Nasal Construction in Congenital Arhinia Due to Novel SMCHD1 Gene Variant.

Arhinia, or congenital absence of the nose, is an exceedingly rare anomaly caused by pathogenic variants in the gene SMCHD1 . Arhinia exhibits unique reconstructive challenges, as the midface is deficient in skeletal and soft tissue structures. The authors present 2 related patients with arhinia who harbor a novel SMCHD1 gene variant and illustrate their surgical midface and nasal construction. Targeted sequencing was carried out on DNA samples from the 2 affected patients, 1 anosmic and 1 healthy parent, to identify variants in exons 3 to 13 of SMCHD1 . The affected patients and anosmic parent were found to have a novel SMCHD1 gene variant p.E473V. A staged surgical approach was applied. First, both patients underwent a LeFort II osteotomy and distraction osteogenesis to improve the projection of the midfacial segment, followed by tissue expansion of the forehead, and nasal construction with a forehead flap that was placed over a costochondral framework derived from rib cartilage. The novel gene variant could guide future investigations on genetic pathways and molecular processes that underly the physiological and pathologic development of the nose. Further investigations on the variable expressivity ranging from anosmia to arhinia could improve clinical genetic screens for risk stratification of individuals with anosmia on passing on arhinia to their children. Due to the exceptional rarity and complexity of congenital arhinia, most surgical approaches are developed on a single-case basis. This case series, albeit limited to 2 cases, is the largest pedigree of such cases in the literature. It highlights key principles of a staged approach to nasal construction in arhinia and discusses nuances and improvements learned between both patients. It subsequently offers an optimized guide to this surgical strategy.

Reconstructive breast surgery with partially absorbable bi-component Seragyn® BR soft mesh: an outcome analysis.

OBJECTIVE: Synthetic meshes and acellular dermal matrices are increasingly used in implant-based breast reconstruction. The objective of this study was to determine the incidence and severity of complications following the implantation of the partially absorbable bi-component soft mesh SERAGYN® BR and assess risk factors for adverse operative outcomes. METHODS: A retrospective clinical study was performed: The SERAGYN® BR soft mesh was utilized in 148 operations (skin-sparing mastectomy, nipple-sparing mastectomy, breast-conserving surgery, and secondary reconstruction after mastectomy) in four different institutions in Germany from June 2012 to February 2014. We analyzed whether the results were affected by tumor morphology (e.g., grading), patient characteristics and comorbidities, previous surgery or therapies, and use of alloplastic materials. RESULTS: The SERAGYN® BR soft mesh was successfully implanted in 131 of 148 operations. The rate of reconstructive failure was 11.5%. The most common complication was seroma (25.7%), followed by hematoma and skin infection (each 14.2%). Wound-healing issues were detected in 13.5% cases, secondary wound infections in 10.8%. 83.8% of operations had no severe complications. Independent predictors for reconstructive failure were wound-healing issues, nipple- or skin necrosis, wound- or skin infections, a high volume of excised tissue, hematomas, seromas, and sentinel lymph node excisions. A higher body mass index was correlated with a higher rate of infection. CONCLUSION: SERAGYN® BR mesh can be used successfully in breast reconstructive surgery. Rates of major complications or reconstructive failure are comparable to the use of other synthetic or biological meshes.

Microbiologic profile of infections in presumed aseptic revision spine surgery.

PURPOSE: Intra-operative cultures may be obtained in revision spine surgery despite the absence of pre-operative clinical markers of infection. The microbiologic profile of culture positive cases in which there is no clear evidence of infection preoperatively has not been described. The aim of this investigation is to report on the microbiologic profile of unexpected culture positive revision spine surgery cases. METHODS: We retrospectively reviewed 595 consecutive revision spine surgeries performed between 2008 and 2013. Five hundred and seventy-eight revision surgeries were performed for diagnoses other than infection and were included in the study. RESULTS: Operative cultures were obtained in 112 cases (19.4 %). Cultures were positive in 45 cases. Pseudarthrosis was not only the most common diagnosis overall (49.1 %) in which intra-operative cultures were obtained, it was also the most common revision surgical diagnosis where cultures were positive (55.6 %). Propionibacterium acnes was cultured in 54.2 % of cases with the primary diagnosis of pseudarthrosis, but only in 40.9 % of cases with other diagnoses (P = 0.554). Overall, staphylococcal species were found most commonly (57.8 % of cases), but P. acnes was at least one of the isolates in 48.9 % of cases and was three times more common than any other organism. CONCLUSIONS: Nearly one in five patients with the diagnosis of pseudarthrosis were culture positive. More specifically, pseudarthrosis was the most common culture positive diagnosis and P. acnes species predominated in this patient population. Propionibacterium acnes was overwhelmingly the most common single organism cultured in revision spine surgery. Given this, we recommend all cultures be held for P. acnes, particularly in the setting of pseudarthrosis.

