Faculty Bibliography

BACKGROUND: Flexor tendon injuries are common problems faced by hand surgeons. To minimise the surgical trauma associated with localisation and retrieval of the proximal tendon end, we investigated the use of surgeon-performed ultrasound in the evaluation of injured flexor tendons in a cadaver model. Our goal was to use surgeon-performed ultrasound: (1) to correctly diagnose flexor tendon injuries and (2) to correctly localise the proximal tendon ends within 1cm. METHODS: Flexor tendon injuries with varying degrees of retraction were randomly created in individual digits of cadaver upper extremities, with a number of tendons left uninjured. A surgeon, blinded to the injury status of each digit, imaged each tendon by ultrasound. Predicted injury status of each tendon and localisation of the proximal stump was recorded. A total of 81 tendons were studied. FINDINGS: Correct diagnosis of flexor tendon injury was made in 78 of 81 tendons (96.2% success). Correct localisation of the proximal tendon stump was made in 39 of 50 lacerated tendons (78% success). Small finger injuries were most difficult to assess (66.7% success). With the small finger excluded from our analysis, the localisation success rate increased to 86.8%. The average time taken to image each digit was just under 2.5min. CONCLUSIONS: Surgeon-performed ultrasound evaluation of the hand is a reliable means to diagnose flexor tendon injuries and to accurately localise the proximal tendon ends. This imaging modality may limit the need for extensive surgical exploration during flexor tendon repair. We do not recommend using this technique to image flexor tendon injuries of the small finger at this time

Abstract This article describes the evolution of a computer-aided design/computer-aided manufacturing (CAD/CAM) process where ceramic paste is deposited in a layer-by-layer sequence using a computer numerical control machine to build up core and fixed partial denture (FPD) structures (robocasting). Al(2)O(3) (alumina) or ZrO(2) (Y-TZP) are blended into a 0.8% aqueous solution of ammonium polyacrylate in a ratio of approximately 1:1 solid:liquid. A viscosifying agent, hydroxypropyl methylcellulose, is added to a concentration of 1% in the liquid phase, and then a counter polyelectrolyte is added to gel the slurry. There are two methods for robocasting crown structures (cores or FPD framework). One is for the core to be printed using zirconia ink without support materials, in which the stereolithography (STL) file is inverted (occlusal surface resting on a flat substrate) and built. The second method uses a fugitive material composed of carbon black codeposited with the ceramic material. During the sintering process, the carbon black is removed. There are two key challenges to successful printing of ceramic crowns by the robocasting technique. First is the development of suitable materials for printing, and second is the design of printing patterns for assembly of the complex geometry required for a dental restoration. Robocasting has room for improvement. Current development involves enhancing the automation of nozzle alignment for accurate support material deposition and better fidelity of the occlusal surface. An accompanying effort involves calculation of optimal support structures to yield the best geometric results and minimal material usage

BACKGROUND: The purpose of this study was to evaluate retrospectively the patients who had undergone radial nerve reconstruction. METHODS: The medical charts of 35 patients with radial nerve lesions and 13 patients with superficial radial nerve lesions who underwent surgical exploration and repair in the authors' center were reviewed. The outcomes were analyzed in relation to various factors, such as age at injury, denervation time, level of injury, length of nerve graft, and type of reconstruction. RESULTS: With regard to the radial nerve, good and excellent motor results were seen in 27 of 35 cases (77.14 percent). Postoperative lateral pinch and grip strength of the affected side were equal to 75.49 percent and 76.42 percent of those of the nonaffected side, respectively. Patient age, level of injury, denervation time, associated nerve injuries, length of nerve graft, and type of surgical reconstruction significantly influenced the functional outcome. For the superficial radial nerve, good and excellent sensory results were seen in 10 of 13 cases (76.92 percent). Postoperatively, pain scores were graded as excellent in 69.23 percent and as good in 23.07 percent of patients. CONCLUSIONS: Better functional results were achieved in younger patients, with denervation time of 3 months or less, in lesions in continuity, in patients without associated nerve injuries, in distal lesions, with neurolysis, and with nerve grafts less than or equal to 5 cm long. Functional outcomes following microsurgical repair of radial nerve injuries are encouraging and should be pursued

We investigated the effects of cannabinoid receptor agonists on (1) oral cancer cell viability in vitro and (2) oral cancer pain and tumor growth in a mouse cancer model. We utilized immunohistochemistry and Western blot to show that human oral cancer cells express CBr1 and CBr2. When treated with WIN55,212-2 (non-selective), ACEA (CBr1-selective) or AM1241 (CBr2-selective) agonists in vitro, oral cancer cell proliferation was significantly attenuated in a dose-dependent manner. In vivo, systemic administration (0.013M) of WIN55,212-2, ACEA, or AM1241 significantly attenuated cancer-induced mechanical allodynia. Tumor growth was also significantly attenuated with systemic AM1241 administration. Our findings suggest a direct role for cannabinoid mechanisms in oral cancer pain and proliferation. The systemic administration of cannabinoid receptor agonists may have important therapeutic implications wherein cannabinoid receptor agonists may reduce morbidity and mortality of oral cancer

