Using a three dimensional model of the pediatric skull for pre-operative planning in the treatment of craniosynostosis - biomed 2009.

Spring mediated cranioplasty and cranial vault reconstruction are two surgical interventions for the treatment of craniosynostosis. The purpose of this study was to examine the use of three-dimensional models in pre-operative planning for these procedures. The methods for this study included the creation of the model and the integration of the model into pre-surgical planning. The patients in this study all received a pre-surgical computed tomography scan as part of the standard pre-operative procedure. The first step in model creation involved processing this image data. From the CT scans, using an automated thresholding command in an image analysis software, the bones of the cranial vault were isolated. Once the identification of the bone was complete a CAD file of the anatomy was created. Then, this geometry was imported into the pre-processing software of the three dimensional printer. The model was printed and hardened using cyanoacrylate. After the model was complete, it was used by the plastic surgery department in their pre-surgical planning. One of the primary uses for this model during the planning process was as a template for pre-bending the springs used in spring cranioplasty. The advantage of this technique was that the surgical procedure was less invasive since less of the skull had to be exposed. Additionally, the force characteristics of the spring could be better quantified. Based on the addition of this pre-surgical planning tool, the plastic surgeons have noted a shorter procedure time and a less invasive approach.

Use of standardized, quantitative digital photography in a multicenter Web-based study.

OBJECTIVE: We developed a Web-based, blinded, prospective, randomized, multicenter trial, using standardized digital photography to clinically evaluate hand burn depth and accurately determine wound area with digital planimetry. METHODS: Photos in each center were taken with identical digital cameras with standardized settings on a custom backdrop developed at Wake Forest University containing a gray, white, black, and centimeter scale. The images were downloaded, transferred via the Web, and stored on servers at the principal investigator's home institution. Color adjustments to each photo were made using Adobe Photoshop 6.0 (Adobe, San Jose, Calif). In an initial pilot study, model hands marked with circles of known areas were used to determine the accuracy of the planimetry technique. Two-dimensional digital planimetry using SigmaScan Pro 5.0 (SPSS Science, Chicago, Ill) was used to calculate wound area from the digital images. RESULTS: Digital photography is a simple and cost-effective method for quantifying wound size when used in conjunction with digital planimetry (SigmaScan) and photo enhancement (Adobe Photoshop) programs. The accuracy of the SigmaScan program in calculating predetermined areas was within 4.7% (95% CI, 3.4%-5.9%). Dorsal hand burns of the initial 20 patients in a national study involving several centers were evaluated with this technique. Images obtained by individuals denying experience in photography proved reliable and useful for clinical evaluation and quantification of wound area. CONCLUSION: Standardized digital photography may be used quantitatively in a Web-based, multicenter trial of burn care. This technique could be modified for other medical studies with visual endpoints.

Animal model for evaluation of soft tissue ingrowth into various types of porous coating.

Results from several studies have suggested that soft tissue ingrowth into porous coating can serve as a biologic containment mechanism to prevent particulate debris migration by sealing off the effective joint space. Therefore, a rabbit animal model was developed to investigate soft tissue ingrowth into various types of metallic rods. After implantation of several types of coated and smooth rods within the thigh musculature of rabbits, a thick encapsulation of soft tissue was observed around porous-coated rods whereas a nonadherent pseudosynovial-lined cavity was observed around smooth rods. Within 3 weeks, soft tissue had grown into the three different types of porous coating on the rods. Histologic evaluation verified that maturation of this ingrowth tissue occurred by 12 weeks. Incomplete soft tissue ingrowth occurred into the depths of large-bead (590-840 mm) porous-coated surfaces. Soft tissue separation from the bead surfaces was observed at 12 weeks in the porous-coated implants that also had been coated with a thin layer of tricalcium phosphate. These findings suggest that soft tissue ingrowth can be expected to occur into the porous coatings tested, but that tricalcium phosphate should not be used as an additional surface coating to obtain long-term adherence of circumferential soft tissue ingrowth.