Faculty Bibliography

PURPOSE: In an attempt to overcome the potential long-term limitations observed with plasma-sprayed hydroxyapatite-coated implants, nanothickness bioceramic coatings have been processed onto previously grit-blasted/acid-etched surfaces. Our objective was to evaluate the bone response to alumina-blasted/acid-etched and a thin ion beam-deposited bioceramic (Test) implant surfaces at 2 and 4 weeks in vivo with a dog tibia model. MATERIALS AND METHODS: Plateau root form implants (5 x 6 mm) were placed bilaterally along the proximal tibia of 6 Doberman dogs and remained for 2 and 4 weeks in vivo (n=6 per implant type and time in vivo). After euthanization, the implants were processed in a nondecalcified form and reduced to approximately 30 mum-thickness plates. Transmitted light optical microscopy at various magnifications was used to qualitatively evaluate the bone healing patterns. Bone-to-implant contact (BIC) was determined and 1-way ANOVA at 95% level of significance with Tukey's post-hoc multiple comparisons was used for statistical analysis. RESULTS: Histomorphology showed new bone formation filling the spaces between the plateaus at both in vivo time intervals through large quantities of woven bone formation. A higher degree of bone organization was observed between the plateaus of Test implants at 4 weeks in vivo than the alumina-blasted/acid-etched implants. No significant differences in BIC were observed for the different groups (P> .86). CONCLUSION: Despite nonsignificant differences between BIC for the different implant surfaces and times in vivo, higher degrees of bone organization were observed for the Test implants at 4 weeks, and biomechanical testing is suggested to verify its biomechanical fixation effectiveness.

BACKGROUND: The cross-facial nerve grafting/free-muscle transfer strategy for smile restoration is superior to static reconstruction or regional muscle transposition. The purpose of this study was to evaluate the long-term outcomes of this technique in adult patients. METHODS: Eighty-one adult patients received a free-muscle transfer for midface reanimation in the authors' center. Of this group, the authors identified 24 cases with follow-up of 5 years or longer. Smile symmetry and function were evaluated at three points: preoperatively, early postoperatively, and at long-term follow-up. To better evaluate the effect of time, patients were divided into groups according to the length of follow-up: group A, 5 to 6 years; group B, 7 to 10 years; group C, 11 to 15 years; and group D, more than 15 years. Four independent observers rated each patient's smile using a five-category scale ranging from poor to excellent. Panelists were asked to comment on whether the patient's smile weakened over time. RESULTS: All patients obtained higher scores at 2 years from free-muscle transfer in comparison with their preoperative rates (p < 0.0001). Late outcomes demonstrated that muscle regeneration continues beyond the initial 2 years, with a further increase of the scores and motor units on electromyography at the late follow-up (p < 0.0001, p = 0.0313). No significance was found when comparing both variables among the four groups, indicating that time does not have a differential effect on muscle function. In 80 percent of the evaluations, the four observers agreed on maintained smile symmetry over time. CONCLUSIONS: Cross-facial nerve grafting/free-muscle transfer is an effective technique for smile restoration in late facial paralysis. These data indicate maintenance of effective muscle function and progressive improvement with time

BACKGROUND: Population-based overall patterns of surgical management of the axilla in women with operable breast cancer during the era of adoption of sentinel lymph node biopsy (SLNB) were studied. METHODS: Women with operable breast carcinoma residing in 14 geographic areas of the Surveillance, Epidemiology, and End Results (SEER) cancer registries (1998-2004, n=239,661) were assessed for axillary surgical patterns of care. RESULTS: Use of SLNB increased from 11 to 59%. Use of no axillary surgery decreased from 14 to 6.6%. In pathologic node-negative women, use of axillary lymph node dissection (ALND) decreased from 94 to 36%. Independent factors most associated with failure to receive SLNB included diagnosis year (2000: 62%; 2004: 29%), surgery (mastectomy: 64%; breast-conserving surgery: 36%), tumor size (T3: 71%; T2: 56%; T1: 40%), age (>or= 70 years: 50%; <70 years: 45%), grade (high: 42%; low: 38%), urbanity (non-large metropolitan area: 49%; large metropolitan area: 42%), and, by quartile, poverty (highest: 47%; lowest: 35%), and white-collar employment (lowest: 56%; highest: 47%). In pathologic node-positive women who had SLNB, failure to undergo completion ALND increased from 20% in 1998 to 32% in 2004. Patients with smaller, lower-grade tumors, and those with smaller size of nodal metastasis, lack of extracapsular extension, age >or= 70 years, increased linguistic isolation, African-American or Hispanic race/ethnicity, and white-collar employment were less likely to undergo completion ALND. CONCLUSIONS: Management of the axilla changed dramatically during the period of rapid adoption of SLNB. Patterns of care suggest both appropriate and inappropriate selection for SLNB and ALND

