Faculty Bibliography

Periosteal grafts can aid in bone repair by providing bone progenitor cells and acting as a barrier to scar tissue. Unfortunately, these grafts have many of the same disadvantages as bone grafts (donor site morbidity and limited donor sites). In this article, we describe a method of synthesizing a periosteum-like material using acellular human dermis and osteoblasts or mesenchymal stem cells (MSC). We show that osteoblasts readily attach to and proliferate on the acellular human dermis in vitro. In addition, osteoblasts retained the potential for differentiation in response to bone morphogenetic protein stimulation. Cells grown on the acellular human dermis were efficiently transfected with adenoviruses with no evidence of cellular toxicity. To assess for in vivo cell delivery and bone-forming potential, the acellular human dermis was seeded with green fluorescent protein (GFP)-positive MSCs, transfected with bone morphogenetic protein 2, wrapped around the adductor muscle in syngeneic mice, and used to treat critical-sized mandibular defects in nude rats. After 3 weeks, GFP-positive cells were still present, and bone had replaced the interface between the muscle and the constructs. After 6 weeks, critical-sized bone defects had been successfully healed. In conclusion, we show that an acellular human dermis can be used to synthesize a tissue-engineered periosteum capable of delivering cells and osteoinductive proteins.

SUMMARY: At present, the literature dedicated to closed mallet thumb injury offers conflicting evidence between conservative and operative approaches. Although conservative treatment is often successful, retraction of the extensor pollicis tendon may lead to improper reattachment and continued deformity. This discussion and case report serve to highlight the use of magnetic resonance imaging as an adjunct in selecting the proper treatment strategy for this injury at initial presentation

BACKGROUND: The supraclavicular island flap has been used successfully for difficult facial reconstruction cases, providing acceptable results without using microsurgical techniques. The authors use this regional flap in reconstructing various head and neck oncologic defects that normally require traditional regional or free flaps to repair surgical wounds. METHODS: A pedicled supraclavicular artery flap was used to reconstruct head/neck oncologic defects. Complications and functional outcomes were assessed. RESULTS: Head and neck oncologic patients underwent tumor resection followed by immediate reconstruction using a supraclavicular artery island flap. Ablative defects included neck, tracheal-stomal, mandible, parotid, and pharyngeal walls. All flaps (n = 18) were harvested in less than 1 hour. All ablative wounds and donor sites were closed primarily and did not require additional surgery. Major complications included a complete flap loss when the vascular pedicle was inadvertently divided and pharyngeal leaks. The leaks resolved without surgical intervention, and both patients regained the ability to swallow using their neo-esophagus. Minor complications included donor-site wound dehiscence and cellulitis. None of the patients reported functional donor-site morbidity. CONCLUSIONS: This thin flap is easy and quick to harvest, has a reliable pedicle, and has minimal donor-site morbidity. It is now the authors' flap of choice for many common head and neck reconstructive problems. Early experience using the supraclavicular artery island flap suggests that it is an excellent flap option for head and neck oncologic disease patients.

BACKGROUND: Cryolipolysis provides a method for noninvasive fat reduction that significantly reduces subcutaneous fat in a pig model without apparent damage to skin and surrounding structures. This study aimed to determine whether fat reduction in humans caused by cold exposure is associated with alteration in local sensory function or nerve fibers. METHODS: In this study, 10 subjects were treated with a prototype cooling device. Fat reduction was assessed in 9 of the 10 subjects via ultrasound before treatment and at the follow-up visit. Sensory function was assessed by neurologic evaluation (n = 9), and biopsies (n = 1) were collected for nerve staining. RESULTS: Treatment resulted in a normalized fat layer reduction of 20.4% at 2 months and 25.5% at 6 months after treatment. Transient reduction in sensation occurred in six of nine subjects assessed by neurologic evaluation. However, all sensation returned by a mean of 3.6 weeks after treatment. Biopsies showed no long-term change in nerve fiber structure. There were no lasting sensory alterations or observations of skin damage in any of the subjects evaluated. CONCLUSION: Noninvasive cryolipolysis results in substantial fat reduction within 2 months of treatment without damage to skin. The procedure is associated with modest reversible short-term changes in the function of peripheral sensory nerves

