Faculty Bibliography

OBJECTIVE: To determine the potential risk of visceral injury during Acumed drill iliac crest cancellous bone graft harvest. DESIGN: Radiographic iliac crest anatomic analysis with simulated drill course to measure cancellous bone available for harvest and proximity of vulnerable pelvic structures. SETTING: Single institution, tertiary care university hospital. PATIENTS AND PARTICIPANTS: One hundred pelvic computed tomography scans performed on children 8 to 12 years old without traumatic or neoplastic pathology. INTERVENTIONS: Radiographic simulation of Acumed drill course within iliac bone. MAIN OUTCOME MEASURES: (1) Potential for pelvic visceral injury. (2) Volume of cancellous bone safely available for harvest. RESULTS: Superior and medial cortical thickness at the reference point remained stable across age groups; however, lateral cortical thickness increased with age (3.13 to 3.74 mm, P < .001). Cancellous bone width increased with age at all depths measured (P < .001). Through radiographic simulation, the drill could reach the bowel in 4% of cases and only through gross deviation (>30 degrees ) from the plane of the ilium. There were no cases of simulated bowel perforation within 3 cm of the reference point. The maximum cancellous volume safely harvested increased with age: 24 cc in 8-year-olds to 36 cc in 12-year-olds (P < .001). CONCLUSIONS: Acumed assisted iliac crest bone graft harvest is a safe technique in which substantial amount of cancellous bone can be obtained. The low risk of bowel perforation can be further minimized by limiting the depth of drill bit penetration to less than 3 cm.

BACKGROUND: Left ventricular assist devices (LVADs) have become useful adjuncts in the treatment of patients with end-stage heart failure. LVAD implantation is associated with a unique set of problems; one such problem is device infection. We report our experience with flap salvage of infected and/or exposed LVAD hardware. METHODS: Between 2011 and 2016, 49 patients underwent LVAD implantation at our institution. Patients were then categorized by infectious status: systemic infection not directly involving the LVAD device, hardware infection responsive to antibiotics, and exposure of LVAD hardware or device infection refractory to antibiotics requiring debridement and flap coverage. RESULTS: Approximately 50% of device-related infections resolved with either oral or intravenous antibiotics while the other 50% necessitated debridement and coverage with healthy tissue. In total, 12 patients (24%) developed a device-related infection ranging from superficial driveline cellulitis to purulent pocket infections. Seven patients (14%) required extensive debridement and/or flap coverage. CONCLUSION: Early debridement and coverage of exposed hardware are crucial to successfully treating these LVAD infections.

To help eliminate reported racial/ethnic and socioeconomic inequities in oral health care, listening to the perspectives of racial/ethnic minority older adults on their experiences with dental school clinics is needed. The aim of this study was to examine the experiences of African American, Puerto Rican, and Dominican older adults who attend senior centers in upper Manhattan, New York City, regarding the care received at dental school clinics. Focus groups were conducted from 2013 to 2015 with 194 racial/ethnic minority men and women aged 50 years and older living in upper Manhattan. All of the 24 focus group sessions were digitally audiorecorded and transcribed for analysis. Groups conducted in Spanish were transcribed first in Spanish and then translated into English. Analysis of the transcripts was conducted using thematic content analysis. Seven subthemes were manifest in the data related to these adults' positive experiences with dental school clinics: excellent outcomes and dentists, painless and safe treatment, affordable care, honest and reputable, benefits of student training, accepting and helpful, and recommended by family and friends. Negative experiences centered around four subthemes: multiple visits required for treatment, loss of interpersonal communication due to use of technology, inconvenient location, and perceived stigma with Medicaid. This study provided novel evidence of the largely positive experiences with dental schools of racial/ethnic minority senior center attendees. Interventions targeted at the organization and provider level, including organizational motivation, resources, staff attributes, climate, and teamwork plus payment programs and services, insurance and affordability, and provider- and system-level supports, may improve health care processes and patient experiences of care.