MarginProbe© reduces the rate of re-excision following breast conserving surgery for breast cancer.

PURPOSE: A positive margin status after breast conserving surgery (BCS) is one of the strongest predictors for local recurrence of intraductal (DCIS) and invasive carcinoma. As much as 20-50 % of patients with BCS need to undergo a second operation to receive free margins. In this study we tested the clinical performance of MarginProbe© (Dune Medical Devices, Paoli, PA, USA), a device for the intraoperative evaluation of surgical margins. METHODS: A prospective clinical study was performed: The device was utilized in BCS of 150 patients treated at a single facility from November 2012 to June 2013. The re-excision rate was compared to the re-excision rate of a historical group of 172 patients treated with BCS at the same hospital without the application of the device. We analyzed whether the results of MarginProbe© are affected by the morphology, grading, size of the tumor, breast density, age, BMI or the use of marker-wires. RESULTS: The application of MarginProbe© resulted in an overall decreased re-excision rate of 14.6 %. In the subgroup of DCIS the re-excision rate was reduced from 61.7 to 23.1 %. In the subgroup of invasive lobular carcinomas the re-excision rate decreased from 37.0 to 19.0 %. MarginProbe© results were not affected by grading, tumor size, breast density, age, BMI or marker-wire application. CONCLUSION: MarginProbe© detects positive margins in invasive carcinoma, DCIS as well as in invasive lobular carcinoma. The device decreases the re-excision rate after BCS significantly. It does not interfere with any of the factors we examined.

Incidence of vascular complications during lateral lumbar interbody fusion: an examination of the mini-open access technique.

PURPOSE: This article examines the incidence and management of vascular injury during Lateral Lumbar Interbody Fusion (LLIF). The details of the mini-open access technique are presented. METHODS: A total of 900 patients who underwent a LLIF at an average 1.94 levels (range: 1-5 levels) by one of six fellowship trained surgeons on 1,754 levels from 2006 to 2013 were identified. The incidence of intraoperative vascular injury was retrospectively determined from the Operative Records. The management of vascular injury was evaluated. The mini-open access adapted by our institution for LLIF is described. RESULTS: The incidence of major vascular complication in our series was 1/900. The incidence of minor vascular injury was 4/900. The overall incidence of vascular injury was calculated to be 0.056 % per case and 0.029 % per level. All minor vascular injuries were identified to be segmental vessel lacerations, which were readily ligated under direct visualization without further extension of the incision with no clinical sequelae. The laceration of the abdominal aorta, the major vascular complication of this series, was emergently repaired through an exploratory laparotomy. None of the patients suffered long-term sequelae from their intraoperative vascular injuries. CONCLUSIONS: The mini-open lateral access technique for LLIF provides for minimal risk of vascular injury to the lumbar spine. In the rare event of minor vascular injury, the mini-open access approach allows for immediate visualization, confirmation and repair of the vessel with no long-term sequelae.

Late-Presenting Sagittal Craniosynostosis: An Update to a Standardized Treatment Protocol.

