Faculty Bibliography

OBJECTIVE:To characterize the mechanical properties of different coating methods of DLC (diamond-like carbon) onto dental implant abutment screws, and their effect on the probability of survival (reliability). METHODS:Seventy-five abutment screws were allocated into three groups according to the coating method: control (no coating); UMS - DLC applied through unbalanced magnetron sputtering; RFPA-DLC applied through radio frequency plasma-activated (n=25/group). Twelve screws (n=4) were used to determine the hardness and Young's modulus (YM). A 3D finite element model composed of titanium substrate, DLC-layer and a counterpart were constructed. The deformation (μm) and shear stress (MPa) were calculated. The remaining screws of each group were torqued into external hexagon abutments and subjected to step-stress accelerated life-testing (SSALT) (n=21/group). The probability Weibull curves and reliability (probability survival) were calculated considering the mission of 100, 150 and 200N at 50,000 and 100,000 cycles. RESULTS:DLC-coated experimental groups evidenced higher hardness than control (p<0.05). In silico analysis depicted that the higher the surface Young's modulus, the higher the shear stress. Control and RFPA showed β<1, indicating that failures were attributed to materials strength; UMS showed β>1 indicating that fatigue contributed to failure. High reliability was depicted at a mission of 100N. At 200N a significant decrease in reliability was detected for all groups (ranging from 39% to 66%). No significant difference was observed among groups regardless of mission. Screw fracture was the chief failure mode. SIGNIFICANCE/CONCLUSIONS:DLC-coating have been used to improve titanium's mechanical properties and increase the reliability of dental implant-supported restorations.

Face transplantation has evolved over the last 12 years into a safe and feasible reconstructive solution, with good aesthetic and functional outcomes for patients with severe facial defects who are not amenable to reconstruction through conventional and autologous approaches. Among patients who underwent face transplantation to date, a significant proportion did so following trauma, mostly ballistic and thermal injuries. It is therefore important for trauma surgeons who deal with these injuries regularly to be familiar with the literature on face transplantation following traumatic injuries. In this study, we provide a focused review on this topic, with an emphasis on highlighting the limitations of conventional craniomaxillofacial reconstruction, while emphasizing data available on the risks, benefits, surgical indications, contraindications, as well as aesthetic and functional outcomes of face transplantation. The authors also provide an update on all face transplants performed to date including traumatic mechanisms of injury, and extent of defects. They finally describe 2 cases performed by the senior author for patients presenting with devastating facial ballistic and thermal injuries. The authors hope that this work serves as an update for the trauma surgery community regarding the current role and limitations of face transplantation as a craniomaxillofacial reconstructive option for their patient population. This can potentially expedite the reconstructive process for patients who may benefit from face transplantation.

INTRODUCTION/BACKGROUND:Breast augmentation is the most common aesthetic surgery performed in the United States (US) annually. Analysis of Google Trends (GT) data may give plastic surgeons useful information regarding worldwide, national, and regional interest for breast augmentation and other commonly performed aesthetic surgeries. METHODS:Data were collected using GT for breast augmentation and associated search terms from January 2004 to May 2017. Case volume was obtained from the American Society of Plastic Surgeons (ASPS) annual reports for the calendar year 2005-2016. RESULTS:Trend analysis showed that total search term volume for breast augmentation and breast implants gradually decreased worldwide and in the US over the study period while the search term boob job slowly increased. Univariate linear regression demonstrated a statistically significant positive correlation between average annual Google search volume of "breast augmentation" and the annual volume of breast augmentations performed in the US according to ASPS data (R 2 = 0.44, p = 0.018). There was no significant correlation between national volume of breast augmentations performed and search volume using the terms "breast implants" or "boob job" over time (p = 0.84 and p = 0.07, respectively). In addition, there appears to be country specific variation in interest based on time of year and peaks in interest following specific policies. CONCLUSIONS:To our knowledge, this is the first and only analysis of GT data in the plastic surgery literature to date. To that end, this study highlights this large and potentially powerful data set for plastic surgeons both in the US and around the world. LEVEL OF EVIDENCE V/UNASSIGNED:This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

BACKGROUND: Recipient vessels proximal to the zone of injury have traditionally been preferred for lower extremity reconstruction. However, more recent data have shown mixed outcomes when performing anastomoses distal to the zone of injury. We investigated the impact of recipient vessel location on free flap outcomes. METHODS: Retrospective review (1979-2016); 312 soft tissue free flaps for open tibia fractures met inclusion criteria. Flap characteristics and perioperative outcomes were examined. Systematic review identified articles evaluating anastomosis location and flap outcomes; pooled data analysis was performed. RESULTS: = 0.39) found no difference in flap failure rates between proximal and distal groups. CONCLUSION/CONCLUSIONS: Our results are congruent with the current lower extremity literature and demonstrate no difference in perioperative complication rates between anastomoses performed proximal or distal to the zone of injury. These findings suggest that anastomotic location choice should be based primarily on recipient vessel quality/flow and ease of access/exposure rather than orientation relative to the zone of injury.

