Maxillary and mandibular osteosyntheses with PLGA and P(L/DL)LA implants: a 5-year inpatient biocompatibility and degradation experience

Pediatric Diaphyseal Forearm Fracture Management with Biodegradable Poly-L-Lactide-Co-Glycolide (PLGA) Intramedullary Implants: A Longitudinal Study

Background: Pediatric forearm fractures represent a substantial proportion of childhood injuries, requiring effective and minimally invasive treatments. Our study investigated the mid-term outcomes of biodegradable poly-L-lactide-co-glycolide (PLGA) intramedullary implants in managing diaphyseal forearm fractures in children. Methods: A follow-up cohort study was conducted with 38 patients treated with PLGA implants. Control examinations were performed one year post-operation, assessing bone healing through radiographic evaluations and functional outcomes using injured and uninjured limb range of motion (ROM) comparisons. Scarring was evaluated employing the Vancouver Scar Scale (VSS), and satisfaction via a questionnaire. Results: Children were predominantly female (76.4%), with a mean age of 9.71 (SD: 2.69) years. Effective fracture stabilization and bone healing were found in all patients, with a minor reduction (mean difference of -1.5°, p = 0.282) in elbow flexion on the operated side (139.3°) compared to the intact (140.8°). Elbow extension presented negligible average changes (0.2°, p = 0.098). Forearm movements were slightly reduced on the operated side (mean pronation: 80.8° vs. 83.7°, p = 0.166; average supination: 83.5° vs. 85.7°, p = 0.141). Wrist palmar flexion and dorsiflexion showed no significant differences. VSS ratings indicated minimal scarring (mean guardian and doctor scores were 1.13 and 0.55, respectively, p = 0.020), and all patients reported satisfaction with the treatment outcomes. Conclusions: Biodegradable implants are effective for pediatric forearm fractures, providing stable bone healing while preserving functional ROM with minimal scarring and high patient satisfaction. PLGA proved to be a viable alternative to traditional metal implants, eliminating secondary removal surgeries.

Electrosprayed Particles Loaded with Kartogenin as a Potential Osteochondral Repair Implant

The restoration of cartilage damage is a slow and not always successful process. Kartogenin (KGN) has significant potential in this space-it is able to induce the chondrogenic differentiation of stem cells and protect articular chondrocytes. In this work, a series of poly(lactic-co-glycolic acid) (PLGA)-based particles loaded with KGN were successfully electrosprayed. In this family of materials, PLGA was blended with a hydrophilic polymer (either polyethyleneglycol (PEG) or polyvinylpyrrolidone (PVP)) to control the release rate. Spherical particles with sizes in the range of 2.4-4.1 µm were fabricated. They were found to comprise amorphous solid dispersions, with high entrapment efficiencies of >93%. The various blends of polymers had a range of release profiles. The PLGA-KGN particles displayed the slowest release rate, and blending with PVP or PEG led to faster release profiles, with most systems giving a high burst release in the first 24 h. The range of release profiles observed offers the potential to provide a precisely tailored profile via preparing physical mixtures of the materials. The formulations are highly cytocompatible with primary human osteoblasts.

Subretinal Implantation of Human Primary RPE Cells Cultured on Nanofibrous Membranes in Minipigs

Purpose: The development of primary human retinal pigmented epithelium (hRPE) for clinical transplantation purposes on biodegradable scaffolds is indispensable. We hereby report the results of the subretinal implantation of hRPE cells on nanofibrous membranes in minipigs. Methods: The hRPEs were collected from human cadaver donor eyes and cultivated on ultrathin nanofibrous carriers prepared via the electrospinning of poly(L-lactide-co-DL-lactide) (PDLLA). “Libechov” minipigs (12–36 months old) were used in the study, supported by preoperative tacrolimus immunosuppressive therapy. The subretinal implantation of the hRPE-nanofibrous carrier was conducted using general anesthesia via a custom-made injector during standard three-port 23-gauge vitrectomy, followed by silicone oil endotamponade. The observational period lasted 1, 2, 6 and 8 weeks, and included in vivo optical coherence tomography (OCT) of the retina, as well as post mortem immunohistochemistry using the following antibodies: HNAA and STEM121 (human cell markers); Bestrophin and CRALBP (hRPE cell markers); peanut agglutining (PNA) (cone photoreceptor marker); PKCα (rod bipolar marker); Vimentin, GFAP (macroglial markers); and Iba1 (microglial marker). Results: The hRPEs assumed cobblestone morphology, persistent pigmentation and measurable trans-epithelial electrical resistance on the nanofibrous PDLLA carrier. The surgical delivery of the implants in the subretinal space of the immunosuppressed minipigs was successfully achieved and monitored by fundus imaging and OCT. The implanted hRPEs were positive for HNAA and STEM121 and were located between the minipig’s neuroretina and RPE layers at week 2 post-implantation, which was gradually attenuated until week 8. The neuroretina over the implants showed rosette or hypertrophic reaction at week 6. The implanted cells expressed the typical RPE marker bestrophin throughout the whole observation period, and a gradual diminishing of the CRALBP expression in the area of implantation at week 8 post-implantation was observed. The transplanted hRPEs appeared not to form a confluent layer and were less capable of keeping the inner and outer retinal segments intact. The cone photoreceptors adjacent to the implant scaffold were unchanged initially, but underwent a gradual change in structure after hRPE implantation; the retina above and below the implant appeared relatively healthy. The glial reaction of the transplanted and host retina showed Vimentin and GFAP positivity from week 1 onward. Microglial activation appeared in the retinal area of the transplant early after the surgery, which seemed to move into the transplant area over time. Conclusions: The differentiated hRPEs can serve as an alternative cell source for RPE replacement in animal studies. These cells can be cultivated on nanofibrous PDLLA and implanted subretinally into minipigs using standard 23-gauge vitrectomy and implantation injector. The hRPE-laden scaffolds demonstrated relatively good incorporation into the host retina over an eight-week observation period, with some indication of a gliotic scar formation, and a likely neuroinflammatory response in the transplanted area despite the use of immunosuppression.

