Bioabsorbable Plates Research Articles

Effect of In Vitro Aging on the Stiffness of Bioabsorbable Fixation Plates

The purpose of this study was to investigate the effect of in vitro aging on the stiffness of bioabsorbable fixation plates. Twenty-four polylactic/polyglycolic acid plates (LactoSorb; Lorenz, Jacksonville, FL) were divided in 3 groups of 8 specimens each. Group A served as control, and groups B and C were immersed in 0.1 M lactic acid for 15 and 30 days, respectively. All specimens were subjected to a 3-point bending test, using a universal testing machine, and the stiffness of each specimen was estimated. When analyzed with one-way analysis of variance, no difference was observed for the control and in vitro-aged specimens with regard to stiffness. Long-term (30 d) in vitro aging of poly-L-lactic acid bioabsorbable fixation plates does not seem to significantly affect the stiffness of the material as derived from a 3-point bending test.

Late Foreign-Body Reaction After Treatment of Distal Radial Fractures with Poly-L-Lactic Acid Bioabsorbable Implants

Since the 1980s, bioabsorbable implants have been increasingly utilized for fracture fixation and also for other orthopaedic procedures, including ligament reconstruction, meniscal repair, rotator cuff repair, and shoulder labral lesion repair1-4. The majority of bioabsorbable materials for implants are monopolymers or copolymers of polylactic acid (PLA) (including a levorotatory [PLLA] and a dextrorotatory [PDLLA] configuration), polyglycolic acid (PGA), and polydioxanone (PDS)3,4. The foreign-body reactions related to polyglycolic acid usually have emerged one to four months after implantation and have been well documented in the literature1,3,5. However, the in vivo degradation time of the stereoisomeric form of polylactic acid copolymers is much longer6. In contrast to polyglycolic acid, the tissue responses associated with polylactic acid (PLLA or PDLLA) are much less common5. From June 2005 to December 2009, seventy-eight distal radial fractures were treated with these implants at our hospital. Three patients (4%) had a late foreign-body reaction twenty-one months after fixation. Debridement and removal of the remaining implant was curative in all three patients. Histopathological examination showed a nonspecific foreign-body reaction, and the retrieved particles were confirmed as polylactic acid polymers with use of Fourier transform infrared spectroscopy. The patients were informed that data concerning their cases would be submitted for publication, and they consented. Case 1. A forty-eight-year-old woman sustained a closed, left distal radial fracture with intra-articular involvement when she slipped and fell in December 2005. She had no known systemic diseases and reported no allergies. Two weeks after the injury, she underwent open reduction and internal fixation with a bioabsorbable plate and screws (Inion OTPS Volar Radius Plates; Inion Oy, Tampere, Finland) (Fig. 1) through a volar radial (Henry) approach between the flexor carpi radialis tendon and the …

Single‐stage laryngotracheal reconstruction using bioabsorbable miniplates

The goal is to review the efficacy and safety of bioabsorbable miniplates as an alternative to autologous grafts in single-stage laryngotracheal reconstruction for subglottic stenosis. : Case series. A standard approach to the laryngotracheal complex is performed. The cricoid cartilage and first two tracheal rings are incised vertically, including the tracheostoma if present. A poly-L-lactic-acid-polyglycolic-acid bioabsorbable miniplate was cut to an approximate 1- to 1.5-cm length and 3- to 4-mm width, and placed over the cricoid defect. This plate was sutured in place using 4-0 undyed nylon sutures, securing the plate at each end to the cricoid cartilage. Care was taken to place these sutures submucosally in the tracheal lumen. If there was concern for suprastomal collapse, additional plates were placed inferiorly. The patient was taken back to the intensive care unit with a penrose drain in place and left sedated and intubated for 1 week and then re-evaluated in the operating room. The procedure has been performed on 10 patients. All patients had a well-healed and fully mucosalized anterior tracheal wall with no evidence of plate or suture exposure at the time of extubation. There were no postoperative complications directly attributable to the use of the absorbable plate. All patients were successfully decannulated at the time of discharge. Long-term follow-up ranges from 14 to 63 months. No patients have required revision laryngotracheal reconstruction or repeat tracheostomy. This study demonstrates that the use of bioabsorbable plates in select patients is a safe and effective alternative to the use of autologous cartilage grafts for single-stage laryngotracheal reconstruction for anterior subglottic stenosis. Donor site morbidity is eliminated, and operative time is decreased.

