Instrumentation Failure in Adult Spinal Deformity Patients.

In recent years, advances in the surgical treatment of adult spinal deformity (ASD) have led to improved outcomes. Although these advances have helped drive the development of deformity surgery to meet the rising volume of patients seeking surgical treatment, many challenges have yet to be solved. Instrumentation failure remains one of the most common major complications following deformity surgery, associated with significant morbidity due to elevated re-operation rates among those experiencing mechanical complications. The two most frequently encountered subtypes of instrumentation failure are rod fracture (RF) and proximal junctional kyphosis/proximal junctional failure (PJK/PJF). While RF and PJK/PJF are both modes of instrumentation failure, they are two distinct entities with different clinical implications and treatment strategies. Considering that RF and PJK/PJF continue to represent a major challenge for patients with ASD and deformity surgeons alike, this review aims to discuss the incidence, risk factors, clinical impact, treatment strategies, preventive measures, and future research directions for each of these substantial complications.

Pelvic index: A new pelvic parameter for assessing sagittal spinal alignment.

Background: The incidence of correctional surgery for adult spinal deformity (ASD) has increased significantly over the past 2 decades. Pelvic incidence, an angular measurement, is the gold standard pelvic parameter and is used to classify spinal shapes into Roussouly types. Current literature states that restoration of the spine to its original Roussouly classification optimizes outcomes. We propose a new pelvic parameter, pelvic index, as a length measurement to complement pelvic incidence in more accurately characterizing Roussouly types. Methods: This study is a retrospective evaluation of sagittal spinal radiographs of 208 patients who were assessed by a single fellowship trained orthopedic spine surgeon between January and December 2020. Measurements included pelvic incidence, sacroacetabular distance, and L5 vertebral height. Pelvic index was calculated as the ratio of sacroacetabular distance to L5 height. Each spine was also classified into one of the Roussouly types: 1, 2, 3 anteverted pelvis (AP), 3, or 4. The 2 pelvic parameters were compared between groups to assess their ability to differentiate between Roussouly types. Results: Of the 208 patients included, 103 (49.5%) were female and 105 (50.5%) were male. The mean pelvic incidence was 54.9 ± 12.3° and the mean pelvic index was 3.99 ± 0.38. The difference in mean pelvic index was statistically significant between types 1 and 2 (0.15; p=.046) and between types 1 and 3 AP (0.19; p=.029). It was not statistically significant between types 3 and 4 (0.05; p=.251). However, in terms of pelvic incidence, the mean difference was statistically significant only between types 3 and 4 (10.4; p<.001). Conclusions: Pelvic index is the ratio of the sacroacetabular distance to the height of the L5 vertebra. In conjunction with pelvic incidence, pelvic index can help to distinguish between Roussouly types 1 and 2 and between types 1 and 3 AP, the low-pelvic incidence types.

Inverted Meckel's Diverticulum Masquerading as a Subepithelial Tumor of the Ileum.

We describe a case of an inverted Meckel's diverticulum presenting as an intraluminal subepithelial lesion on intraoperative enteroscopy. A 53-year-old woman presented with chronic iron deficiency anemia unresponsive to escalating iron supplementation. After equivocal upper and lower endoscopy and negative cross-sectional imaging, capsule endoscopy suggested a submucosal mass lesion in the proximal ileum. Antegrade double-balloon enteroscopy was unsuccessful in reaching the lesion. A large pedunculated, submucosal-appearing lesion was finally identified on intraoperative enteroscopy. The mass was surgically resected, and final pathology confirmed an inverted Meckel's diverticulum.

Systemic Mastocytosis Presenting as Pathologic Intertrochanteric Femur Fracture.