Advantages of nanofibrous membranes for culturing of primary RPE cells compared to commercial scaffolds

PURPOSE

Dysfunction of the retinal pigment epithelium (RPE) causes numerous forms of retinal degeneration. RPE replacement is a modern option to save vision. We aimed to test the results of transplanting cultured RPEs on biocompatible membranes.

METHODS

We cultivated porcine primary RPE cells isolated from cadaver eyes from the slaughterhouse on two types of membranes: commercial polyester scaffolds Transwell (Corning Inc., Kenneburg, ME, USA) with 0.4 µm pore size and prepared Poly (L-lactide-co-DL-lactide) (PDLLA) nanofibrous membranes with an average pore size of 0.4 µm.

RESULTS

Five types of assays were used for the analysis: immunocytochemistry (ICC), phagocytosis assay, Western blotting, real-time qPCR (RT-qPCR) and electron microscopy. RT-qPCR demonstrated that RPEs cultured on nanofibrous membranes have higher expressions of BEST1 (bestrophin 1), RLBP1 (retinaldehyde-binding protein 1), RPE65 (retinal pigment epithelium-specific 65 kDa protein), PAX6 (transcription factor PAX6), SOX9 (transcription factor SOX9), DCT (dopachrome tautomerase) and MITF (microphthalmia-associated transcription factor). ICC of the RPEs cultured on nanofibrous membranes showed more intensive staining of markers such as BEST1, MCT1 (monocarboxylate transporter 1), Na⁺ /K⁺ ATPase, RPE65 and acetylated tubulin in comparison with commercial ones. Additionally, the absence of α-SMA proved the stability of the RPE polarization state and the absence of epithelial-to-mesenchymal transition. RPE possessed high phagocytic activity. Electron microscopy of both membranes confirmed a confluent layer of RPE cells and their genuine morphological structure, which was comparable to native RPEs.

CONCLUSIONS

Retinal pigment epitheliums cultured on polylactide nanofibrous membranes improved the final quality of the cell product by having better maturation and long-term survival of the RPE monolayer compared to those cultured on commercial polyester scaffolds. PDLLA-cultured RPEs are a plausible source for the replacement of non-functioning RPEs during cell therapy.

Stability in Pelvic Triple Osteotomies in Children Using Resorbable PLGA Screws for Fixation

BACKGROUND

The triple pelvic osteotomy (TPO) is a major redirectional osteotomy used to improve the acetabular coverage of the femoral head in selected pediatric patients with hip disorders. Traditionally the iliac osteotomy is stabilized by metal screws that require a second surgery for removal. Despite favorable results for both adults and children in related pelvic osteotomies, resorbable implants have not previously been used for TPOs.This study aims to suggest a novel modified TPO surgical method in children using resorbable poly lactic-co-glycolic acid (PLGA) screws for fixation and to radiographically evaluate the postoperative stability achieved by these implants in a case series.

METHODS

All patients (n=11) with dysplasia of the hip (2), Perthe disease (5), or Down syndrome (4), who underwent primary TPO surgery during 2013 to 2019, using resorbable PLGA screws for fixation were included. The stability of the osteotomy was evaluated in the postoperative radiograph series using the acetabular index, migration percentage, Sharp's angle and the center-edge angle. The osteotomy angle was introduced as a parameter to confirm the postoperative integrity of the achieved correction. All cases were evaluated until radiographic healing of the iliac osteotomy. Hospital notes were analyzed for complications or local reactions in relation to the implants.

RESULTS

In all studied hips, the overall achieved correction was well maintained. The mean (SD) correction achieved, from the preoperative images to the last measurable postoperative image, was a 16.7 degrees decrease for Sharp angle, a 20.9 degrees decrease in acetabular index and a 24.7 degrees increase for the center-edge angle, respectively. There were no complications related to the bioabsorption of the implants.

CONCLUSION

The present findings suggest that the modified TPO method, using resorbable PLGA screws, provides sufficient stability and appears to be a promising alternative to traditional TPO. Avoiding implant removal is a major benefit in a pediatric population. Resorbable screws enable the surgeon to place implants with more degrees of freedom since later implant removal is not a limiting factor.

LEVEL OF EVIDENCE

Level IV-case series.

The Effect of Diclofenac Sodium-Loaded PLGA Rods on Bone Healing and Inflammation: A Histological and Histomorphometric Study in the Femur of Rats

Implants made of poly(lactide-co-glycolide) (PLGA) are biodegradable and frequently provoke foreign body reactions (FBR) in the host tissue. In order to modulate the inflammatory response of the host tissue, PLGA implants can be loaded with anti-inflammatory drugs. The aim of this study was to analyze the impact of PLGA 80/20 rods loaded with the diclofenac sodium (DS) on local tissue reactions in the femur of rats. Special emphasis was put on bone regeneration and the presence of multinucleated giant cells (MGCs) associated with FBR. PLGA 80/20 alone and PLGA 80/20 combined with DS was extruded into rods. PLGA rods loaded with DS (PLGA+DS) were implanted into the femora of 18 rats. Eighteen control rats received unloaded PLGA rods. The follow-up period was of 3, 6 and 12 weeks. Each group comprised of six rats. Peri-implant tissue reactions were histologically and histomorphometrically evaluated. The implantation of PLGA and PLGA+DS8 rods induced the formation of a layer of newly formed bone islands parallel to the contour of the implants. PLGA+DS rods tended to reduce the presence of multi-nucleated giant cells (MGCs) at the implant surface. Although it is known that the systemic administration of DS is associated with compromised bone healing, the local release of DS via PLGA rods did not have negative effects on bone regeneration in the femora of rats throughout 12 weeks.

