Accuracy and revision rate of intraoperative computed tomography point-to-point navigation for lateral mass and pedicle screw placement: 11-year single-center experience in 1054 patients

Lumbar Decompression versus Decompression and Fusion in Octogenarians: Complications and Clinical Course With 3-Year Follow-Up

STUDY DESIGN

Retrospective review.

OBJECTIVES

This study aimed to assess and compare the clinical course and complications between surgical decompression and decompression with fusion in lumbar spine patients aged ≥80 years.

METHODS

A retrospective review of electronic medical records at a single institution was conducted between September 2005 and December 2021. Logistic regression was used to identify potential risk factors for the occurrence of complications.

RESULTS

Over a 16-year period, 327 patients were allocated to the decompression only group and 89 patients were allocated to the decompression and instrumented fusion group. The study had a mean follow-up duration of 36.7 ± 12.4 months. When assessing the CCI, patients of the instrumentation group had fewer comorbidities (8.9 ± .5 points vs 6.2 ± 1.5 points; P < .001), significantly longer surgical duration (290 ± 106 minutes vs 145 ±50.2 minutes; P < .001), significantly higher volume of intraoperative blood loss (791 ± 319.3 ml vs 336.1 ± 150.8 ml; P < .001), more frequent intraoperative blood transfusion (7 ± 2.1% vs 16± 18.0%; P < .001), and extended stays in the intensive care unit and hospitalization rates. Logistic regression analysis revealed that surgical duration and extent of surgery were unique risk factors for the occurrence of complications.

CONCLUSIONS

Lumbar decompression and additional fusion in octogenarians are considerable treatment techniques; albeit associated with increased complication risks. Prolonged operative time and extent of surgery are critical confounding factors associated with higher rates of postoperative complications. Surgery should only be performed after careful outweighing of potential benefits and risks.

High Rate of Pulmonary Cement Embolism after Cement-Augmented Pedicle Screw Fixation: A 12-Year Single-Center Study

BACKGROUND

 The global trend toward increased life expectancy because of remarkable improvements in health care quality has drawn increased attention to osteoporotic fractures and degenerative spine diseases. Cement-augmented pedicle screw fixation has been established as the mainstay treatment for patients with poor bone quality. This study aimed to determine the number of patients with cement leakage and pulmonary cement embolism (PCE) as detected on thoracic computed tomography (CT), and to assess the potential risk factors for PCE.

METHODS

 Patients undergoing cement-augmented pedicle screw placement in our institution between May 2008 and December 2020 were included. Data regarding baseline characteristics, complications, and cement leakage rates were collected. Indications for the performance of a postoperative thoracic CT due to the suspicion of PCE were intra- or postoperative complications, or postoperative oxygen supplementation. Moreover, PCE was accidently diagnosed because the thoracic CT was performed for medical reasons other than the suspicion of PCE (tumor staging, severe pneumonia, or exacerbated chronic pulmonary obstructive disease).

RESULTS

 A total of 104 patients with a mean age of 72.8 years (standard deviation of 6.7) were included. Of 802 screws, 573 were cement augmented. Of the 104 patients, 44 (42.3%) underwent thoracic CT scans to diagnose PCE; additionally, 67 (64.4%) demonstrated cement leakage, of whom 27 developed PCE and 4 were symptomatic. Cement-augmented thoracic screws were a risk factor for PCE (odds ratio: 1.5; 95% confidence interval: 1.2-2.1; p = 0.004).

CONCLUSIONS

 This study showed a high prevalence of cement leakage after cement-augmented pedicle screw insertion, with a relatively frequent incidence of PCE, as tracked by thoracic CT scans. Cement-augmented thoracic screw placement was a unique risk factor for PCE.

Prospective insights into spinal surgery outcomes and adverse events: A comparative study between patients 65-79 years vs. ≥80 years from a German tertiary center

Introduction

In light of an aging global population, understanding adverse events (AEs) in surgeries for older adults is crucial for optimal outcomes and patient safety.

Research question

Our study compares surgical outcomes and AEs in patients aged 65-79 with those aged ≥80, focusing on clinical outcomes, morbidity and mortality rates, and age-related risk factors for AEs.

Material and methods

Our study, from January 2019 to December 2022, involved patients aged 65-79 and ≥ 80 undergoing spinal surgery. Each patient was evaluated for AEs post-discharge, defined as negative clinical outcomes within 30 days post-surgery. Patients were categorized based on primary spinal diagnoses: degenerative, oncological, traumatic, and infectious.