Background/UNASSIGNED:Widespread application of vascularized composite allotransplantation (VCA) is currently limited by the required lifelong systemic immunosuppression and its associated morbidity and mortality. This study evaluated the efficacy of ex vivo (after procurement but before transplantation) engineering of allografts using small interfering RNA to knockdown major histocompatibility complex I (MHC-I) and prolong rejection-free survival. Methods/UNASSIGNED:Endothelial cells (ECs) were transfected with small interfering RNA targeted against MHC-I (siMHC-I) for all in vitro experiments. MHC-I surface expression and knockdown duration were evaluated using quantitative polymerase chain reaction (qPCR) and flow cytometry. After stimulating Lewis recipient cytotoxic lymphocytes (CTL) with allogeneic controls or siMHC-I-silenced ECs, lymphocyte proliferation, CTL-mediated and natural killer-mediated EC lysis were measured. Using an established VCA rat model, allografts were perfused ex vivo with siMHC-I before transplantation. Allografts were analyzed for MHC-I expression and clinical/histologic evidence of rejection. Results/UNASSIGNED:< 0.05). Conclusions/UNASSIGNED:Ex vivo siMHC-I engineering can effectively modify allografts and significantly prolong rejection-free allograft survival. This novel approach may help reduce future systemic immunosuppression requirements in VCA recipients.

BACKGROUND:Chest wall masculinization by means of mastectomy is an important gender affirming surgery for transmasculine and non-binary patients. Limited data exist comparing commonly used techniques in masculinizing top surgery, and most are single institution studies. METHODS:A systematic review was performed on primary literature dedicated specifically to the technical aspects and outcomes of mastectomy for masculinizing top surgery. For each study, patient demographics and surgical outcomes were compared. RESULTS:Eight studies met inclusion criteria. There were 2138 breasts with an average patient age of 28.6 years and the average breast weight was 353 g. The most commonly reported techniques are those without skin resection (8.0%), those with periareolar skin resection (34.1%), inferior pedicle mammoplasty (15.7%), and inframammary fold skin excision with free nipple grafting (FNG, 42.2%). In total, 6.0% of all breasts required acute reoperation for hematoma and 26.5% required secondary operations. Acute reoperation occurred significantly less often in the FNG cohort (4.8%) compared with both the inferior pedicle mammaplasty cohort (8.9%, P < 0.05) and techniques without skin resection cohort (10.3%, P < 0.05). Secondary operations occurred significantly more often in the periareolar skin resection cohort (37.5%) than techniques without skin resection cohort (19.0%, P < 0.01), inferior pedicle mammaplasty cohort (27.9%, P < 0.01), and FNG cohort (20.3%, P < 0.05). In addition, secondary operations occurred significantly more often in inferior pedicle mammaplasty cohort (27.9%) compared with FNG cohort (20.3%, P < 0.01). CONCLUSIONS:This analysis notes several significant differences with regard to percentage requiring acute reoperation and percentage requiring secondary revision based on technique. Candidates for masculinizing top surgery should be educated on these differences.

BACKGROUND:In October 2012, a freely available, internet-based cleft simulator was created in partnership between academic, nonprofit, and industry sectors. The purpose of this educational resource was to address global disparities in cleft surgery education. This report assesses demographics, usage, and global effect of our simulator, in its fifth year since inception. OBJECTIVE:Evaluate the global effect, usage, and demographics of an internet-based educational digital simulation cleft surgery software. SETTING AND PARTICIPANTS/METHODS:Simulator modules, available in five languages demonstrate surgical anatomy, markings, detailed procedures, and intraoperative footage to supplement digital animation. Available data regarding number of users, sessions, countries reached, and content access were recorded. Surveys evaluating the demographic characteristics of registered users and simulator use were collected by direct e-mail. RESULTS:The total number of simulator new and active users reached 2865 and 4086 in June 2017, respectively. By June 2017, users from 136 countries had accessed the simulator. From 2015 to 2017, the number of sessions was 11,176 with a monthly average of 399.0 ± 190.0. Developing countries accounted for 35% of sessions and the average session duration was 9.0 ± 7.3 minutes. This yields a total simulator screen time of 100,584 minutes (1676 hours). Most survey respondents were surgeons or trainees (87%) specializing in plastic, maxillofacial, or general surgery (89%). Most users found the simulator to be useful (88%), at least equivalent or more useful than other resources (83%), and used it for teaching (58%). CONCLUSIONS:Our internet-based interactive cleft surgery platform reaches its intended target audience, is not restricted by socioeconomic barriers to access, and is judged to be useful by surgeons. More than 4000 active users have been reached since inception. The total screen time over approximately 2 years exceeded 1600 hours. This suggests that future surgical simulators of this kind may be sustainable by stakeholders interested in reaching this target audience.

