An Introduction to The Orbital Buttresses.

Facial buttresses are supportive bony structures of the facial skeleton that form a thick, strong, and protective framework for the face. Surgical fixation may be required to restore morphology and function when damage to these buttresses occurs. We sought to determine if, similar to buttresses of the facial skeleton, buttresses of the internal orbit exist. Hence, we analyzed 10 human cadaver skulls imaged by microcomputed tomography (micro-CT). Image processing and thickness/heat mapping were performed using Avizo and ImageJ softwares. After identifying the orbital buttresses, we reviewed CT scans of patients who had orbital fractures across three years to determine the frequency of fracture of the orbital buttresses. We identified 5 buttresses of the internal orbit: superomedial fronto-ethmoidal strut with the deep orbital buttress, inferomedial strut with the posterior ledge, inferior orbital fissure, sphenoid-frontal superolateral strut, and the sphenoid lip. The average threshold orbital buttress thickness was 1.36 (0.25) mm. A total of 1186 orbits of 593 individuals were analyzed for orbital buttress involvement. Orbital buttresses were spared in 770 (65%) orbits. The inferomedial strut with the posterior ledge was the most commonly fractured buttress in 14.4% of orbits (n=171), followed by the sphenoid strut and lip (66 [5.6%]). To our knowledge, this is the first description of the buttresses of the internal orbit. Orbital reconstruction for fracture repair or oncologic purposes requires the support of orbital buttresses. Understanding the anatomy of orbital buttresses is crucial for successful surgical planning, proper implant positioning, and restoration of function and appearance.

Cobalt ions induce a cellular senescence secretory phenotype in human synovial fibroblast-like cells that may be an early event in the development of adverse local tissue reactions to hip implants.

Objectives: Total hip arthroplasty is a successful procedure for treating advanced osteoarthritis (OA). Metal bearing surfaces remain one of the most widely implanted prosthesis, however approximately 10% of patients develop adverse local tissue reactions (ALTRs), namely lymphocytic predominant soft tissue reaction with or without necrosis and osteolysis resulting in high revision rates. The mechanism(s) for these reactions remains unclear although T lymphocyte mediated type IV hypersensitivity to cobalt (Co) and chromium (Cr) ions have been described. The purpose of this study was to determine the prolonged effects of Co and Cr metal ions on synovial fibroblasts to better understand the impact of the synovial membrane in the development of ALTRs. Methods: Human synovial fibroblast-like cells were isolated from donors undergoing arthroplasty. DNA content and Alamar blue assay were used to determine cellular viability against exposure to Co and Cr. A beta-galactosidase assay was used to determine the development of cellular senescence. Western blotting and RT-qPCR were employed to determine changes in senescent associated secretory factors, signaling and anti-oxidant enzyme expression. A fluorescent assay was used to measure accumulation of hydrogen peroxide. Results: We demonstrate that prolonged cobalt exposure results in a downregulation of the enzyme catalase resulting in cytosolic accumulation of hydrogen peroxide, decreased Akt activity and cellular senescence. Senescent fibroblasts demonstrated upregulation of proinflammatory cytokines IL-1ß and TNFα in addition to the neurotrophic factor NGF. Conclusion: Our results provide evidence that metal ions induce a senescent associated secretory phenotype in synovial fibroblasts that could contribute to the development of adverse local tissue reactions.

Traumatic Brain Injury and Its Association With Orbital Fracture Characteristics and Repair.