Tooth-borne distraction of the lower anterior subapical segment for correction of class II malocclusion, subsequent to genioplasty

Alveolar distraction is mainly used to increase height and width of the alveolar crest. This technique, however, is not typically used for lengthening the perimeter of the dental arch or improving teeth axes. We applied alveolar distraction in a tooth-borne manner in the second stage of our original method and obtained favorable results. We therefore present an outline of this method. Genioplasty was first performed to create an infrastructure for sequential advancement of the subapical alveolar segment. After bone union, anterior subapical alveolar osteotomy was performed. The stump of the osteotomized dentate segment was moved forward without changing the incisal edge position, and a box-type bioabsorbable plate with four holes was fixed only onto the dentate segment using two screws. After a latency period, two distraction devices were placed bilaterally to the brackets and activated at 1.0 mm/day. After reaching the desired position, the distractor was immobilized, and then replaced by resin temporary teeth to retain the created space. After the consolidation period, orthodontic treatment was restarted and teeth moved into the newly created space. Bimaxillary surgery was performed after completing pre-surgical orthodontic treatment. Finally, both desirable occlusion and functional masticatory function were obtained. This tooth-borne distraction system is one applicable method for patients with skeletal class II and crowding of lower anterior teeth, achieving good results particularly in combination with our original method.

Finite element study of maxillary Le Fort-I osteotomy with rigid internal fixation

To study the biomechanical characteristic of maxillary Le fort- I osteotomy with rigid internal fixation (RIF) , so as to choose best fixation method. The 3-dimensional finite element models of maxillary Le Fort-I osteotomy with 9 kinds of RIF methods were established. Then the models were divided into three groups to calculate the stress distribution of the maxilla and the displacement of bone segment under 3 kinds of occlusion condition. The fixation stability of the different RIF methods was evaluated. Under the incisor occlusion condition, the stress of the cranio maxillary complex transmits mainly along the nasal-maxillary buttress. Under the premolar and molar occlusion condition, the stress transmits along the alveolar process first, then turns to the nasal-maxillary and zygomatic-maxillary buttress. The focused stress position of the internal fixation system is at the connection between the screws and the plate and at the plate near the osteotomy line. Under the premolar occlusion condition, the displacement of bone segment with different RIF methods was (in a decreasing order) 0.396509 mm (with bio-absorbable plate), 0.148393 mm (with micro-plate ), 0.078436 mm (with mini-plate) in group 1; 0.188791 mm (fixing at the nasal-maxillary buttress), 0.121718 mm (fixing at the zygomatic-maxillary buttress), 0.078436 mm (fixing at the both buttress) in group 2; 0.091023 mm (with straight plate), 0.078436 mm (with L shape plate), 0.072450 mm (with Y shape plate), 0.065617 mm (with T shape plate) in group 3. The fixation stability of using the bio-absorbable plate in Le Fort-I osteotomy is less stable than using the titanium plate. Fixing at the zygomatic-maxillary buttress is more stable than at the naso-maxillary buttress. The fixation stability is different by using different shapes of plates.