Bioabsorbable Osteofixation Materials for Maxillofacial Bone Surgery: A Review on Polymers and Magnesium-Based Materials

Clinical application of osteofixation materials is essential in performing maxillofacial surgeries requiring rigid fixation of bone such as trauma surgery, orthognathic surgery, and skeletal reconstruction. In addition to the use of titanium plates and screws, clinical applications and attempts using bioabsorbable materials for osteofixation surgery are increasing with demands to avoid secondary surgery for the removal of plates and screws. Synthetic polymeric plates and screws were developed, reaching satisfactory physical properties comparable to those made with titanium. Although these polymeric materials are actively used in clinical practice, there remain some limitations to be improved. Due to questionable physical strength and cumbersome molding procedures, interests in resorbable metal materials for osteofixation emerged. Magnesium (Mg) gained attention again in the last decade as a new metallic alternative, and numerous animal studies to evaluate the possibility of clinical application of Mg-based materials are being conducted. Thanks to these researches and studies, vascular application of Mg-based biomaterials was successful; however, further studies are required for the clinical application of Mg-based biomaterials for osteofixation, especially in the facial skeleton. The review provides an overview of bioabsorbable osteofixation materials in maxillofacial bone surgery from polymer to Mg.

MRI evaluation of resorbable poly lactic-co-glycolic acid (PLGA) screws used in pelvic osteotomies in children-a retrospective case series

Purpose

The orthopaedic use of resorbable poly lactic-co-glycolic acid (PLGA) implants carries multiple potential benefits. To our knowledge, only one publication exists regarding the use of PLGA implants in pelvic osteotomies in children, and data regarding resorption and potential side effects are lacking for resorbable pelvic screws in children. The aim of this study is to present an MRI-based evaluation of the resorption pattern and local tissue reactions in a paediatric case series after pelvic osteotomies fixated with PLGA screws.

Methods

Twelve children who had undergone a Salter or triple pelvic osteotomy fixated with 4.5 mm PLGA screws were included. A total of 18 MRIs was performed 0.5–4.5 years after surgery and were retrospectively analysed. Eight parameters relating to screw resorption, local reactions and re-formation of bone were interpreted.

Results

The screw canals were > 90% replaced with solid bone after 2–4.5 years in all cases but one, where the canals were only partly replaced with bone. There were no major soft tissue reactions but small (< 12 mm) bone cysts were observed in 3 of the 18 MRIs and discrete fatty patches in the adjacent bone were common.

Conclusion

PLGA screws in the paediatric pelvis appear to be resorbed and replaced with solid bone in most cases but this process takes at least 2 years. Minor reactions could be seen in the adjacent bone but were judged to be of no clinical significance.

Long-term study on the osteogenetic capability and mechanical behavior of a new resorbable biocomposite anchor in a canine model

Background

Biodegradable suture anchors are commonly used for repairing torn rotator cuffs, but these biodegradable materials still suffer from low mechanical strength, poor osteointegration, and the generation of acidic degradation byproducts.

Method

The purpose of this study was to evaluate the long-term mechanical behavior and osteogenetic capabilities of a biocomposite anchor injection molded with 30% β-tricalcium phosphate microparticles blended with 70% poly (L-lactide-co-glycolide) (85/15). This study investigated in vitro degradation and in vivo bone formation in a canine model. The initial mechanical behavior, mechanical strength retention with degradation time, and degradation features were investigated.

Results

The results showed that the biocomposite anchor had sufficient initial mechanical stability confirmed by comparing the initial shear load on the anchor with the minimum shear load borne by an ankle fracture fixation screw, which is considered a worst-case implantation site for mechanical loading. The maximum shear load retention of the biocomposite anchor was 83% at 12 weeks, which is desirable, as it aligns with the rate of bone healing. The β-tricalcium phosphate fillers were evenly dispersed in the polymeric matrix and acted to slow the degradation rate and improve the mechanical strength of the anchor. The interface characteristics between the β-tricalcium phosphate particles and the polymeric matrix changed the degradation behavior of the biocomposite. Phosphate buffer saline was shown to diffuse through the interface into the biocomposite to inhibit the core accelerated degradation rate. In vivo, the addition of β-tricalcium phosphate induced new bone formation. The biocomposite material developed in this study demonstrated improved osteogenesis in comparison to a plain poly (L-lactide-co-glycolide) material. Neither anchor produced adverse tissue reactions, indicating that the biocomposite had favorable biocompatibility following long-term implantation.

Conclusion

In summary, the new biocomposite anchor presented in this study had favorable osteogenetic capability, mechanical property, and controlled degradation rate for bone fixation.

Translational potential of this article

The new biocomposite anchor had sufficient initial and long-term fixation stability and bone formation capability in the canine model. It is indicated that the new biocomposite anchor has a ​potential for orthopedic application.

A Comparison of Endoscopic Reduction for Medial Blowout Fractures Using a Bioresorbable Panel and Silastic Sheet

BACKGROUND

The aim of the study was to compare the effectiveness of endoscopic endonasal reduction using a bioresorbable panel and silastic sheet packed with Merocel for blowout fractures of the medial orbital wall.

DESIGN

Retrospective study.

METHODS

The study group consisted of 147 patients who underwent endoscopic endonasal reduction of a blowout fracture of the medial orbital wall between January 2005 and December 2016. Fifty-seven fractures were repaired using a splint formed by a silastic sheet and Merocel (splint group), whereas 90 fractures were repaired using a bioresorbable panel for interposition (interposition group). Postoperative complications and surgical outcomes of the 2 groups were compared.

RESULTS

Preoperative diplopia in both groups (n = 30) was resolved except 1 in interposition group after the reduction. Enophthalmos was resolved in 10 cases in the splint group and in 6 cases in the interposition group. In postoperative CT scans, 20 of the 57 cases in the splint group exhibited under- or overcorrection, compared with 9 of the 90 cases in the interposition group (P < 0.05). There were no sinus infections or implant-related side effects in the interposition group except for implant extrusion in 4 cases, whereas 7 cases developed sinusitis in the splint group (P < 0.05).

CONCLUSIONS

Endonasal endoscopic reduction using a bioresorbable panel may be considered as a surgical alternative for the treatment of medial orbital blowout fractures.

