An observational analysis of costs and effectiveness of an intraoperative compared with a preoperative image-guided system in spine surgery fixation: analysis of 10 years of experience.

BACKGROUND: Image-guided navigation systems are well established technologies; their use in clinical practice is constantly growing. To date many publications have demonstrated their accuracy and safety. However, the acquisition and maintenance costs are high. In an era in which health expenditures are rising exponentially, analyses of the economic impact of new technologies are mandatory to assess their sustainability. METHODS: This is a retrospective analysis to assess the overall costs of a series of patients admitted to our Department of Neurosurgery for spinal instrumentation. We compared two different types of spinal navigation systems: based on preoperative CT scan (January 2003-April 2009) and on intraoperative CT-like scan (April 2009-March 2013). We used a micro-costing approach by a hospital perspective considering all the phases of the treatment process, from preadmission testing to discharge. RESULTS: The study includes 875 patients. Baseline data, hospitalization and complications were similar for both. Mean cost was € 7305.9 for intraoperative CT scan procedure and € 7666.2 for preoperative image-guided system. The effectiveness, in terms of screw accuracy was similar. Higher costs were related to implanted materials, human resources, and disposable. CONCLUSIONS: There was a statistically significant difference between the two groups in terms of costs. A break-even point for the acquisition of an intraoperative image system is calculated in almost 130 procedures. Moreover, nowadays this system is used for more than only screw insertion reducing the financial impact of this technology on a hospital.

Intracranial Meningiomas in the Elderly: Clinical, Surgical and Economic Evaluation. A Multicentric Experience.

Meningioma is one of the most common intracranial tumors. It is benign and slow growing in the majority of cases. Given the increase in life expectancy and the number of radiological tests performed, the incidence in the elderly population (≥65 years) is continuously increasing. The surgical outcomes and prognostic factors in this age group are unclear. A retrospective analysis of all the patients treated for intracranial meningiomas in two different Italian institutions was performed. The clinical, radiological, surgical and follow-up data were retrospectively reviewed. Statistical analyses were performed to identify relationships between factors and outcomes. We also carried out an economic analysis. We analyzed 321 patients with intracranial meningioma. The mean age was 72.6 years (range, 65-90), with a female predominance (F/M, 1.41). Pre-operative deficits, cognitive impairment and seizures (p < 0.001) were associated with a worse post-operative Karnofsky performance scale (KPS) score (<80). A high pre-operative KPS score was associated with a good clinical and neurological outcome (p < 0.001). Being aged between 65 and 74 years, low surgical timing and Simpson removal grades of I and II were associated with a good outcome (p < 0.001). The length of hospitalization was significantly related to the outcome (p < 0.001). The complication rate was 14.3%. At 6-month follow-up, the mortality rate was 2.5%. The average cost was higher in patients with a pre-operative KPS score lower than 80. The outcome of intracranial-meningioma resection in elderly individuals is favorable when the pre-operative KPS score is >80. Treatment should be patient-specific, and additional factors should be considered. Patients with poor pre-operative clinical conditions might benefit from a combined strategy with partial resection and radiosurgery in order to reduce surgical timing and the complication rate.

Economic study: a cost-effectiveness analysis of an intraoperative compared with a preoperative image-guided system in lumbar pedicle screw fixation in patients with degenerative spondylolisthesis.