OBJECTIVE:Osteoarthritis (OA) is a leading cause of disability in the world. Mesenchymal stem cells (MSCs) have been studied to treat OA. This review was performed to systematically assess the quality of literature and compare the procedural specifics surrounding MSC therapy for osteoarthritis. DESIGN/METHODS:PubMed, CINAHL, EMBASE and Cochrane Central Register of Controlled Trials were searched for studies using MSCs for OA treatment (final search December 2017). Outcomes of interest included study evidence level, patient demographics, MSC protocol, treatment results and adverse events. Level I and II evidence articles were further analyzed. RESULTS:Sixty-one of 3,172 articles were identified. These studies treated 2,390 patients with osteoarthritis. Most used adipose-derived stem cells (ADSCs) (n=29) or bone marrow-derived stem cells (BMSCs) (n=30) though the preparation varied within group. 57% of the sixty-one studies were level IV evidence, leaving five level I and nine level II studies containing 288 patients to be further analyzed. Eight studies used BMSCs, five ADSCs and one peripheral blood stem cells (PBSCs). The risk of bias in these studies showed five level I studies at low risk with seven level II at moderate and two at high risk. CONCLUSION/CONCLUSIONS:While studies support the notion that MSC therapy has a positive effect on OA patients, there is limited high quality evidence and long-term follow-up. The present study summarizes the specifics of high level evidence studies and identifies a lack of consistency, including a diversity of MSC preparations, and thus a lack of reproducibility amongst these articles' methods.

BACKGROUND:Significantly fewer replantations have been performed at the authors' institution in recent years, with similar trends observed across the United States. A study of three national databases was performed to evaluate this trend, its possible cause, and national health care implications. METHODS:The National Electronic Injury Surveillance System, Bureau of Labor Statistics, and National Inpatient Sample databases were queried for cases with a diagnosis of finger amputation over available years from 2000 to 2011. Data were weighted and analyzed to give appropriate national estimates of amputations, replantations, and related clinical variables. Trend analysis was performed using modified Poisson regression. RESULTS:Although workplace finger amputation rates decreased 40 percent from 2000 to 2010 (p < 0.0001), the overall finger amputation incidence did not change significantly (26,668 versus 24,215; p = 0.097). Compared with 930 replantations in 2001, only 445 were performed in 2011, more than a 50 percent decrease (p < 0.001). In all years, the majority of hospitals performing replantation performed only one (49.3 to 64.1 percent) each year, with a small minority (2.2 to 8.1 percent) performing more than 10 per year. In 2000, 120 hospitals (12.1 percent) performed at least one replantation, compared with only 80 hospitals (7.6 percent) in 2010, a 4.6 percent annual decline (p = 0.002). CONCLUSIONS:There has been a striking decline in digital replantations being performed, despite a relatively stable incidence of amputations. Apparently independent of declining work-related injuries, evolving clinical decision-making may be responsible for this trend. Decreasing replantation experience among hand surgeons lends credence to the development of specialized regional centers designed to treat these complex injuries.

BACKGROUND:Reconstructive trends and outcomes for nipple-sparing mastectomy continue to be defined. The graduated impact of breast size and mastectomy weight remains incompletely evaluated. METHODS:All patients undergoing nipple-sparing mastectomy from 2006 to June of 2016 were identified. Demographics and outcomes were analyzed and stratified by mastectomy weight of 800 g or higher (large group), between 799 and 400 g (intermediate group), and less than 400 g (small group). RESULTS:Of 809 nipple-sparing mastectomies, 66 (8.2 percent) had mastectomy weights of 800 g or higher, 328 (40.5 percent) had mastectomy weights between 799 and 400 g, and 415 nipple-sparing mastectomies (51.3 percent) had mastectomy weights less than 400 g. Nipple-sparing mastectomies in the large group were significantly more likely to be associated with major mastectomy flap necrosis (p = 0.0005), complete nipple-areola complex necrosis (p < 0.0001), explantation (p < 0.0001), cellulitis treated with oral (p = 0.0008) and intravenous (p = 0.0126) antibiotics, abscess (p = 0.0254), and seroma (p = 0.0126) compared with those in the intermediate group. Compared with small nipple-sparing mastectomies, patients in the large group had greater major mastectomy flap necrosis (p < 0.0001), complete (p < 0.0001) and partial (p = 0.0409) nipple-areola complex necrosis, explantation (p < 0.0001), cellulitis treated with oral (p < 0.0001) and intravenous (p < 0.0001) antibiotics, abscess (p = 0.0119), and seroma (p < 0.0001). Patients in the intermediate group were more likely to experience major (p < 0.0001) and minor (p < 0.0001) mastectomy flap necrosis, complete (p = 0.0015) and partial (p < 0.0001) nipple-areola complex necrosis, cellulitis treated with oral antibiotics (p = 0.0062), and seroma (p = 0.0248) compared with those undergoing small nipple-sparing mastectomies. Larger mastectomy weights were significant predictors of complications on logistic regression analysis. CONCLUSION/CONCLUSIONS:Reconstructive and ischemic complications in nipple-sparing mastectomy are progressively greater as mastectomy weight and breast size increase. CLINICAL QUESTION/LEVEL OF EVIDENCE/METHODS:Risk, II.