Surface analysis of titanium maxillofacial plates and screws retrieved from patients

Inflammatory tissue response in human soft tissue is caused by a higher particle load near carbon fiber-reinforced PEEK compared to titanium plates

Titanium as the leading implant material in locked plating is challenged by polymers such as carbon fiber-reinforced polyetheretherketone (CFR-PEEK), which became the focus of interest of researchers and manufacturers in recent years. However, data on human tissue response to these new implant materials are rare. Osteosynthesis plates and peri‑implant soft tissue samples of 16 healed proximal humerus fractures were examined (n = 8 CFR-PEEK, n = 8 titanium). Soft tissue was analyzed by immunohistochemistry and µCT. The entrapped foreign bodies were further examined for their material composition by FTIR. To gain insight into their origin and formation mechanism, explanted and new plates were evaluated by SEM, EDX, profilometry and HR-CT. In the peri‑implant soft tissue of the CFR-PEEK plates, an inflammatory tissue reaction was detected. Tissues contained foreign bodies, which could be identified as tantalum wires, carbon fiber fragments and PEEK particles. Titanium particles were also found in the peri‑implant soft tissue of the titanium plates but showed a less intense surrounding tissue inflammation in immunohistochemistry. The surface of explanted CFR-PEEK plates was rougher and showed exposed and broken carbon fibers as well as protruding and deformed tantalum wires, especially in used screw holes, whereas scratches were identified on the titanium plate surfaces. Particles were present in the peri‑implant soft tissue neighboring both implant materials and could be clearly assigned to the plate material. Particles from both plate materials caused detectable tissue inflammation, with more inflammatory cells found in soft tissue over CFR-PEEK plates than over titanium plates. STATEMENT OF SIGNIFICANCE: Osteosynthesis plates are ubiquitously used in various medical specialties for the reconstruction of bone fractures and defects and are therefore indispensable for trauma surgeons, ENT specialists and many others. The leading implant material are metals such as titanium, but recently implants made of polymers such as carbon fiber-reinforced polyetheretherketone (CFR-PEEK) have become increasingly popular. However, little is known about human tissue reaction and particle generation related to these new implant types. To clarify this question, 16 osteosynthesis plates (n = 8 titanium and n = 8 CFR-PEEK) and the overlying soft tissue were analyzed regarding particle occurrence and tissue inflammation. Tissue inflammation is clinically relevant for the development of scar tissue, which is discussed to cause movement restrictions and thus contributes significantly to patient outcome.

Cross-Sectional Study of Serum Metal Ions in Patients With Metal Implants in the Maxillofacial Region

Purpose

The purpose of the present study was to measure the serum metal ion levels (titanium, cobalt, chromium) in patients who have metal implants in the maxillofacial region.

Methods

The investigators implemented a cross sectional study on patients treated with procedures requiring metal implants for management of maxillofacial trauma, fixation for orthognathic surgery, and total temporomandibular joint replacement (TJR). Inductively coupled plasma mass spectrometry was used as an analytical method to detect metal ions in serum samples.

Results

The study comprised of 50 patients who were divided into 4 groups- group I- total TJR (n = 18), group II- orthognathic (n = 8), group III- trauma (n = 8), and group IV- control (n = 16). The mean values of metal ions level were raised than the control group.

Conclusion

The present study's results suggest a rise in serum metal ion levels after the metal implantation in maxillofacial region. None of the patients had any abnormal signs and symptoms due to raised metal levels. Further studies are warranted to correlate the serum metal ion levels and their clinical relevance.

