Man versus machine: Automatic pedicle screw planning using registration-based techniques compared with manual screw planning for thoracolumbar fusion surgeries.

OBJECTIVE: This study evaluates the precision of a commercially available spine planning software in automatic spine labelling and screw-trajectory proposal. METHODS: The software uses automatic segmentation and registration of the vertebra to generate screw proposals. 877 trajectories were compared. Four neurosurgeons assessed suggested trajectories, performed corrections, and manually planned pedicle screws. Additionally, automatic identification/labelling was evaluated. RESULTS: Automatic labelling was correct in 89% of the cases. 92.9% of automatically planned trajectories were in accordance with G&R grade A + B. Automatic mode reduced the time spent planning screw trajectories by 7 s per screw to 20 s per vertebra. Manual mode yielded differences in screw-length between surgeons (largest distribution peak: 5 mm), automatic in contrast at 0 mm. The size of suggested pedicle screws was significantly smaller (largest peaks in difference between 0.5 and 3 mm) than the surgeon's choice. CONCLUSION: Automatic identification of vertebrae works in most cases and suggested pedicle screw trajectories are acceptable. So far, it does not substitute for an experienced surgeon's assessment.

Improvement of Back and Leg Pain after Lumbar Spinal Decompression without Fusion.

BACKGROUND: To evaluate whether decompression in lumbar spinal stenosis without fusion leads to sufficient improvement of back pain and leg pain and whether re-decompression alone is sufficient for recurrent lumbar spinal stenosis for patients without signs of instability. MATERIAL AND METHODS: A successive series of 102 patients with lumbar spinal stenosis (with and without previous lumbar surgery) were treated with decompression alone during a 3-year period. Data on pre- and postoperative back pain and leg pain (numerical rating scale [NRS] scale) were retrospectively collected from questionnaires with a return rate of 65% (n = 66). The complete cohort as well as patients with first-time surgery and re-decompression were analyzed separately. Patients were dichotomized to short-term follow-up (< 100 weeks) and long-term follow-up (> 100 weeks) postsurgery. RESULTS: Overall, both back pain (NRS 4.59 postoperative versus 7.89 preoperative; p < 0.0001) and leg pain (NRS 4.09 versus 6.75; p < 0.0001) improved postoperatively. The short-term follow-up subgroup (50%, n = 33) showed a significant reduction in back pain (NRS 4.0 versus 6.88; p < 0.0001) and leg pain (NRS 2.49 versus 6.91: p < 0.0001). Similar results could be observed for the long-term follow-up subgroup (50%, n = 33) with significantly less back pain (NRS 3.94 versus 7.0; p < 0.0001) and leg pain (visual analog scale 3.14 versus 5.39; p < 0.002) postoperatively. Patients with previous decompression surgery benefit significantly regarding back pain (NRS 4.82 versus 7.65; p < 0.0024), especially in the long-term follow-up subgroup (NRS 4.75 versus 7.67; p < 0.0148). There was also a clear trend in favor of leg pain in patients with previous surgery; however, it was not significant. CONCLUSIONS: Decompression of lumbar spinal stenosis without fusion led to a significant and similar reduction of back pain and leg pain in a short-term and a long-term follow-up group. Patients without previous surgery benefited significantly better, whereas patients with previous decompression benefited regarding back pain, especially for long-term follow-up with a clear trend in favor of leg pain.

Lacking Benefit of Intraoperative High-Dose Dexamethasone in Instrumented Surgery for Cervical Spondylotic Myelopathy.

BACKGROUND: Our objective was to investigate the effect of intraoperative dexamethasone administration on wound healing, complications, and clinical outcome in patients with posterior surgery for cervical spondylotic myelopathy (CSM). METHODS: We conducted a retrospective study of patients with CSM undergoing dorsal instrumentation and decompression of the cervical spine. The senior surgeon decided if administration of dexamethasone (40 mg intravenously) was indicated. Patients were divided into two groups: dexamethasone group (DG) and non-dexamethasone group (nDG). All patients were monitored for pre- and postoperative neurologic symptoms and complications. Clinical follow-up was evaluated with the Neck Disability Index (NDI) and the modified Japanese Orthopaedic Association (mJOA) score. RESULTS: A total of 49 patients were included (DG, 25; nDG, 24). DG and nDG patients showed no significant differences in pre- and postoperative findings. Five patients in the DG had wound healing complications compared with patients in the nDG (p = 0.021), and one died due to infection. Apart from that, we did not observe any significant differences between the two groups regarding complications, neurologic symptoms, and follow-up (NDI and mJOA). CONCLUSION: Intraoperative dexamethasone administration had no influence on the postoperative outcome and follow-up. A significantly higher rate of wound infections was detected in the DG. These data support the hypothesis that intraoperative dexamethasone bolus application in CSM lacks benefit.

