Analysis of craniectomy bone flaps stored in a neurosurgical cryopreservation freezer: microorganism culture results and reimplantation rates.

BACKGROUND: Cryopreservation of bone flaps after decompressive craniectomies is a common practice. A frequent complication after bone flap reimplantation is postoperative infection, so culturing of frozen craniectomy bone flaps is a crucial practice that can prevent patient morbidity and mortality. Although many studies report on infection rates after cranioplasty, no study reports on the results of bone flaps stored in a cryopreservation freezer, reimplanted or otherwise. We sought to analyze the flaps in our medical center's bone bank freezer, including microorganism culture results and reimplantation rates of cryopreserved bone flaps. METHODS: Patients who underwent craniectomy and had bone flaps cryopreserved between January 1, 2016, and July 1, 2022, were included in this retrospective study. Information about bone flap cultures and reimplantation or discard was obtained from a prospectively maintained cryopreservation database. Information including infection rates and mortality was acquired from a retrospective review of patient records. Culture results were obtained for all flaps immediately before cryopreservation and again at the time of reimplantation at the operator's discretion. RESULTS: There were 148 bone flaps obtained from 145 patients (3 craniectomies were bilateral) stored in our center's freezer. Positive culture results were seen in 79 (53.4%) flaps. The most common microorganism genus was Propionibacterium with 47 positive flaps, 46 (97.9%) of which were P. acnes. Staphylococcus was the second most common with 23 positive flaps, of which 8 (34.8%) tested positive for S. epidermidis. Of the 148 flaps, 25 (16.9%) were reimplanted, 116 (78.4%) were discarded, and 7 (4.7%) are still being stored in the freezer. Postcranioplasty infections were seen in 3 (12%) patients who had flap reimplantation. CONCLUSIONS: Considering the substantial number of positive cultures and limited reimplantation rate, we have reservations about the logistical efficiency of cryopreservation for flap storage. Future multicenter studies analyzing reimplantation predictors could help to reduce unnecessary freezing and culturing.

Cervical Vertebral Bone Quality Score Independently Predicts Distal Junctional Kyphosis After Posterior Cervical Fusion.

BACKGROUND AND OBJECTIVE: Posterior cervical fusion is the surgery of choice when fusing long segments of the cervical spine. However, because of the limited presence of this pathology, there is a paucity of data in the literature about the postoperative complications of distal junctional kyphosis (DJK). We aimed to identify and report potential associations between the preoperative cervical vertebral bone quality (C-VBQ) score and the occurrence of DJK after posterior cervical fusion. METHODS: The authors retrospectively reviewed records of patients who underwent posterior cervical fusion at a single hospital between June 1, 2010, and May 31, 2020. Patient data were screened to include patients who were >18 years old, had baseline MRI, had baseline standing cervical X-ray, had immediate postoperative standing cervical X-ray, and had clinical and radiographic follow-ups of >1 year, including a standing cervical X-ray at least 1 year postoperatively. Univariate analysis was completed between DJK and non-DJK groups, with multivariate regression completed for relevant clinical variables. Simple linear regression was completed to analyze correlation between the C-VBQ score and total degrees of kyphosis angle change. RESULTS: Ninety-three patients were identified, of whom 19 (20.4%) had DJK and 74 (79.6%) did not. The DJK group had a significantly higher C-VBQ score than the non-DJK group (2.97 ± 0.40 vs 2.26 ± 0.46; P < .001). A significant, positive correlation was found between the C-VBQ score and the total degrees of kyphosis angle change (r 2 = 0.26; P < .001). On multivariate analysis, the C-VBQ score independently predicted DJK (odds ratio, 1.46; 95% CI, 1.27-1.67; P < .001). CONCLUSION: We found that the C-VBQ score was an independent predictive factor of DJK after posterior cervical fusion.

Comparative Analysis of the 3 Cervical Vertebral Bone Quality (C-VBQ) Score Methodologies and Their Correlations to the Lumbar Vertebral Bone Quality (VBQ) Score.