Intravenous sustained-release nifedipine ameliorates nonalcoholic fatty liver disease by restoring autophagic clearance

Obesity and overweight, the most serious health problems, are associated with chronic metabolic complications such as type 2 diabetes, insulin resistance, and nonalcoholic fatty liver disease (NAFLD). However, current pharmacological therapies for obesity are challenged by potential side effects, low effectiveness, and low aqueous solubility, which limit their clinical application. Here, we develop nifedipine-loaded nanoparticles (NFD-NPs) that alleviate obesity-related metabolic dysfunction to be used as instruments for translational medicine. Nanoparticles (NPs) composed of poly (lactic-co-glycolic acid) (PLGA) not only enhance water solubility of hydrophobic nifedipine (NFD), a calcium channel blocker, without modifying the chemical structure of NFD for intravenous administration, but also allow prolonged release of NFD in vivo. NFD-NPs do not show cytotoxicity and reduce palmitate-induced protein inclusions and endoplasmic reticulum stress in human hepatoma HepG2 cells. Importantly, tail-vein injection of NFD-NPs into diet-induced obese mice results in sustained retention of NFD-NPs in the liver and suppression of metabolic derangements associated with NAFLD by enhancing autophagic clearance through Ca2+/calmodulin-dependent kinase II (CaMKII) phosphorylation, consequently decreasing diet-induced insulin resistance and improving glucose tolerance. Our findings offer new clinical tools for NP-mediated pharmaceutical strategies to treat NAFLD and its related metabolic dysfunction.

Absorbable Implant Foreign Body Reaction Masquerading as Orbital Cellulitis

Poly-DL-lactide polymer implants absorb over a period of 6 to 12 months and have been used with increasing frequency for repair of orbital fractures. The authors describe the case of a 7-year-old boy who presented with orbital inflammation 10 months following repair of a white-eyed blowout fracture with a poly-DL-lactide implant. Rapid improvement in symptoms followed initiation of oral steroids, with excellent long-term result. Clinical presentation and treatment response implicated a foreign body inflammatory reaction as the underlying etiology of symptoms. Ophthalmologists and orbital surgeons should be aware that absorbable implants can demonstrate this late idiosyncratic complication.

Poly(Lactic-co-Glycolic Acid): Applications and Future Prospects for Periodontal Tissue Regeneration

Periodontal tissue regeneration is the ultimate goal of the treatment for periodontitis-affected teeth. The success of regenerative modalities relies heavily on the utilization of appropriate biomaterials with specific properties. Poly (lactic-co-glycolic acid) (PLGA), a synthetic aliphatic polyester, has been actively investigated for periodontal therapy due to its favorable mechanical properties, tunable degradation rates, and high biocompatibility. Despite the attractive characteristics, certain constraints associated with PLGA, in terms of its hydrophobicity and limited bioactivity, have led to the introduction of modification strategies that aimed to improve the biological performance of the polymer. Here, we summarize the features of the polymer and update views on progress of its applications as barrier membranes, bone grafts, and drug delivery carriers, which indicate that PLGA can be a good candidate material in the field of periodontal regenerative medicine.

Biodegradable Polyphosphazene-Based Blends for Regenerative Engineering

The occurrence of musculoskeletal tissue injury or disease and the subsequent functional impairment is at an alarming rate. It continues to be one of the most challenging problems in the human health care. Regenerative engineering offers a promising transdisciplinary strategy for tissues regeneration based on the convergence of tissue engineering, advanced materials science, stem cell science, developmental biology and clinical translation. Biomaterials are emerging as extracellular-mimicking matrices designed to provide instructive cues to control cell behavior and ultimately, be applied as therapies to regenerate damaged tissues. Biodegradable polymers constitute an attractive class of biomaterials for the development of scaffolds due to their flexibility in chemistry and the ability to be excreted or resorbed by the body. Herein, the focus will be on biodegradable polyphosphazene-based blend systems. The synthetic flexibility of polyphosphazene, combined with the unique inorganic backbone, has provided a springboard for more research and subsequent development of numerous novel materials that are capable of forming miscible blends with poly (lactide-co-glycolide) (PLAGA). Laurencin and co-workers has demonstrated the exploitation of the synthetic flexibility of Polyphosphazene that will allow the design of novel polymers, which can form miscible blends with PLAGA for biomedical applications. These novel blends, due to their well-tuned biodegradability, and mechanical and biological properties coupled with the buffering capacity of the degradation products, constitute ideal materials for regeneration of various musculoskeletal tissues.

LAY SUMMARY

Regenerative engineering aims to regenerate complex tissues to address the clinical challenge of organ damage. Tissue engineering has largely focused on the restoration and repair of individual tissues and organs, but over the past 25 years, scientific, engineering, and medical advances have led to the introduction of this new approach which involves the regeneration of complex tissues and biological systems such as a knee or a whole limb. While a number of excellent advanced biomaterials have been developed, the choice of biomaterials, however, has increased over the past years to include polymers that can be designed with a range of mechanical properties, degradation rates, and chemical functionality. The polyphosphazenes are one good example. Their chemical versatility and hydrogen bonding capability encourages blending with other biologically relevant polymers. The further development of Polyphosphazene-based blends will present a wide spectrum of advanced biomaterials that can be used as scaffolds for regenerative engineering and as well as other biomedical applications.

Patient-specific biodegradable implant in pediatric craniofacial surgery

Surgical correction of premature fusion of calvarial sutures involving the fronto-orbital region can be challenging due to the demanding three-dimensional (3D) anatomy. If fronto-orbital advancement (FOA) is necessary, surgery is typically performed using resorbable plates and screws that are bent manually intraoperatively. A new approach using individually manufactured resorbable implants (KLS Martin Group, Tuttlingen, Germany) is presented in the current paper. Preoperative CT scan data were processed in iPlan (ver. 3.0.5; Brainlab, Feldkirchen, Germany) to generate a 3D reconstruction. Virtual osteotomies and simulation of the ideal outer contour with reassembled bony segments were performed. Digital planning was transferred with a cutting guide, and an individually manufactured resorbable implant was used for rigid fixation. A resorbable patient-specific implant (Resorb X-PSI) allows precise surgery for FOA in craniosynostosis using a complete digital workflow and should be considered superior to manually bent resorbable plates.