Titanium Internal Fixator Removal in Maxillofacial Surgery: Is It Necessary? A Systematic Review and Meta-Analysis

Titanium plates and screws are essential devices in maxillofacial surgery since late 1980s, but despite their wide use there is no consensus in titanium internal fixators removal after bone healing. A systematic literature review and meta-analysis were conducted on seventeen retrospective studies. Effect size and 95% confidence intervals were calculated for plate removal (per plate and per patient) and for removal causes (infection, pain, screws complications, exposition, palpability). Odds ratio, 95% confidence intervals, and χ 2 test were measured for sex, smoking, and implant site. Heterogeneity was evaluated with Cochran and Inconstancy test. Obtained data were used to design Forest and Funnel plots. The aim of the study is to identify and clarify reasons and risk factors for plates and screws removal. Infection is the most frequent reason; the habit of tobacco usage and implant site (mandibula) are the main risk factors. The administration of antibiotic prophylaxis is essential, and patients must quit smoking before and after surgery. In conclusion there is no scientific evidence supporting the removal of internal devices as mandatory step of the postoperative procedure.

Management of failed stainless steel implants in the oromaxillofacial region of dogs

Management of complications of fracture fixation in the oromaxillofacial (OMF) region may present a diagnostic and therapeutic challenge. While titanium and stainless steel implants have been utilized in successful fracture fixation in the OMF region, the use of titanium implants is preferred due to the superior intrinsic properties of titanium. Nonetheless, stainless steel materials are still used due to their availability and familiarity. In the present methods report, we describe our approach to the management of failed stainless steel plates and screws used to treat traumatic injuries in the OMF region. Furthermore, we exemplify our approach with five dogs that exhibited complications of stainless steel implants in the OMF region and their subsequent management. In those cases, all failed implants were removed. Reconstruction with a combination of recombinant human bone morphogenetic protein-2 (rhBMP-2) and titanium implants was utilized in two cases while a mandibulectomy was performed in one case. Three cases required removal of the stainless-steel implant with no additional surgical therapy. We conclude that the success of treatment of failed stainless steel implants depends on the use of advanced imaging findings, appropriate antimicrobial therapy, as well as potentially regenerative reconstructive surgery.

A 7-Year Retrospective Analysis of Titanium Plates Removal Following Orthognathic Surgery

Objective

The aim of this study was to investigate the incidence of plate removal in orthognathic surgery patients and the reasons for their removal and to potentially identify the factors that may contribute to it.

Methods

A retrospective study included all patients who underwent orthognathic surgery at Selayang Hospital from January 2011 to December 2017. The variables of interest recorded included patient age, gender, the existing skeletal deformity, type of surgery undertaken and number and location of plates inserted and removed. In addition, the reasons for plate removal and duration between plate insertion and removal were also recorded.

Results

Ninety-seven patients with a mean age of 21.33 were included in the study. Nine patients with total of 33 plates had their miniplate fixation removed. Three patients underwent bi-maxillary surgery, and six patients underwent BSSO. The average time from insertion to removal was 22.33 months. The reasons for removal included pain, palpable and exposed plates, infection and on patient request.

Conclusion

We report a 9.28% incidence of plate removal in patients who undergo orthognathic surgery which is comparable to the existing literature.

The Implications of Titanium Alloys Applied in Maxillofacial Osteosynthesis

Titanium alloys are known for their biological, mechanical and chemical properties, which have successfully expanded their use in the maxillofacial field. The internal fixation using titanium miniplates and screws offer a new perspective for the treatment of trauma and in orthognathic surgery and maxillofacial oncology. Although, titanium is highly recommended for its excellent biocompatibility, recent research has focused on identifying the potential local and general implications of the interactions between the human tissue and the metallic particles. This present review aims to outline the existing tissue changes, cellular alterations and future perspectives regarding the use of titanium-based alloys as osteosynthesis materials, taking into consideration the existing present debate whether the routinely removal of these materials should be an indication.

Histological Change in Soft Tissue Surrounding Titanium Plates after Jaw Surgery

The aim of this study was to evaluate the microscopic structure of soft tissue covering titanium plates and screws used in jaw surgery (mandible fracture and orthognathic surgery), after a minimum period of 12 months from insertion, and to quantify the presence of any metallic particles. Periosteum covering the osteosynthesis plates was removed from 20 patients and examined by light microscopy in order to assess the cell morphological changes and the possibility of metal particles presence in the soft tissue. Local signs of tissue toxicity or inflammation were taken into consideration when evaluating the routine removal of titanium maxillofacial miniplates. No signs of screw loosening or acute inflammation were detected on the osteosynthesis site, but de-coloration of the periosteum was seen, and metallic particles were observed to have migrated into the soft tissues. Even if the titanium is well-tolerated by the human body in time, without severe local or general complications, our findings suggest that plate removal should be considered after bone healing has occurred.