Traumatic brain injury (TBI) is common in up to 50% of patients with facial fractures. Orbital fractures account for 25% of all facial fractures. The authors sought to determine the prevalence and risk factors for TBI in patients undergoing orbital fracture repair (OFR) and assess the impact of TBI on surgical timing. A retrospective review of trauma patients who underwent OFR at a single trauma center from 2015 to 2020 was conducted. Excluded were patients <18 years old and those with unreported GCS on presentation. TBI was defined as GCS <15 or any neurological symptom on presentation. TBI was categorized into mild (GCS=14-15), moderate (GCS=9-13), and severe TBI (GCS=3-8). Our primary and secondary outcomes were the prevalence of TBI on presentation and duration from injury to surgery, respectively. Of the 200 patients analyzed, 99 (49.5%) had concomitant TBI on presentation. The most common neurological symptom on presentation was loss of consciousness [n=80 (40%)]. Patients with TBI were significantly more likely to have an orbital roof [n=11 (11.1%), n=4 (4.0%), P=0.048] and lateral wall fractures [n=25 (25.3%), n=14 (13.9%), P=0.031] compared with patients without TBI. Patients with severe TBI were more likely to have delayed OFR-a significantly greater proportion of patients who had severe TBI had OFR after 60 days of injury compared with those without TBI or with mild TBI [5 (39%), 12 (12%), 4 (5%), P=0.032]. Craniofacial surgeons must suspect and screen for TBI in patients presenting with facial trauma, especially those with orbital roof and lateral wall fractures.

The Role of the Fascia-Only Anterolateral Thigh Flap in Extremity Reconstruction: The Fascia-Only Anterolateral Thigh Flap.

BACKGROUND: Free flap selection in extremity reconstruction can be challenging. The ideal flap has to be thin and pliable to achieve optimal contour and function. We explore the role of the fascia-only anterolateral thigh (fALT) flap in extremity reconstruction. METHODS: We conducted a retrospective review of our experience using fALT-free flap for extremity reconstruction over a 2-year period. Patient demographics, mechanism of injury, flap characteristics, complications- and follow-up were recorded. Descriptive statistics were calculated. RESULTS: Twelve patients were included. The median (interquartile range [IQR]) age was 34 (28-52) years. One fALT flap was used for upper extremity reconstruction, while 11 flaps were used for lower extremity reconstruction (4 for lower third of the leg, 4 for dorsum of foot, and 3 for heel). The median (IQR) flap surface area was 90 (63-120) cm2 and time from injury to reconstruction was 10 (6-16) days. The postoperative course was uneventful for all flaps except for 1 flap failure and 1 delayed healing. The median (IQR) follow-up was 2 (1-4) months. In all cases, durable soft tissue reconstruction was achieved with no need for revisions. CONCLUSIONS: The fALT-free flap can be successfully used in extremity reconstruction. The ALT fascia has robust perfusion that allows for the harvest of a large flap that can be surfaced with a split thickness skin graft. Its thin pliable tissue provides excellent contour for the hand, distal leg, and foot that does not require future thinning, optimizing the cosmetic and functional result.

The Association Between Craniofacial Fracture Patterns and Traumatic Optic Neuropathy.

Traumatic optic neuropathy (TON) is a rare but potentially devastating complication of craniofacial trauma. Approximately half of patients with TON sustain permanent vision loss. In this study, we sought to identify the most common fracture patterns associated with TON. We performed a retrospective review of craniomaxillofacial CT scans of trauma patients who presented to the R Adams Cowley Shock Trauma Center from 2015 to 2017. Included were adult patients who had orbital fractures with or without other facial fractures. Patients diagnosed with TON by a formal ophthalmologic examination were analyzed. Craniofacial fracture patterns were identified. Bivariate analysis and multivariate logistic regression were performed to identify craniofacial fracture patterns most commonly associated with TON. A total of 574 patients with orbital fractures who met inclusion criteria [15 (2.6%)] were diagnosed with TON. The median [interquartile range (IQR)] age was 44 (28-59) years. Patients with optic canal fractures and sphenoid sinus fractures had greater odds of TON compared with patients who did not have these fracture types [adjusted odds ratio (aOR) 95% confidence interval (CI) 31.8 (2.6->100), 8.1 (2.7-24.4), respectively]. Patients who sustain optic canal and sphenoid sinus fractures in the setting of blunt facial trauma are at increased odds of having a TON. Surgeons and other physicians involved in the care of these patients should be aware of this association.

Development and validation of a risk calculator for postoperative diplopia following orbital fracture repair in adults.