Development of a methacrylate-terminated PLGA copolymer for potential use in craniomaxillofacial fracture plates

We synthesised methacrylate-terminated PLGA (HT-PLGA, 85:15 LA:GA, 169kDa), for potential use as an adhesively attached craniomaxillofacial fracture fixation plate. The in vitro degradation of molecular weight, pH and flexural modulus were measured over 6weeks storage in PBS at 37°C, with commercially available high (225kDa, H-PLGA) and low (116kDa, L-PLGA) molecular weight 85:15 PLGAs used as comparators. Molecular weights of the materials reduced over 6weeks, HT-PLGA by 48%, H-PLGA by 23% and L-PLGA by 81%. HT-PLGA and H-PLGA exhibited a near constant pH (7.35) and had average flexural moduli in excess of 6GPa when produced, similar to that of the mandible. After 1week storage both exhibited a significant reduction in average modulus, however, from weeks 1-6 no further significant changes were observed, the average modulus never dropped significantly below 5.5GPa. In contrast, the L-PLGA caused a pH drop to below 7.3 by week 6 and an average modulus drop to 0.6 from an initial 4.6GPa. Cell culture using rat bone marrow stromal cells, revealed all materials were cytocompatible and exhibited no osteogenic potential. We conclude that our functionalised PLGA retains mechanical properties which are suitable for use in craniofacial fixation plates.

Perspectives of patients about bioabsorbable internal fixation for maxillofacial fractures

PURPOSE

Resorbable/bioabsorbable internal fixation provides effective treatment for maxillofacial fractures and avoids the need for metal hardware removal. We evaluated the initial knowledge, attitudes, subjective demand, and treatment satisfaction of patients concerning bioabsorbable osteofixation for maxillofacial trauma.

MATERIALS AND METHODS

From May 2007 to October 2009, there were 71 patients (63 males and 8 females; mean age: 35 ± 15 years) included in this prospective study. The patients completed preoperative and postoperative (4-6 weeks and 1 year) questionnaires.

RESULTS

After receiving information, 70 patients (99%) preferred resorbable/bioabsorbable bone fixation, usually because they preferred to avoid a second operation to remove metal hardware (67 patients [94%]). The higher cost of resorbable/bioabsorbable bone fixation was believed and justified by 41 patients (58%) and not justified by 30 patients (42%). No adverse events were reported by 27 of 34 patients (79%) at 4-6 weeks and by 14 of 21 patients (67%) at 1 year after surgery. Most patients were very satisfied with the outcome of surgery.

CONCLUSION

Patients who have maxillofacial trauma have a high frequency of preference and high satisfaction with resorbable/bioabsorbable than metal osteofixation. Literature review showed increased activity in research and publication worldwide about resorbable bone fixation, suggesting that there may be increased patient demand for resorbable bone fixation in the future.

Graft osteolysis and recurrent instability after the Latarjet procedure performed with bioabsorbable screw fixation

HYPOTHESIS AND BACKGROUND

The Latarjet procedure is a reliable treatment of recurrent anterior shoulder instability. The coracoid process is usually fixed with metallic screws; however, these can lead to irritation and the necessity for hardware removal and also can produce artifacts on imaging studies. The use of resorbable screws could avoid these complications. The purpose of this study was to assess the clinical results of the Latarjet procedure performed with bioabsorbable screws in addition to healing of the graft and resorption of the screws.

METHODS

In 2009, we performed a prospective study (case series,

LEVEL OF EVIDENCE

IV) of 11 patients (12 shoulders) who underwent a Latarjet procedure fixed with resorbable screws. Each patient was observed clinically and had a computed tomography scan at 3 months and 2 years of follow-up.

RESULTS

Every graft healed at 3-month follow-up. At 2-year follow-up, 4 patients had at least one instability episode, and one underwent a revision surgery. Three of these 4 patients were unhappy or disappointed. The Walch-Duplay score was excellent or good for 7 shoulders and medium or poor for 5. Screw resorption appeared complete in every case. No drill hole enlargement was observed. Every drill hole was partially filled with bone. Of 12 shoulders, 8 (66.67%) were associated with a severe osteolysis and an almost complete disappearance of the graft.

CONCLUSION

Coracoid graft osteolysis, previously reported after the Latarjet procedure, appears to be exacerbated with a risk of complete disappearance of the graft when the procedure is performed with the bioabsorbable screws used in this study.

Application of biodegradable plates for treating pediatric mandibular fractures

OBJECTIVE

We assessed the clinical results of a biodegradable plate system for the internal fixation of mandibular fractures in children, and observed the imaging features of fracture healing and bone changes around the biodegradable plates and screws during follow-up.

PATIENTS AND METHODS

We enrolled 39 patients (22 male, 17 female, average age 4 years 10 months) with different mandibular fractures. We used 2.0-mm resorbable plates to repair the fractures. Postoperative follow-up ranged from 6 months to 5 years; average follow-up was 1 year 2 months. The outcome measures identified and assessed included facial symmetry, mouth opening, occlusal relationship, infection, nonunion, malunion, and plate dehiscence.

RESULTS

We fixed 42 fractures with 43 resorbable plates; the fracture site of one patient (aged 11 years 3 months) was fixed with two plates. Two patients developed small fistulas at the intraoral incision 2 months after surgery; the fistulas healed after 1 month without special treatment. In the other patients, the incision healed well, there was facial symmetry, mouth opening was >35 mm, and occlusion was good. Follow-up computed tomography examination data were available for 20 cases, and revealed different degrees of radiolucency indicating that osteolysis had occurred. Radiolucency was observed around the resorbable plates 1 month after the surgery. The extent and depth of the radiolucent region were obvious within 1 year of surgery. In the second year, there were obvious repairs, with the bony defect areas becoming shallower. After 2 years, the bony defect areas had almost disappeared.

CONCLUSION

Biodegradable fixation devices are safe and efficient for treating pediatric mandibular fractures. Osteolysis commonly follows biodegradable fixation of pediatric mandibular fractures, and has no adverse effect on fracture healing.