53 A randomised prospective trial comparing bioabsorbable versus titanium plates in the treatment of mandibular and zygomatic fractures

53 A randomised prospective trial comparing bioabsorbable versus titanium plates in the treatment of mandibular and zygomatic fractures

Absorbable Plate Strength Loss During Molding

Bioabsorbable plating systems play an integral role in cranial vault remodeling. After experiencing a case of plate failure requiring emergent reexploration, we investigated the potential causes. We hypothesize that extended submersion in the molding bath during plate preparation might advance the rate of hydrolysis and compromise plate structural integrity. Using an absorbable poly-D/L-lactic acid plating system, we assessed the effect of extended submersion on plate strength and stiffness when loaded in a cantilever fashion and with pure tension. We assessed these differences with the Student t test and linear regression modeling. We also generated a computer model of the plates for finite element analysis. When left in the molding bath for extended periods, the plates changed color and lost strength. After 5 minutes, 30% of maximum plate load capacity was lost in a cantilever beam test (P < 0.001) consistent with use of a 15% thinner plate. Tensile testing revealed the initial elastic modulus of 6.42 +/- 0.13 GPa decreased 16% to 5.41 +/- 0.50 GPa after 5 minutes of submersion (P = 0.027). The changes in plate strength and elastic modulus both worsened with increased submersion times. Finite element analysis of the plates also predicted clinically significant increases in plate deviation under normal loading conditions. Our study demonstrates that extended submersion of absorbable plates during molding results in a significant loss of plate strength and stiffness. Further, our computer model predicts that these changes could result in an unacceptable plate deviation under normal loading conditions. Together, these data caution against overmolding of plates to avoid compromising their structural integrity.

Bioabsorbable Plates and Screws for Fixation of Mandibulotomies in Ablative Oral Cancer Surgery

The use of bioabsorbable self-reinforced poly(L/DL)lactide 70/30 (SR-PLDLA) miniplates and screws could offer many benefits compared with conventional metallic devices for fixation of access osteotomies in oral cancer surgery. The material neither interferes with imaging nor with postoperative radiotherapy. The plates and screws do not need to be removed. The number of operations can be diminished and rehabilitation with dental implants shortened. The purpose of the present study was to report our experience with bioabsorbable osteosynthesis in the fixation of access osteotomies of the mandible. A total of 15 patients (11 men and 4 women, mean age 63.1 years) were enrolled in the present study. All patients had oral squamous cell carcinoma. Three patients developed tumor recurrence, 2 of whom had previously undergone radiotherapy. Nine patients had radiotherapy scheduled postoperatively. The osteotomies were a straight-line cut and were situated medially or paramedially. For fixation, SR-PLDLA miniplates and screws (Biosorb 2.0 and 2.4 systems) were used without any maxillomandibular fixation. The follow-up ranged from 0.3 to 7.1 years (median 3.5). No problems were encountered during the operation. One patient required reoperation owing to failure in fixation. Twelve osteotomy lines (80%) were clinically stable; radiologically, 6 were totally and 3 partly consolidated. During follow-up, 6 nonunions were radiographically noted, 3 of which were clinically stable. Because of the high incidence of radiologic nonunion, bioabsorbable devices should not yet be used for fixation of access osteotomies in cancer surgery.

Bioabsorbable instrumentation for single-level cervical degenerative disc disease: a radiological and clinical outcome study