Results

We enrolled 546 patients aged 65-79 and 184 octogenarians. Degenerative diseases were most common in both groups, with higher infection and tumor rates in the younger cohort. Octogenarians had a higher Charlson Comorbidity Index and longer ICU/hospital stays. Surgery-related AE rates were 8.1% for 65-79-year-olds and 15.8% for octogenarians, with mortality around 2% in both groups.

Discussion and conclusion

Our prospective analysis shows octogenarians are more susceptible to surgical AEs, linked to greater health complexities. Despite higher AEs in older patients, low mortality rates across both age groups highlight the safety of spinal surgery. Tracking AEs is crucial for patient communication and impacts healthcare accreditation and funding.

Anterior cervical discectomy fusion versus posterior decompression and fusion in octogenarians with cervical myelopathy: Clinical outcomes and complications with a 3-year follow-up

Introduction

Cervical stenosis and concurrent Cervical Spondylotic Myelopathy (CSM) are prevalent in the elderly. Treatment options include Anterior Cervical Discectomy Fusion (ACDF) and Posterior Decompression and Fusion (PDF).

Research question

This study aims to compare clinical outcomes and complications between ACDF and PDF in patients aged 80 and above.

Material and methods

Data from electronic medical records between 2005 and 2021 at a single institution were analyzed. Logistic and linear regression analyses were performed to explore risk factors and the relationship between comorbidities and neurological conditions.

Results

21 patients with ACDF and 26 with PDF were studied over 16 years. PDF patients had more operated levels, higher blood loss, and longer hospital stays, but mortality rates and mJOA improvements were similar in both groups. The presence of comorbidities was a unique risk factor for postoperative complications.

Discussion and conclusion

ACDF and PDF led to neurological improvements in elderly CSM patients. However, the decision of surgical procedure should carefully consider the potential for postoperative complications, particularly in patients with comorbidities.

Outcomes of cervical spinal stenosis surgery in patients aged ≥ 65 years based on insurance status: a single-center cohort study from a tertiary center in Germany

OBJECTIVE

The prevalence of degenerative disorders of the spine, such as cervical spinal stenosis with cervical spine myelopathy (CSM) in the geriatric population, has rapidly increased worldwide. To date, there has been no systematic analysis comparing outcomes in older patients suffering from progressive CSM and undergoing surgery depending on their health insurance status. We sought to compare the clinical outcomes and complications after anterior cervical discectomy and fusion (ACDF) or posterior decompression with fusion in patients aged ≥ 65 years with multilevel cervical spinal canal stenosis and concomitant CSM with special focus on their insurance status.

METHODS

Clinical and imaging data were retrieved from patients' electronic medical records at a single institution between September 2005 and December 2021. Patients were allocated into two groups with respect to their health insurance status: statutory health insurance (SHI) vs. private insurance (PI).

RESULTS

A total of 236 patients were included in the SHI group and 100 patients in the privately insured group (PI) group. The overall mean age was 71.7 ± 5.2 years. Regarding comorbidities, as defined with the age-adjusted CCI, SHI patients presented with higher rates of comorbidities as defined by a CCI of 6.7 ± 2.3 and higher prevalence of previous malignancies (9.3%) when compared to the PI group (CCI 5.4 ± 2.5, p = 0.051; 7.0%, p = 0.048). Both groups underwent ACDF (SHI: 58.5% vs. PI: 61.4%; p = 0.618), and the surgical duration was similar between both groups. Concerning the intraoperative blood transfusion rates, no significant differences were observed. The hospital stay (12.5 ± 1.1 days vs. 8.6 ± 6.3 days; p = 0.042) and intenisve care unit stay (1.5 ± 0.2 days vs. 0.4 ± 0.1 days; p = 0.049) were significantly longer in the PI group than in the SHI group. Similar in-hospital and 90-day mortality rates were noted across the groups. The presence of comorbidities, as defined with the age-adjusted CCI, poor neurological status at baseline, and SHI status, was significant predictor for the presence of adverse events, while the type of surgical technique, operated levels, duration of surgery, or blood loss was not.

CONCLUSIONS

Herein, we found that surgeons make decisions independent of health insurance status and aim to provide the most optimal therapeutic option for each individual; hence, outcomes were similar between the groups. However, longer hospitalization stays were present in privately insured patients, while SHI patients presented on admission with poorer baseline status.