BACKGROUND: The authors previously published their protocol to treat patients who present with sagittal craniosynostosis after the age of 1 year. The purpose of this article is to present a follow-up and update of this cohort to evaluate outcomes of their treatment protocol. METHODS: Patients with isolated sagittal craniosynostosis who presented after the age of 1 year between July of 2013 and April of 2021 were included. RESULTS: A total of 108 patients met inclusion criteria. The average age at presentation was 5.2 ± 3.4 years, and 79 patients (73.1%) were male. The indications for imaging were head shape (54.6%), headache (14.8%), trauma (9.3%), seizure (4.6%), papilledema (2.8%), and other (13.9%). Of the 108 patients, 12 (11.1%) underwent surgery following their initial consultation: five for papilledema, four for elevated intracranial pressure, two for severely scaphocephalic head shapes, and one for abnormal funduscopic findings. Two of these patients underwent additional reconstructive surgery, one for the recurrence of papilledema and headache and the other for progressive scaphocephaly. The average length of time between operations was 4.9 years. Of the 96 patients who were managed conservatively, four (4.2%) underwent surgery at an average of 1.2 ± 0.5 years later (average age, 4.4 ± 1.5 years) for brain growth restriction ( n = 2), aesthetic concerns ( n = 1), and refractory headaches ( n = 1). The average follow-up of all patients with craniofacial surgery was 2.7 ± 2.3 years (median, 2.1 years; interquartile range, 3.7 years). CONCLUSIONS: Patients with late-presenting sagittal craniosynostosis require surgical correction less often than younger patients, likely because of milder phenotype. Few patients in the conservative treatment arm ultimately required surgery (4%). CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Using patient-reported outcome measures to assess psychological well-being in a non-representative US general population during the COVID-19 pandemic.

PURPOSE: The impact of the COVID-19 pandemic on psychological well-being will likely be long-lasting. Efforts directed towards monitoring the onset and progression of distress and mental health disorders are needed to identify and prioritize at-risk populations. This study assesses the psychological well-being of the United States (US) general population during the early phase of the COVID-19 COVID-19 pandemic using validated patient-reported outcome measures (PROMs). METHODS: A cross-sectional study design was used. Adults (18 years or older) who could read and write in English were recruited through Prolific in May 2020. Participants completed a REDCap survey including demographic and health-related questions and three PROMs measuring global health (PROMIS-10 Global Health), anxiety [Generalized Anxiety Disorder Scale-7 (GAD-7)], and depression [Patient Health Questionnaire-9 (PHQ-9)]. A multivariable linear regression was used to identify key factors associated with worse psychological well-being. RESULTS: Mean age of the 2023 participants was 31.92 ± 11.57 years (range, 18-82). Participants were mainly White (64.7%, n = 1309), female (52.2%, n = 1057), working full-time before the pandemic (43.5%, n = 879), and completed a college, trade, or university degree (40.7%, n = 823). Most participants reported mild to severe anxiety (57.3%, n = 1158) and depression (60%, n = 1276) on the GAD-7 and PHQ-9, respectively. Patient characteristics associated with worse psychological well-being included: age ≤ 39 years, non-White, female or gender diverse, BMI ≥ 30, uninsured, annual income ≤ $49,999 (USD), lower educational attainment, and belief that COVID-19 is deadlier than flu. CONCLUSION: PROMs can be used to assess and monitor psychological well-being during the COVID-19 pandemic and to inform the planning and delivery of targeted public health interventions to support at-risk populations.

Zebrafish models of alx-linked frontonasal dysplasia reveal a role for Alx1 and Alx3 in the anterior segment and vasculature of the developing eye.

The cellular and genetic mechanisms that coordinate formation of facial sensory structures with surrounding skeletal and soft tissue elements remain poorly understood. Alx1, a homeobox transcription factor, is a key regulator of midfacial morphogenesis. ALX1 mutations in humans are linked to severe congenital anomalies of the facial skeleton (frontonasal dysplasia, FND) with malformation or absence of eyes and orbital contents (micro- and anophthalmia). Zebrafish with loss-of-function alx1 mutations develop with craniofacial and ocular defects of variable penetrance, likely due to compensatory upregulation in expression of a paralogous gene, alx3. Here we show that zebrafish alx1;alx3 mutants develop with highly penetrant cranial and ocular defects that resemble human ALX1-linked FND. alx1 and alx3 are expressed in anterior cranial neural crest (aCNC), which gives rise to the anterior neurocranium (ANC), anterior segment structures of the eye and vascular pericytes. Consistent with a functional requirement for alx genes in aCNC, alx1; alx3 mutants develop with nearly absent ANC and grossly aberrant hyaloid vasculature and ocular anterior segment, but normal retina. In vivo lineage labeling identified a requirement for alx1 and alx3 during aCNC migration, and transcriptomic analysis suggested oxidative stress response as a key target mechanism of this function. Oxidative stress is a hallmark of fetal alcohol toxicity, and we found increased penetrance of facial and ocular malformations in alx1 mutants exposed to ethanol, consistent with a protective role for alx1 against ethanol toxicity. Collectively, these data demonstrate a conserved role for zebrafish alx genes in controlling ocular and facial development, and a novel role in protecting these key midfacial structures from ethanol toxicity during embryogenesis. These data also reveal novel roles for alx genes in ocular anterior segment formation and vascular development and suggest that retinal deficits in alx mutants may be secondary to aberrant ocular vascularization and anterior segment defects. This study establishes robust zebrafish models for interrogating conserved genetic mechanisms that coordinate facial and ocular development, and for exploring gene--environment interactions relevant to fetal alcohol syndrome.