BACKGROUND CONTEXT: In spinal surgery, newly developed technology seems to play a key role, especially with the use of computer-assisted image-guided navigation, giving excellent results. However, these tools are expensive and may not be affordable for many facilities. PURPOSE: To compare the cost-effectiveness of preoperative versus intraoperative CT (computed tomography) guidance in spinal surgery. STUDY DESIGN: A retrospective economic study. METHODS: A cost-effectiveness study was performed analyzing the overall costs of a population of patients operated on for lumbar degenerative spondylolisthesis using an image-guided system (IGS) based on a CT scan. The population was divided into two groups according to the type of CT data set acquisition adopted: Group I (IGS based on a preoperative spiral CT scan), Group II (IGS based on an intraoperative CT scan-O-Arm system). The costs associated with each procedure were assessed through a process analysis, where clinical procedures were broken down into single phases and the related costs from each phase were evaluated. No benefits in any form have been or will be received from commercial parties directly or indirectly related to the subject of this article. RESULTS: Four hundred ninety-nine patients met the criteria for this study. In total, 2,542 screws were inserted with IGS. Baseline data were similar for the two groups, as were hospitalization and complications. The surgical time was 119±43 minutes in Group I and 92±31 minutes in Group II. The full cost of the two procedures was analyzed: the mean cost, using the O-Arm system (Group II), was found to be €255.83 (3.80%) less than the cost of Group I. Moreover, the O-Arm system was also used in other surgical procedures as an intraoperative control, thus reducing the final costs of radiologic examinations (a reduction of around 550 CT scans/year). CONCLUSIONS: In conclusion, the authors of the study are of the opinion that the surgical procedure of pedicle screw fixation, using a CT-based computer-guidance system with support of the O-Arm system, allows a shortening of procedure time that might improve the clinical result. However, the present study failed to determine a clear cost-effectiveness with respect to other CT-based IGS.

The influence of the axial, antero-posterior and lateral positions of the center of rotation of a ball-and-socket disc prosthesis on the cervical spine biomechanics.

BACKGROUND: Previous studies documented the importance of the positioning and the design parameters of the prosthesis in determining the biomechanics of the implanted spine. However, a comprehensive biomechanical evaluation of the significance of these parameters is still lacking. Therefore, the paper is aimed to the quantification of their influence on the flexibility of the implanted spine and the force transmitted through the facet joints. METHODS: A finite element model of the C5-C6 spine unit including a ball-and-socket disc prosthesis was built. Three probabilistic variables were considered: the axial, antero-posterior and lateral positions of the center of rotation. Randomized input parameters were generated with the Monte Carlo method. Pure moments of 1.6 Nm in flexion, extension, lateral bending and axial rotation were imposed to the upper endplate of C5; 100 simulations were conducted for the each of the considered loading conditions. FINDINGS: Axial position of the center of rotation influenced the spine flexibility in all loading conditions and the facet force in extension, lateral bending and axial rotation. The antero-posterior position was found to influence the spine flexibility in flexion and extension, and the facet force in lateral bending and axial rotation. The lateral position was not significant. INTERPRETATION: The effects of the positioning of a cervical disc prosthesis were estimated. A wide range of mechanical behaviors can be obtained by the manufacturers by appropriately manipulating the position of the center of rotation. A proper positioning of the artificial disc during the surgery, in particular in the antero-posterior direction, was found to be of critical importance.

Quantitative assessment of intervertebral disc glycosaminoglycan distribution by gadolinium-enhanced MRI in orthopedic patients.

Our hypothesis was that the enhanced MRI of cartilage (dGEMRIC) imaging protocol could be used in patients to quantify the sulfated glycosaminoglycan (sGAG) in intervertebral discs (IVD). To test this hypothesis, 23 patients with degenerative disc pathology scheduled for surgery were studied by a specific dGEMRIC protocol: each patient underwent two MRI scans, before and 3.5 hr after Gd(DTPA)2-injection of a nonconventional dose of 40 mL. Then, T(1PRE-ENH) and T(1POST-ENH) parametric images of the disc were obtained, from which a new index DeltaT(1) of the molecular status of the IVD was computed (T(1PRE-ENH) - T(1POST-ENH)). A total of 31 tissue samples (one or two from each patient) obtained at herniectomy were collected and biochemically analyzed for sGAG content and used as the gold standard for comparison. DeltaT(1) values in correspondence to degenerated sectors were higher (158 +/- 36 ms) compared to normal sectors (80 +/- 13 ms). Linear regression analysis between MRI-derived and biochemistry-derived measurements resulted in a significant correlation (r = 0.73, P < 0.0001). The DeltaT(1) parametric images, calculated using the modified dGEMRIC technique, provided noninvasive quantitative information about sGAG content within discal tissue in vivo, which resulted in agreement with biochemical analysis. The application of this new MRI method could provide diagnostic information for standard treatment of lumbar discopathy and for innovative therapies of regenerative medicine.