Morbidity and mortality related to type II odontoid fractures in octogenarians undergoing surgery: a retrospective study with 5 year follow up

Introduction

The prevalence of trauma is increasing in the geriatric population. The optimal therapy for type II odontoid fractures in the elderly is controversial. This study aims to assess the morbidity and mortality associated with odontoid fractures in octogenarians undergoing C1/C2 posterior screw fixation and describe the perioperative and post-operative complications and risk factors associated with mortality.

Materials and methods

Electronic medical records from a single institution pertaining to the period between September 2005 and December 2020 were retrieved. Data on patient demographics, neurological conditions, surgical characteristics, complications, hospital course, and 90-day mortality were collected.

Results

Over a 16-year period, 60 patients aged ≥80 years diagnosed with type II odontoid fractures were enrolled in the study. The mean age was 85.0 ± 1.9 years. The mean Charlson Comorbidity Index (CCI) was >6 indicating a poor baseline reserve (8.5 ± 1.9), while cardiovascular diseases were the most prevalent among comorbidities. The mean surgical duration was 217.5 ± 65.9 min, with a mean blood loss of 725.5 ± 275.7 mL. The in-hospital was 5-0% and the 90-day mortality rates increased at 10.0%. No revision surgery was needed in any of the cases. Intraoperative and post-operative X-ray and computed tomography (CT) imaging revealed correct screw placement. Proper alignment of the atlantoaxial spine and fusion could be achieved in all cases. The unique risk factors for mortality included the presence of comorbidities and the occurrence of post-operative complications.

Conclusion

The complication and mortality rates associated with odontoid fractures in octogenarians are relatively high. However, the therapeutic goals in this population also include bone union and preservation of neurological status. Despite the often-high comorbidity rate, we still recommend that surgery should be considered in patients over 80 years. However, it is necessary to evaluate several approaches when treating such frail patients.

Mortality, complication risks, and clinical outcomes after surgical treatment of spinal epidural abscess: a comparative analysis of patients aged 18-64 years, 65-79 years, and ≥ 80 years, with a 3-year follow-up

Spinal epidural abscess (SEA) with pyogenic vertebral osteomyelitis (PVO) is a rare illness with a steadily increasing incidence. However, comparative analyses of young and older patients with SEA are lacking. We aimed to compare the clinical course of patients aged 18-64 years, 65-79 years, and ≥ 80 years undergoing surgery for SEA. Clinical and imaging data were retrospectively collected from the institutional database between September 2005 and December 2021. Ninety-nine patients aged 18-64 years, 45 patients aged 65-79 years, and 32 patients ≥ 80 years were enrolled. Patients ≥ 80 years presented with a poorer baseline history (9.2 ± 2.4), as indicated by the CCI, than their younger counterparts (18-74 years: 4.8 ± 1.6;6.5 ± 2.5; p < 0.001). Patients aged 65-79 years and 80 years had a significantly longer length of stay. In-hospital mortality was significantly higher in those aged ≥ 80 years compared to their younger counterparts (≥ 80 years, n = 3, 9.4% vs. 18-64 years, n = 0, 0.0%; 65-79 years, n = 0, 0.0%; p < 0.001), while no differences in 90-day mortality or 30-day readmission were observed. After surgery, a significant decrease in C-reactive protein levels and leukocytes and amelioration of motor scores were observed in all the groups. Of note, older age (> 65 years), presence of comorbidities, and poor preoperative neurological condition were significant predictors of mortality. Surgical management led to significant improvements in laboratory and clinical parameters in all age groups. However, older patients are prone to multiple risks, requiring meticulous evaluation before surgery. Nevertheless, the risk profile of younger patients should not be underestimated. The study has the limitations of a retrospective design and small sample size. Larger randomized studies are warranted to establish the guidelines for the optimal management of patients from every age group and to identify the patients who can benefit from solely conservative management.

Perioperative morbidity and mortality in octogenarians sustaining traumatic osteoporotic type 4 and 5 thoracolumbar and lumbar fractures: a retrospective study with 3 years follow-up

PURPOSE

This study aimed to guide the more efficient management of type 4 and 5 thoracolumbar or lumbar osteoporotic fractures (OF) in patients aged 80 years and older with an acute onset of neurological decline. This aim was achieved by assessing the clinical course and morbidity and mortality rates and identifying potential risk factors for patient mortality METHODS: Electronic medical records were retrieved from a single institution pertaining to the period between September 2005 and December 2020. Data on patient demographics, neurological conditions, surgical characteristics, complications, hospital course, and 90-day mortality were also collected.

