Faculty Bibliography

This in vivo study investigated the in vivo performance of two newly developed synthetic bone substitutes and compared them to commercially available xenografts (Bio-Oss, Geistlich Pharma AG, Switzerland; OsteoGraf, Dentsply, USA). The materials were tested in a rabbit calvaria model, and the bone forming properties were observed at 4 and 8 weeks after implantation by means of histomorphometry and micro computed tomography (micro-CT). Defects without any graft material were used as negative controls. Micro-CT showed that all materials tested presented new bone formation that filled the defects at both time points, whereas the negative control presented less bone formation, with soft tissue infiltration into the defects. Comparable bone fill percentages were observed for histomorphometric and micro-CT results. Even though no statistically significant difference was found quantitatively between all of the bone graft substitute groups, a higher mean decrease in graft material filling the defects, along with higher remodelling activity, was evident for the experimental materials compared to the commercially available xenografts at 8 weeks. The results indicate that the experimental materials possess high degradability, along with osteoconduction comparable to commercially available xenografts.

BACKGROUND: This study is a 10-year follow-up to our previous publication reviewing the complication rates of tissue expansion in the pediatric burn population. The purpose of this study was to determine if our institutional experience with tissue expanders had remained stable during the subsequent 10 years. METHODS: There were 240 patients who were identified at a major pediatric burn center who underwent reconstruction with a tissue expander (256 tissue expanders) from 1996 to 2006. Data were obtained retrospectively by reviewing patient medical records. Complications were categorized into absolute and relative complications. RESULTS: Absolute complications occurred in 36 (14.1%) of 256 expanders placed and relative complications occurred in 26 (10.2%) of 256 expanders placed. There was no statistical difference between this study and our previous study for overall complication rates and complications for all sites. The highest complication rate occurred when the scalp was a surgical site. Betadine skin preparation was associated with a 10% reduction in infection-related complications compared to other skin preparations. The operating surgeon or age of patient was not found to be associated with increased complication rates. CONCLUSIONS: After changing our tissue expander protocol, the complication rates at our institution have remained stable during the 10-year follow-up period. Tissue expansion in the pediatric burn population continues to be a safe and effective reconstructive option with acceptable complication rates.

It is over 20 years since the inaugural deep inferior epigastric perforator (DIEP) flap breast reconstruction. We review the type of flap utilized and indications in 2,850 microvascular breast reconstruction over the subsequent 20 years in the senior author's practice (Robert J. Allen). Data were extracted from a personal logbook of all microsurgical free flap breast reconstructions performed between August 1992 and August 2012. Indication for surgery; mastectomy pattern in primary reconstruction; flap type, whether unilateral or bilateral; recipient vessels; and adjunctive procedures were recorded. The DIEP was the most commonly performed flap (66%), followed by the superior gluteal artery perforator flap (12%), superficial inferior epigastric artery perforator flap (9%), inferior gluteal artery perforator flap (6%), profunda artery perforator flap (3%), and transverse upper gracilis flap (3%). Primary reconstruction accounted for 1,430 flaps (50%), secondary 992 (35%), and tertiary 425 (15%). As simultaneous bilateral reconstructions, 59% flaps were performed. With each flap, there typically ensues a period of enthusiasm which translated into surge in flap numbers. However, each flap has its own nuances and characteristics that influence patient and physician choice. Of note, each newly introduced flap, either buttock or thigh, results in a sharp decline in its predecessor. In this practice, the DIEP flap has remained the first choice in autologous breast reconstruction.

Bone tissue is characterized by a constant turnover in response to mechanical stimuli, and osteocytes play an essential role in bone mechanical adaptation. However, little to no information has been published regarding osteocyte density as a function of implantation time in vivo. The aim of this retrospective histological study was to evaluate the osteocyte density of the peri-implant bone in implants retrieved because of different reasons in a time period from 4 weeks to 27 years. A total of 18 samples were included in the present study. Specimens were divided into 3 groups depending on the loading history of the implants: loading between 4 weeks and 7 months (group 1); loading between 1 and 5 years (group 2); loading between 14 and 27 years (group 3). All the samples were histologically evaluated and osteocyte density was obtained using the ratio of the number of osteocytes to the bone-area (mm2 ). The osteocyte density values significantly increased in the Group 2 (1-5 years) compared with Group 1 (4 weeks-7 months), and significantly decreased in the Group 3 (14-27 years) compared to Group 2. No significant differences were detected between Group 1 and Group 3. The decrease in osteocyte density observed in samples that were in vivo for long periods of time under loading is possibly because of the fact that once the bone structure is well aligned and biomechanically competent, a lower number of osteocytes are necessary to keep the tissue homeostasis under loading. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.