Systemic mastocytosis (SM) is pathologically characterized by the proliferation of mast cells with infiltrates in various organs, almost always including bone marrow, leading to defects in bone remodeling. Osteoporosis and subsequent fragility fractures are the most common and clinically relevant presentation, although pathologic fracture through the focal lytic lesions can also be observed. Here, we report the case of a 54-year-old woman, with a recent history of unexplained severe allergic reactions, presenting with intertrochanteric fracture of the left femur which on careful history, physical and radiological evaluation was determined to be pathological. The patient was found to have lytic lesions on the CT scan at the fracture site and the pelvis, bilateral femurs, ribs, and sternum, raising suspicion for malignancy. The malignancy workup failed to reveal a primary neoplasm, and the patient was indicated for intramedullary fixation of the left femur along with intraoperative biopsy. Pathologic evaluation of the femoral biopsy was positive for aggregates of mast cells with CD117 (c-KIT, D816V). This finding prompted a bone marrow biopsy, which ultimately led to the diagnosis of aggressive SM. Femoral intramedullary fixation was done with a trochanteric femoral nail, and the patient was postoperatively started on calcium, vitamin D, and physical therapy. Systemic disease was managed by the hematology-oncology team, and the patient was given an epinephrine autoinjector (EpiPen) and managed with midostaurin (Rydapt, Novartis Pharmaceuticals). Treating surgeons should be aware that a pathological long bone fracture can be the initial presentation of SM. Furthermore, surgeons should consider following patients with SM for longer than usual considering a higher risk of complications, such as implant loosening, nonunion, and refracture due to poor and progressively worsening quality of the bone. Our patient was followed with routine visits for 30 months and showed no clinical or radiographical signs of any complications.

Autoimmune-mediated congenital heart block.

Autoimmune-mediated congenital heart block (CHB) is a severe manifestation of neonatal lupus in which conduction tissues of the fetal heart are damaged. This occurs due to passive transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies and subsequent inflammation and fibrosis of the atrioventricular (AV) node. Notably, the disease manifests after the fetal heart has structurally developed, ruling out other anatomical abnormalities that could otherwise contribute to the block of conduction. Complete AV block is irreversible and the most common manifestation of CHB, although other cardiac complications such as endocardial fibroelastosis (EFE), dilated cardiomyopathy, and valvular insufficiency have been observed. In this review, we detail the classification, prevalence, pathogenesis, and clinical management recommendations for autoimmune CHB.

Study Comparing Traditional Versus Alternative Metrics to Measure the Impact of the Critical Care Medicine Literature.

Our objective was to evaluate the association between traditional metrics such as Impact Factor and Eigenfactor with respect to alternative metrics. The Altmetric Attention Score for the top nine pulmonary and critical care journals was compared with Impact Factor, Eigenfactor, and citations over two time periods (2007-2011 and 2012-2016). There was a significant increase in the Altmetric Attention Score (52 from 2007 to 2011 vs 1,061 from 2012 to 2016; p < 0.001) but no significant differences in Total Citations, Impact Factor, or Eigenfactor. There was a strong positive correlation between citations and Altmetric Attention Score, negative correlations between Eigenfactor and Altmetric Attention Score for most journals, and no clear association between Impact Factor and Altmetric Attention Score. Over time, the digital reach of traditional publications has increased significantly, while no significant increase was noted for the traditional metrics. These findings likely reflect discussions of articles online that are not captured by traditional metrics and hence their impact on the community at large.

Preparation of Colloidal Organosilica Spheres through Spontaneous Emulsification.

Colloidal particles of controlled size are promising building blocks for the self-assembly of functional materials. Here, we systematically study a method to synthesize monodisperse, micrometer-sized spheres from 3-(trimethoxysilyl)propyl methacrylate (TPM) in a benchtop experiment. Their ease of preparation, smoothness, and physical properties provide distinct advantages over other widely employed materials such as silica, polystyrene, and poly(methyl methacrylate). We describe that the spontaneous emulsification of TPM droplets in water is caused by base-catalyzed hydrolysis, self-condensation, and the deprotonation of TPM. By studying the time-dependent size evolution, we find that the droplet size increases without any detectable secondary nucleation. Resulting TPM droplets are polymerized to form solid particles. The particle diameter can be controlled in the range of 0.4 to 2.8 µm by adjusting the volume fraction of added monomer and the pH of the solution. Droplets can be grown to diameters of up to 4 µm by adding TPM monomer after the initial emulsification. Additionally, we characterize various physical parameters of the TPM particles, and we describe methods to incorporate several fluorescent dyes.