RESULTS

Over a 16-year period, 35 patients aged ≥80 years diagnosed with thoracolumbar and lumbar OF were enrolled in the study. The mean Charlson comorbidity index (CCI) was >6, indicating a poor baseline reserve (9.4 ± 1.9), while cardiovascular diseases were the most prevalent among comorbidities. The mean surgical duration was 231.6 ± 89.3 min, with a mean blood loss of 694.4± 200.3 mL. The in-hospital was 8.6% and 90-day mortality rates at 11.4%. Two patients underwent revision surgery for deep wound infection. Intraoperative and postoperative radiography and computed tomography (CT) imaging revealed correct screw placement. Proper alignment of the thoracolumbar spine was achieved in all the patients. Unique risk factors for mortality included the presence of comorbidities and the occurrence of postoperative complications.

CONCLUSIONS

Emergent instrumentation in patients with acute onset of neurological decline and potentially unstable spines due to thoracolumbar and lumbar OF improved functional outcomes at discharge. Age should not be a determinant of whether to perform surgery.

Anterior cervical discectomy and fusion with plate versus posterior screw fixation after traumatic subaxial fractures in octogenarians: complications and outcomes with a 2-year follow-up

INTRODUCTION

Surgical intervention for management of spinal instability after traumatic subaxial fractures in octogenarians requires a clear consensus on optimal treatments. This study aimed to provide a guide for more efficient management through comparison and assessment of clinical outcomes and complications of anterior cervical discectomy and fusion with plate (pACDF) and posterior decompression fusion (PDF) instrumentation alone in patients aged 80 years.

METHODS

A single institution retrospective review of electronic medical records was undertaken between September 2005 and December 2021. Comorbidities were assessed using the age-adjusted Charlson comorbidity index (CCI). Logistic regression was used to identify potential risk factors for ACDF complications.

RESULTS

The rate of comorbidities were similarly high between the pACDF (n=13) and PDF (n=15) groups (pACDF: 8.7 ± 2.4 points vs. 8.5 ± 2.3 points; p=0.555). Patients in the PDF group had significantly longer surgical duration (235 ± 58.4 min vs. 182.5 ± 32.1 min; p<0.001) and significantly higher volumes of intraoperative blood loss (661.5 ± 100.1 mL vs. 487.5 ± 92.1 mL; p<0.001). The in-hospital mortality was 7.7% for the pACDF group and 6.7% for the PDF group. On day 90, the mortality rate increased in both groups from baseline (pACDF: 15.4% vs. PDF: 13.3; p>0.05). Motor scores (MS) improved significantly after surgery in both groups (pACDF: preOP MS: 75.3 ± 11.1 vs. postOP MS: 82.4 ± 10.1; p<0.05; PDF: preOP MS: 80.7 ± 16.7 vs. postOP MS: 89.5 ± 12.1; p<0.05). Statistically significant predictors for postoperative complications included longer operative times (odds ratio 1.2, 95% confidence interval 1.1-2.1; p=0.005) and larger volume of blood loss (odds ratio 1.5, 95% confidence interval 1.2-2.2; p=0.003).

CONCLUSIONS

Both pACDF and PDF can be considered safe treatment strategies for octogenarians with a poor baseline profile and subaxial fractures as they lead to patients substantial neurological improvements, and they are accompanied with low morbidity and mortality rates. Operation duration and intraoperative blood loss should be minimized to increase the degree of neurological recovery in octogenarian patients.