ALX1-related frontonasal dysplasia results from defective neural crest cell development and migration.

A pedigree of subjects presented with frontonasal dysplasia (FND). Genome sequencing and analysis identified a p.L165F missense variant in the homeodomain of the transcription factor ALX1 which was imputed to be pathogenic. Induced pluripotent stem cells (iPSC) were derived from the subjects and differentiated to neural crest cells (NCC). NCC derived from ALX1L165F/L165F iPSC were more sensitive to apoptosis, showed an elevated expression of several neural crest progenitor state markers, and exhibited impaired migration compared to wild-type controls. NCC migration was evaluated in vivo using lineage tracing in a zebrafish model, which revealed defective migration of the anterior NCC stream that contributes to the median portion of the anterior neurocranium, phenocopying the clinical presentation. Analysis of human NCC culture media revealed a change in the level of bone morphogenic proteins (BMP), with a low level of BMP2 and a high level of BMP9. Soluble BMP2 and BMP9 antagonist treatments were able to rescue the defective migration phenotype. Taken together, these results demonstrate a mechanistic requirement of ALX1 in NCC development and migration.

Risk Factors for Positive Cultures in Presumed Aseptic Revision Spine Surgery.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: To report culturing patterns and results in the setting of presumed aseptic revision spinal surgery. SUMMARY OF BACKGROUND DATA: The indications for obtaining cultures in revision spinal surgery remain unclear in the absence of a definitive diagnosis of infection. Culture results and risk factors for having positive cultures in this setting have not been previously studied. METHODS: We retrospectively reviewed 595 consecutive revision spine surgeries performed by four senior spine surgeons between 2008 and 2013. Preoperative workup revealed the diagnosis of infection in 17 cases which were excluded from review. The remaining 578 presumed aseptic cases were included. Univariate and multivariate analyses were performed to identify variables associated with obtaining cultures and risk factors for positive cultures. RESULTS: Cultures were obtained in 112 (19.4%) cases and were positive in 40.2%. Pseudarthrosis was the most common revision diagnosis when cultures were obtained (49.1%) and Propionibacterium acnes was the most common organism isolated from positive cultures (48.8%). Regarding culture results, multivariate analysis demonstrated that male sex (odds ratio [OR] = 3.4) and pseudarthrosis (OR = 4.1) were significantly associated with having positive cultures while fusion procedures (OR = 0.3) were negatively correlated, with area under the curve (AUC) 0.71. CONCLUSION: Unexpected positive cultures occurred commonly and P. acnes was the predominant isolated organism. Male sex, pseudarthrosis, and non-fusion cases predicted positive cultures. Considering these results, we recommend cultures be obtained in revision cases for pseudarthrosis, even in the setting of negative infectious work-up preoperatively. LEVEL OF EVIDENCE: 4.

Effect of Steroid-Soaked Gelatin Sponge on Soft Tissue Swelling Following Anterior Cervical Discectomy and Fusion: A Radiographic Analysis.

STUDY DESIGN: Retrospective radiological review and analysis of 79 patients who underwent primary anterior cervical discectomy and fusion (ACDF) of 2 or 3 levels between 2011 and 2013. PURPOSE: This study aimed to determine the effect of the local placement of a steroid-soaked gelatin sponge after ACDF on prevertebral soft tissue swelling. OVERVIEW OF LITERATURE: Although ACDF has become a popular choice for cervical fusion, the surgical involvement of the delicate anatomy of the neck frequently results in tissue irritation and edema. Swelling of the prevertebral soft tissue may consequently lead to mild-to-severe complications, ranging from dysphonia to dyspnea. METHODS: Out of the 79 patients who underwent primary ACDF, 52 received a gelatin sponge soaked with 40 mg of Depo-Medrol placed adjacent to the operated cervical levels. Prevertebral soft tissue swelling was detected using postoperative lateral X-ray. The radiographic values were compared to those of 27 patients who did not receive the treatment. RESULTS: Soft tissue swelling was markedly decreased in patients who received the placement of the steroid-soaked gelatin sponge next to their fused levels after surgery compared with that in patients who did not receive it. No complications were documented with the use of steroids. CONCLUSIONS: The placement of a steroid-soaked gelatin sponge markedly reduces postoperative soft tissue swelling following 2- or 3-level primary ACDF.