Postoperative diplopia is the most common complication following orbital fracture repair (OFR). Existing evidence on its risk factors is based on single-institution studies and small sample sizes. Our study is the first multi-center study to develop and validate a risk calculator for the prediction of postoperative diplopia following OFR. We reviewed trauma patients who underwent OFR at two high-volume trauma centers (2015-2019). Excluded were patients < 18 years old and those with postoperative follow-up < 2 weeks. Our primary outcome was incidence/persistence of postoperative diplopia at ≥ 2 weeks. A risk model for the prediction of postoperative diplopia was derived using a development dataset (70% of population) and validated using a validation dataset (remaining 30%). The C-statistic and Hosmer-Lemeshow tests were used to assess the risk model accuracy. A total of n = 254 adults were analyzed. The factors that predicted postoperative diplopia were: age at injury, preoperative enophthalmos, fracture size/displacement, surgical timing, globe/soft tissue repair, and medial wall involvement. Our predictive model had excellent discrimination (C-statistic = 80.4%), calibration (P = 0.2), and validation (C-statistic = 80%). Our model rules out postoperative diplopia with a 100% sensitivity and negative predictive value (NPV) for a probability < 8.9%. Our predictive model rules out postoperative diplopia with an 87.9% sensitivity and a 95.8% NPV for a probability < 13.4%. We designed the first validated risk calculator that can be used as a powerful screening tool to rule out postoperative diplopia following OFR in adults.

Patient-Specific Implant Customization for Treatment of Internal Orbital Fractures Using Office-Based Three-Dimensional Printing.

OBJECTIVE: Three-dimensional (3D) modeling technology aids the reconstructive surgeon in designing and tailoring individualized implants for the reconstruction of complex craniofacial fractures. Three-dimensional modeling and printing have traditionally been outsourced to commercial vendors but can now be incorporated into both private and academic craniomaxillofacial practices. The goal of this report is to present a low-cost, standardized office-based workflow for restoring bony orbital volume in traumatic orbital fractures. METHODS: Patients with internal orbital fractures requiring open repair were identified. After the virtual 3D models were created by iPlan 3.0 Cranial CMF software (Brainlab), the models were printed using an office-based 3D printer to shape and modify orbital plates to correctly fit the fracture defect. The accuracy of the anatomic reduction and the restored bony orbital volume measurements were determined using postoperative computed tomography images and iPlan software. RESULTS: Nine patients fulfilled the inclusion criteria: 8 patients had unilateral fractures and 1 patient had bilateral fractures. Average image processing and print time were 1.5 hours and 3 hours, respectively. The cost of the 3D printer was $2500 and the average material cost to print a single orbital model was $2. When compared with the uninjured side, the mean preoperative orbital volume increase and percent difference were 2.7 ± 1.3 mL and 10.9 ± 5.3%, respectively. Postoperative absolute volume and percent volume difference between the orbits were -0.2 ± 0.4 mL and -0.8 ± 1.7%, respectively. CONCLUSIONS: Office-based 3D printing can be routinely used in the repair of internal orbital fractures in an efficient and cost-effective manner to design the implant with satisfactory patient outcomes.

Geometric Mismatch Promotes Anatomic Repair in Periorbital Bony Defects in Skeletally Mature Yucatan Minipigs.

Porous tissue-engineered 3D-printed scaffolds are a compelling alternative to autografts for the treatment of large periorbital bone defects. Matching the defect-specific geometry has long been considered an optimal strategy to restore pre-injury anatomy. However, studies in large animal models have revealed that biomaterial-induced bone formation largely occurs around the scaffold periphery. Such ectopic bone formation in the periorbital region can affect vision and cause disfigurement. To enhance anatomic reconstruction, geometric mismatches are introduced in the scaffolds used to treat full thickness zygomatic defects created bilaterally in adult Yucatan minipigs. 3D-printed, anatomically-mirrored scaffolds are used in combination with autologous stromal vascular fraction of cells (SVF) for treatment. An advanced image-registration workflow is developed to quantify the post-surgical geometric mismatch and correlate it with the spatial pattern of the regenerating bone. Osteoconductive bone growth on the dorsal and ventral aspect of the defect enhances scaffold integration with the native bone while medio-lateral bone growth leads to failure of the scaffolds to integrate. A strong positive correlation is found between geometric mismatch and orthotopic bone deposition at the defect site. The data suggest that strategic mismatch >20% could improve bone scaffold design to promote enhanced regeneration, osseointegration, and long-term scaffold survivability.

