Alkaline phosphatase (ALP) is an enzyme which has been proven useful as a biomarker for bone turnover and inflammation. We hypothesized that high serum ALP levels are associated with increased ...complication rates following lumbar spinal fusion.
Lumbar spinal fusion procedures from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database. Serum alkaline phosphatase levels were stratified into low <44 IU/L, normal 44–147 IU/L, and high >147 IU/L. A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor for complications.
A total of 16,441 patients who underwent lumbar fusion procedures were included. Adjusted multivariate logistic regression analysis demonstrated that patients with a high serum ALP level had a significantly increased risk for developing septic shock (OR 4.68, 95% CI 1.83–11.97), pneumonia (OR 2.89, 95% CI 1.59–5.25), requiring a transfusion (OR 2.09, 95% CI 1.68–2.59), reoperation within 30 days (OR 1.68, 95% CI 1.12–2.52), readmission within 30 days (OR 1.60, 95% CI 1.16–2.21), increased length of stay (OR 1.87, 95% CI 1.49–2.36), and nonhome discharge (OR 2.18, 95% CI 1.80–2.66).
Elevated serum ALP in patients undergoing lumbar fusion procedures is associated with increased risk for multiple in-hospital complications as well as higher rates of readmission and reoperation.
Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding ...domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.
Visceral myopathy is a rare, life-threatening disease linked to identified genetic mutations in 60% of cases. Mostly due to the dearth of knowledge regarding its pathogenesis, effective treatments ...are lacking. The disease is most commonly diagnosed in children with recurrent or persistent disabling episodes of functional intestinal obstruction, which can be life threatening, often requiring long-term parenteral or specialized enteral nutritional support. Although these interventions are undisputedly life-saving as they allow affected individuals to avoid malnutrition and related complications, they also seriously compromise their quality of life and can carry the risk of sepsis and thrombosis. Animal models for visceral myopathy, which could be crucial for advancing the scientific knowledge of this condition, are scarce. Clearly, a collaborative network is needed to develop research plans to clarify genotype–phenotype correlations and unravel molecular mechanisms to provide targeted therapeutic strategies. This paper represents a summary report of the first ‘European Forum on Visceral Myopathy’. This forum was attended by an international interdisciplinary working group that met to better understand visceral myopathy and foster interaction among scientists actively involved in the field and clinicians who specialize in care of people with visceral myopathy.
Graphical Abstract
Abstract Background Context The use of a novel lumbar pedicle cortical bone trajectory (CBT) screw has recently gained popularity, allowing for a minimally invasive approach and potentially improved ...screw purchase. However, to date, no studies have identified the ideal patient population to utilize this technology. Purpose This study reports the bone mineral density (BMD) using Hounsfield units (HUs) along a CBT screw pathway. Patients with a greater difference in density of bone in the lumbar vertebrae between the fixation points of the CBT and traditional pedicle screw may be optimal candidates to realize the advantages of this technique. Study Design/Setting A cross-sectional observational anatomic study was carried out. Patient Sample The sample comprised 180 randomly selected patients with lumbar computed tomography imaging from L1 to L5 spinal levels. Outcome Measures This study used computed tomography image-derived HUs as a metric for BMD. Methods A total of 180 patients without previous lumbar surgery with computed tomography imaging of the lumbar spine met the inclusion criteria. Patients were chosen randomly from an institutional database based on age (evenly distributed by decade of life) and gender. Hounsfield units were measured at the expected end fixation point for both a cortical (superior/posterior portion of the vertebral body) and traditional pedicle trajectory (mid-vertebral body). Results Hounsfield unit values measured at the end fixation point for the CBT screw were significantly greater than that of the traditional pedicle screw in all age groups. The relative difference in HU values significantly increased with each decade of age (p<.001) and caudal lumbar level (p<.001). In the osteoporotic group, as determined by well-established HU values, there was a significantly greater difference in the BMD of the CBT fixation point compared with the traditional trajectory (p=.048–<.001). Conclusions Bone mineral density as measured by HU values for the fixation point of the CBT screw is significantly greater than that of the traditional pedicle screw. This difference is even more pronounced when comparing osteoporotic and elderly patients to the general population. The data in this study suggest that the potential advantages from the CBT screw such as screw purchase may increase linearly with age and in osteoporotic patients.