Bioabsorbable plates and screws fixation in mandible fractures: clinical retrospective research during a 10-year period

We present the basic guidelines for the safe fixation of a mandible fracture using a bioabsorbable system with less strength than the metallic system based on our 10 years of experience.We conducted a retrospective review of 75 patients who had undergone fixation using a bioabsorbable system for a mandible fracture. We analyzed the method of fixation and the size and thickness of the plates and screws that were selected depending on the mandible's fracture site.Minor complications including intraoral wound disruptions and infections occurred in 12 (16%) patients, and 2 (2.7%) patients among 10 patients who presented with infections had nonunion; therefore, they underwent replacement of the absorbable system with the titanium system. Bone resorption that was caused by the absorbable plate occurred in 12 (16%) patients.The bioabsorbable system also may be able to replace the metallic system in the fixation of comminuted mandible fractures if further research on the development of the system is supported.

Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration.

Treatment of malar and midfacial fractures with osteoconductive forged unsintered hydroxyapatite and poly-L-lactide composite internal fixation devices

PURPOSE

To evaluate the internal fixation of malar and midfacial fractures, long-term results, and biocompatibility of osteoconductive internal fixation devices composed of a forged composite of unsintered hydroxyapatite and poly-L-lactide (F-u-HA/PLLA).

MATERIALS AND METHODS

From January 2006 to June 2010, 29 patients (24 males and 5 females; age 33 ± 15 years) were included in the present prospective study. The fracture type was malar in 24 patients, midfacial in 5, isolated orbital floor blowout in 2, and frontal sinus, cranial base in 2 patients. The fractures were fixed with internal fixation devices; these were plates and screws composed of F-u-HA/PLLA. The 24 patients with malar fractures were treated with a single 4-hole L-plate or a straight plate at the infrazygomatic crest.

RESULTS

All fractures with internal fixation using devices composed of F-u-HA/PLLA healed well. All malar and midfacial fractures had satisfactory long-term stability. The follow-up examinations at 12 to 67 months after surgery showed that most patients had no complaints, although 2 patients (15%) had a foreign body reaction that was treated by implant removal, with complete symptom resolution. At 5 years after fracture fixation, 2 patients had ultrasound and 2 had radiographic evidence of residual material. An exemplar biopsy showed direct bone growth into the material.

CONCLUSIONS

In patients with malar and midfacial fractures, hardware composed of the F-u-HA/PLLA composite provided reliable and satisfactory internal fixation, intraoperative handling, long-term stability, and biocompatibility. Direct bone growth into the material could be histopathologically exemplified, in contrast to previous polymer fixations that were resorbed and surrounded by a connective tissue layer. This finding indicates that long-term F-u-HA/PLLA residual material will be included into the remodeled bone, which was confirmed on long-term follow-up radiographs.

Peculiarities of employment of polymeric miniplates for mandibular osteosynthesis: a preliminary study

Searching for new materials for bone substitution, fixation, and reconstruction is a challenging task that attracts scientists and researchers of different fields of medicine. During the last few decades, much interest has been paid to polymeric materials, polyethylene in particular. The aim of this study is to present generalizations about our own experience in the employment of polyethylene miniplates for the surgical treatment of mandibular fractures. Ninety patients with 139 uni- and bilateral mandibular fractures in different locations were involved. Treatment modalities included open reduction and internal fixation with self-made polyethylene miniplates of straight, T-shaped, Y-shaped, and X-shaped configurations and titanium screws. In 88 (97.8%) cases of surgical treatment of mandibular fractures using polymer miniplates, good anatomical and functional results were achieved. Regardless of the necessity for improvement of some mechanical properties of polyethylene, the results obtained in our clinical investigation allow us to recommend polyethylene miniplates for routine practice.

Local foreign-body reaction to commercial biodegradable implants: an in vivo animal study

Biodegradable plates have been used extensively in fracture fixation since the 1960s. They rarely cause stress-protection atrophy or problems requiring secondary plate removal, common complications seen with metallic plates. However, aseptic foreign-body reactions have been reported, sometimes years after the original implantation. Both inadequate polymer degradation and debris accumulation have been implicated as causes. The current generation of commercial biodegradable plates is formulated to minimize this complication by altering the ratio of polylactic and polyglycolic acids. This in vivo study compares the degree of local foreign-body reaction of two commercially available resorbable plates in rabbits. Two types of biodegradable plates were examined: poly(D/L)lactide acid (PDLLA) and polylactide-co-glycolide acid (PLGA). Each plate was placed into a periosteal pericalvarial pocket created beneath the anterior or posterior scalp of a rabbit. Humane killing occurred at 3, 6, and 12 months postoperatively. Foreign-body reaction was evaluated histologically. The PDLLA plates demonstrated marked local foreign-body reactions within the implant capsule as early as 3 months after implantation, with presence of inflammatory cells and granulomatous giant cells in close association with the implant material. All local foreign-body reactions were subclinical with no corresponding tissue swelling requiring drainage. PLGA plates did not demonstrate any signs of inflammatory reactions. In addition, the PLGA plates did not appear to resorb or integrate at 12 months. Neither PDLLA nor PLGA plates demonstrated inflammation of the soft tissue or adjacent bone outside the implant capsule. In our study, the PDLLA plates demonstrated histological evidence of foreign-body reaction that is confined within the implant capsule, which was not seen with the PLGA plates. This finding may be attributable to the lack of significant resorption seen in the PLGA plates. Both PDLLA and PLGA plates were biocompatible with the rabbit tissue environment and should be considered for continued use in craniofacial, maxillofacial, and orthopedic reconstruction.