OBJECTIVE: Common complications after spinal fusion, such as pseudoarthrosis, cage subsidence, or instrumentation failure, are affected by patients' bone quality. The cervical-vertebral bone quality (C-VBQ) score, a magnetic resonance imaging (MRI)-based adaption of the lumbar vertebral bone quality (VBQ) score, was developed by 3 separate research groups simultaneously to evaluate bone quality in cervical spinal fusion patients. We present the first analysis comparing these scoring methods to the well-validated VBQ score. METHODS: A retrospective analysis of data for consecutive patients who underwent spine surgery at a single institution was completed. The VBQ score was calculated using the Ehresman et al. METHOD: The C-VBQ scores, named according to placement of the region of interest within the cerebral spinal fluid, were calculated separately using the methods of Soliman et al. (C2-VBQ), Razzouk et al. (C5-VBQ), and Huang et al. (T1-VBQ). Linear regression models were utilized to evaluate correlations to the VBQ score. RESULTS: A total of 105 patients were identified (mean age, 57.0 ± 11.9 years; women, 50.5%). Mean scores were C2-VBQ, 2.37 ± 0.55; C5-VBQ, 2.36 ± 0.61; and T1-VBQ, 2.64 ± 0.68. The C-VBQ scores for the C2 level were significantly higher than those for the C3-C6 levels (3.18 ± 0.96 vs. 2.63 ± 0.77, P < 0.001), whereas the C7 level was found to have significantly lower C-VBQ scores (2.42 ± 0.78 vs. 2.63 ± 0.77, P = 0.04). The C2-VBQ (r = 0.63) score had the strongest correlation to the VBQ score, compared to C5-VBQ (r = 0.41) and T1-VBQ (r = 0.43) (P < 0.001). CONCLUSIONS: This study demonstrates that the C2-VBQ had the strongest correlation to the lumbar VBQ score among all C-VBQ scores.

Pack Years of Tobacco Cigarette Smoking as a Predictor of Bony Fusion after Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Smoking tobacco cigarettes negatively impacts bone healing after spinal fusion. Smoking history is often assessed based on current smoker and nonsmoker status. However, in current research, smoking history has not been quantified in terms of pack years to estimate lifetime exposure and assess its effects. Our goal was to investigate the influence of smoking history, quantified in pack years, on bony fusion after anterior cervical discectomy and fusion (ACDF). METHODS: A retrospective chart review of consecutive patients who underwent ACDF for cervical disc degeneration between September 21, 2017 and October 17, 2018 was conducted. Patient demographics, procedural variables, and postoperative outcomes were analyzed. Multivariate logistic regression analysis was performed to identify predictive factors for bony fusion following ACDF. Receiver operating characteristic curve analysis was used to determine the optimal discrimination threshold for smoking history pack years in association with nonfusion. RESULTS: Among 97 patients identified, 90 (93%) demonstrated bony fusion on postoperative imaging. Mean number of smoking history pack years was 6.1 ± 13 for the fusion group and 16 ± 21 for the nonfusion group. Multivariate logistic regression analysis suggested that increased pack years of tobacco cigarette smoking was a significant predictor of nonfusion (95% confidence interval, [1.0,1.1], P = 0.045). The receiver operating characteristic curve analysis revealed that 6.1 pack years best stratified the risk for nonfusion (area under the curve, 0.8). CONCLUSIONS: Patients with a history of tobacco cigarette smoking ≥6.1 pack years may have an increased risk of nonfusion after ACDF.

The Effect of Diabetes on Complications after Spinal Fusion: A Systematic Review and Meta-Analysis.

OBJECTIVE: Spinal fusion procedures are used to treat a wide variety of spinal pathologies. Diabetes mellitus (DM) has been shown to be a significant risk factor for several complications following these procedures in previous studies. To the authors' knowledge, this is the first systematic review and meta-analysis elucidating the relationship between DM and complications occurring after spinal fusion procedures. METHODS: Systematic literature searches of PubMed and EMBASE were performed from their inception to October 1, 2022, to identify studies that directly compared postfusion complications in patients with and without DM. Studies met the prespecified inclusion criteria if they reported the following data for patients with and without DM: (1) demographics; (2) postspinal fusion complication rates; and (3) postoperative clinical outcomes. The included studies were then pooled and analyzed. RESULTS: Twenty-eight studies, with a cumulative total of 18,853 patients (2695 diabetic patients), were identified that met the inclusion criteria. Analysis showed that diabetic patients had significantly higher rates of total number of postoperative complications (odds ratio [OR] = 1.33; 95% confidence interval [CI] = 1.12-1.58; P = 0.001), postoperative pulmonary complications (OR=2.01; 95%CI=1.31-3.08; P = 0.001), postoperative renal complications (OR=2.20; 95%CI=1.27-3.80; P = 0.005), surgical site infection (OR=2.65; 95%CI=2.19-3.20; P < 0.001), and prolonged hospital stay (OR=1.67; 95%CI=1.47-1.90; P < 0.001). CONCLUSIONS: Patients with DM had a significantly higher risk of developing complications after spinal fusion, particularly pulmonary and renal complications, in addition to surgical site infections and had a longer length of stay. These findings are important for informed discussions of surgical risks with patients and families before surgery.