Pediatric Orbital Fractures.

The unique anatomy and physiology of the growing craniofacial skeleton predispose children to different fracture patterns as compared to adults. Diagnosis and treatment of pediatric orbital fractures can be challenging. A thorough history and physical examination are essential for the diagnosis of pediatric orbital fractures. Physicians should be aware of symptoms and signs suggestive of trapdoor fractures with soft tissue entrapment including symptomatic diplopia with positive forced ductions, restricted ocular motility (regardless of conjunctival abnormalities), nausea/vomiting, bradycardia, vertical orbital dystopia, enophthalmos, and hypoglobus. Equivocal radiologic evidence of soft tissue entrapment should not withhold surgery. A multidisciplinary approach is recommended for the accurate diagnosis and proper management of pediatric orbital fractures.

Treatment of Persistent Post-traumatic Diplopia - An Algorithmic Approach to Patient Stratification and Operative Management.

Study Design: Retrospective chart review of revisional orbital surgery outcomes in patients with diplopia from prior operative treatment of orbital trauma. Objective: Our study seeks to review our experience with management of persistent post-traumatic diplopia in patients with previous orbital reconstruction and present a novel patient stratification algorithm predictive of improved outcomes. Methods: A retrospective chart review was performed on adult patients at Wilmer Eye Institute at Johns Hopkins Hospital and at the University of Maryland Medical Center who underwent revisional orbital surgery for correction of diplopia for the years 2005-2020. Restrictive strabismus was determined by Lancaster red-green testing coupled with computed tomography and/or forced duction. Globe position was assessed by computed tomography. Seventeen patients requiring operative intervention according to study criteria were identified. Results: Globe malposition affected fourteen patients and restrictive strabismus affected eleven patients. In this select group, improvement in diplopia occurred in 85.7% of cases with globe malposition and in 90.1% of cases with restrictive strabismus. One patient underwent additional strabismus surgery subsequent to orbital repair. Conclusions: Post-traumatic diplopia in patients with prior orbital reconstruction can be successfully managed in appropriate patients with a high degree of success. Indications for surgical management include (1) globe malposition and (2) restrictive strabismus. High resolution computer tomography and Lancaster red-green testing discriminate these from other causes that are unlikely to benefit from orbital surgery.

Local health department engagement with workplaces during the COVID-19 pandemic-Examining barriers of and facilitators to outbreak investigation and mitigation.

Objectives: To document local health department (LHD) COVID-19 prevention or mitigation activities at workplaces in the United States and identify facilitators for and barriers to these efforts. Methods: We conducted a web-based, cross-sectional national probability survey of United States LHDs (n = 181 unweighted; n = 2,284 weighted) from January to March 2022, collecting information about worker complaints, surveillance, investigations, relationships and interactions with employers/businesses, and LHD capacity. Results: Overall, 94% LHD respondents reported investigating workplace-linked COVID-19 cases; however, 47% reported insufficient capacity to effectively receive, investigate and respond to COVID-19-related workplace safety complaints. Prior relationships with jurisdiction employers and LHD personnel with formal occupational health and safety (OHS) training were predictors of proactive outreach to prevent COVID-19 spread in workplaces (p < 0.01 and p < 0.001). LHD size predicted OHS personnel and sufficient financial resources to support workplace investigation and mitigation activities (p < 0.001). Conclusions: Differences in LHD capacity to effectively respond to communicable disease spread in workplaces may exacerbate health disparities, especially between rural and urban settings. Improving LHD OHS capacity, especially in smaller jurisdictions, could facilitate effective prevention and mitigation of workplace communicable disease spread.

Integrated Plastic Surgery Residency Applicant Perceptions of Virtual Interviews.