PURPOSE: Orthopedic and maxillofacial bone fractures are routinely treated by titanium internal fixation, which may be prone to exposure, infection or intolerance. Magnesium (Mg) and its alloys represent promising alternatives to produce biodegradable osteosynthesis devices, with biocompatibility and, specifically, hydrogen gas production during the degradation process, being the main drawback. Aim of this study is to test and compare biocompatibility, degradation rate and physiscochemical properties of two Mg-alloys to identify which one possesses the most suitable characteristics to be used as resorbable hardware in load-bearing fracture sites. MATERIALS AND METHODS: As-cast (WE43) and T5 Mg-alloys were tested for biocompatibility, physical, mechanical and degradation properties. Microstructure was assessed by optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS); mechanical properties were tested utilizing quasi-static compression and failure analysis. Locoregional biocompatibility was tested by sub-periosteal implantation on the fronto-nasal region of large-animal model (sheep): regional immunoreaction and metal accumulation was analyzed by LA-ICP of tributary lymph-nodes, local reactions were analyzed through histological preparation including bone, implant and surrounding soft tissue. RESULTS: Mechanically, T5 alloy showed improvement in strength compared to the as-cast. Lymph-node Mg accumulation depicted no differences between control (no implant) and study animals. Both alloys showed good biocompatibility and osteogenesis-promoting properties. CONCLUSION: This study demonstrated excellent biocompatibility and osteogenesis-promoting capabilities of the tested alloys, providing a platform for further studies to test them in a maxillofacial fracture setting. T-5 alloy displayed more stability and decreased degradation rate than the as-cast.

PURPOSE: Based on the current evidence, the effect of implant macrogeometry has a significant influence on osseointegration. Thus, this study evaluated histomorphometrically and histologically the bone response to acid-etched in comparison to grit-blasted/acid-etched (GB) and machined control (C) surfaced implants possessing identical macrogeometry placed in high-density bone. MATERIALS AND METHODS: Implant surface topography of the 3 different surfaced implants has previously been characterized. The macrogeometry of the implants were conical, and healing chambers were created in the cortical regions. The 3 groups were placed in the external mandibular body of adult male sheep (n = 5). After 6 weeks in vivo, all samples were retrieved for histologic observation and histomorphometry (eg, bone-to-implant contact [BIC] and bone area fraction occupancy [BAFO]). RESULTS: No statistical difference was observed for BIC and for BAFO, although there was a tendency that the mean values for BAFO was higher for the textured surface groups. CONCLUSIONS: It is suggested that the effect of surface topography is minimal in high-density bone and osseointegration seemed to be macrogeometry dependent.

BACKGROUND: Wide variations in fat graft survival have been reported. The authors hypothesize that treating the adipose tissue on Telfa gauze creates a processed lipoaspirate with a more functional adipokine profile that improves fat graft survival. METHODS: Suction-assisted lipoaspirate was harvested from humans and was either processed by centrifugation, rolled on Telfa gauze, or left unprocessed. Progenitor cell populations were quantified and characterized by flow cytometry. Glycerol-3-phosphate dehydrogenase assay was used to measure the functional adipocytes. The lipoaspirates were grafted into (n = 45) wild-type mice and harvested to assess fat graft persistence. Vascular endothelial growth factor and platelet-derived growth factor-BB secretions were measured by enzyme-linked immunosorbent assay technique. RESULTS: Centrifuged lipoaspirate had a greater number of progenitor cells per gram of tissue than Telfa-processed and unprocessed lipoaspirate. However, Telfa-processed lipoaspirate had a greater number of functional adipocytes (0.104 U/ml) than centrifuged (0.080 U/ml) and unprocessed lipoaspirate (0.083 U/ml) on glycerol-3-phosphate dehydrogenase assay (p < 0.05). After 10 weeks of grafting, it had greater fat graft persistence (70.9 +/- 6.2 percent) than centrifuged (56.7 +/- 5.5 percent) and unprocessed lipoaspirate (42.2 +/- 2.7 percent) (p < 0.05). It also maintained a greater secretion of vascular endothelial growth factor and platelet-derived growth factor-BB at weeks 1 and 2 than centrifuged and unprocessed lipoaspirate. Furthermore, CD31 staining demonstrated an increase in vascular density of the Telfa-processed lipoaspirate at week 2 compared with the centrifuged lipoaspirate (37 +/- 1 percent and 14 +/- 4 percent per high-power field; p < 0.05). CONCLUSIONS: Lipoaspirate processing technique has a significant impact on fat graft survival rate. Increasing the number of functional adipocytes by processing the fat on Telfa gauze may augment the secretion of angiogenic and mitogenic adipokines within the graft, thereby improving its survivability. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.