Strong Correlation Between the Vertebral Bone Quality Score and the Cervical-Vertebral Bone Quality Score in Spine Surgery Patients.

OBJECTIVE: Osteoporosis is a burgeoning public health problem for over 44 million people in the United States. The magnetic resonance imaging-based vertebral bone quality (VBQ) score and cervical VBQ (C-VBQ) score are two novel approaches that use data routinely gathered during preoperative evaluation to assess bone quality. The goal of this study was to investigate the relationship between the VBQ and C-VBQ scores. METHODS: We performed a retrospective review of chart data for patients who underwent spine surgery for degenerative conditions between 2015 and 2022. Patients eligible for study inclusion had preoperative T1-weighted magnetic resonance imaging of the lumbar and cervical spine available for review. Demographics of each patient were collected. The VBQ score was determined by dividing the median signal intensity (SI) of the L1-L4 vertebral bodies by the SI of the cerebrospinal fluid at L3. The C-VBQ score was calculated by dividing the median SI of the C3-C6 vertebral bodies by the SI of the C2 cerebrospinal fluid space. Pearson's correlation test was utilized to evaluate the association between the scores. RESULTS: We identified 171 patients, with a mean age of 57.44 ± 11.79 years. The interrater reliability of the VBQ and C-VBQ measurements was excellent (intraclass correlation-coefficients were 0.89 and 0.84, respectively). A statistically significant, positive correlation was found between the VBQ score and the C-VBQ score (r = 0.757,P < 0.001). CONCLUSIONS: This is the first study, to our knowledge, to assess the degree to which the newly developed C-VBQ score correlates with the VBQ score. We found a strong positive correlation between the scores.

Vertebral Bone Quality Score Independently Predicts Proximal Junctional Kyphosis and/or Failure After Adult Spinal Deformity Surgery.

BACKGROUND: Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) can be catastrophic complications associated with adult spinal deformity (ASD) surgery. These complications are markedly influenced by osteoporosis, leading to additional vertebral fracture and pedicle screw loosening. The MRI-based vertebral bone quality score (VBQ) is a newly developed tool that can be used to assess bone quality. OBJECTIVE: To investigate the utility of the VBQ score in predicting PJK and/or PJF (PJF/PJK) after ASD correction. METHODS: We conducted a retrospective chart review to identify patients age ≥50 years who had received ASD surgery of 5 or more thoracolumbar levels. Demographic, spinopelvic parameters, and procedure-related variables were collected. Each patient's VBQ score was calculated using preoperative T1-weighted MRI. Univariate analysis and multivariate logistic regression were performed to determine potential risk factors of PJK/PJF. Receiver operating characteristic analysis and area-under-the-curve values were generated for prediction of PJK/PJF. RESULTS: A total of 116 patients were included (mean age, 64.1 ± 6.8 years). Among them, 34 patients (29.3%) developed PJK/PJF. Mean VBQ scores were 3.13 ± 0.46 for patients with PJK/PJF and 2.46 ± 0.49 for patients without, which was significantly different between the 2 groups ( P < .001). On multivariate analysis, VBQ score was the only significant predictor of PJK/PJF (odds ratio = 1.745, 95% CI = 1.558-1.953, P < .001), with a predictive accuracy of 94.3%. CONCLUSION: In patients undergoing ASD correction, higher VBQ was independently associated with PJK/PJF occurrence. Measurement of VBQ score on preoperative MRI may be a useful adjunct to ASD surgery planning.

Outcomes of 2-Level Versus 3- or 4-Level Anterior Cervical Discectomy and Fusion Using a Biomimetic Surface Titanium Cage: Multicenter Experience.

OBJECTIVE: Interbody cages for spinal fusions are primarily constructed from polyetheretherketone or titanium compositions. However, these crude macroscopic materials pose limitations for improving the rates of bony fusions. The authors aimed to compare the fusion rates and postoperative complications in patients who underwent 2-level or 3-or 4-level anterior cervical discectomy and fusion (ACDF) performed with the use of a novel biomimetic surface titanium cage. METHODS: A retrospective multicenter study was conducted that included all patients who underwent multilevel ACDF with this cage between January 2017 and April 2021. Patient demographics and procedure-related, radiographic, and postoperative complication data were collected. RESULTS: A total of 124 patients were identified; 69 (55.6%) had a 3-or 4-level fusion and 55 (44.4%) had a 2-level fusion. The demographics of the 2 groups differed significantly only in terms of age (P = 0.01). At 3 months, a significantly higher solid fusion rate was found for 2-level fusions than 3-or 4-level fusions (83.7% vs. 56.3%, P = 0.004); however, significance was lost at 6-months (98.2% vs. 88.4%, respectively; P = 0.08). No patients required posterior supplemental fixation. Transient dysphagia was the only postoperative complication that was significantly increased in the 3-or 4-level fusion group compared to the 2-level group (27.5% vs. 9.1%, P = 0.02). CONCLUSIONS: Radiographic and clinical outcomes were equivalent in 3-or 4-level and 2-level ACDFs in which these biomimetic surface titanium cages were used. Furthermore, the use of this technology led to high fusion rates with no requirement for posterior supplemental fusions.

