant differences were found between the one- and three- month assessments in terms of newly formed bone ratio values (p<0.05). There was more new bone formation at the third month on both the CT and histomorphometric examinations. A better adaptation of the bone tissues to the resorbable mini-plate and screws was observed on SEM at three months. CONCLUSION: The resorbable mini-plates provided a fixation stable enough to allow immediate oral alimentation and callus formation in both groups.

Treatment of Nonsyndromic Craniosynostosis Using Multi-Split Osteotomy and Rigid Fixation with Absorbable Plates

BACKGROUND: Nonsyndromic craniosynostosis is a relatively common craniofacial anomaly and various techniques were introduced to achieve its operative goals. Authors found that by using smaller bone fragments than that used in conventional cranioplasty, sufficiently rigid bone union and effective regeneration capacity could be achieved with better postoperative outcome, only if their stable fixation was ensured. METHODS: Through bicoronal incisional approach, involved synostotic cranial bone together with its surrounding areas were removed. The resected bone flap was split into as many pieces as possible. The extent of this ‘multi-split osteotomy’ depends on the degree of dysmorphology, expectative volume increment after surgery and probable dead space caused by bony gap between bone segments. Rigid interosseous fixation was performed with variable types of absorbable plate and screw. In all cases, the pre-operational three-dimensional computed tomography (3D CT) was checked and brain CT was taken immediately after the surgery. Also about 12 months after the operation, 3D CT was checked again to see postoperative morphology improvement, bone union, regeneration and intracranial volume change. RESULTS: The bony gaps seen in the immediate postoperative brain CT were all improved as seen in the 3D CT after 12 months from the surgery. No small bone fragment resorption was observed. Brain volume increase was found to be made gradually, leaving no case of remaining epidural dead space. CONCLUSION: We conclude that it is meaningful in presenting a new possibility to be applied to not only nonsyndromic craniosynostosis but also other reconstructive cranial vault surgeries.

Absorbable Plate-Related Infection after Facial Bone Fracture Reduction

Absorbable plates are used widely for fixation of facial bone fractures. Compared to conventional titanium plating systems, absorbable plates have many favorable traits. They are not palpable after plate absorption, which obviates the need for plate removal. Absorbable plate-related infections are relatively uncommon at less than 5% of patients undergoing fixation of facial bone fractures. The plates are made from a mixture of poly-L-lactic acid and poly-DL-lactic acid or poly-DL-lactic acid and polyglycolic acid, and the ratio of these biodegradable polymers is used to control the longevity of the plates. Degradation rate of absorbable plate is closely related to the chance of infection. Low degradation is associated with increased accumulation of plate debris, which in turn can increase the chance of infection. Predisposing factors for absorbable plate-related infection include the presence of maxillary sinusitis, plate proximity to incision site, and use of tobacco and significant amount of alcohol. Using short screws in fixating maxillary fracture accompanied maxillary sinusitis will increase the rate of infection. Avoiding fixating plates near the incision site will also minimize infection. Close observation until complete absorption of the plate is crucial, especially those who are smokers or heavy alcoholics. The management of plate infection is varied depending on the clinical situation. Severe infections require plate removal. Wound culture and radiologic exam are essential in treatment planning.

The Efficacy of Bioabsorbable Mesh in Craniofacial Trauma Surgery

BACKGROUND: The ultimate goal of craniofacial reconstructive surgery is to achieve the most complete restoration of facial functions. A bioabsorbable fixation system which does not need secondary operation for implant removal has been developed in the last decade. The purpose of this study is to share the experience of authors and to demonstrate the efficacy of bioabsorbable mesh in a variety of craniofacial trauma operations. METHODS: Between October 2008 and February 2015, bioabsorbable meshes were used to reconstruct various types of craniofacial bone fractures in 611 patients. Any displaced bone fragments were detached from the fracture site and fixed to the mesh. The resulting bone-mesh complex was designed and molded into an appropriate shape by the immersion in warm saline. The mesh was molded once again under simultaneous warm saline irrigation and suction. RESULTS: In all patients, contour deformities were restored completely, and bone segments were fixed properly. The authors found that the bioabsorbable mesh provided rigid fixation without any evidence of integrity loss on postoperative computed tomography scans. CONCLUSION: Because bioabsorbable meshes are more flexible than bioabsorbable plates, they can be molded and could easily reconstruct the facial bone in three dimensions. Additionally, it is easy to attach bone fragments to the mesh. Bioabsorbable mesh and screws is effective and can be easily applied for fixation in various craniofacial trauma reconstructive scenarios.

Delayed Foreign Body Reaction Caused by Bioabsorbable Plates Used for Maxillofacial Fractures

BACKGROUND: Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws. METHODS: A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla. RESULTS: Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction. CONCLUSIONS: Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations.