The authors present the radiological and clinical outcome data obtained in patients who underwent single-level anterior cervical discectomy and fusion (ACDF) for cervical spondylosis and/or disc herniation; bioabsorbable plates were used for instrumentation. The use of metallic plates in ACDF has gained acceptance as a stabilizing part of the procedure to increase fusion rates, but when complications occur with these devices, the overall effectiveness of the procedure is compromised. As a possible solution, bioabsorbable implants for ACDF have been developed. This study investigates the feasibility and radiological and clinical outcomes of the bioabsorbable plates for ACDF. The radiological and clinical outcomes of 30 patients were investigated retrospectively. All patients presented with cervical radiculopathy or myelopathy and underwent single-level ACDF in which a bioabsorbable anterior cervical plate and an allograft bone spacer were placed at a level between C-3 and C-7. Radiological outcome was assessed based on the fusion rate, subsidence, and Cobb angle of the surgical level. Clinical outcome was determined by using a visual analog scale, the Neck Disability Index, and the Odom criteria. There were no intraoperative complications, and no hardware failure was observed. No signs or symptoms of adverse tissue reaction caused by the implant were seen. Two reoperations were necessary due to postoperative blood collections. The overall complication rate was 16.7%. After 6 months, radiographic fusion was seen in 92.3% of patients. Subsidence at 11.3 +/- 7.2 months was 3.1 +/- 5.8 mm (an 8.2% change over the immediately postoperative results), and the change in the sagittal curvature was -2.7 +/- 2.7 degrees . The visual analog scale score for neck and arm pain and Neck Disability Index improved significantly after surgery (p < 0.001). Overall at 19.5 months postoperatively, 83% of the patients had favorable outcomes based on the Odom criteria. Absorbable instrumentation provides better stability than the absence of a plate but graft subsidence and deformity rates may be higher than those associated with metal implants. There were no device-related complications, but adverse late effects cannot be excluded. The fusion rate and outcome are comparable to the results achieved with metallic plates. The authors were satisfied with the use of bioabsorbable plates as a reasonable alternative to metal, avoiding the need for lifelong metallic implants.

Evolution of Surgery for Sagittal Synostosis

Techniques for sagittal synostosis correction continue to evolve to improve outcomes and minimize morbidity. The techniques now used by our craniofacial service are spring-assisted cranioplasty for younger children (generally up to 9 months of age) and biparietal barrel staving with cross-struts using bioabsorbable plates for older children. We evaluate the evolution of, and rationale for, our current methods of treatment. All patients who underwent surgery for craniosynostosis over the period 1982 to 2007 were retrospectively reviewed. Patients with sagittal synostosis were analyzed according to the type of operative procedure performed. Blood loss, operative time, and hospital stay were compared between techniques using analysis of variance. Seventy-one patients had a cranial vault remodeling procedure for craniosynostosis. Thirty-four patients had sagittal synostosis with scaphocephaly. During the period 1982 to 2000, 13 patients had a strip craniectomy, and 5 patients had a barrel stave and morcellation procedure. Since 2001, the cross-strut technique using bioabsorbable plates has been used in 7 patients. In 2005, the spring cranioplasty technique was introduced and has been used in 9 patients. There were no deaths and no serious complications. One patient treated with springs had a second spring procedure performed to further increase biparietal width. Spring-assisted cranioplasty had a significantly shorter operating time than other techniques (P < 0.01). The availability of both absorbable plates and expansile cranial springs has revolutionized the techniques our unit uses for scaphocephaly correction. Our early experience with these techniques has shown that the techniques are reliable and give good cranial shape and form with minimal treatment morbidity.

Bioabsorbable osteofixation devices in craniosynostosis. Clinical experience in 216 cases

The pursuit of bone fixation systems capable of affording appropriate stability for osteosynthesis has gone through several stages from the use of metal wires, plates, and screws to the current stage of bioabsorbable systems. In our Pediatric Neurosurgery Service and Craniofacial Surgery Unit we began employing these systems in June 1997. The object of this paper is to present a review of the bioabsorbable materials most commonly used in pediatric age, and more specifically in treating craniosynostosis, to describe the characteristics of each one of them and our experience. From June 1997 to May 2006 we implanted bioabsorbable fixation systems in 216 patients diagnosed with craniosynostosis. Age at treatment ranged between 4 and 24 months (mean age 6.38 months). Brain computed tomography (CT) scans, and three-dimensional (3-D) reconstruction of CT scans were performed before and after treatment. An 82: 18 L-lactic acid: glycolic acid copolymer was used in 92.2% of these cases, and a 70:30 L-lactic acid: D-lactic acid copolymer was used in the remaining 7.8% of cases. The follow-up of the patients ranged between six months and five years. There was no displacement of bioabsorbable plates or screws in any case. In one case (0.46%), radiological imaging revealed osteolysis underneath the implant eight months after the surgical procedure. Prominences caused by the plates and screws employed were visible in two cases (0.93%). We found fractures in the osteosynthesis mesh in two patients (0.93%). Four patients (1.85%) presented local inflammation. No alterations of cranial morphology secondary to inadequate stability were observed. 1) Bioabsorbable fixation systems provide excellent stability during the bone "healing" period, without a higher complication rate than with other systems. 2) They help the bone grafts keep their remodeled shape. 3) They promote reossification by preventing the bone grafts from moving after osteosynthesis. 4) No interference with normal growth of the cranial vault has been observed.