Postoperative Emergency Department Utilization and Hospital Readmission After Cervical Spine Arthrodesis: Rates, Trends, Causes, and Risk Factors.

STUDY DESIGN: Retrospective state database analysis. OBJECTIVE: To quantify the 30- and 90-day emergency department (ED) utilization and inpatient readmission rates after primary cervical arthrodesis, to stratify these findings by surgical approach, and to describe risk factors and conditions precipitating these events. SUMMARY OF BACKGROUND DATA: Limited data exist on ED utilization and hospital readmission rates after cervical spine arthrodesis. METHODS: The New York State all-payer health-care database was queried to identify all 87,045 patients who underwent primary subaxial cervical arthrodesis from 1997 through 2012. Demographic data and clinical information were extracted. Readmission data were available for the entire study period, whereas ED utilization data collection began later and was therefore analyzed starting in 2005. Incidences of these events within 30 and 90 days of discharge as well as trends over time were tabulated. The conditions prompting these encounters were also collected. Data were analyzed with respect to surgical approach. RESULTS: The hospital readmission rate was 4.2% at 30 days and 6.2% at 90 days postoperatively. Approximately 6.2% of patients were managed in the ED without inpatient admission within 30 days and 11.3% within 90 days of surgery. The most common conditions prompting such events were dysphagia or dysphonia, respiratory complications, and infection. ED utilization and readmission rates were lowest after anterior surgeries. A preoperative Charlson Comorbidity Index of 1 or greater and traumatic pathologies were associated with increased risk of subsequent ED utilization or hospital readmission. Thirty-day hospital readmission rates declined after 2010, whereas 30-day ED utilization continued to increase. CONCLUSION: Patient comorbidities, traumatic pathologies, and surgical approach are associated with increased postoperative complications. Anterior procedures carry the lowest risk, followed by posterior and then circumferential. Awareness of these findings should help to encourage development of strategies to minimize the rate of postoperative ED utilization and hospital readmission. LEVEL OF EVIDENCE: 3.

Cervical Spinal Fusion: 16-Year Trends in Epidemiology, Indications, and In-Hospital Outcomes by Surgical Approach.

BACKGROUND: The rate of cervical spinal fusion has been increasing significantly. However, there is a paucity of literature describing trends based on surgical approach using complete population databases. We investigated the approach-based trends in epidemiology, indications, and in-hospital outcomes of cervical spinal fusion. METHODS: New York's Statewide Planning and Research Cooperative System database was queried to identify patients who underwent primary subaxial cervical fusion from 1997 to 2012. Demographic and clinical information was obtained. Subgroup analyses were performed based on surgical approach: anterior (A), posterior (P), and circumferential (C). RESULTS: A total of 87,045 cervical fusions were included. Over the study period, the population-adjusted annual fusion rate increased from 23.7 to 50.6 per 100,000 population (P < 0.001). A fusion was most common (85.2%), followed by P (12.3%), and C (2.5%). Mean ages were 49.8 ± 11.9, 59.9 ± 15.2, and 55.1 ± 14.5 years (P < 0.001), respectively. Although rates remained steady among younger patients, they increased for older patients. Overall, degenerative conditions were the predominant indications for surgery and increased in rate over time. The mean length of stay was: A, 3.1 ± 10.5; P, 9.1 ± 14.1; and C, 14.1 ± 22.5 days (P < 0.001). Rates of in-hospital complications were A, 3.0%; P, 10.5%; and C, 18.9% (P < 0.001), and mortality was A, 0.3%, P, 1.8%, and C, 2.5% (P < 0.001). CONCLUSIONS: The rate of subaxial spinal fusions increased 114% from 1997 to 2012 in New York State. Rates remained stable in younger patients but increased in the older population. Preoperative indications and postoperative courses differed significantly among the various approaches, with patients undergoing anterior fusion having better short-term outcomes.