A 4-Year Multicentre Audit of Complications Following ORIF Treatment of Mandibular Fractures

Purpose

To ascertain the complications arising from open reduction and internal fixation of mandibular fractures and to elucidate if different osteosynthesis plating systems vary in treatment outcome.

Materials and Methods

This is a retrospective study. Parameters such as patient data, injury details, osteosynthesis implant system information, stability of fracture fragments, occlusion and complications were evaluated at different time intervals and logistic regression applied to determine the association of these factors with complications.

Results

Five hundred and ninety-three patients with mandibular fractures were included in this study (male 87.9% and female 12.1%), age range of 13-72 years (median = 22 years). Most fractures were caused by motor vehicle accidents (85.8%), assault (6.2%) and falls (4.7%). Parasymphyseal fractures were the most common (50.1%), followed by angle (35.2%) and body of mandible (25%). Median time interval between injury and intervention was 7 days (IQR 4-10). Median duration of follow-up from date of surgery was 72 days (IQR 30-230). 76.9% (456) were completely free of complications. Most complications (46%) occurred in the intermediate post-surgical period (1-6 weeks). Median interval period between surgery and complication was 15 days (IQR 7-67.5). Nerve injury and surgical site infection were the most common complications at 6.7% and 5.7%, respectively. There was a significant difference between the plating system in terms of complication outcome (p = 0.017).

Conclusion

Whilst the miniplate dimensions may be similar across different manufacturers, the complication outcome may differ between systems.

Review of In Vivo Bone Strain Studies and Finite Element Models of the Zygomatic Complex in Humans and Nonhuman Primates: Implications for Clinical Research and Practice

The craniofacial skeleton is often described in the clinical literature as being comprised of vertical bony pillars, which transmit forces from the toothrow to the neurocranium as axial compressive stresses, reinforced transversely by buttresses. Here, we review the literature on bony microarchitecture, in vivo bone strain, and finite-element modeling of the facial skeleton of humans and nonhuman primates to address questions regarding the structural and functional existence of facial pillars and buttresses. Available bone material properties data do not support the existence of pillars and buttresses in humans or Sapajus apella. Deformation regimes in the zygomatic complex emphasize bending and shear, therefore conceptualizing the zygomatic complex of humans or nonhuman primates as a pillar obscures its patterns of stress, strain, and deformation. Human fossil relatives and chimpanzees exhibit strain regimes corroborating the existence of a canine-frontal pillar, but the notion of a zygomatic pillar has no support. The emerging consensus on patterns of strain and deformation in finite element models (FEMs) of the human facial skeleton corroborates hypotheses in the clinical literature regarding zygomatic complex function, and provide new insights into patterns of failure of titanium and resorbable plates in experimental studies. It is suggested that the "pillar and buttress" model of human craniofacial skeleton function be replaced with FEMs that more accurately and precisely represent in vivo function, and which can serve as the basis for future research into implants used in restoration of occlusal function and fracture repair. Anat Rec, 299:1753-1778, 2016. © 2016 Wiley Periodicals, Inc.

Mini-plate removal in maxillofacial trauma patients during a five-year retrospective study

OBJECTIVES

The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients.

MATERIALS AND METHODS

The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal.

RESULTS

The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%).

CONCLUSION

The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

Surface analytical studies of maxillofacial implants: influence of the preoperational treatment and the human body on the surface properties of retrieved implants

In the present work, surface analytical investigation of unimplanted as well as retrieved pyrolytic carbon-covered carbon/carbon composite implants and Ti osteosynthesis plates is reported. The Ti plates were covered by a 200-nm-thick, anodically and thermally formed TiO2 layer. Our results suggest that although the oxide layer on the Ti miniplates remained stable during the time spent in the human body, there is still material transport between the implant and the human body. In case of the carbon/carbon composite implants, damage of the carbon fibers constituting the material was found on one side of the sterile implant and attributed to the manufacturing process. The NaCl crystals originally present on the surface of the sterile material disappeared during the time spent in the human body. As a result of the interaction with the human body, a new surface layer (mainly constituted of carbon) appeared on the implant. The results indicate that both the time spent in the human organism and the preparation of the implants before operation can have detectable effects on the investigated surface properties. Surface analytical investigations could therefore provide information not only about the biocompatibility of these materials but also about the effect of their treatment before operation.

