OBJECTIVE In the surgical treatment of isthmic spondylolisthesis, it is debatable whether instrumented fusion is mandatory in addition to decompression. The objective of this prospective cohort... Show moreOBJECTIVE In the surgical treatment of isthmic spondylolisthesis, it is debatable whether instrumented fusion is mandatory in addition to decompression. The objective of this prospective cohort study was to assess the long-term effect of decompression alone compared with decompression and instrumented fusion in patients who underwent the intervention of their own preference. The results were compared with those in patients who underwent randomly assigned treatment.METHODS The authors performed a prospective observational multicenter cohort study, including 91 patients with isthmic spondylolisthesis assigned to undergo either decompression alone (n = 44) or decompression and fusion (n = 47). The main outcomes were the Roland-Morris Disability Questionnaire (RDQ) scores and the patient's perceived recovery at the 2-year follow-up. Secondary outcomes were visual analog scale (VAS) leg pain and back pain scores and the reoperation rate. A meta-analysis was performed for data from this cohort study (n = 91) and from a randomized controlled trial (RCT) previously reported by the authors (n = 84). Subgroup analyses were performed on these combined data for age, sex, weight, smoking, and Meyerding grade.RESULTS At the 12-week follow-up, improvements of RDQ scores were comparable for the two procedures (decompression alone [D group] 4.4, 95% CI 2.3-6.5; decompression and fusion [DF group] 5.8, 95% CI -4.3 to 1.4; p = 0.31). Likewise, VAS leg pain scores (D group 35.0, 95% CI 24.5-45.6; DF group 47.5, 95% CI 37.4-57.5; p = 0.09) and VAS back pain scores (D group 23.5, 95% CI 13.3-33.7; DF group 34.0, 95% CI 24.1-43.8; p = 0.15) were comparable. At the 2-year follow-up, there were no significant differences between the two groups in terms of scores for RDQ (difference -3.1, 95% CI -6.4 to 0.3, p = 0.07), VAS leg pain (difference -7.4, 95% CI -22.1 to 7.2, p = 0.31), and VAS back pain (difference -11.4, 95% CI -25.7 to 2.9, p = 0.12). In contrast, patient-perceived recovery from leg pain was significantly higher in the DF group (79% vs 51%, p = 0.02). Subgroup analyses did not demonstrate a superior outcome for decompression alone compared with decompression and fusion. Nine patients (20.5%) underwent reoperation in total, all in the D group. The meta-analysis including both the cohort and RCT populations yielded an estimated pooled mean difference in RDQ of -3.7 (95% CI -5.94 to -1.55, p = 0.0008) in favor of decompression and fusion at the 2-year follow- up.CONCLUSIONS In patients with isthmic spondylolisthesis, at the 2-year follow-up, patients who underwent decompression and fusion showed superior functional outcome and perceived recovery compared with those who underwent decompression alone. No subgroups benefited from decompression alone. Therefore, decompression and fusion is recommended over decompression alone as a primary surgical treatment option in isthmic spondylolisthesis. Show less
OBJECTIVE A major obstacle to improving bedside neurosurgical procedure safety and accuracy with image guidance technologies is the lack of a rapidly deployable, real-time registration and tracking... Show moreOBJECTIVE A major obstacle to improving bedside neurosurgical procedure safety and accuracy with image guidance technologies is the lack of a rapidly deployable, real-time registration and tracking system for a moving patient. This deficiency explains the persistence of freehand placement of external ventricular drains, which has an inherent risk of inaccurate positioning, multiple passes, tract hemorrhage, and injury to adjacent brain parenchyma. Here, the authors introduce and validate a novel image registration and real-time tracking system for frameless stereotactic neuronavigation and catheter placement in the nonimmobilized patient.METHODS Computer vision technology was used to develop an algorithm that performed near- continuous, automatic, and marker-less image registration. The program fuses a subject's preprocedure CT scans to live 3D camera images (Snap-Surface), and patient movement is incorporated by artificial intelligence- driven recalibration (Real-Track). The surface registration error (SRE) and target registration error (TRE) were calculated for 5 cadaveric heads that underwent serial movements (fast and slow velocity roll, pitch, and yaw motions) and several test conditions, such as surgical draping with limited anatomical exposure and differential subject lighting. Six catheters were placed in each cadaveric head (30 total placements) with a simulated sterile technique. Postprocedure CT scans allowed comparison of planned and actual catheter positions for user error calculation.RESULTS Registration was successful for all 5 cadaveric specimens, with an overall mean (+/- standard deviation) SRE of 0.429 +/- 0.108 mm for the catheter placements. Accuracy of TRE was maintained under 1.2 mm throughout specimen movements of low and high velocities of roll, pitch, and yaw, with the slowest recalibration time of 0.23 seconds. There were no statistically significant differences in SRE when the specimens were draped or fully undraped (p = 0.336). Performing registration in a bright versus a dimly lit environment had no statistically significant effect on SRE (p = 0.742 and 0.859, respectively). For the catheter placements, mean TRE was 0.862 +/- 0.322 mm and mean user error (difference between target and actual catheter tip) was 1.674 +/- 1.195 mm.CONCLUSIONS This computer vision-based registration system provided real-time tracking of cadaveric heads with a recalibration time of less than one-quarter of a second with submillimetric accuracy and enabled catheter placements with millimetric accuracy. Using this approach to guide bedside ventriculostomy could reduce complications, improve safety, and be extrapolated to other frameless stereotactic applications in awake, nonimmobilized patients. Show less