PURPOSE: The 2020-2021 interview cycle for integrated plastic surgery applicants was the first to be held virtually because of the COVID-19 pandemic. Here, we detail the largest study on integrated plastic surgery applicant perceptions after the virtual interview cycle. METHODS: A 35-question institutional review board-approved survey was distributed to medical students who had applied to the Johns Hopkins/University of Maryland or University of California San Diego integrated residency programs during the 2020-2021 interview cycle. Survey questions assessed the structure, strengths, and weaknesses of the exclusively virtual interview process. Survey administration and data collection were performed using the Qualtrics platform. RESULTS: Of 318 distributed surveys, 94 were completed. In addition, 91.5% of respondents preferred in-person interviews before the interview season, whereas 54.3% preferred in-person interviews afterward. Applicants who favored virtual interviews did not view being unable to physically meet with program staff as a detriment (P = .001) and felt they could effectively advocate for themselves (P = .002). Overall, the most cited strengths were the ability to complete more interviews (P = .01) and cost benefits (P = .02). Criticisms were directed at the impersonal nature of the exchange (86.2%), lack of physical tour (56.4%), and difficulties at self-advocacy (52.1%). CONCLUSION: Preference for virtual interviews increased from 7.5% to 34.0% after the virtual interview cycle. For several students, the ideal interview structure permits both in-person and virtual interviews to maximize flexibility. Augmenting with virtual city tours and one-on-one interviews may mitigate the impersonal nature of virtual interviews as perceived by some applicants.

Craniofacial Fellowship Applicant Perceptions of Virtual Interviews.

INTRODUCTION: The 2021 interview cycle for craniofacial fellowship applicants was the first to be held virtually due to the coronavirus disease 2019 pandemic. Here, we detail the craniofacial fellowship applicant perceptions and experience on the virtual interview process. MATERIALS AND METHODS: An institutional review board-approved 35-question survey study on the perception of the virtual interview process among craniofacial fellowship applicants was conducted. Surveys were distributed to individuals who had applied through the match, overseen by the American Society of Craniofacial Surgeons (ASCFS). RESULTS: Ten surveys were fully completed with a corresponding response rate of 48%. The average number of interviews completed was 12.7±7.7 and 50% of applicants interviewed at >1 program in a single day. Overall, 90% of respondents preferred in-person interviews before the interview season, however, only 10% preferred the in-person format afterwards. Preference for a virtual-only format increased from 10% to 70%. Applicants cited cost (100%), ease of scheduling (90%), and ability to participate in more interviews (70%) as the primary strengths of the virtual platform; none reported difficulties with self-advocacy. After the interview cycle, 90% stated they would recommend virtual interviews. CONCLUSIONS: The greatest strengths of virtual interviews were the ability to participate in more interviews, the ease of scheduling, and the cost benefits. Most applicants reported the same or increased ability for self-advocacy with virtual interviews. Following the index interview cycle for 2021, the majority of fellowship applicants now appear to prefer a virtual-only or hybrid format and would recommend virtual interviews in the future.

Point-of-care treatment of geometrically complex midfacial critical-sized bone defects with 3D-Printed scaffolds and autologous stromal vascular fraction.

Critical-sized midfacial bone defects present a unique clinical challenge due to their complex three-dimensional shapes and intimate associations with sensory organs. To address this challenge, a point-of-care treatment strategy for functional, long-term regeneration of 2 cm full-thickness segmental defects in the zygomatic arches of Yucatan minipigs is evaluated. A digital workflow is used to 3D-print anatomically precise, porous, biodegradable scaffolds from clinical-grade poly-ε-caprolactone and decellularized bone composites. The autologous stromal vascular fraction of cells (SVF) is isolated from adipose tissue extracts and infused into the scaffolds that are implanted into the zygomatic ostectomies. Bone regeneration is assessed up to 52 weeks post-operatively in acellular (AC) and SVF groups (BV/DV = 0.64 ± 0.10 and 0.65 ± 0.10 respectively). In both treated groups, bone grows from the adjacent tissues and restores the native anatomy. Significantly higher torque is required to fracture the bone-scaffold interface in the SVF (7.11 ± 2.31 N m) compared to AC groups (2.83 ± 0.23 N m). Three-dimensional microcomputed tomography analysis reveals two distinct regenerative patterns: osteoconduction along the periphery of scaffolds to form dense lamellar bone and small islands of woven bone deposits growing along the struts in the scaffold interior. Overall, this study validates the efficacy of using 3D-printed bioactive scaffolds with autologous SVF to restore geometrically complex midfacial bone defects of clinically relevant sizes while also highlighting remaining challenges to be addressed prior to clinical translation.