Kinetic effects of TiO2 fine particles and nanoparticles aggregates on the nanomechanical properties of human neutrophils assessed by force spectroscopy

Background

Increasing applications of titanium dioxide (TiO₂) fine particles (FPs) and nanoparticles (NPs) require coupled knowledge improvement concerning their biokinetic effects. Neutrophils are quickly recruited to titanium implantation areas. Neutrophils mechanical properties display a crucial role on cell physiology and immune responsive functions. Then, micro and nanomechanical characterization assessed by force spectroscopy (FS) technique has been largely applied in this field.

Results

Scanning electron microscopy (SEM) images highlighted neutrophils morphological changes along TiO₂ FPs and NPs aggregates exposure time (1, 5, and 30 min) compared to controls. FS approaches showed an increasing on attraction forces to TiO₂ FPs and NPs treated neutrophils. This group depicted stronger stiffness features than controls just at 1 min of exposure. Treated neutrophils showed a tendency to increase adhesive properties after 1 and 5 min of exposure. These cells maintained comparatively higher elasticity behavior for a longer time possibly due to intense phagocytosis and cell stiffness opposing to the tip indentation. Neutrophils activation caused by FPs and NPs uptake could be related to increasing dissipated energy results.

Conclusions

Mechanical modifications resulted from TiO₂ FPs and NPs aggregates interaction with neutrophils showed increasing stiffness and also cell morphology alteration. Cells treatment by this metal FPs and NPs caused an increase in attractive forces. This event was mainly observed on the initial exposure times probably regarding to the interaction of neutrophils membrane and phagocytosis. Similar results were found to adhesion forces and dissipated energy outcomes. Treated cells presented comparatively higher elasticity behavior for a longer time. SEM images clearly suggested cell morphology alteration along time course probably related to activation, cytoskeleton rearrangement and phagocytosis. This scenario with increase in stiffness strongly suggests a direct relationship over neutrophil rolling, arrest, and transmigration. Scrutinizing these interactions represents an essential step to clarify the mechanisms involved on treatments containing micro and nanomaterials and their fates on the organisms.

Resorbable implants in maxillofacial surgery: a reality check

BACKGROUND

Stability is the main feature of fixation techniques in fracture management modalities, in vogue today. One of the most significant landmarks in the armamentarium of maxillofacial fracture management has been the introduction of rigid internal fixation (RIF). The biomaterials used in RIF have seen a gradual change from Stainless steel to titanium due to the evidence based advantages of the latter. However, the inherent problems with metallic implants led to the introduction of resorbable polymers in RIF.

MATERIALS AND METHOD

This article evaluates the efficacy of these polymers in fixation of bone segments as compared to titanium fixation implants in 40 patients of zygomatic complex fractures. The study compared the clinical efficacy, technique, cost and time factors in the use of these two biomaterials.

RESULTS

The results showed very little difference after the use of these two biomaterials in spite of the increased time, technique sensitivity and cost of the resorbable system.

CONCLUSION

The argument for use of the resorbable fixation implants as a better alternative to titanium in maxillofacial fracture management seems overstated considering the insignificant differences in the results obtained but significant differences in the time taken and economics of the two biomaterials. The resorbabale system should ideally be restricted for use in pediatric craniofacial surgery.

Plates removal in orthognathic surgery and facial fractures: when and why

BACKGROUND

There is agreement that symptomatic plates should be removed, but there is no consensus among maxillofacial surgeons on the need for routine removal of asymptomatic plates. Only by evaluating long follow-up studies conducted with large-volume data that guidelines about when to remove and why remove plates used for internal rigid fixation can be traced.