Demographic, Clinical, and Operative Factors Affecting Long-Term Revision Rates After Cervical Spine Arthrodesis.

BACKGROUND: Limited data exist on long-term revision rates following cervical spine arthrodeses. The purposes of this study were to define reoperation rates after primary cervical arthrodeses and to identify risk factors for revisions. METHODS: New York State's all-payer health-care database was queried to identify all primary subaxial cervical arthrodeses occurring in the 16 years from 1997 through 2012. A total of 87,042 patients were included in the study cohort. Demographic information was extracted. Patients' preoperative medical comorbidities, surgical indications, and operative approaches were assembled using codes from the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification). The cohort was followed to revision surgical procedures, death, or the end of the study period. All subsequent contiguous spinal arthrodeses, including in the subaxial cervical spine, were considered revisions. The overall revision risk and the risk associated with various preoperative characteristics, surgical indications, and operative approaches were assessed using a Cox proportional hazard model. RESULTS: During the study period, 6,721 patients (7.7%) underwent revision. The median time to revision was 24.5 months. The probability of undergoing at least one revision by 192 months was 12.6%. Arthrodeses performed via anterior-only approaches had a significantly higher probability of revision (p < 0.001) at 13.4% (95% confidence interval [95% CI], 12.9% to 13.9%) than those performed via posterior approaches at 7.4% (95% CI, 6.6% to 8.4%) or circumferential (anterior and posterior) approaches at 5.2% (95% CI, 4.0% to 6.8%). This relationship persisted in multivariate analysis; compared with anterior surgical procedures, there was a significantly lower risk of revision (p < 0.001) for posterior surgical approaches at a hazard ratio of 0.76 (95% CI, 0.69 to 0.84) and circumferential approaches at a hazard ratio of 0.53 (95% CI, 0.42 to 0.66). Patient age of 18 to 34 years, white race, insurance status of Workers' Compensation or Medicare, and surgical procedures for spinal stenosis, spondylosis, deformity, and neoplasm were associated with elevated revision risk. Arthrodeses spanning few levels and those performed for fractures had a lower revision risk. CONCLUSIONS: Primary subaxial cervical spine arthrodeses had a probability of revision approaching 13% over a 16-year period, with elevated reoperation rates in patients undergoing anterior-only surgical procedures. Age, race, insurance status, surgical indication, and number of spinal levels included in the arthrodesis were also associated with reoperation risk. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Atlantoaxial Fusion: Sixteen Years of Epidemiology, Indications, and Complications in New York State.

STUDY DESIGN: A retrospective state database analysis. OBJECTIVE: The aim of this study was to describe the epidemiology and complications of as well as indications for primary isolated atlantoaxial fusion. SUMMARY OF BACKGROUND DATA: Atlantoaxial fusion involves unique indications, techniques, and complications. There is limited epidemiologic literature focused specifically on this procedure. METHODS: New York's Statewide Planning and Research Cooperative System database, an all-payer hospitalization reporting system, was queried to identify all patients undergoing primary isolated atlantoaxial fusion in the state from 1997 to 2012. Demographic and clinical data were extracted and analyzed. United States Census Bureau figures were used to calculate population-adjusted surgical rates. RESULTS: One thousand five hundred fifty-nine patients underwent isolated primary atlantoaxial fusion during the study period. The overall population-adjusted annual surgical rate did not change significantly over time. By 2012, individuals aged ≥70 years had the highest incidence of surgery [2.37 per 100,000 population; 95% confidence interval (95% CI) 1.68-3.07]. Medicare was the most common payer (44.0% of claims). Approximately 85% of patients had a Charlson/Deyo Comorbidity Index of zero or one. Over time, a significantly lower proportion of atlantoaxial fusions were attributable to rheumatic disease, and a significantly higher proportion were due to fracture. By 2012, management of fractures was the most common indication for C1-C2 fusion (44.1% of cases). Dysphagia or dysphonia occurred after 0.8% of cases, dural tear after 0.3%, infection after 0.5%, and seroma, hematoma, or hemorrhage after 0.5%. In-hospital mortality was 2.7%, of which 76% had fracture as the surgical indication. CONCLUSION: Isolated atlantoaxial fusions have been performed at a stable, low level over the past 16 years in New York. Although most of these patients are relatively healthy pre-operatively, approximately one in 10 experience an in-hospital complication and nearly 3% die in-hospital. Knowledge of these risks will hopefully spur further efforts to minimize them and allow for more accurate counseling of patients and their families. LEVEL OF EVIDENCE: 4.