Black Bone Disease of the Skull.

We present an image of a patient's skull characterized by dark, irregular discoloration. This was discovered incidentally in a 66-year-old man who underwent craniotomy for resection of a glioblastoma. This image demonstrates cranial black bone disease. This is an abnormal bone pigmentation associated with long-term tetracycline use, as occurred in this patient.

Navigating a proximal loop in the radial artery and avoiding the recurrent radial artery.

Several anatomical variations of the radial artery have been described in the literature. Common variations include radial artery loop, recurrent branch, and anastomotic channels connecting the radial and brachial arteries. These variations can pose significant technical challenges to safe radial artery catheterization. Because radial access for neurointervention is becoming popular, appreciation of these variations and mastery of techniques for safe radial artery catheterization are of paramount importance. In this operative video,(video 1) we present a case of a 75-year-old man who underwent middle meningeal artery embolization for treatment of chronic subdural hematoma using a transradial approach. The patient was found to have a radial artery loop and a recurrent branch off the radial artery. The loop could not be negotiated with the conventional technique. We therefore used a microcatheter system with a stiff microwire to navigate and straighten the radial loop under road map guidance. The remaining procedure was performed successfully.

Cervical Kyphotic Deformity Worsening After Extensor Cervical Muscle Paralysis from Botulinum Toxin Injection.

BACKGROUND: Botulinum toxin (Botox) has long been used therapeutically to treat a variety of diseases, including migraine headaches, cervical spine dystonia, and chronic cervical spine pain, among many others. Although quite useful, Botox has been reported to cause adverse events, some of which may lead to devastating morbidity. CASE DESCRIPTION: An elderly woman presented with severe neck pain after a motor vehicle collision. She underwent Botox administration to the neck extensor muscles, after which she developed severe cervical kyphotic deformity, a complication previously reported only in patients with a history of cervical fusion. In addition, the patient had a pre-existing cervical spine degenerative disc disease with listhesis resulting in cervical kyphotic deformity and loss of cervical lordosis. CONCLUSIONS: This case illustrates a potential danger of using Botox in the neck of an elderly patient who may have pre-existing cervical spine instability, underlying cervical musculature weakness, and pre-existing cervical kyphosis. It demonstrates the need to evaluate patients who are predisposed to developing cervical kyphotic deformities before offering them Botox treatment.

Changes in pediatric tracheostomy tubes exposed to home dishwashing.

OBJECTIVE: Determine the effects of household dishwashing on Tracheostomy Tube safety. INTRODUCTION: Tracheostomy tubes accumulate biofilms, which may limit their lifespan. Frequent cleaning of the tubes is a method for biofilm prevention. Cleaning practices vary widely. Some families prefer dishwashing of tubes, but its effects are currently unknown. We hypothesize that dishwashing has no significant effect on the physical properties of tracheostomy tubes and can be recommended as a safe way to clean tracheostomy tubes. METHODS: Twenty 4.0 Shiley™ pediatric tracheostomy tubes were randomly assigned into dishwashed (DW) and non-dishwashed (NDW) groups, 10/group. DW tubes were subjected to 12 wash cycles. Each tube's hardness along with the surface spectra were analyzed to assess for chemical composition changes. Three cannula samples from each group were also randomly assessed with scanning-electron microscopy and scored by blinded examiners to assess for changes in surface heterogeneity. RESULTS: Hardness testing revealed a statistically significant difference (p = 0.0009) between the NDW and the DW group indicating increased fragility in the dishwashed tubes. Spectral analysis revealed loss of plasticizers, indicating decreased flexibility. Blinded electron microscopy scoring revealed increased surface heterogeneity in the DW group (p = 0.00007). CONCLUSION: A significant decrease in tube hardness and increased surface heterogeneity were found with dishwashing. The spectral analysis demonstrated increasing fragility. We believe these effects could potentially lead to decreased mechanical safety. With increased surface heterogeneity there is a greater potential for biofilm formation. At this time, dishwashing cannot be recommended as a tracheostomy tube cleaning method.