Comparison of Cortical Bone Trajectory to Pedicle-Based Dynamic Stabilization: An Analysis of 291 Patients

Objective Pedicle-based dynamic stabilization (DS) has gained popularity outside of America. Although pedicle screw (PS) loosening has always been a concern, it is reportedly innocuous. Cortical bone trajectory (CBT) screw is an emerging option with less invasiveness and similar effectiveness to PS in short-segment lumbar fusion. This study aimed to verify the use of CBT for DS by comparing the outcomes between pedicle- and CBT-based DS. Methods Consecutive patients with lumbar spondylosis or low-grade spondylolisthesis who underwent 1- or 2-level DS between L3–5 with a minimum follow-up of 24 months were reviewed. Screw loosening was determined by computed tomography and the incidences were compared. Results A total of 291 patients who underwent Dynesys DS (235 pedicle- and 56 CBT-based, respectively) were compared. The demographics and preoperative conditions were similar. All the clinical outcomes improved at 24-month postoperation, while the CBT-based group had less operation time and blood loss than the pedicle-based group. The rates of screw loosening were lower in the CBT-based (5.4% per screw and 12.5% per patient) than the pedicle-based group (9% per screw and 26.4% per patient). Furthermore, there were no differences in the clinical outcomes and complication profiles. Conclusion The CBT-based DS for 1- or 2-level lumbar degeneration demonstrated equivalent clinical improvement as the pedicle-based DS. The adaption of CBT-based screws for DS could be a less invasive approach (shorter operation time and less blood loss), with lower chances of screw loosening than the conventional PS-based DS

Measurement of Deformity at the Craniovertebral Junction: Correlation of Triangular Area and Myelopathy

Objective Diseases of the craniovertebral junction (CVJ) are commonly associated with deformity, malalignment, and subsequent myelopathy. The misaligned CVJ might cause compression of neuronal tissues and subsequently clinical symptoms. The triangular area (TA), measured by magnetic resonance imaging/images (MRI/s), is a novel measurement for quantification of the severity of compression to the brain stem. This study aimed to assess the normal and pathological values of TA by a comparison of patients with CVJ disease to age- and sex-matched controls. Moreover, postoperative TAs were correlated with outcomes. Methods Consecutive patients who underwent surgery for CVJ disease were included for comparison to an age- and sex-matched cohort of normal CVJ persons as controls. The demographics, perioperative information, and pre- and postoperative 2-year cervical MRIs were collected for analysis. Cervical TAs were measured and compared. Results A total of 201 patients, all of whom had pre- or postoperative MRI, were analyzed. The TA of the CVJ deformity group was larger than the healthy control group (1.62 ± 0.57 cm2 vs. 1.01 ± 0.18 cm2, p < 0.001). Moreover, patients who had combined anterior odontoidectomy and posterior laminectomy with fixation had the greatest reduction in the TA (1.18 ± 0.58 cm2). Conclusion In CVJ deformity, the measurement of the cervical TA could indicate the severity of brain stem compression. After surgery, the TA had a varying degree of improvement, which could represent the efficacy of surgery

A Pathophysiological Approach to Reduce Peritumoral Edema with Gamma Knife Radiosurgery for Large Incidental Meningiomas

Background: Peritumoral edema may be a prohibitive side effect in treating large incidental meningiomas with stereotactic radiosurgery. An approach that limits peritumoral edema and achieves tumor control with SRS would be an attractive management option for large incidental meningiomas. Methods: This is a retrospective cohort study of patients with large incidental meningiomas (&ge;2 mL in volume and/or 2 cm in diameter) treated with gamma knife radiosurgery (GKRS) between 2000 and 2019 in Taiwan and followed up for 5 years. The outcomes of a pathophysiological approach targeting the dural feeding artery site with a higher marginal dose (18&ndash;20 Gy) to enhance vascular damage and the parenchymal margin of the tumor with a lower dose (9&ndash;11 Gy) to reduce parenchymal damage were compared with those of a conventional approach targeting the tumor center with a higher dose and tumor margin with a lower dose (12&ndash;14 Gy). Results: A total of 53 incidental meningiomas were identified, of which 23 (43.4%) were treated with a pathophysiological approach (4 cases underwent a two-stage approach) and 30 (56.7%) were treated with a conventional approach. During a median follow-up of 3.5 (range 1&ndash;5) years, tumor control was achieved in 19 (100%) incidental meningiomas that underwent a single-stage pathophysiological approach compared with 29 (96.7%) incidental meningiomas that underwent a conventional approach (log-rank test: p = 0.426). Peritumoral edema developed in zero (0%) incidental meningiomas that underwent a single stage pathophysiological approach compared to seven (23.3%) incidental meningiomas that underwent a conventional approach (log-rank test: p = 0.023). Conclusions: Treatment of large incidental meningiomas with a pathophysiological approach with GKRS achieves similar rates of tumor control and reduces the risk of peritumoral edema. GKRS with a pathophysiological approach may be a reasonable management strategy for large incidental meningiomas

Reduction of high-grade lumbosacral spondylolisthesis by minimally invasive transforaminal lumbar interbody fusion: A technical note

Objective: To demonstrate the feasibility and efficacy of reduction of high-grade lumbosacral spondylolisthesis via a minimally invasive approach. Summary of background data: Reduction of high-grade spondylolisthesis remains controversial and technically challenging. Although minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has gained wide acceptance in recent years, it still has not been reported to achieve complete reduction of high grade slips. Methods: In this technical note, the authors present a case of L5/S1 Meyerding Grade III fixed spondylolisthesis managed by MI-TLIF with percutaneous screws. Surgical techniques and key steps for reduction are described in detail. Results: A 50-year-old woman had low back pain for 8 years. She also presented with radiculopathy of lower limbs and frequency/urgency of urination. The radiographs and computed tomography (CT) of the lumbar spine demonstrated degenerative spondylolisthesis, Meyerding grade III, at the level of L5/S1. The slippage was fixed on dynamic radiographs and there was neuroforaminal stenosis on the magnetic resonance image. The patient underwent MI-TLIF with percutaneous pedicle screw-rod fixation for arthrodesis at L5/S1. Her symptoms subsided after the operation. The one-and-half year follow-up radiographs, including CT, demonstrated complete reduction of the high-grade slippage and fusion of the lumbosacral spondylolisthesis. Conclusion: Minimally invasive TLIF is a viable option for reduction of high-grade spondylolisthesis at L5/S1

Intracranial subdural hematoma coexisting with improvement in spontaneous intracranial hypotension after an epidural blood patch

A 36-year-old male had spontaneous intracranial hypotension (SIH) presenting with refractory headache for 4 months. Multiple epidural blood patches (EBPs) yielded relief of symptoms, but the course was complicated, with asymptomatic intracranial subdural hematoma (SDH). Except for SDH, other radiological diagnostic signs of SIH were resolved and the patient’s headaches improved after EBP. Owing to a mass effect and persistent cerebrospinal fluid (CSF) leakage, surgical repair of the spinal leakage was performed, but no cranial procedures were carried out. Postoperatively, the SDH completely resolved, but there was still CSF leakage at the level where surgery was performed. The patient has remained free of headache or other events for 3 years. It was reduction rather than elimination of the spinal CSF leak that yielded remission of SIH. In summary, intracranial SDH can be a complication of inadequately treated SIH (i.e. persistent minor CSF leakage). Management of SDH should focus on correction of the underlying SIH rather than craniotomy for hematoma evacuation