MATERIALS AND METHODS

This study was conducted as a retrospective study. Clinical findings of all the patients presented at the department of maxillofacial surgery of 2 Italian hospitals, in whom miniplates were inserted between January 2004 and December 2007, were included: a follow-up of these patients was conducted until August 2009.

RESULTS

The region most involved with plates' insertion was the upper maxilla (49.8%), followed by mandibular body (38.1%), angle (7.9%), condyle (2.4%), and symphysis (1.8%). The region most involved in plates' removal was the maxilla in 9%, followed by mandibular body in the 7.5%. All plates inserted in angle regions were removed. Plates placed in the condylar area did not need any plate removal.

CONCLUSIONS

From this study, there is no evidence to support the advice for routine removal of titanium miniplates from the maxillofacial skeleton, although when using plates in the mandibular angle region, it would be necessary to inform the patient about the very high probability of a second operation necessary for the plates' removal.

Removal of bone plates in patients with maxillofacial trauma: a retrospective study

OBJECTIVE

The aim of this retrospective study was to assess the incidence of and indication for the removal of bone plates over a 5-year period in patients with maxillofacial trauma who had received treatment at the Oral and Maxillofacial Surgery Unit, Al-Nahda Hospital, Muscat, Oman.

STUDY DESIGN

The medical records of all patients who underwent removal of bone plates after facial bone trauma were reviewed over a 5-year period (2000 to 2004). Data concerning age and gender distribution, cause of trauma, year of removal, time between insertion and removal, indication for removal, site of removal, and general medical factors were evaluated for each patient.

RESULTS

Facial bone fractures in 1,177 cases were diagnosed during the study period, of which 465 cases underwent open reduction and internal fixation using bone plates and screws. In 109 cases bone plates were removed (79 males and 30 females), with an overall removal rate of 23.4%. The most common indication for removal was young age (53.4%) followed by infection (25%). The mandible was the most common site of removal (80%). Most of the plates (86%) that required removal in adults were removed within the first year after insertion.

CONCLUSIONS

Based on this study, the incidence of bone plate removal was relatively low, and the most common indications for plate removal were young age followed by infection.

Effect of human organism on the oxide layer formed on titanium osteosynthesis plates: a surface analytical study

The question of whether or not to remove the titanium osteosynthesis plates used in maxillofacial surgery is not yet answered. These plates can be left a long time in the organism if there is no harmful interaction between the plates and the organism. The authors examined the properties of the surface oxide layers formed on osteosynthesis titanium plates by subsequent thermal and anodic oxidation, together with the properties of plates removed from patients after three years. Surface analytical method Secondary Ion Mass Spectroscopy (SIMS) was chosen. It was found that inside of the about 200-mum thick oxide on the original plates the concentration of impurities is much lower than near the oxide/titanium interface. On the surface of plates removed from the human body, a C (carbon), Ca (calcium) and P (phosphorus) enrichment was detected, suggesting a biological interaction between the organism and the plate. The passivating layer formed with thermal and anodic oxidation has not changed significantly in three years; it resisted to the corrosive effect of the human organism.

Removal of miniplates in maxillofacial surgery: a follow-up study

PURPOSE

We sought to follow-up a cohort of patients who had miniplates (plates) inserted in the oral and maxillofacial region during a 13-month period over 4 years to study the incidence and factors associated with plate removal.

PATIENTS AND METHODS

One hundred fifty-three patients had plates inserted in the oral and maxillofacial region in the Department of Oral & Maxillofacial Surgery, University Hospital Birmingham, UK, between November 1, 1998, and November 30, 1999. All 153 patients' records were revisited on or after October 31, 2002, giving a minimum follow-up of 3 years and a maximum of 4 years.