Comparison of robot versus fluoroscopy-assisted pedicle screw instrumentation in adolescent idiopathic scoliosis surgery: A retrospective study

The aim of this study was to explore whether a robot-assisted (RA) technique has advantages over the conventional fluoroscopy-assisted (FA) technique in clinical and radiological outcomes and whether it could decrease the incidence of mis-implantations of pedicle screws in adolescent idiopathic scoliosis (AIS) correction surgery. A total of 101 patients with AIS were recruited (RA group: 45 patients underwent RA screw insertion; FA group: 56 patients underwent FA screw insertion). When comparing the radiological data between the two groups, the major and secondary curves were both corrected proficiently with no difference in Cobb angle comparison at the last follow-up, suggesting that both the RA technique and the FA technique could lead to efficient radiographic correction and similar clinical outcomes (all, p > 0.05). In the RA group, operation time, blood loss, and transfusion volume were significantly greater than those in the FA group, while the accuracy of screw implantations in patients with AIS with a thoracic scoliotic curve in the RA group was higher than that in the FA group. In conclusion, both the RA and FA techniques could approach proficient radiographic correction and similar clinical outcomes in AIS surgery. Compared with the conventional fluoroscopy technique, the RA technique might improve the accuracy of screw implantations in patients with AIS with a thoracic scoliotic curve, while the increased operation time, blood loss, and transfusion volume might be the disadvantages due to the preliminary stage of the learning curve.

Surgical Management of Spinal Epidural Abscess in Elderly Patients: A Comparative Analysis Between Patients 65-79 Years and ≥80 Years with 3-Year Follow-Up

BACKGROUND

Recently, the incidence of pyogenic vertebral osteomyelitis with spinal epidural abscess (SEA) has increased. However, the most appropriate surgical management remains debatable, especially for older patients. This study aimed to compare the clinical course in older patients aged between 65 and 79 years and those 80 years or older undergoing surgery for SEA.

METHODS

Data on patient demographics, surgical characteristics, complications, hospital clinical course, and 90-day mortality of patients diagnosed with pyogenic vertebral osteomyelitis and SEA between September 2005 and December 2021 were collected. Comorbidities were assessed using the age-adjusted Charlson comorbidity index.

RESULTS

We enrolled 45 patients aged 65-79 years and 32 patients ≥80 years. Patients ≥80 years had significantly higher rates of Charlson comorbidity index (9.2 ± 2.4) than younger patients (6.5 ± 2.5; P < 0.001). Arterial hypertension, renal failure, and dementia were significantly more prevalent in octogenarians (P < 0.05). Patients aged ≥80 years had a significantly longer length of hospitalization, while the intensive care unit stay was similar between groups. In-hospital mortality was significantly greater in those ≥80 years (n = 3, 9.4% vs. n = 0, 0.0%; P = 0.029), whereas no differences in 90-day mortality or 30-day readmission were observed. In the second-stage analysis, significant improvements in blood infection parameters and neurologic status were detected in both groups. Of adverse events, pneumonia occurred significantly more frequently in patients aged ≥80 years.

CONCLUSIONS

Surgical management leads to significant improvements in both laboratory and clinical parameters in older patients. Nevertheless, a personalized medical approach is mandatory in frail patients, especially octogenarians. A clear discussion regarding the potential risk is unambiguously recommended.

Development and validation of an automated planning tool for navigated lumbosacral pedicle screws using a convolutional neural network

BACKGROUND CONTEXT

Navigation and robotic systems have been increasingly applied to spinal instrumentation but dedicated screw planning is a time-consuming prerequisite to tap the full potential of these techniques.

PURPOSE

To develop and validate an automated planning tool for lumbosacral pedicle screw placement using a convolutional neural network (CNN) to facilitate the planning process.

STUDY DESIGN/SETTING

Retrospective analysis and processing of CT and screw planning data randomly selected from a consecutive registry of CT-navigated instrumentations from a single academic institution.

PATIENT SAMPLE

Data from 179 cases was processed for CNN training and validation (155 for training, 24 for validation) leveraging a total of 1182 screws (1052 for training, 130 for validation).

OUTCOME MEASURES

Quantitative and qualitative (Gertzbein-Robbins classification [GR]) validation via comparison of automatically and manually planned reference screws, inter-rater and intra-rater variability.

METHODS

Annotated data from CT-navigated instrumentation was used to train a CNN operating in a vertebra instance-based approach employing a state-of-the-art U-Net framework. Internal five-fold cross-validation and external validation on an independent cohort not previously involved in training was performed. Quantitative validation of automatically planned screws was performed in comparison to corresponding manually planned screws by calculating the minimal absolute difference (MAD) of screw head and tip points, length and diameter, screw direction and Dice coefficient. Results were evaluated in relation to inter-rater and intra-rater variability of manual screw planning.