Subchronic oral exposure of tungsten induces myofibroblast transformation and various markers of kidney fibrosis.

Tungsten is a naturally occurring transition element used in a broad range of applications. As a result of its extensive use, we are increasingly exposed to tungsten from our environment, including potable water, since tungsten can become bioaccessible in ground sources. The kidneys are particularly susceptible to tungsten exposure as this is the main site for tungsten excretion. In this study, we investigated the prolonged effects of tungsten on the kidneys and how this may impact injury and function. When mice were exposed to tungsten in their drinking water for 1 mo, kidney function had not significantly changed. Following 3-mo exposure, mice were presented with deterioration in kidney function as determined by serum and urine creatinine levels. During 3 mo of tungsten exposure, murine kidneys demonstrated significant increases in the myofibroblast marker α-smooth muscle actin (αSMA) and extracellular matrix products: fibronectin, collagen, and matricellular proteins. In addition, Masson's trichrome and hematoxylin-eosin (H&E) staining revealed an increase in fibrotic tissue and vacuolization of tubular epithelial cells, respectively, from kidneys of tungsten-treated mice, indicative of renal injury. In vitro treatment of kidney fibroblasts with tungsten led to increased proliferation and upregulation of transforming growth factor ß1 (TGFß1), which was consistent with the appearance of fibroblast-to-myofibroblast transition (FMT) markers. Our data suggest that continuous exposure to tungsten impairs kidney function that may lead to the development of chronic kidney disease (CKD).

Many Moving Pieces: Virtual Preoperative Surgical Planning for Traumatic Occlusal Splints.

INTRODUCTION: Achieving anatomic reduction and re-establishing premorbid occlusion in patients with complex maxillomandibular fractures is challenging even for seasoned surgeons. Historically, surgeons have utilized occlusal splints to help establish occlusal relationships before fracture reduction and fixation. These acrylic splints are fabricated from dental impressions and require manual repositioning of tooth bearing segments along the fracture line to reapproximate premorbid occlusion. The process is laborious, requires a dental lab, and is less efficacious in edentulous patients or those with significantly comminuted fractures; as such it has largely fallen out of practice. Recently, with advances in virtual 3D modeling and printing, we demonstrate that occlusal splints can be designed from computed tomography scans, manipulated virtually, and printed without obtaining impressions from the patient. METHODS/RESULTS: In our series of 3 patients with complex maxillomandibular fractures, occlusal splints were created by 1) obtaining maxillofacial computed tomography scans, 2) reducing the fractures virtually, and 3) using orthognathic virtual surgery software to create the splint. The time between planning and delivery of the splint was 4 to 7 days. These splints were successfully utilized to help establish premorbid occlusion in conjunction with maxillomandibular fixation and aided in expeditious intraoperative fracture reduction and fixation. CONCLUSIONS: In the treatment of complex facial fractures, occlusal splints can be a useful adjunct in the operative reduction and fixation of fractures. With the advent of virtual preoperative surgical planning via 3D modeling and 3D printing, these occlusal splints can be created of a sufficient fidelity to avoid the strict need for dental impressions.

Blunt Cerebrovascular Injury-Like Injury Observed in Patients With Craniofacial Self-Inflicted Gunshot Wounds.

