Faculty Bibliography

OBJECTIVE:To define "high osteotomy" and determine the feasibility of performing this procedure. DESIGN/METHODS:Single institution, retrospective review. SETTING/METHODS:Academic tertiary referral hospital. PATIENTS, PARTICIPANTS/METHODS:34 skeletally mature, nonsyndromic patients with unilateral CLP who underwent Le Fort I osteotomy between 2013 and 2020. Patients with cone-beam computed tomography (CBCT) scans completed both pre- (T1) and post-operatively (T2) were included. Patients with bilateral clefts and rhinoplasty prior to post-operative imaging were excluded. INTERVENTIONS/METHODS:Single jaw one-piece Le Fort I advancement surgery. MAIN OUTCOME MEASURES/METHODS:Measurements of the superior ala and inferior turbinates were taken from the post-operative CBCT. RESULTS:The sample included 26 males and 8 females, 12 right- and 22 left-sided clefts. The inferior turbinates are above the superior alar crease at a rate of 73.53% and 76.48% on the cleft and non-cleft sides, respectively. One (2.9%) osteotomy cut was above the level of the cleft superior alar crease, and no cuts were above the level of the non-cleft superior ala. On average, the superior ala was 2.63 mm below the inferior turbinates. The average vertical distances from the superior alar crease and the inferior turbinates to the base of the non-cleft side pyriform aperture were 12.17 mm (95% CI 4.00-20.34) and 14.80 mm (95% CI 4.61-24.98), respectively. To complete a "high osteotomy," with 95% confidence, the cut should be 20.36 mm from the base of the pyriform aperture. CONCLUSIONS:A "high" osteotomy is not consistently possible due to the relationship between the superior alar crease and the inferior turbinate.

The calvaria (top part of the skull) is made of pieces of bone as well as multiple soft tissue joints called sutures. The latter is crucial to the growth and morphogenesis of the skull, and thus a loss of calvarial sutures can lead to severe congenital defects in humans. During embryogenesis, the calvaria develops from the cranial mesenchyme covering the brain, which contains cells originating from the neural crest and the mesoderm. While the mechanism that patterns the cranial mesenchyme into bone and sutures is not well understood, function of Lmx1b, a gene encoding a LIM-domain homeodomain transcription factor, plays a key role in this process. In the current study, we investigated a difference in the function of Lmx1b in different parts of the calvaria using neural crest-specific and mesoderm-specific Lmx1b mutants. We found that Lmx1b was obligatory for development of the interfrontal suture and the anterior fontanel along the dorsal midline of the skull, but not for the posterior fontanel over the midbrain. Also, Lmx1b mutation in the neural crest-derived mesenchyme, but not the mesoderm-derived mesenchyme, had a non-cell autonomous effect on coronal suture development. Furthermore, overexpression of Lmx1b in the neural crest lineage had different effects on the position of the coronal suture on the apical part and the basal part. Other unexpected phenotypes of Lmx1b mutants led to an additional finding that the coronal suture and the sagittal suture are of dual embryonic origin. Together, our data reveal a remarkable level of regional specificity in regulation of calvarial development.

BACKGROUND:Condylar adaptations following orthognathic surgery remain an area of interest. Prior studies do not use 3-dimensional imaging modalities and lack standardization in the choice of osteotomy and movement when assessing condylar changes. PURPOSE:The purpose of this study was to use 3-dimensional cephalometry to measure the association between osteotomy type (sagittal split osteotomy [SSO] vs vertical ramus osteotomy [VRO]) and changes in condylar volume and position. STUDY DESIGN, SETTING, AND SAMPLE:This is a retrospective cohort study from January 2021 through December 2022 of patients at Bellevue Hospital in New York City, New York who were treated with either SSO or VRO for the correction of Class III skeletal malocclusion. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE:The primary predictor was the type of mandibular osteotomy, sagittal split osteotomy, and vertical ramus osteotomy. MAIN OUTCOME VARIABLES:) and relative position (anterior-posterior change utilizing the Pullinger and Hollinder method). COVARIATES:Covariates included patient age, sex, setback magnitude, temporomandibular joint symptoms, and fixation method for SSO patients. ANALYSES:tests. If there were multiple significant univariate predictors, multiple regression models were created to predict volume and position changes. A P < .05 value was considered statistically significant. RESULTS:; P = .03) and positional change (68.2 vs 12.5%; P < .01). Self-reported measures of postoperative pain, internal derangement, and myofascial symptoms were not significantly associated with either volume or positional changes. CONCLUSIONS AND RELEVANCE:The SSO resulted in greater postoperative condylar volume loss and positional changes. These volume and positional changes were not correlated with self-reported temporomandibular disorder symptoms.