Evaluation of skeletal and surgical factors related to relapse of mandibular setback surgery using the bioabsorbable plate

This study was to evaluate the stability of the bioabsorbable plate used in the orthognathic surgery for patients with prognathic mandibles and to evaluate the relapse tendency after surgery and the factors affecting the relapse. The sample consisted of 30 subjects (14 males and 16 females) who underwent bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback using the poly-l/dl-lactide plate system (Biosorb FX), Linvatec Biomaterials Ltd., Tampere, Finland). The lateral cephalometric radiographs of each subject were taken pre-operatively within 1 month (T0), post-operatively within 1 month (T1), and post-operatively between 4 and 10 months (T2) and skeletal changes were analyzed with V-Ceph (CyberMed), Seoul, Korea) software. The changes between T1 and T2 were evaluated with a paired t-test to estimate the stability of the surgery. The post-operative changes of mandibular body length and ramus height were used for a K-means clustering analysis to separate subjects into either the less changed (LC), or the more changed (MC) group. The two groups were compared with T0 and the surgical changes (T1-T0) using the t-test. Significant relapse after surgery was shown in vertical measurements but not in the horizontal plane measurements. The MC group showed significantly more vertical operative changes than the LC group independent of horizontal measurements. Usage of a bioabsorbable plate in mandibular setback surgery could provide stable fixation in the horizontal dimension, but also may allow an increase of vertical relapse due to the increase in vertical dimension post-operatively.

Effect of low-level laser therapy after implantation of poly-L-lactic/polyglycolic acid in the femurs of rats

This study evaluated the use of red and infrared lasers on tissue surrounding the femurs of 60 rats randomly divided into three groups after implantation of bioabsorbable plates. The control group were not subjected to laser irradiation; group A was treated with red laser [indium-gallium-aluminum-phosphide (InGaAlP) laser, wavelength 685 nm, 35 mW, continuous wave (CW), Ø = 0.06 cm, 2.23 min], and group B was subjected to infrared laser [gallium-aluminum-arsenium (GaAlAs) laser, wavelength 830 nm, 50 mw, CW, Ø = 0.06 cm, 1.41 min], both at 10 J/cm(2). Samples were stained with hematoxylin and eosin (H&E) and examined microscopically. Results showed that the laser irradiation had had a positive photobiomodulation effect on inflammation, confirmed by a better histologic pattern than that of the control group at 3 days and 7 days. Semiquantitative analysis revealed that groups A and B had a histologic score significantly greater than that of the control group at 3 days. At 21 days, histomorphometric analysis revealed a more intense inflammation in the red laser group than in the other groups. We concluded that low-level laser therapy (LLLT) has positive effects on the photobiomodulation of inflammation in the tissues surrounding the poly-L-lactic/polyglycolic acid (PLLA/PGA) bioabsorbable plate. It stimulated vascularization, fibroblast proliferation, and collagen deposition.