Synthetic niche to modulate regenerative potential of MSCs and enhance skeletal muscle regeneration.

Severe injury to the skeletal muscle often results in the formation of scar tissue, leading to a decline in functional performance. Traditionally, tissue engineering strategies for muscle repair have focused on substrates that promote myogenic differentiation of transplanted cells. In the current study, the reported data indicates that mesenchymal stromal cells (MSCs) transplanted via porous alginate cryogels promote muscle regeneration by secreting bioactive factors that profoundly influence the function of muscle progenitor cells. These cellular functions, which include heightened resistance of muscle progenitor cells to apoptosis, migration to site of injury, and prevention of premature differentiation are highly desirable in the healing cascade after acute muscle trauma. Furthermore, stimulation of MSCs with recombinant growth factors IGF-1 and VEGF165 was found to significantly enhance their paracrine effects on muscle progenitor cells. Multifunctional alginate cryogels were then utilized as synthetic niches that facilitate local stimulation of seeded MSCs by providing a sustained release of growth factors. In a clinically relevant injury model, the modulation of MSC paracrine signaling via engineered niches significantly improved muscle function by remodeling scar tissue and promoting the formation of new myofibers, outperforming standalone cell or growth factor delivery.

Stem cells for spine surgery.

In the past few years, stem cells have become the focus of research by regenerative medicine professionals and tissue engineers. Embryonic stem cells, although capable of differentiating into cell lineages of all three germ layers, are limited in their utilization due to ethical issues. In contrast, the autologous harvest and subsequent transplantation of adult stem cells from bone marrow, adipose tissue or blood have been experimentally utilized in the treatment of a wide variety of diseases ranging from myocardial infarction to Alzheimer's disease. The physiologic consequences of stem cell transplantation and its impact on functional recovery have been studied in countless animal models and select clinical trials. Unfortunately, the bench to bedside translation of this research has been slow. Nonetheless, stem cell therapy has received the attention of spinal surgeons due to its potential benefits in the treatment of neural damage, muscle trauma, disk degeneration and its potential contribution to bone fusion.

Evidence for the adverse effect of starvation on bone quality: a review of the literature.

Malnutrition and starvation's possible adverse impacts on bone health and bone quality first came into the spotlight after the horrors of the Holocaust and the ghettos of World War II. Famine and food restrictions led to a mean caloric intake of 200-800 calories a day in the ghettos and concentration camps, resulting in catabolysis and starvation of the inhabitants and prisoners. Severely increased risks of fracture, poor bone mineral density, and decreased cortical strength were noted in several case series and descriptive reports addressing the medical issues of these individuals. A severe effect of severely diminished food intake and frequently concomitant calcium- and Vitamin D deficiencies was subsequently proven in both animal models and the most common cause of starvation in developed countries is anorexia nervosa. This review attempts to summarize the literature available on the impact of the metabolic response to Starvation on overall bone health and bone quality.

Posterior reversible encephalopathy syndrome: temporary visual loss after spinal deformity surgery.

Posterior reversible encephalopathy syndrome (PRES) is a rare cause of temporary postoperative visual loss (POVL) after spinal deformity surgery. We report on 2 patients diagnosed with PRES after spinal deformity surgery, who were closely examined postoperatively. A 78-year-old woman with severe disability due to degenerative lumbar spondylosis after laminectomy was treated with transpsoas lumbar interbody fusion from L1 to L4 and posterior spinal fusion from T10 to pelvis. She developed confusion and bilateral visual loss on postoperative day 7. A second patient, a 51-year-old woman with progressive pain and decompensation caused by adult scoliosis, was treated with posterior spinal fusion from T3 to pelvis and interbody fusion from L4 to S1 via a presacral interbody fusion approach. She developed bilateral visual loss on postoperative day 15. Both patients achieved a complete recovery of their vision after medical management of PRES. Timely diagnosis of PRES and prompt intervention allow for a good patient prognosis and complete recovery of eyesight.