This study aimed to develop a recycling process for the remnants of milled 3Y-TZP and enhance their properties using glass infiltration. 3Y-TZP powder was gathered from the vacuum system of CAD-CAM milling equipment, calcined and sieved (x < 75 μm). One hundred twenty discs were fabricated and pre-sintered at 1000 °C/h. These specimens were then divided into four groups, categorized by glass infiltration (non-infiltrated [Zr] or glass-infiltrated [Zr-G]) and sintering temperature (1450 °C [Zr-1450] or 1550 °C [Zr-1550]/2h). After sintering, the specimens were characterized by X-Ray Diffraction (XRD), relative density measurement, and scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). The biaxial flexural strength test was performed according to the ISO 6872 and followed by fractographic analysis. Subsequent results were analyzed using Weibull statistics. Relative density values of the sintered specimens from Zr-1450 and Zr-1550 groups were 86.7 ± 1.5% and 92.2 ± 1.7%, respectively. Particle size distribution revealed particles within the range of 0.1-100 μm. XRD analysis highlighted the presence of the ZrO₂-tetragonal in both the Zr-1450 and Zr-1550 groups. Glass infiltration, however, led to the formation of the ZrO₂-monoclinic of 9.84% (Zr-1450-G) and 18.34% (Zr-1550-G). SEM micrographs demonstrated similar microstructural characteristics for Zr-1450 and Zr-1550, whereas the glass-infiltrated groups exhibited comparable infiltration patterns. The highest characteristic strength was observed in the glass-infiltrated groups. Fractographic analyses suggested that fracture origins were related to defects on the tensile side, which propagated to the compression side of the samples. Both the sintering temperature and glass infiltration significantly influenced the mechanical properties of the 3Y-TZP recycled.

CASE/METHODS:Given the rare incidence of sternal nonunion after traumatic injury, literature describing the management of posttraumatic sternal reconstruction is limited. We present a case of a 54-year-old man with a history of traumatic chest wall injury with multiple unsuccessful attempts at sternal repair who presented with chronic sternal nonunion and persistent bone defect. Sternal reconstruction using a vascularized double-barrel free fibula flap with rigid fixation in multiple planes was performed, with confirmed bony union at 6 months. CONCLUSION/CONCLUSIONS:This novel approach to sternal nonunion management allowed effective bridging of posttraumatic sternal bone defects while facilitating osseous integration and long-term stabilization.

BACKGROUND/UNASSIGNED:In properly selected patients, combined face and whole eye transplantation (FWET) may offer a more optimal aesthetic and potentially functional outcome while avoiding the complications and stigma of enucleation and prosthetics. This study presents the most comprehensive cadaveric assessment for FWET to date, including rehearsal allograft procurement on a brain-dead donor. METHODS/UNASSIGNED:Over a 2-year period, 15 rehearsal dissections were performed on 21 cadavers and one brain-dead donor. After identification of a potential recipient, rehearsals assessed clinical feasibility and enabled operative planning, technical practice, refinement of personalized equipment, and improved communication among team members. Operative techniques are described. RESULTS/UNASSIGNED:Facial allograft procurement closely followed previously described face transplant techniques. Ophthalmic to superficial temporal (O-ST) vessel anastomosis for globe survival was assessed. Craniectomy allowed for maximal optic nerve and ophthalmic vessel pedicle length. Appropriate pedicle length and vessel caliber for O-ST anastomosis was seen. Research procurement demonstrated collateral blood flow to the orbit and surrounding structures from the external carotid system as well as confirmed the feasibility of timely O-ST anastomosis. Personalized cutting guides enabled highly accurate bony inset. CONCLUSIONS/UNASSIGNED:This study formalizes an approach to FWET, which is feasible for clinical translation in judiciously selected patients. O-ST anastomosis seems to minimize retinal ischemia time and allow perfusion of the combined allograft on a single external carotid pedicle. Although restoration of vision likely remains out of reach, globe survival is possible.