BACKGROUND: Osteoradionecrosis is a serious complication of head and neck radiotherapy. Advanced cases are not amenable to periodic debridement, systemic antibiotics, or hyperbaric oxygen therapy. The authors sought to describe a cost-effective approach for patients with advanced craniofacial osteoradionecrosis. METHODS: Fifteen consecutive patients with craniofacial osteoradionecrosis were treated with radical resection and immediate microvascular free flap reconstruction at Johns Hopkins Hospital or R Adams Cowley Shock Trauma Center from 2002 to 2008. Demographic data were reviewed, and procedure costs were used to compare treatment options. RESULTS: All patients presented with intractable osteoradionecrosis, and most failed conservative therapy. Most cases (60 percent) involved the mandible, and the fibula was the flap of choice (73 percent). The median follow-up was 14 months, with 13 percent complications. Relative cost analysis for hyperbaric oxygen, surgical debridement, and a hospital stay was $25,010; simultaneous resection-microvascular free flap reconstruction and 7-day hospital stay were $30,030. The majority of patients, however, had prior attempts at conservative therapy followed by simultaneous resection and reconstruction; therefore, the average total relative cost per patient was $55,040 ($25,010 + $30,030). CONCLUSION: Definitive treatment of advanced or intractable osteoradionecrosis with simultaneous resection and microvascular composite flap reconstruction is not only definitive but financially sound.

Classic tissue engineering paradigms are limited by the incorporation of a functional vasculature and a reliable means for reimplantation into the host circulation. We have developed a novel approach to overcome these obstacles using autologous explanted microcirculatory beds (EMBs) as bioscaffolds for engineering complex three-dimensional constructs. In this study, EMBs consisting of an afferent artery, capillary beds, efferent vein, and surrounding parenchymal tissue are explanted and maintained for 24 h ex vivo in a bioreactor that preserves EMB viability and function. Given the rapidly advancing field of stem cell biology, EMBs were subsequently seeded with three distinct stem cell populations, multipotent adult progenitor cells (MAPCs), and bone marrow and adipose tissue-derived mesenchymal stem cells (MSCs). We demonstrate MAPCs, as well as MSCs, are able to egress from the microcirculation into the parenchymal space, forming proliferative clusters. Likewise, human adipose tissue-derived MSCs were also found to egress from the vasculature and seed into the EMBs, suggesting feasibility of this technology for clinical applications. We further demonstrate that MSCs can be transfected to express a luciferase protein and continue to remain viable and maintain luciferase expression in vivo. By using the vascular network of EMBs, EMBs can be perfused ex vivo and seeded with stem cells, which can potentially be directed to differentiate into neo-organs or transfected to replace failing organs and deficient proteins

BACKGROUND: Frontal sinus injury involving nasofrontal outflow tract obstruction is routinely managed by obliteration or cranialization; however, a small percentage of patients develop persistent indolent infections despite routine measures. The authors discuss the course of persistent infection following frontal sinus fractures and propose a novel treatment that definitively obliterates and separates the nasofrontal outflow tract from the cranium in these patients. METHODS: Seven consecutive patients with persistent indolent infections associated with frontal sinus fractures were identified and treated at the R Adams Cowley Shock Trauma Center and The Johns Hopkins Hospital from 2005 to 2008. RESULTS: There were three women and four men, with an average age of 41 years. Injury resulted from motor vehicle crashes (n = 4), motorcycle crash (n = 1), fall (n = 1), and other accident (n = 1). All patients were previously treated with conventional techniques (average, 3.6 procedures and 11 years from initial injury) and prolonged antibiotic therapy without resolution of symptoms. Definitive treatment included radical debridement and obliteration with a free fibula flap in a single stage. All flaps survived and resulted in complete sinonasal separation and eradication of infection. There were no donor-site or frontal sinus complications. CONCLUSIONS: Radical debridement, meticulous removal of the tenacious sinus mucosa, and reconstruction with a free fibular flap in a single stage is a superb choice for eliminating persistent infectious complications associated with frontal sinus fractures in patients who have failed conventional management. The fibular flap provides a secure horizontal buttress, seals the nasofrontal outflow tract with vascularized muscle, and obliterates dead space.