RESULTS

Automated screw planning was successful in all targeted 130 screws. Compared with manually planned screws as a reference, mean MAD of automatically planned screws was 4.61±2.27 mm for screw head, 3.96±2.19 mm for tip points and 5.51±3.64° for screw direction. These differences were either statistically comparable or significantly smaller when compared with interrater variability of manual screw planning (p>.99 for head point and direction, p=.004 for tip point, respectively). Mean Dice coefficient of 0.61±0.16 indicated significantly greater agreement of automatic screws with the manual reference compared with interrater agreement (Dice 0.56±0.18, p<.001). Automatically planned screws were marginally shorter (MAD 3.4±3.2 mm) and thinner (MAD mean 0.3±0.6 mm) compared with the manual reference, but with statistical significance (p<.0001, respectively). Automatically planned screws were GR grade A in 96.2% in qualitative validation. Planning time was significantly shorter with the automatic approach (0:41 min vs. 6:41 min, p<.0001).

CONCLUSIONS

We derived and validated a fully automated planning tool for lumbosacral pedicle screws using a CNN. Our validation showed noninferiority to manual screw planning and provided sufficient accuracy to facilitate and expedite the screw planning process. These results offer a high potential to improve workflows in spine surgery when integrated into navigation or robotic assistance systems.

CT-Navigated Spinal Instrumentations-Three-Dimensional Evaluation of Screw Placement Accuracy in Relation to a Screw Trajectory Plan

Background and Objectives: In the literature, spinal navigation and robot-assisted surgery improved screw placement accuracy, but the majority of studies only qualitatively report on screw positioning within the vertebra. We sought to evaluate screw placement accuracy in relation to a preoperative trajectory plan by three-dimensional quantification to elucidate technical benefits of navigation for lumbar pedicle screws. Materials and Methods: In 27 CT-navigated instrumentations for degenerative disease, a dedicated intraoperative 3D-trajectory plan was created for all screws. Final screw positions were defined on postoperative CT. Trajectory plans and final screw positions were co-registered and quantitatively compared computing minimal absolute differences (MAD) of screw head and tip points (mm) and screw axis (degree) in 3D-space, respectively. Differences were evaluated with consideration of the navigation target registration error. Clinical acceptability of screws was evaluated using the Gertzbein−Robbins (GR) classification. Results: Data included 140 screws covering levels L1-S1. While screw placement was clinically acceptable in all cases (GR grade A and B in 112 (80%) and 28 (20%) cases, respectively), implanted screws showed considerable deviation compared to the trajectory plan: Mean axis deviation was 6.3° ± 3.6°, screw head and tip points showed mean MAD of 5.2 ± 2.4 mm and 5.5 ± 2.7 mm, respectively. Deviations significantly exceeded the mean navigation registration error of 0.87 ± 0.22 mm (p < 0.001). Conclusions: Screw placement was clinically acceptable in all screws after navigated placement but nevertheless, considerable deviation in implanted screws was noted compared to the initial trajectory plan. Our data provides a 3D-quantitative benchmark for screw accuracy achievable by CT-navigation in routine spine surgery and suggests a framework for objective comparison of screw outcome after navigated or robot-assisted procedures. Factors contributing to screw deviations should be considered to assure optimal surgical results when applying navigation for spinal instrumentation.

Decompression only versus fusion in octogenarians with spinal epidural abscesses: early complications, clinical and radiological outcome with 2-year follow-up

Despite increased life expectancy due to health care quality improvements globally, pyogenic vertebral osteomyelitis (PVO) treatment with a spinal epidural abscess (SEA) remains challenging in patients older than 80 years. We aimed to assess octogenarians for PVO prevalence with SEA and compare after-surgery clinical outcomes of decompression and decompression and instrumentation. A retrospective review of electronic medical records at a single institution was conducted between September 2005 and December 2020. Patient demographics, surgical characteristics, complications, hospital course, and 90-day mortality were collected. Comorbidities were assessed using the age-adjusted Charlson comorbidity index (CCI). Over 16 years, 35 patients aged ≥80 years with PVO and SEA were identified. Eighteen patients underwent surgical decompression (“decompression group”), and 17 underwent surgical decompression with instrumentation (“instrumentation group”). Both groups had a CCI >6 (mean±SD, 8.9±2.1 vs. 9.6±2.7, respectively; p=0.065). Instrumentation group patients had a significantly longer hospital stay but no ICU stay. In-hospital and 90-days mortality rates were similar in both groups. The mean follow-up was 26.6±12.4 months. No further surgeries were performed. Infection levels and neurological status were improved in both groups at discharge. At the second-stage analysis, significant improvements in the blood infection parameters and the neurological status were detected in the decompression group. Octogenarians with PVO and SEA have a high adverse events risk after surgical procedures. Surgical decompression might contribute to earlier clinical recovery in older patients. Thus, the surgical approach should be discussed with patients and their relatives and be carefully weighed.