Persistent pain following breast cancer surgery is a significant clinical problem. Although immune mechanisms may play a role in the development and maintenance of persistent pain, few studies have evaluated for associations between persistent breast pain following breast cancer surgery and variations in cytokine genes. In this study, associations between previously identified extreme persistent breast pain phenotypes (ie, no pain vs severe pain) and single nucleotide polymorphisms (SNPs) spanning 15 cytokine genes were evaluated. In unadjusted analyses, the frequency of 13 SNPs and 3 haplotypes in 7 genes differed significantly between the no pain and severe pain classes. After adjustment for preoperative breast pain and the severity of average postoperative pain, 1 SNP (ie, interleukin [IL] 1 receptor 2 rs11674595) and 1 haplotype (ie, IL10 haplotype A8) were associated with pain group membership. These findings suggest a role for cytokine gene polymorphisms in the development of persistent breast pain following breast cancer surgery. PERSPECTIVE: This study evaluated for associations between cytokine gene variations and the severity of persistent breast pain in women following breast cancer surgery. Variations in 2 cytokine genes were associated with severe breast pain. The results suggest that cytokines play a role in the development of persistent postsurgical pain.

PURPOSE: Currently, nearly 1 in 5 Americans is at least 60 years of age. Bone atrophy, decreased capacity for tissue repair, and chronic disease are known to influence fracture patterns and operative algorithms in this age group. This study presents craniofacial trauma injury patterns and treatment in an elderly population at a major urban trauma center. METHODS: Patient records were retrospectively reviewed from February 1998 through December 2010. Patients at least 60 years of age who met the inclusion criteria for craniofacial fractures identified by International Classification of Diseases, Ninth Revision code review and confirmed by author review of available computed tomograms were studied. Demographic information, fracture type, concomitant injuries, and management were recorded. RESULTS: Of 11,084 patients presenting with facial fracture, 1,047 were older than 60 years. The most common mechanism of injury was falls (50%), and most patients were men (59%). Commonly fractured areas included the nose (n = 452, 43%), maxilla (316, 30%), zygoma (312, 30%), orbital floor (280, 27%), and mandible (186, 18%), with 51 patients (5%) having a concomitant basilar skull fracture. Inpatient mortality and length of stay were significantly increased compared with the nongeriatric population (P < .01), although only 5% of all fractures were treated operatively. CONCLUSIONS: Fractures in the elderly tend to be minimally displaced midfacial fractures that do not warrant surgical intervention. Despite conservative management, the elderly are hospitalized longer than their younger counterparts, have increased critical care needs, and have higher mortality. These data support national medical preparedness in anticipating the craniofacial trauma needs of the aging US population and can be used to update treatment algorithms for these patients.

Use of the ulnar forearm flap (UFF) is limited by concerns for ulnar nerve injury and impaired perfusion in the donor extremity. Twenty UFFs were performed over a 6-year period. All patients underwent postoperative bilateral upper extremity arterial duplex studies. A subset of postoperative patients (n = 10) also had bilateral upper extremity sensory and motor evaluations, and functional evaluation via the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH). Motor function was tested by digital and key grip dynamometry. Ulnar nerve sensation was tested by evaluation of one- and two-point perceived pressure thresholds and two-point discrimination using the Pressure-Specified Sensory Device (Sensory Management Services, LLC, Baltimore, MD). All UFFs were viable postoperatively. Mean follow-up was 28.8 months for vascular studies and 45.3 months for motor, sensory, and QuickDASH evaluations. Although mid and distal radial artery flow velocities were significantly higher in donor versus control extremities evaluated at less than 1 year postoperatively, there was no significant difference in extremities evaluated at later time points. Digital pressures, grip strength, key pinch strength, and ulnar sensation were equivalent between donor and control extremities. The mean QuickDASH score was 17.4 +/- 23.8. The UFF can be harvested reliably and long-term follow-up shows no evidence of impaired vascular, motor, or sensory function in the donor extremity.

BACKGROUND: Tendon gliding is key to optimal recovery of hand function after complex tendon injuries. Gliding is facilitated by a low-friction gliding surface that is normally provided by the periosteum of the underlying bone. However, significant injuries may damage the periosteum, which must be reconstructed to allow uninterrupted tendon excursion. The absence of the periosteum may compromise a tendon's ability to glide freely, thereby limiting the range of motion. METHODS: Six digits in 4 patients with complex, composite soft tissue defects involving tendon, periosteum, and skin of the hand underwent surgical repair. Each digit had disruption of the bony cortex underlying the tendon injury including periosteal loss. Through an incision on the dorsum of the ipsilateral wrist, an extensor retinaculum graft corresponding to the size of the periosteal defect was harvested. It was then sutured into place over the bare cortex to replace the lost periosteum. RESULTS: All the 6 digits in the 4 patients had complete return to function. Additionally, all patients had near normal strength in the repaired hand along with excellent tendon excursion in both flexion and extension. The average time of follow-up of this series of patients was 1.5 years. CONCLUSIONS: Extensor retinaculum grafting to replace lost periosteum is a technique that is easily used, uses locally available autogenous tissues, and produces excellent tendon function. Additionally, the histologic similarities between extensor retinaculum and periosteum add scientific merit to this novel approach. On the basis of our experience, we recommend the use of extensor retinaculum for periosteal reconstruction to provide an adequate gliding surface for a reconstructed tendon.