Peptide amphiphile (PA) nanofibers formed by self-assembly can be customized for specific applications in regenerative medicine through the use of molecules that display bioactive signals on their ...surfaces. Here, the use of PA nanofibers with binding affinity for the bone promoting growth factor BMP-2 to create a gel scaffold for osteogenesis is reported. With the objective of reducing the amount of BMP-2 used clinically for successful arthrodesis in the spine, amounts of growth factor incorporated in the scaffolds that are 10 to 100 times lower than that those used clinically in collagen scaffolds are used. The efficacy of the bioactive PA system to promote BMP-2-induced osteogenesis in vivo is investigated in a rat posterolateral lumbar intertransverse spinal fusion model. PA nanofiber gels displaying BMP-2-binding segments exhibit superior spinal fusion rates relative to controls, effectively decreasing the required therapeutic dose of BMP-2 by 10-fold. Interestingly, a 42% fusion rate is observed for gels containing the bioactive nanofibers without the use of exogenous BMP-2, suggesting the ability of the nanofiber to recruit endogenous growth factor. Results obtained here demonstrate that bioactive biomaterials with capacity to bind specific growth factors by design are great targets for regenerative medicine.
Visceral myopathies are debilitating conditions characterized by dysfunction of smooth muscle in visceral organs (bowel, bladder, and uterus). Individuals affected by visceral myopathy experience ...feeding difficulties, growth failure, life-threatening abdominal distension, and may depend on intravenous nutrition for survival. Unfortunately, our limited understanding of the pathophysiology of visceral myopathies means that current therapies remain supportive, with no mechanism-based treatments. We developed a patient-derived iPSC line with a c.769C > T p.R257C/+ mutation, the most common genetic cause of visceral myopathy. This cell line will facilitate studies of how the ACTG2 R257C heterozygous variant affects smooth muscle development and function.
Dysfunction of visceral smooth muscle (“visceral myopathy”) impairs bowel, bladder, and uterine function. Symptoms of this life-threatening condition include massive intestinal distension with slow ...transit, vomiting, feeding intolerance, growth failure, poor bladder emptying, and difficult vaginal delivery. The most common genetic cause of visceral myopathy is a heterozygous point mutation (R257C) in gamma smooth muscle actin (
ACTG2
). We genetically modified the WAe0009-A human embryonic stem cell line to carry the c.769C>T p.R257C/+ mutation. This cell line will facilitate studies of how the ACTG2 R257C heterozygous variant affects smooth muscle development and function.
Abstract Fixation of the distal portion of the femur in patients with total knee arthroplasties can be challenging. Locking plates have emerged as a promising treatment. Twenty-seven patients with ...periprosthetic distal femur fractures after total knee arthroplasties were treated using a contralateral reverse distal femoral locking plate. The average time for union and weight-bearing was 4.5 ± 2.7 months. The union rate was 89%. Thirty-seven percent experienced complications, with 2 delayed unions (7.4%), 1 nonunion (3.7%), and 7 fixation failures (26%). Alteration in blood supply and biomechanics as well as poor existing bone quality and minimal distal femur bone stock may contribute to treatment difficulties.
Background
Pretreatment variables have been shown to be associated with the fulfillment of patient expectations, yet in treating thumb trapeziometacarpal osteoarthritis (OA) it remains unclear how ...patient expectations correlate with the effectiveness of treatment. An increased understanding of the variables that affect patient expectations enables tailored patient education and patient-provider communication.