BACKGROUND: Although blunt cerebrovascular injury (BCVI) is recognized as a risk factor for trauma morbidity and mortality, little is described regarding similar cerebrovascular injury (CVI) in patients with penetrating wounds. The authors aim to characterize these injuries in the craniofacial self-inflicted gunshot wound (SIGSW) population. METHODS: An institutional review board (IRB)-approved retrospective nstudy was conducted on patients presenting to the R Adams Cowley Shock Trauma Center with SIGSWs between 2007 and 2016. All CVIs were categorized by location, type, and associated neurologic deficits. Demographic data, patient characteristics, additional studies, and long-term outcomes were collected. A multivariate analysis determining independent predictors of CVI in the SIGSW population was performed. RESULTS: Of the 73 patients with SIGSWs, 5 (6.8%) had CVIs separate from the bullet/cavitation tract (distant CVIs) and 9 had CVIs along the bullet/cavitation tract (in-tract CVIs). A total of 55.6% of in-tract and 40% of distant injuries were missed on initial radiology read. One distant CVI patient suffered a stroke during admission. The anterior to posterior gunshot wound trajectory was positively associated with distant CVIs when compared with no CVIs ( P  = 0.01). Vessel dissection was more prevalent in patients with distant CVIs, when compared against patients with in-tract CVIs ( P  = 0.02). CONCLUSIONS: Nearly 20% of craniofacial SIGSW patients have CVIs and 6.8% have BCVI-like injuries, which is 2-to-6-fold times higher than traditional BCVIs. Craniofacial SIGSWs serve as an independent screening criterion with comparable screening yields; the authors recommend radiographic screening for these patients with particular scrutiny for CVIs as they are frequently missed on initial radiographic interpretations.

Gaseous and Particulate Content of Laser Tattoo Removal Plume.

BACKGROUND: There is increasing awareness of the potential hazards of surgical plumes. The plume associated with laser tattoo removal remains uncharacterized. OBJECTIVE: To determine the gaseous, particulate, and microbiological content of the laser tattoo removal plume. MATERIALS AND METHODS: Air sampling was performed during laser tattoo removal from pig skin and from patients. Measurement of metals, volatile organic compounds (VOCs), carbon monoxide (CO), hydrogen sulfide (HS), and ultrafine particulates (UPs) as well as bacterial 16S ribosomal DNA sequencing were performed. RESULTS: Metals were identified in the plume from both pig and human skin. Volatile organic compounds were found at similar levels within and outside the treatment room. Several bacterial phyla were detected in the treatment room, but not outside. High levels of UPs were measured throughout the treatment room during tattoo removal from pig skin. Ultrafine particulates were detected at low levels in the room periphery during tattoo removal from human skin, but at higher levels in the immediate treatment zone. HS and CO were not detected. CONCLUSION: Metals, VOCs, HS, and CO were found at levels below applicable occupational exposure limits. The presence of bacteria is of uncertain significance, but may be hazardous. High levels of UPs require further investigation.

Tungsten Increases Sex-Specific Osteoclast Differentiation in Murine Bone.

Tungsten is a naturally occurring metal that is increasingly used in industry and medical devices, and is labeled as an emerging environmental contaminant. Like many metals, tungsten accumulates in bone. Our previous data indicate that tungsten decreases differentiation of osteoblasts, bone-forming cells. Herein, we explored the impact of tungsten on osteoclast differentiation, which function in bone resorption. We observed significantly elevated osteoclast numbers in the trabecular bone of femurs following oral exposure to tungsten in male, but not female mice. In order to explore the mechanism(s) by which tungsten increases osteoclast number, we utilized in vitro murine primary and cell line pre-osteoclast models. Although tungsten did not alter the adhesion of osteoclasts to the extracellular matrix protein, vitronectin, we did observe that tungsten enhanced RANKL-induced differentiation into tartrate-resistant acid phosphatase (TRAP)-positive mononucleated osteoclasts. Importantly, tungsten alone had no effect on differentiation or on the number of multinucleated TRAP-positive osteoclasts. Enhanced RANKL-induced differentiation correlated with increased gene expression of differentiated osteoclast markers Nfatc1, Acp5, and Ctsk. Although tungsten did not alter the RANK surface receptor expression, it did modulate its downstream signaling. Co-exposure of tungsten and RANKL resulted in sustained positive p38 signaling. These findings demonstrate that tungsten enhances sex-specific osteoclast differentiation, and together with previous findings of decreased osteoblastogenesis, implicate tungsten as a modulator of bone homeostasis.