Development of a short scale for assessing economic environmental aspects in patients with spinal diseases using Rasch analysis.

BACKGROUND: Economic environmental factors represent important barriers to participation and have deleterious effects on quality of life (QOL) in persons with spinal diseases (SpD). While economic factors are anchored in the International Classification of Functioning, Disability and Health, their influence on QOL and participation from patients' perspectives is an infrequent focus of research. The aim of the present research is to calibrate a culturally adapted Rasch-based questionnaire assessing economic QOL in patients with SpD. METHODS: The 11-items of the German economic-QOL-scale were answered by 325 patients with SpD on a four-point Likert-scale. Fit to the Rasch measurement model was investigated by testing for stochastic ordering of the items, unidimensionality, local independence, and differential item functioning (DIF). RESULTS: After adjusting for local dependency, fit to the Rasch model was achieved with a non-significant item-trait interaction (chi-squaredf = 20 = 34.8, p = 0.021). The person separation reliability equaled 0.88, the scale was free from age- or gender-related DIF, and unidimensionality could be verified. CONCLUSIONS: The Rasch-based German version of the economic-QOL-scale represents a suitable instrument to investigate the influences of economic factors on patients' QOL at a group and individual level. It can be easily applied in research and practice and may be administered quickly in combination with other instruments. The short test duration implies a low test burden for patients and a minimum of time expenditure by clinicians when evaluating the results.

Volume determination of amygdala and hippocampus at 1.5 and 3.0T MRI in temporal lobe epilepsy.

Since magnetic resonance imaging (MRI) technique is constantly evolving with higher field strength scanners, the question arises whether images from different field strength scanners can be used interchangeably for scientific and clinical purposes. We address this issue in a study group of patients with temporal lobe epilepsy (TLE). Two different quantification methods for analysing structural (MRI) were used. Conventional volumetry was performed by manually tracing amygdala and hippocampus volumes on both 1.5 and 3T scans of 10 TLE patients. Additionally a voxel-based morphometry (VBM)-based extraction of those structures was conducted. As an answer to the main question, it was determined that the volumetrically derived volumes of amygdala and hippocampus from 1.5 and 3.0T images did not differ. Our findings concerning the volumetry are consistent with findings in healthy controls, thus offering the possibility to use volumetry of the different scanners interchangeably. The results of the VBM-analyses show satisfying inter-scanner volume quantification but not consistent enough to be deemed interchangeable. Further investigations analysing the outcomes of conventional VBM of different field strength scanners are necessary.

Blood flow velocities in the basal cerebral vein after head trauma: a prospective study in 82 patients.

BACKGROUND AND PURPOSE: The authors' aim was to evaluate the time course of the basal vein's (BVR) mean flow velocity (VBVR) in patients after traumatic brain injury and its relation to intracranial pressure (ICP), cerebral perfusion pressure (CPP), and the clinical outcome. METHODS: In 82 head-injured patients (13 women and 69 men, median age = 31 years, Glasgow Coma Score = 15 to 3), daily measurement of the basal cerebral vein's and the middle cerebral artery's (MCA) flow velocities and pulsatilities was performed during each patient's entire stay in the intensive care unit. No angle correction was performed. A computerized sonography system (SD 800, Philips, Irvine, CA) with a 2.0-MHz to 2.5-MHz transducer was used for all measurements. The Glasgow Outcome Score (GOS) was evaluated after 6 months. RESULTS: During the study period, VBVR values on the side of trauma were higher in the patients with favorable outcomes (GOS = 4 and 5) compared to patients with unfavorable outcomes (GOS = 2 and 3). This was statistically significant on days 4, 6, 7, and 11 and was not observed in the mean flow velocity of the MCA (VMCA). VBVR values among the good-outcome group tended to exceed the normal mean flow velocity (9.1 cm/s), whereas the unfavorable-outcome group was below this level. A correlation between venous flow velocity or pulsatility and ICP or CPP was not observed. CONCLUSIONS: Repetitive Doppler examination of the basal cerebral veins may add new aspects to the monitoring of head-injured patients.