Evaluation of the Fatigue Performance and Degradability of Resorbable PLDLLA-TMC Osteofixations

The fatigue performance of explanted in-situ degraded osteofixations/osteosyntheses, fabricated from poly (70L-lactide-co-24DL-lactide-6-trimethylane-carbonate or PLDLLA-TMC) copolymer was compared to that of virgin products. The fatigue test was performed on 21 explants retrieved from 12 women and 6 men; 16-46 years by a custom-designed three-point bend apparatus using a staircase method and a specified failure criterion (an increase of the deflection of the specimen > 1 mm) with run-out designated as “no failure” after 150,000 loading cycles. While all the virgin products showed run-out at 38N, all of the specimens fabricated from explants failed at this load level. For the explant specimens, although there was a trend of decreased failure load with increased in-situ time, this decrease was pronounced after 4 months in-situ, however, not yet statistically significant, while a 6-month in-situ explant had significantly less failure load. Three and four month in-situ explants had highly significant differences in failure load between measurements close and distant to the osteotomy line: p=0.0017 (the region of maximum load in-situ). In the virgin products, there were only traces of melt joining and cooling, left from a stage in the manufacturing process. For the implants retrieved after 4.5 months in-situ, the fracture surfaces showed signs of degradation of the implants, possibly caused by hydrolysis, and for those retrieved after 9 months in-situ, there were cracks and pores. Thus, the morphological results are consistent with those obtained in the fatigue test. The present results suggest that resorbable osteofixations fabricated from PLDLLA-TMC are stable enough to allow loading of the healing bone and degrade reliably

Frontal sinus fractures: a conservative shift

This article reflects on the changing management of frontal sinus fractures. Severity of these injuries has decreased tremendously since the universal adoption of seat belts and air bags. Recently, there has been a shift from aggressive surgical management to more conservative management strategies, some forgoing surgery all together. New technologies, such as bioabsorbable plates and endoscopic sinus surgery, are leading the way in improved surgical management strategies and offer promising alternatives to the more traditional approaches.

Maxillary stability after Le Fort I osteotomy with self-setting α-tricalcium phosphate and an absorbable plate

The purpose of this study was to compare retrospectively postoperative differences in maxillary stability after Le Fort I osteotomy and fixation with an unsintered hydroxyapatite (u-HA)/poly-l-lactic acid (PLLA) plate with or without self-setting α-tricalcium phosphate (Biopex(®)) as interpositional material. Subjects comprised 45 patients diagnosed with mandibular prognathism with maxillary retrognathism and mandibular prognathism with bimaxillary asymmetry. All patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy with fixation by uHA/PLLA plates. Patients were divided into 4 groups consisting of 9 maxillary impaction cases with Biopex(®) (group 1) to fill the gap between the bone segments, 14 maxillary advancement cases with Biopex(®) (group 2), 8 maxillary impaction cases without Biopex(®) (group 3) and 14 maxillary advancement cases without Biopex(®) (group 4). Changes in cepahalometric parameters at time intervals (1, 3 and 12 months) between the groups were compared. Results showed that stability did not depend on the use or otherwise of Biopex(®).

Effects of lactic acid and glycolic acid on human osteoblasts: a way to understand PLGA involvement in PLGA/calcium phosphate composite failure

The use of degradable composite materials in orthopedics remains a field of intense research due to their ability to support new bone formation and degrade in a controlled manner, broadening their use for orthopedic applications. Poly (lactide-co-glycolide) acid (PLGA), a degradable biopolymer, is now a popular material for different orthopedic applications and is proposed for use in tissue engineering scaffolds either alone or combined with bioactive ceramics. Interference screws composed of calcium phosphates and PLGA are readily available in the market. However, some reports highlight problems of screw migration or aseptic cyst formation following screw degradation. In order to understand these phenomena and to help to improve implant formulation, we have evaluated the effects of PLGA degradation products: lactic acid and glycolic acid on human osteoblasts in vitro. Cell proliferation, differentiation, and matrix mineralization, important for bone healing were studied. It was found that the toxicity of polymer degradation products under buffering conditions was limited to high concentrations. However, non-toxic concentrations led to a decrease in cell proliferation, rapid cell differentiation, and mineralization failure. Calcium, whilst stimulating cell proliferation was not able to overcome the negative effects of high concentrations of lactic and glycolic acids on osteoblasts. These effects help to explain recently reported clinical failures of calcium phosphate/PLGA composites, but further in vitro analyses are needed to mimic the dynamic situation which occurs in the body by, for example, culture of osteoblasts with materials that have been pre-degraded to different extents and thus be able to relate these findings to the degradation studies that have been performed previously.

[Implant materials for the internal fixation of midfacial fractures]

The material used for osteosynthesis plays a crucial role in the management of facial fractures. Plates need to be flexible enough to be bent and should not be palpable through the skin, while ensuring stable fixation und adequate biocompatibility. Although stainless steel was initially the material of choice, titanium has become the standard material due to its superior biocompatibility. While the explantation of titanium plates and screws appears unnecessary in general, it should be considered in cases of dislocation, cosmetic concerns, pain and infection. Due to their limited initial stability and a potential increase in local complications, resorbable materials based on polymeric lactose are used with caution in midfacial fractures in adults. Our own retrospective study comparing the postoperative complications after fixation of lateral midfacial fractures with titanium and resorbable systems demonstrated a low complication rate for both systems (7-8%) and no statistically significant difference between the two. The appropriate material for fixation should be selected based on the localization and severity of the fracture, the experience of the surgeon as well as on the age and overall condition of the patient.

Effects of lactide monomer on the hydrolytic degradation of poly(lactide-co-glycolide) 85L/15G

The hydrolytic degradation of oriented poly(L-lactide-co-glycolide) 85 L/15 G (PLGA 85/15) sample materials with various amounts of lactide monomer was monitored in vitro at 37 °C. The materials were manufactured from medical grade PLGA 85/15 by a two-step melt extrusion-die drawing process. Results showed that the hydrolytic degradation rate depended highly on the lactide monomer content, which in turn influenced the retention of mechanical properties, mass loss, crystallinity, and dimensional stability. Even small quantities of lactide monomer (0.05-0.20 wt%) affected especially the retention of mechanical properties, which started to decline rapidly upon the inherent viscosity reaching 0.6-0.8 dl/g due to hydrolytic degradation. Based on our hydrolytic degradation data, we constructed a simplified mathematical model of degradation-related strength retention and recommend it as a functional quality control tool for melt-processed biodegradable medical devices manufactured from poly(L-lactide-co-glycolide) 85 L/15 G.