Morbidity and Mortality in Patients over 90 Years of Age Following Posterior Stabilization for Acute Traumatic Odontoid Type II Fractures: A Retrospective Study with a Mean Follow-Up of Three Years

Odontoid type II fractures represent the most common cervical spine injuries in the elderly. The decision for surgical treatment in very elderly patients is still controversial. The aim of this study was to assess morbidity and mortality in patients over 90 years of age undergoing CT-guided posterior stabilization for unstable odontoid type II fractures. A total of 15 patients with an acute traumatic odontoid type II fracture who received surgical treatment for unstable odontoid type II fractures were retrospectively analyzed. Complications, morbidity, and mortality as well as length of ICU and hospital stay were determined. Clinical follow-up evaluation was based on outpatient presentation and information from family members and general practitioners. Finally, we conducted a comparison of complications rates between patients over 90 years of age and patients between 65 and 89 years old with a type II odontoid fracture after CT-guided posterior stabilization in our institution. The mean age was 91.4 years. Patients were predominately female (87%). In-hospital deaths did not occur. The average length of the hospital stay was 13.4 days and 1.9 days for the ICU. Blood transfusion was necessary in two patients (13%). Two patients (13%) developed urinary tract infection, one patient (7%) a delirium, and another epistaxis (7%). One patient (7%) developed pneumonic sepsis and fully recovered within several weeks. The mean follow-up was 36 months (range 9–72 months). Implant-related complications developed in one patient (7%). Five patients died during the follow-up period, with an average time to death of 26.6 months. Postoperative bracing was not needed in any of the patients. Posterior stabilization of unstable odontoid fractures type II using CT-guided navigation in patients over 90 years of age is a safe and effective procedure with low complications and mortality rates.

Combined Ultrasound and Photoacoustic Image Guidance of Spinal Pedicle Cannulation Demonstrated With Intact ex vivo Specimens

OBJECTIVE

Spinal fusion surgeries require accurate placement of pedicle screws in anatomic corridors without breaching bone boundaries. We are developing a combined ultrasound and photoacoustic image guidance system to avoid pedicle screw misplacement and accidental bone breaches, which can lead to nerve damage.

METHODS

Pedicle cannulation was performed on a human cadaver, with co-registered photoacoustic and ultrasound images acquired at various time points during the procedure. Bony landmarks obtained from coherence-based ultrasound images of lumbar vertebrae were registered to post-operative CT images. Registration methods were additionally tested on an ex vivo caprine vertebra.

RESULTS

Locally weighted short-lag spatial coherence (LW-SLSC) ultrasound imaging enhanced the visualization of bony structures with generalized contrast-to-noise ratios (gCNRs) of 0.99 and 0.98-1.00 in the caprine and human vertebrae, respectively. Short-lag spatial coherence (SLSC) and amplitude-based delay-and-sum (DAS) ultrasound imaging generally produced lower gCNRs of 0.98 and 0.84, respectively, in the caprine vertebra and 0.84-0.93 and 0.34-0.99, respectively, in the human vertebrae. The mean ± standard deviation of the area of -6 dB contours created from DAS photoacoustic images acquired with an optical fiber inserted in prepared pedicle holes (i.e., fiber surrounded by cancellous bone) and holes created after intentional breaches (i.e., fiber exposed to cortical bone) was 10.06 ±5.22 mm ² and 2.47 ±0.96 mm ², respectively (p 0.01).

CONCLUSIONS

Coherence-based LW-SLSC and SLSC beamforming improved visualization of bony anatomical landmarks for ultrasound-to-CT registration, while amplitude-based DAS beamforming successfully distinguished photoacoustic signals within the pedicle from less desirable signals characteristic of impending bone breaches.

SIGNIFICANCE

These results are promising to improve visual registration of ultrasound and photoacoustic images with CT images, as well as to assist surgeons with identifying and avoiding impending bone breaches during pedicle cannulation in spinal fusion surgeries.