Treatment of Facial Fractures Using poly-5d/95l-lactide (PLA95) Copolymer Plates and Screws

Bioabsorbable plates and screws were first introduced approximately 30 years ago, and various copolymers are now commercially available. This is a retrospective study reporting our clinical data using new bioabsorbable poly-SD/95L-lactide (PLA9S) copolymer plates and screws (Bonamates(superscript ®); Bio Tech One, Taipei, Taiwan) for the osteosynthesis of facial bone fractures. There were 40 patients including 26 males and 14 females, whose ages ranged 11~85 years. The follow-up ranged 2~20 (mean, 10.3) months. Four patients had solitary zygomatic fractures, 3 patients had isolated maxillary fractures, 6 had mandibular fractures, 14 had zygomatic-maxillary fractures, and 13 had multiple fracture sites (7 cases of maxillary plus mandibular fractures, 3 bi-maxillary fractures, and 3 maxillary plus frontal fractures). Three patients developed postoperative complications which required further treatment. Thirty-seven patients showed good clinical results either objectively or subjectively with high satisfaction. The advantages vs. disadvantages and indications vs. limitations of bioabsorbable devices are discussed. So far, bioabsorbable implants cannot completely replace titanium plates and screws. However, Bonamates(superscript ®) devices seem to be an alternative choice to clinically achieve rigid fixation in facial fractures.

Outcomes and Complications Based on Experience With Resorbable Plates in Pediatric Craniosynostosis Patients

The structure and functional relationship of polymers have long been the purview of engineers and polymer chemists. Bioabsorbable fixation devices have been used for decades as dissolvable suture meshes and, recently, routinely by orthopedic surgeons. During the past decade, bioabsorbable fixation systems have become available for use by craniomaxillofacial surgeons for cranial vault remodeling. This study evaluates the application of a bioabsorbable fixation system in reconstructive craniofacial procedures in a pediatric population. We reviewed 146 cases of cranial vault reconstruction including 98 boys and 48 girls ranging from 2 months to 16 years (mean, 15 months) in age. The procedures were performed for 6 years between January 1998 and June 2004. Bioabsorbable plates and screws were used in each case; most of these cases were craniosynostosis reconstructions. There were 69 cases of frontal sagittal craniosynostosis, 36 metopic, 20 unicoronal, 12 bicoronal, 5 lamboid, 2 deformational plagiocephaly, and 2 multiple fusion of sutures. Postoperative evaluation consisted of clinical examination and three-dimensional computed tomography scan reconstructions at 3, 6, and 12 months. Items specifically screened for on the clinical examination included wound healing, signs of infection, and palpability of implant through the skin. Six patients had palpable plates, 2 patients had palpable screw, and 5 patients had infection at the incision site (of which only 3 were treated with inpatient care including incision drainage and intravenous antibiotics). Our experience has been overwhelmingly positive, and we feel that our results suggest that resorbable fixation is a superior option in pediatric plastic and craniofacial surgery.

Rapid cooling through the glass transition transiently increases ductility of PGA/PLLA copolymers: a proposed mechanism and implications for devices

Heating bioabsorbable plates above T(g) allows for temporary softening to facilitate adaptation to bone. This can, however, transiently alter the mechanical properties, a better understanding of which would provide further insight into the use of these polymers. Two types of unoriented L-lactide/glycolide copolymer wafer specimens (82:18 and 95:5 molar ratios) were heated to 90 degrees C, cooled at various rates, and mechanically tested (three-point bend). Long cooling times ( approximately 8 h) did not change mechanical properties compared to unheated controls, whereas faster cooling rates resulted in increased ductility (50-200% increase in energy to break and peak deformation), however, there was gradual recovery. Under simulated physiological incubation conditions (pH 7.4 buffer, 37 degrees C) partial recovery occurred within 48 h. These results fit well into the theoretical framework of free volume considerations. Following rapid cooling to below T(g), the polymer is not initially at equilibrium, containing excess free volume that contributes to increased molecular mobility and ductile behavior. As equilibrium is approached, free volume decreases and the material behaves as a glassy solid. While there is little clinical consequence as regards internal fixation devices, possible transient changes in permeability and other properties could have implications in drug delivery and other applications.