Questions/purposes
(1) Is there a correlation between patient demographics and clinical characteristics, and the expectations the patients have when seeking treatment for trapeziometacarpal OA? (2) What factors are independently associated with the total expectations score and frequency of expecting “back to normal” among patients treated for trapeziometacarpal OA?
Methods
Between March 2011 and October 2013, 89 patients of all 96 eligible patients seeking treatment for trapeziometacarpal OA were approached and agreed to participate in this study. Participants completed a validated expectations survey measuring the number of expectations and the degree of improvement expected. Comparative analysis of demographic and clinical characteristics and multivariate regression analysis against patients’ expectations were performed to assess and identify factors that correlate with the number and degree of expectations. Sample size was determined with an a priori power analysis (with 80% power and statistical significance set at p < 0.05), which showed that 88 patients were needed to detect the minimal clinical difference of 12 points in the Michigan Hand Questionnaire; we then increased this by 10% to allow for potential dropouts.
Results
After controlling for potential confounding variables such as age, hand dominance, and work status, the following factors were associated with a higher expectations score: choice of surgery (β = 11.5; 95% CI, 0.7–23.8; p = 0.044), female gender (β = 19.0; 95% CI, 5.3–32.7; p = 0.007), and dominant side affected (β = −41.6; 95% CI, −63.7 to −19.5; p < 0.001). For the frequency of “back to normal” responses, surgical treatment (β = 7.4; 95% CI, 2.3–12.4; p = 0.005) and history of previous injury (β = 8.2; 95% CI, 0.1–16.3; p = 0.047) were independently associated factors after controlling for confounding variables. There were no independent associations with age, marital status, work status, depression or anxiety, or prior contralateral surgery.
Conclusions
Patients whose dominant side was affected, were female, and chose surgical treatment, had higher total expectations. Patients who reported an antecedent injury and chose surgical treatment more frequently expected a return to normal. With identification of these factors, orthopaedic surgeons can recognize patients who are prone to higher expectations, and, thus, have the opportunity to implement efficient pretreatment education. In addition, identification of specific factors enables a focused measure of the effect of these factors on the fulfillment of expectations.
Level of Evidence
Level II, prognostic study.
COVID-19 has been shown to adversely affect multiple organ systems, yet little is known about its effect on perioperative complications after spine surgery or the optimal timing of surgery after an ...infection. We used the NIH National COVID Cohort Collaborative (N3C) database to characterize the risk profile in patients undergoing spine surgery during multiple time windows following COVID-19 infection.
We queried the National COVID Cohort Collaborative, a database of 17.4 million persons with 6.9 million COVID-19 cases, for patients undergoing lumbar spinal fusion surgery. Patients were stratified into those with an initial documented COVID-19 infection within 3 time periods: 0 to 2 weeks, 2 to 6 weeks, or 6 to 12 weeks before surgery.
A total of 60,541 patients who underwent lumbar spinal fusion procedures were included. Patients who underwent surgery within 2 weeks of their COVID-19 diagnosis had a significantly increased risk for venous thromboembolic events (OR 2.29, 95% CI 1.58-3.32), sepsis (OR 1.56, 95% CI 1.03-2.36), 30-day mortality (OR 5.55, 95% CI 3.53-8.71), and 1-year mortality (OR 2.70, 95% CI 1.91-3.82) compared with patients who were COVID negative during the same period. There was no significant difference in the rates of acute kidney injury or surgical site infection. Patients undergoing surgery between 2 and 6 weeks or between 6 and 12 weeks from the date of COVID-19 infection did not show significantly elevated rates of any complication analyzed.
Patients undergoing lumbar spinal fusion within 2 weeks from initial COVID-19 diagnosis are at increased risk for perioperative venous thromboembolic events and sepsis. This effect does not persist beyond 2 weeks, however, so it may be warranted to postpone non-urgent spine surgeries for at least 2 weeks following a COVID-19 infection or to consider a more aggressive VTE chemoprophylaxis regimen for urgent surgery in COVID-19 patients.
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