RESULTS

During a period of 13 months (November 1, 1998 through November 30, 1999), 308 plates were inserted into 153 patients. A total of 32 plates were removed from 21 patients by October 31, 2002, (10.4%) over 4 years; 27 plates were removed from 16 patients for purely plate-related symptoms, with infection being the most common cause accounting for 16 plates (50%) in 9 patients. Symptoms necessitating plate removal occurred within 52 weeks after insertion in 16 patients, accounting for 23 of the plates removed (72%). The age of the patient at plate insertion may have some influence on plate removal but this was not significant. Seniority of the operator did not affect plate removal.

CONCLUSION

Our experience with the removal of miniplates compares with previously published reports. Longitudinal follow-up at 4 years indicates that plate-related problems leading to removal are likely to occur in the first year after insertion.

Fixation of zygomatic fractures with a biodegradable copolymer osteosynthesis system: short- and long-term results

Biodegradable osteosynthesis devices can be viewed as addition to, not yet replacement for conventional metal osteosynthesis materials. In a series of 65 patients with zygomatic fractures, a short-term complication/sequelae rate of 22.8% and a long-term complication rate of 9.4% were recorded. Lactosorb plates, panels and screws were the only devices used for osteosynthesis. All complications associated with the biodegradable material could be considered minor and were resolved by the use of minor surgical procedures or conservative measures. The results of this study indicate that treatment of zygomatic fractures with biodegradable osteosynthesis material has no major long-term adverse effects beyond the total material resorption time.

X-ray microanalysis of biological specimens by high voltage electron microscopy

For the purpose of analyzing and imaging chemical components of cells and tissues at the electron microscopic level, 3 fundamental methods are available, chemical, physical and biological. Among the physical methods, two methods qualifying and quantifying the elements in the structural components are very often employed. The first method is radioautography which can demonstrate the localization of radiolabeled compounds which were incorporated into cells and tissues after the administration of radiolabeled compounds. The second method is X-ray microanalysis which can qualitatively analyze and quantify the total amounts of elements present in cells and tissues. We have developed the two methodologies in combination with intermediate high or high voltage transmission electron microscopy (200-400 kV) and applied them to various kinds of organic and inorganic compounds present in biological materials. As for the first method, radioautography, I had already contributed a chapter to PHC (37/2). To the contrary, this review deals with another method, X-ray microanalysis, using semi-thin sections and intermediate high voltage electron microscopy developed in our laboratory. X-ray microanalysis is a useful method to qualify and quantify basic elements in biological specimens. We first quantified the end-products of histochemical reactions such as Ag in radioautographs, Ce in phosphatase reaction and Au in colloidal gold immunostaining using semithin sections and quantified the reaction products observing by intermediate high voltage transmission electron microscopy at accelerating voltages from 100 to 400 kV. The P/B ratios of all the end products Ag, Ce and Au increased with the increase of the accelerating voltages from 100 to 400 kV. Then we analyzed various trace elements such as Zn, Ca, S and Cl which originally existed in cytoplasmic matrix or cell organelles of various cells, or such elements as Al which was absorbed into cells and tissues after oral administration, using both conventional chemical fixation and cryo-fixation followed by cryo-sectioning and freeze-drying, or freeze-substitution and dry-sectioning, or freeze-drying and dry-sectioning producing semithin sections similarly to radioautography. As the results, some trace elements which originally existed in cytoplasmic matrix or cell organelles of various cells in different organs such as Zn, Ca, S and Cl, were effectively detected. Zn was demonstrated in Paneth cell granules of mouse intestines and its P/B ratios showed a peak at 300 kV. Ca was found in human ligaments and rat mast cells with a maximum of P/B ratios at 350 kV. S and Cl were detected in mouse colonic goblet cells with maxima of P/B ratios at 300 kV. On the other hand, some elements which were absorbed by experimental administration into various cells and tissues in various organs, such as Al in lysosomes of hepatocytes and uriniferous tubule cells in mice was detected with a maximum of P/B ratios at 300 kV. From the results, it was shown that X-ray microanalysis using semi-thin sections observed by intermediate high voltage transmission electron microscopy at 300-400 kV was very useful resulting in high P/B ratios for quantifying some trace elements in biological specimens. These methodologies should be utilized in microanalysis of various compounds and elements in various cells and tissues in various organs.