OBJECTIVE: this study aimed to develop a nondecalcified bone sample processing technique enabling immunohistochemical labeling of proteins by kappa-beta nuclear factor (NF-kB) utilizing the Technovit 7200 VCR(R) in adult male Wistar rats. STUDY METHOD: A 1.8 mm diameter defect was performed 0.5 mm from the femur proximal joint by means of a round bur. Experimental groups were divided according to fixing solution prior to histologic processing: Group 1--ethanol 70%; Group 2--10% buffered formalin; and Group 3--Glycerol diluted in 70% ethanol at a 70/30 ratio + 10% buffered formalin. The post-surgical periods ranged from 01 to 24 hours. Control groups included a non-surgical procedure group (NSPG) and surgical procedures where bone exposure was performed (SPBE) without drilling. Prostate carcinoma was the positive control (PC) and samples subjected to incomplete immunohistochemistry protocol were the negative control (NC). Following euthanization, all samples were kept at 4 degrees C for 7 days, and were dehydrated in a series of alcohols at -20 degrees C. The polymer embedding procedure was performed at ethanol/polymer ratios of 70%-30%, 50%-50%, 30%-70%, 100%, and 100% for 72 hours at -20 degrees C. Polymerization followed the manufacturer's recommendation. The samples were grounded and polished to 10-15 m thickness, and were deacrylated. The sections were rehydrated and were submitted to the primary polyclonal antibody anti-NF-kB on a 1:75 dilution for 12 hours at room temperature. RESULTS: Microscopy showed that the Group 2 presented positive reaction to NF-kB, diffuse reactions for NSPG and SPBE, and no reaction for the NC group. CONCLUSION: The results obtained support the feasibility of the developed immunohistochemistry technique.

PURPOSE: This study evaluated the bone mineral apposition rate (MAR) at the bone-implant interface region of alumina-blasted/acid-etched (AB/AE), plasma-sprayed hydroxyapatite (PSHA), and nanometric-scale bioceramic-coated surfaces at early implantation times in a dog tibia model. MATERIALS AND METHODS: Implants (n = 12 per group) with three different surfaces-AB/AE, PSHA, and a bioceramic coating in the 300- to 500-nm thickness range-were placed bilaterally along the proximal tibiae of six male beagles. Implants remained for 3 and 5 weeks in vivo. Ten and 2 days prior to euthanization, calcein green and oxytetracycline were administered for bone labeling. Following euthanization, the limbs were retrieved by sharp dissection and the implants and bone were processed nondecalcified into ~30-Mum-thick sections along the implant long axis. MAR was measured by the distance between bone labels over time at the interface region (to 0.5 mm from the implant surface) and at regions > 3 mm from the implant surface (remote site). A generalized linear mixed-effects analysis of variance model was conducted with significance levels set at .05. RESULTS: Irrespective of implant surface, the MAR at the interface region was significantly higher than the MAR at the remote site. Significant MAR differences in the interface region were observed between the different surfaces (PSHA > AB/AE > nano). CONCLUSIONS: Bone kinetics during early healing stages were influenced by implant surface modifications.

BACKGROUND: The aim of lower extremity reconstruction has focused on early wound coverage and functional recovery but rarely aesthetics. Free muscle flaps provide durable coverage; however, they require skin graft coverage and result in muscle atrophy limiting future revisions. Perforator-based flap reconstructions can be easily elevated to allow for both orthopedic and contouring procedures. The authors reviewed the role of secondary procedures in achieving improved functional and aesthetic results following perforator flap reconstruction of lower extremity defects. METHODS: A retrospective review identified 70 patients treated at R Adams Cowley Shock Trauma Center with 73 free perforator flaps for coverage of lower extremity wounds from 2002 to 2009. RESULTS: Seventy patients were identified who underwent reconstruction with a perforator flap: 65 with anterolateral thigh flaps and five with superficial circumflex iliac artery flaps. Nineteen of these patients underwent 32 refinement procedures of the reconstructed limb. Fifteen refinements were performed with suction-assisted lipectomy, 21 with complex tissue rearrangement, including sharp debulking, and one with tissue expanders. Twenty-seven of the 70 patients underwent 40 orthopedic-related secondary procedures in which the free flap was elevated. The most common reasons for the orthopedic interventions were tibial nonunion requiring bone grafting (n = 17) and osteomyelitis (n = 11). CONCLUSIONS: Limb salvage remains the primary goal of lower extremity reconstruction. Following convalescence and functional recovery, however, appearance becomes increasingly important with regard to quality of life. Initial flap selection with free perforator flaps, meticulous inset, and secondary refinements provide superior functional and aesthetic outcomes.

This study tested the hypothesis that all-ceramic core-veneer system crown reliability is improved by modification of the core design. We modeled a tooth preparation by reducing the height of proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. The CAD-based tooth preparation was replicated and positioned in a dental articulator for core and veneer fabrication. Standard (0.5 mm uniform thickness) and modified (2.5 mm height lingual and proximal cervical areas) core designs were produced, followed by the application of veneer porcelain for a total thickness of 1.5 mm. The crowns were cemented to 30-day-aged composite dies and were either single-load-to-failure or step-stress-accelerated fatigue-tested. Use of level probability plots showed significantly higher reliability for the modified core design group. The fatigue fracture modes were veneer chipping not exposing the core for the standard group, and exposing the veneer core interface for the modified group