Absorbable screw and metal screw fixation for ankle fractures:comparison of biocompatibility and ankle function / 中国组织工程研究

BACKGROUND:Previous ankle fracture surgery mainly uses the internal fixation materials such as metal screws or Kirschner wire, which can achieve a strong internal fixation, but al need to be taken out in the secondary surgery. In recent years, elastic modulus of biodegradable absorbable screw is identical to that of cancel ous bone, and has been widely used in clinic. OBJECTIVE:To compare the biocompatibility and functional recovery of ankle joint in the repair of ankle fractures with absorbable screws and metal screws. METHODS:100 patients with ankle fractures were selected, including 70 males and 30 females, at the age of 19 to 55 years old. Fifty patients were repaired with absorbable screws and fifty patients were repaired with metal screws. Clinical efficacy, Kofoed score, fracture healing time and adverse events were observed between the two groups after repair. RESULTS AND CONCLUSION:Patients were fol owed up for over 6 months in both groups, showing good bony cal us, good contraposition and alignment at the fracture end. No delayed union or nonunion occurred. The excel ent and good rate of clinical effect was 96%and 94%in the absorbable screw group and metal screw group, respectively, showing no significant difference. There was no significant difference in ankle Kofoed score, fracture healing time and incidence of adverse events between the two groups (P>0.05). These results suggest that absorbable screw fixation for ankle fractures had good biocompatibility and could effectively restore ankle function;its effects are similar to that of traditional metal screws.

Estudo comparativo entre osteossíntese em fratura de tornozelo com implantes convencionais e bioabsorvíveis / Comparative study between osteosynthesis in conventional and bioabsorbable implants in ankle fractures

Objetivo: Comparar os resultados funcionais de fraturas de tornozelo tratadascom placas metálicas e absorvíveis. Métodos: Vinte pacientes foramrandomizados e seguidos de forma prospectiva em dois grupos, metálicoe absorvível. No período pós-operatório imediato os pacientes foram imobilizadoscom tala gessada por uma semana, que foi substituída por órteseremovível por quatro semanas adicionais. Carga parcial foi autorizada comtrês semanas, e carga total com seis semanas. Os vinte pacientes foramseguidos por nove meses e avaliados funcionalmente aos seis e nove meses.Resultados: A recuperação funcional foi similar nos dois grupos. Aosseis meses, três pacientes no grupo metálico queixaram-se de problemaslocais, e tiveram seus implantes removidos. Um paciente do grupo absorvívelteve uma deiscência precoce da sutura, submetida a desbridamentoe sutura com boa evolução. Aos seis e nove meses o escore da AmericanOrthopaedic Foot and Ankle Society (AOFAS) foi aplicado para todosexceto um paciente do grupo metálico, que foi perdido do seguimento.Os resultados funcionais foram semelhantes nos dois grupos, nos doismomentos. Conclusão: Os implantes absorvíveis permitiram resultadosclínicos e funcionais semelhantes aos metálicos em fraturas de tornozelo.Nível de Evidência II, Estudo Prospectivo Comparativo.

Objective: To compare the functional results of ankle fracturestreated with metallic and absorbable plates. Twentypatients were randomized into two groups (metallic and absorbableimplant groups) and followed prospectively. In theimmediate postoperative period, patients were immobilizedwith plaster casts for one week, which was replaced by aremovable cast for another four weeks. Partial weight-bearingwas allowed after three weeks, and full weight-bearing aftersix weeks. Functional recovery was similar in both groups. Atsix months, three patients in the metallic group complainedof local pain, and had their implants removed. One patientin the absorbable group exhibited early dehiscence of thesuture and underwent debridement and suturing with goodevolution. The American Orthopaedic Foot and Ankle Society(AOFAS) score was similar between the two groups after sixand nine months of follow-up. The absorbable implants showedclinical and functional results that were similar to thoseof metallic implants. Level of Evidence II, ProspectiveComparative Study.

Application value of medical absorbable suture in upper limb fingers extensor tendon injury / 中国基层医药

Objective To study the application value of medical absorbable suture in upper limb fingers extensor tendon injury.Methods According to the digital table,100 patients with upper limb fingers extensor tendon injury were randomly divided into the two groups.Patients in group A were repaired by medical absorbable suture,while patients in group B were repaired by tendon trocars.Functional evaluation and postoperative adverse reactions of the two groups were recorded after surgery.Results The total effective rate of group A (92.0％) was higher than that of group B (82.0％) (u =-2.596,P =0.009).The incidence rate of adverse reactions of group A was 14.0％ and which of group B was 10.0％,the difference was no significant (x2 =0.378,P =0.538).Conclusion Medical absorbable suture can effectively improve upper limb fingers extensor tendon injury treatment effect and significantly improve clinical symptoms.It's safe and the postoperative adverse reactions is less.