Bioabsorbable Anterior Cervical Plating

Prospective clinical trial. The authors present their initial multicenter experience in the surgical management of 1-level degenerative disc disease of the cervical spine with anterior cervical discectomy and fusions (ACDF) using a bioabsorbable polymer plate. The introduction of a radiolucent bioabsorbable polymer plate and screws for ACDF presents a novel opportunity to gain the some of the potential added benefit of stabilization with internal immobilization while possibly reducing some of the long-term complications and imaging artifacts associated with titanium instrumentation. We prospectively analyze 52 patients who were treated at 6 different institutions across the United States with bioabsorbable polymer plate and screws for ACDF surgery. Patients were prospectively enrolled. A retrospective review of patients' charts and imaging was performed to determine clinical and radiographic outcome following anterior cervical spine surgery. Specifically, the authors looked at need for additional surgeries, local reaction to bioabsorbable polymer, fusion rate, and complications. Surgeries involved the C4-C5, C5-C6, C6-C7, and/or C7-T1 levels. Cadaveric bone was used in 42 patients, polyetheretherketone (PEEK) cages in 6 patients, and iliac crest autograft in 4 patients. The patients were observed for an average of 13.3 months. Radiographic fusion was achieved in 98.1% (51 of 52 patients) of the cases at 6 months. One patient has evidence of nonunion on flexion-extension imaging but remains asymptomatic. A different patient developed mild kyphosis after surgery and had persistence of radicular symptoms but refused further surgery. There were no clinical signs or symptoms of reaction to the bioabsorbable material. The rates of fusion following single-level ACDF with internal fixation using bioabsorbable polymer plate and screws in this study match those previously reported in the literature with metallic implants and are superior to noninstrumented fusions. Preliminary results suggest that this newly available technology for anterior fusion may be as effective as traditional titanium plating systems in single-level disease. The bioabsorbable material appears to be well tolerated by patients. A larger, randomized, controlled study is necessary to bring the results to statistical significance.

An Experimental Study of Heat Adaptation of Bioabsorbable Craniofacial Meshes and Plates

Intraoperative heating of bioabsorbable plates and mesh panels to above the glass transition temperature is commonly performed to assist their adaptation to bone. Some studies suggest that once heat-adapted, such implants under certain conditions tend to partially revert to their preadapted shape, termed a "memory effect." We investigated this phenomenon by using heat-adapted 82:18 poly-L-lactic acid:polyglycolic acid copolymer mesh panel and plate specimens with a glass transition temperature of 57 degrees C. The specimens retained limited malleability even at temperatures as low as 45 degrees C, substantially below the nominal glass transition temperature, as measured by shape relaxation experiments. At 40 degrees C to 42 degrees C, however, shape relaxation was not observed. A three-dimensional synthetic bone construct was also fixated using 90 degrees C heat-adapted plates, then incubated in a 37 degrees C buffer bath for 4 weeks, with periodic measurement of the shape of the construct. No changes in shape were recorded over this interval, suggesting that heat-adapted bioabsorbable implants forming a three-dimensional fixation network with multiple bone fragments cannot independently shape relax with the overall interconnectedness of the network ensuring its stability over time.

The use of bioabsorbable plate fixation for nasal fractures under local anaesthesia through open lacerations

Nasal fractures are the most common facial fractures. The majority of nasal fractures have been discussed as minor injuries and managed by closed reduction and intranasal packing. However, in cases of a nasal fracture with open laceration on fracture site, the plates fixation may be accomplished with definite reduction through the open laceration. But, metallic reconstruction plates can sometimes produce palpable irregularity at the site of fixation in nasal bone fractures. We performed rigid fixation through open laceration wound with bioabsorbable plate and screws under local anesthesia. Satisfactory result was obtained in both functional and aesthetic aspect. Open reduction through external laceration and bioabsorbable fixation under local anesthesia is a reliable and useful method for the treatment of extensive and comminuted nasal fractures.

A case of mandibular fracture applied internal fixation with a bioabsorbable plate (PLLA) system in a 1.5-year-old child

A case of mandibular fracture applied internal fixation with a bioabsorbable plate (PLLA) system in a 1.5-year-old child