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: Large experience in Asia has shown that the contralateral C7 nerve transfer has proved one of the major treatments for brachial plexus root avulsions. The authors report their experience in North America using the selective contralateral C7 transfer for neurotization of multiple targets. METHODS: A retrospective review of 56 patients with posttraumatic root avulsion brachial plexus injuries who underwent contralateral C7 transfer using selective technique was conducted. The targets included the axillary, musculocutaneous, radial, and median nerves. Additionally, neurotization of future free muscle transplantation was performed. The mean follow-up period was 6.1 years (range, 2.5 to 14 years). RESULTS: Motor recovery reached a level of M3+ or greater in 20 percent (two of 10) of patients for the deltoid, 52 percent (12 of 23) for the biceps, 24 percent (five of 21) for the triceps, 34 percent (10 of 29) for the wrist and finger flexors, and 20 percent (two of 10) for the wrist and finger extensors. In addition, sensory recovery of S2 or greater was achieved in 76 percent (22 of 29) of patients with median nerve neurotization. As far as the postoperative morbidity of the donor limb, by 6 months, there was no discernible motor or sensory deficit. Patients with a surgical delay of 9 months or less and patients aged 18 years or younger achieved significantly better results. CONCLUSIONS: Brachial plexus root avulsions, long considered to be irreparable, are by no means unreconstructable. The selective contralateral C7 transfer appears to be a safe procedure, and it can be successfully applied for simultaneous reconstruction of several different nerves and/or for neurotization of future free muscle transfers

Reconstructive algorithms for composite craniofacial defects have focused on soft tissue flaps with or without bone grafts. However, volumetric loss over time limits long-term preservation of facial contour. Application of craniofacial skeletal buttress principles to high-energy trauma or oncologic defects with composite vascularized bone flaps restores the soft tissue as well as the buttresses and ultimately preserves facial contour. We conducted a retrospective review of 34 patients with craniofacial defects treated by a single surgeon with composite bone flaps at R Adams Cowley Shock Trauma Center and Johns Hopkins Hospital from 2001 to 2007. Data collected included age, sex, mechanism of injury, type of defect, type of reconstructive procedures, and outcome. Thirty-four patients with composite tissue loss, primarily males (n = 24) with an average age of 37.4 years, underwent reconstruction with vascularized bone flaps (28 fibula flaps and 6 iliac crest flaps). There were 4 cranial defects, 8 periorbital defects, 18 maxillary defects, and 4 maxillary and periorbital defects. Flap survival rate was 94.1% with an average follow-up time of 20.5 months. Restoration of facial height, width, and projection is achieved through replacement of skeletal buttresses and is essential for facial harmony. Since 2001, our unit has undergone a paradigm shift with regard to treatment of composite oncologic and traumatic defects, advocating vascularized bone flaps to achieve predictable long-term outcomes.

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: Nasoalveolar molding was developed to improve dentoalveolar, septal, and lower lateral cartilage position before cleft lip repair. Previous studies have documented the long-term maintenance of columella length and nasal dome form and projection. The purpose of the present study was to determine the effect of presurgical nasoalveolar molding on long-term unilateral complete cleft nasal symmetry. METHODS: A retrospective review of 25 consecutively presenting nonsyndromic complete unilateral cleft lip-cleft palate patients was conducted. Fifteen patients were treated with presurgical nasoalveolar molding for 3 months before surgical correction, and 10 patients were treated by surgical correction alone. The average age at the time of follow-up was 9 years. Four nasal anthropometric distances and two angular relationships were measured to assess nasal symmetry. RESULTS: All six measurements demonstrated a greater degree of nasal symmetry in nasoalveolar molding patients compared with the patients treated with surgery alone. Five symmetry measurements were significantly more symmetric in the nasoalveolar molding patients and one measurement demonstrated a nonsignificant but greater degree of symmetry compared with the patients treated with surgery alone. CONCLUSIONS: The data demonstrate that the lower lateral and septal cartilages are more symmetric in the nasoalveolar molding patients compared with the surgery-alone patients. Furthermore, the improved symmetry observed in nasoalveolar molding-treated noses during the time of the primary surgery is maintained at 9 years of age

Osteomyelitis affects up to 32% of full-thickness pressure ulcers and increases treatment costs and the risk of systemic complications. Current diagnosis and treatment practices are variable. A literature and retrospective chart review, using a wound electronic medical record (WEMR), were conducted to develop an evidence-based protocol of care for treatment of osteomyelitis in pressure ulcers and to evaluate outcomes of care. The seven steps in the protocol of care include: 1) acknowledgment of osteomyelitis risk in patients with Stage IV pressure ulcers, 2) clinical evaluation for local or systemic signs of infection upon initial presentation, 3) radiographic evaluation (magnetic resonance imaging or bone scan), 4) surgical debridement to remove all nonviable tissue and/or scarred and infected bone, 5) obtaining pathology reports from sterile bone biopsy and deep microbial cultures, 6) targeted systemic antimicrobial therapy, and 7) tissue reconstruction following resolution of infection. WEMR data review (177 patients) identified 50 patients with osteomyelitis (prevalence 28%). Of those, 41 underwent 87 bone debridements for osteomyelitis. Eight (20%) patients experienced complications elated to treatment. Average time to discharge following debridement was 4.3 +/- 5.7 days and 76% of wounds with more than two consecutive WEMR entries showed a decrease in area at their final visit. The outcomes observed are encouraging and the WEMR facilitates implementation and evaluation of the treatment protocol. Ongoing data acquisition will help assess outcomes and refine the current management protocol and should improve diagnosis and care

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