Skeletal stability and morbidity with self-reinforced P (L/DL) LA resorbable osteosynthesis in bimaxillary orthognathic surgery

INTRODUCTION

We present a retrospective study of 30 consecutive cases of bimaxillary orthognathic surgery with biodegradable self-reinforced poly-L/DL-lactide plates and tacks, for the same indication of Angle class III malocclusion. We reported the skeletal stability and morbidity at 1 year after surgery.

PATIENTS AND METHODS

All patients underwent bimaxillary procedure. We used self-reinforced poly-L/DL lactic acid copolymer. Stabilization of Lefort I osteotomy was achieved by four plates L-shaped. Sagittal split osteotomies were fixed by two straight-plates. Lateral cephalograms were taken before (T0), soon after (T1) and more than 1 year after surgery (T2). Eight standard landmarks and four angular measurements were taken into account. All differences of the landmarks and angles were measured at T1 and T2. The regular clinical follow-up was scheduled for a minimum period of 1 year.

RESULTS

The mean advanced maxillary was 3.33 mm and the mean mandibular setback was 6.13 mm. The mean mandibular relapse was 2.2 mm (non-significant). Horizontal maxilla mean variation was 0.8 mm at 1 year at A-point. Vertical maxilla stability depends on maxillary movements: impaction stability is better as an isolated advancement or associated with pull-down movement. We found six inflammatory reactions and two of them need the removal of the plates.

CONCLUSION

Bimaxillary orthognathic procedure with bioresorbable osteosynthesis is a reliable and reproducible method. Angle class III malocclusions could be entirely and successfully managed with bioresorbable osteosynthesis. The stability and suites at 1 year are comparable to titanium osteosynthesis.

Biodegradable implants for sustained drug release in the eye

The safety and effectiveness of systemic and topical medical therapies for ocular disorders are limited due to poor ocular drug uptake, nonspecificity to target tissues, systemic side effects, and poor adherence to therapy. Intravitreal injections can enhance ocular drug delivery, but the need for frequent retreatment and potential injection-related side effects limit the utility of this technique. Sustained-release drug delivery systems have been developed to overcome these limitations; such systems can achieve prolonged therapeutic drug concentrations in ocular target tissues while limiting systemic exposure and side effects and improving patient adherence to therapy. A critical factor in the development of safe and effective drug delivery systems has been the development of biocompatible polymers, which offer the versatility to tailor drug release kinetics for specific drugs and ocular diseases. Ocular implants include nonbiodegradable and biodegradable designs, with the latter offering several advantages. The polymers most commonly used in biodegradable delivery systems are synthetic aliphatic polyesters of the poly-α-hydroxy acid family including polylactic acid, polyglycolic acid, and polylactic-co-glycolic acid. The characteristics of these polymers for medical applications as well as the pharmacological properties, safety, and clinical effectiveness of biodegradable drug implants for the treatment of ocular diseases are reviewed herein.

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.

Dipeptide-based polyphosphazene and polyester blends for bone tissue engineering

Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)(1)(phenyl phenoxy)(1)phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2<Matrix1<PLAGA in phosphate buffered saline at 37 degrees C over 12 weeks. Significantly higher pH values of degradation media were observed for blends compared to PLAGA confirming the neutralization of PLAGA acidic degradation by polyphosphazene hydrolysis products. The blend components PLAGA and polyphosphazene exhibited a similar degradation pattern as characterized by the molecular weight loss. Furthermore, blends demonstrated significantly higher osteoblast growth rates compared to PLAGA while maintaining osteoblast phenotype over a 21-day culture. Both blends demonstrated improved biocompatibility in a rat subcutaneous implantation model compared to PLAGA over 12 weeks.

Equivalence randomized controlled trial of bioresorbable versus titanium miniplates in treatment of mandibular fracture: a pilot study

PURPOSE

The present study was undertaken to test bioresorbable fixation versus titanium for equivalence in terms of clinical union and complications using the American Association of Oral and Maxillofacial Surgeons parameters of care. The study design was a randomized, controlled, equivalence trial.

MATERIALS AND METHODS

A total of 40 patients were enrolled and allocated to the titanium group and bioresorbable group using a computerized randomization table. All were plated using standard plating principles. In the bioresorbable group, 2 weeks of maxillomandibular fixation was also used. Evaluation of the study endpoint was done at 8 weeks postoperatively. For statistical analysis, the upper limit of the 95% confidence interval was calculated for failure to achieve the primary outcome variable and compared with the maximal clinically acceptable difference between the standard and test modalities in the failure to achieve clinical union (delta). Delta was predetermined as 2%. The other complications were tested for significance using Fisher's exact test.

RESULTS

Of the 40 patients, 21 were in the titanium group and 19 were in the bioresorbable group, with 20 men and 1 woman in the titanium group and 18 men and 1 woman in the bioresorbable group. The mean age was 28.7 years in the titanium group and 26.6 years in the bioresorbable group. In the titanium group, the complications noted were nonunion in 0%, malocclusion in 7.7%, continued postoperative swelling in 0%, chronic pain in 2%, infection in 5.2%, an inability to chew hard food after 8 weeks in 7.7%, the need for alternative treatment in 0%, and the need for reoperation in 31%. In the bioresorbable group, the complications were nonunion in 4.17%, malocclusion in 11.1%, swelling in 8.3%, chronic pain in 37.5%, infection in 0%, an inability to chew hard food in 11.1%, the need for alternative treatment in 11.1%, and need for reoperation for plate removal in 0%.

CONCLUSIONS

The small sample size did not allow any meaningful conclusion to be drawn from the present study in terms of the primary question of achieving union. Both groups matched in outcomes when evaluated only on a clinical basis. The avoidance of repeat surgery for plate removal is a definite advantage of using resorbable plates. However, the results are inconclusive in favor of any particular plating system.