BACKGROUND:Hand transplantation (HT) has emerged as an intervention of last resort for those who endured amputation or irreparable loss of upper extremity function. However, because of the considerable effort required for allograft management and the risks of lifelong immunosuppression, patient eligibility is critical to treatment success. Thus, the objective of this article is to investigate the reported eligibility criteria of HT centers globally. METHODS:A systematic review of the HT literature was conducted according to Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines, using PubMed, Cochrane, Ovid/Medline, and Scopus. Program Web sites and clinicaltrials.gov entries were included where available. RESULTS:A total of 354 articles were reviewed, 101 of which met inclusion criteria. Furthermore, 10 patient-facing Web sites and 11 clinical trials were included. The most reported criteria related to the capacity to manage the allograft posttransplantation, including access to follow-up, insurance coverage, psychological stability, and history of medical compliance. Other factors related to the impact of immunosuppression, such as active pregnancy and patient immune status, were less emphasized. CONCLUSIONS:Because of the novelty of the field, eligibility criteria continue to evolve. While there is consensus on certain eligibility factors, other criteria diverge between programs, and very few factors were considered absolute contraindications. As the popularity of the field continues to grow, we encourage the development of consensus evidence-based eligibility criteria.

Hydrogels with long-term storage stability, controllable sustained-release properties, and biocompatibility have been garnering attention as carriers for drug/growth factor delivery in tissue engineering applications. Chitosan (CS)/Graphene Oxide (GO)/Hydroxyethyl cellulose (HEC)/β-glycerol phosphate (β-GP) hydrogel is capable of forming a 3D gel network at physiological temperature (37 °C), rendering it an excellent candidate for use as an injectable biomaterial. This work focused on an injectable thermo-responsive CS/GO/HEC/β-GP hydrogel, which was designed to deliver Atsttrin, an engineered derivative of a known chondrogenic and anti-inflammatory growth factor-like molecule progranulin. The combination of the CS/GO/HEC/β-GP hydrogel and Atsttrin provides a unique biochemical and biomechanical environment to enhance fracture healing. CS/GO/HEC/β-GP hydrogels with increased amounts of GO exhibited rapid sol-gel transition, higher viscosity, and sustained release of Atsttrin. In addition, these hydrogels exhibited a porous interconnected structure. The combination of Atsttrin and hydrogel successfully promoted chondrogenesis and osteogenesis of bone marrow mesenchymal stem cells (bmMSCs) in vitro. Furthermore, the work also presented in vivo evidence that injection of Atsttrin-loaded CS/GO/HEC/β-GP hydrogel stimulated diabetic fracture healing by simultaneously inhibiting inflammatory and stimulating cartilage regeneration and endochondral bone formation signaling pathways. Collectively, the developed injectable thermo-responsive CS/GO/HEC/βG-P hydrogel yielded to be minimally invasive, as well as capable of prolonged and sustained delivery of Atsttrin, for therapeutic application in impaired fracture healing, particularly diabetic fracture healing.

BACKGROUND:An update on the epidemiology of distal radius fractures in the United States is necessary, particularly as the elderly population grows. Additionally, age and frailty have been associated with complications following surgical fixation of DRFs. Herein, we utilize the National Trauma Data Bank, a robust nationwide resource, to investigate the relationship between demographics, comorbidities, injury and fracture characteristics, and admission details. METHODS:Patients with isolated distal radius fractures were identified from the National Trauma Data Bank (2016-2019) according to ICD-10 codes. Univariate and multivariate regressions were conducted to determine independent risk factors for bilateral fractures, displaced fractures, open fractures, as well as length of hospital stay and adverse discharge disposition for patients undergoing inpatient surgical fixation. RESULTS:The incidence of DRFs was 3.6/1,000 trauma-related emergency department visits and 10.8/1,000 upper extremity traumas. Trauma mechanism was significantly associated with displaced and open fractures. Age (OR 1.01, 95% CI 1.01-1.01), BMI (OR 1.02, 95% CI 1.01-1.02), smoking (OR 1.34, 95% CI 1.15-1.57), and alcohol level (trace: OR 2.18, 95% CI 1.41-3.29; intoxicated: OR 2.20, 95% CI 1.63-2.95) were significantly associated with open fractures. Machinery (β=2.04, 95% CI 1.00-3.08) and MVT (β=0.39, 95% CI 0.08-0.69) mechanisms were independent risk factors for longer length of stay. mFI-5 was an independent risk factor, in a stepwise fashion, for both length of stay and adverse discharge disposition. CONCLUSIONS:High-energy mechanisms and risk factors for poor skin quality were significantly associated with open fractures. mFI-5 was an independent risk factor for longer length of stay and non-routine discharges in patients of all ages, despite controlling for other comorbidities, unrelated complications, and mechanism of injury. Trauma mechanism was an independent risk factor for prolonged length of stay only, particularly in patients younger than 65 years of age.