BACKGROUND: Infection in severe pressure ulcers can lead to sepsis with a 6-month mortality as high as 68%. METHODS: Operative records of 142 consecutive operative debridements on 60 patients in a dedicated wound healing inpatient unit were reviewed, from the Wound Electronic Medical Record, for identification of key steps in debridement technique, mortality, unexpected returns, and time to discharge following debridement. RESULTS: The mean age of the patients was 73.1 years, and 45% were men. Most wounds (53%) were located on the hip (ischial or trochanteric); others were on the sacrum (32%) and the heels (14%). The mean initial wound area prior to debridement was 14.0 cm(2), and 83% of debridements were performed on stage IV pressure ulcers. The postoperative hospital stay averaged 4.1 days. Key steps in the technique included (1) exposure of areas of undermining by excising overlying tissue; (2) removal of callus from wound edges; (3) removal of all grossly infected tissue; and (4) obtaining a biopsy of the deep tissue after debridement of all nonviable or infected tissue for culture and pathology to determine the presence of infection, fibrosis, and granulation tissue. There was one death 9 days post-debridement of a sacral ulcer and one unplanned return to the operating room for bleeding 8 days post-debridement. CONCLUSIONS: Operative debridement of pressure ulcers is safe, despite the medical co-morbidities in patients with severe pressure ulcers. Proper debridement technique may prevent sepsis and death in patients with multiple co-morbid conditions

The aim of this study was to evaluate the biomechanical fixation, bone-to-implant contact, and bone morphology of an ion beam assisted deposition of a 300-500 nm thick Ca- and P-based bioceramic surface on a previously alumina-blasted/acid-etched Ti-6Al-4V implant surface in a dog model. MATERIALS AND METHODS: Thirty-six 4.5 x 11 mm plateau root form implants, control (alumina-blasted/acid-etched-AB/AE) and test groups (AB/AE+300-500 nm bioceramic coating, Nanotite) were placed along a proximal tibia of six beagle dogs remaining for 2 and 4 weeks (n = 3 animals per implantation time). Following euthanization, the implants were torqued to interface fracture at approximately 0.196 radians/sec until a 10% maximum load drop was detected. The implants in bone were nondecalcified processed to approximately 30 microm thickness slides for histomorphologic and bone-to-implant contact (BIC) assessment. Statistical analyses for torque to interface fracture were performed using a mixed model ANOVA, and BIC was evaluated by the chi2 test at 95% level of significance. RESULTS: At 4 weeks, significantly higher torque to interface fracture was observed for the Test implant surface. Histomorphologic analysis showed higher degrees of bone organization for test implants compared to control at 2 and 4 weeks. Significantly higher BIC was observed at 4 weeks compared to 2 weeks (no statistical differences between control and test implants). CONCLUSION: The higher torque to interface fracture and increased bone maturity obtained in this study support that the surface modification comprising a 300-500 nm Ca- and P-based bioceramic coating positively influenced healing around pleateau root form implants.

BACKGROUND: The technical success of facial composite tissue allotransplantation demands full understanding of superficial and deep perfusion for reliable microvascular transfer. Candidates with composite midface defects require an appreciation of the circulatory patterns to design a composite midface allotransplant. METHODS: External carotid vascular territories were evaluated in 10 cadavers to determine the reliability of facial soft-tissue flaps based on a single vascular pedicle. The right common carotid artery was injected with red latex and the left was injected with blue latex. Dual perfusion was confirmed by purple, following two-color mixing. Vascular pedicles included the superficial temporal, transverse facial, and facial arteries. In five additional cadavers, the midface segment was isolated by Le Fort III osteotomy after two-color latex injection with inclusion of the internal maxillary vascular pedicle. Cadavers were imaged with three-dimensional computed tomographic reconstructions following latex injection to confirm perfusion patterns. RESULTS: In soft-tissue facial flaps, unilateral carotid dominance was seen in the nasal dorsum and tip, confirming reliable supply by a single external carotid artery. In midface flaps, bilateral perfusion was seen in the maxilla. Ipsilateral perfusion was observed at the zygomaticomaxillary complex without any contralateral contribution. CONCLUSIONS: Dual soft-tissue perfusion was confirmed in most specimens at the nasal, central face, and maxilla. The inclusion of the maxilla in the design of a facial composite allotransplant demands bilateral vascular pedicles based on the internal maxillary arteries. The authors highlight a procurement strategy for design of such flaps.

In end-to-side neurorrhaphy, 'noninjury' models of the donor nerve do not seem to offer worthwhile functional outcomes. The role of donor nerve injury distal to the coaptation site remains unclear. End-to-side neurorrhaphy was studied in a rat model in which the proximal stump of the transected musculocutaneous nerve was sutured to the median nerve by end-to-side coaptation. Twenty Sprague-Dawley rats were randomized to four groups of five animals each, in which three different types of donor injury (crush, ligation, or transection injury) distal to the coaptation site were executed; findings were compared with a similar end-to-side model without donor nerve injury (control). Behavioral analysis, electrophysiological studies, muscle morphometric studies, and nerve fibers counts showed no significant differences among groups. However, there was a significant difference regarding mean myelin area (P = 0.0362) and mean fiber diameter (P = 0.0159) for the crush injury group as compared with the control group. No significant differences were found among the other groups. These data suggest that donor crush injury distal to the coaptation site may increase the rate of myelin formation in regenerating axons across an end-to-side model; however, at 4 weeks of follow-up, there was no significant behavioral or functional significance in this treatment group