Functional and Aesthetic Tragal Reconstruction in the Age of Mobile Electronic Devices.

We present a method to create a tragus using the patient's conchal cartilage. It is a simplified, single-stage technique with well-hidden incisions, yet it maintains the rigidity of a natural tragus. This patient did not have a history of radiation to the area, which may compromise healing with this technique. The cosmetic importance of the tragus has been described, but its functionality in accommodating modern technology has not been previously discussed. The main treatment goal for this patient was to gain the ability to wear earphones (clinical question/level of evidence: therapeutic, V).

Characteristics of maxillofacial injuries and safety of in-theater facial fracture repair in severe combat trauma.

The study objectives were to characterize maxillofacial injuries and assess the safety of in-theater facial fracture repair in U.S. military personnel with severe combat trauma from Iraq and Afghanistan. We performed a retrospective chart review of the Expeditionary Medical Encounter Database from 2004 to 2010. 1,345 military personnel with combat-related maxillofacial injuries were identified. Injury severity was quantified with the Abbreviated Injury Scale and Injury Severity Score. Service members with maxillofacial injury and severe combat trauma (Injury Severity Score ≥ 16) were included. The distribution of facial fractures, types, and outcomes of surgical repairs, incidence of traumatic brain injury, concomitant head and neck injuries, burn rate/severity, and rates of Acinetobacter baumannii colonization and surgical site infection were analyzed. The prevalence of maxillofacial injury in the Expeditionary Medical Encounter Database was 22.7%. The most common mechanism of injury was improvised explosive device (65.7%). Midface trauma and facial burns were common. Approximately 64% of the study sample sustained traumatic brain injury. Overall, 45.6% (109/239) had at least one facial bone fracture. Of those with facial fractures, 64.2% (n = 70) underwent surgical repair. None of the service members who underwent in-theater facial fracture repair developed A. baumannii facial wound infection or implant extrusion.

Biomechanics of the rhombic transposition flap.

OBJECTIVE: To develop a computational model of cutaneous wound closures comparing variations of the rhombic transposition flap. STUDY DESIGN: A nonlinear hyperelastic finite element model of human skin was developed and used to assess flap biomechanics in simulated rhombic flap wound closures as flap geometric parameters were varied. SETTING: In silico. METHODS: The simulation incorporated variables of transposition angle, flap width, and tissue undermining. A 2-dimensional second-order Yeoh hyperelastic model was fit to published experimental skin data. Resultant stress and strain fields as well as local surface changes were evaluated. RESULTS: For the rhombus defect, closure stress and strain were minimized for the transposition flap with a distal flap angle of 30° by recruiting skin from opposing sides of the defect. Alteration of defect dimensions showed that peak stress and principal strain were minimized with a square defect. Likelihood of a standing cutaneous deformity was driven by the magnitude of angle closure at the flap base. Manipulation of the transposition angle reoriented the primary skin strain vector. Asymmetric undermining decoupled wound closure tension from strain, with direct effects on boundary deformation. CONCLUSIONS: The model demonstrates that flap width determines the degree of secondary tissue movement and impact on surrounding tissues. Transposition angle determines the orientation of maximal strain. Local flap design requires consideration of multiple factors apart from idealized biomechanics, including adjacent "immobile" structures, scar location, local skin thickness, and orientation of relaxed skin tension lines. Finite element models can be used to analyze local flap closures to optimize outcomes.

Biomechanics of the monopedicle skin flap.

OBJECTIVE: The design and implementation of skin flaps remains a puzzle for the reconstructive surgeon. The objective of the present study is to use finite element (FE) analysis to characterize and understand the biomechanics of the monopedicle skin flap design. STUDY DESIGN: The current study uses a nonlinear hyperelastic FE model of the human skin to understand the biomechanics of monopedicle-based flap designs as geometric flap parameters are varied. SETTING: In silico. SUBJECTS AND METHODS: The simulation included the displacement loading, stitching, and relaxation of various forms of the flap design. Stress and strain outcomes, previously correlated with scarring, necrosis, and blood perfusion, are reported for a basic monopedicle design as well as a number of modifications to this design. RESULTS: The results suggest that the length of the monopedicle flap should not exceed 3 times the size of the defect, as the benefit in reducing principal strain (deformation) is diminished beyond this point. Further, to minimize skin strain, the ideal Burrow's triangle size can be described as proportional to flap length and inversely proportional to defect height, according to a linear function. CONCLUSION: The ideal flap design should attempt to minimize not only the stress in the skin, but the size of the incisions and the degree of undermining. The results of our analyses provide guidance to increase the general understanding of monopedicle flap mechanics and provide context for the clinician and insight into designing a better monopedicle flap for individual situations.