Neural Arch Preservation-Posterior Vertebral Column Resection: 2-Dimensional Operative Video.

This technique is a modification of the posterior vertebral column resection (PVCR) for patients with kyphoscoliosis with vertebral column resection indications (Cobb angle >100° angular and rigid with flexibility <20%-30%). The neural arch (preservation)-PVCR has the biomechanical advantage of maintaining the dural sac and the spinal cord attached within the neural arch and ligamentum flavum (dorsal meningovertebral ligaments are in tension in kyphosis), avoiding spinal cord deviation during the vertebrectomy. Preserving the neural arch did not interfere with corrective maneuvers of the anterior and middle columns and avoided the spinal translation in any anatomic plane. Standard posterior spinal midline approach and insertion of pedicle screws, a temporary rod is placed on contralateral side to maintain the stability of the spine during neural arch (preservation)-PVCR and to prevent translation of the spine. A costotransversectomy for an anterior approach is performed in the apex level and discectomies of the upper and lower levels. The anterior column reconstruction is made with a structural graft or titanium mesh cage with autograft. The correction is made with compression of the segment of the osteotomy, kyphosis correction with "in situ" rod benders, and Cantilever maneuver for final correction. A multiple rod construction is placed to increase stability. This technique has the potential benefits of decreasing operative time and blood loss, protecting the neural elements from fibrous scars and more posterior fusion for decreasing pseudoarthrosis. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of his/her image.

Full-endoscopic discectomy for thoracic disc herniations: a single-arm meta-analysis of safety and efficacy outcomes.

INTRODUCTION: Surgical intervention is the treatment of choice in patients with thoracic disc herniation with refractory symptoms and progressive myelopathy. Due to high occurrence of complications from open surgery, minimally invasive approaches are desirable. Nowadays, endoscopic techniques have become increasingly popular and full-endoscopic surgery can be performed in the thoracic spine with low complication rates. METHODS: Cochrane Central, PubMed, and Embase databases were systematically searched for studies that evaluated patients who underwent full-endoscopic spine thoracic surgery. The outcomes of interest were dural tear, myelopathy, epidural hematoma, recurrent disc herniation, and dysesthesia. In the absence of comparative studies, a single-arm meta-analysis was performed. RESULTS: We included 13 studies with a total of 285 patients. Follow-up ranged from 6 to 89 months, age from 17 to 82 years, with 56.5% male. The procedure was performed under local anesthesia with sedation in 222 patients (77.9%). A transforaminal approach was used in 88.1% of the cases. There were no cases of infection or death reported. The data showed a pooled incidence of outcomes as follows, with their respective 95% confidence intervals (CI)-dural tear (1.3%; 95% CI 0-2.6%); dysesthesia (4.7%; 95% CI 2.0-7.3%); recurrent disc herniation (2.9%; 95% CI 0.6-5.2%); myelopathy (2.1%; 95% CI 0.4-3.8%); epidural hematoma (1.1%; 95% CI 0.2-2.5%); and reoperation (1.7%; 95% CI 0.1-3.4%). CONCLUSION: Full-endoscopic discectomy has a low incidence of adverse outcomes in patients with thoracic disc herniations. Controlled studies, ideally randomized, are warranted to establish the comparative efficacy and safety of the endoscopic approach relative to open surgery.

Translaminar screw of C1 for the reinforcement of subaxial cervical spine reconstruction.

Translaminar screws in the cervical spine have been mostly employed at C2 level when conventional trajectories are challenging. However, reports in the literature of translaminar screw of C1 are remarkably anecdotal. We aimed to report a case using C1 translaminar in addition to C1 lateral mass screws for the reinforcement of subaxial cervical spine reconstruction. We present a 22-year-old female patient, who developed persistent cervical pain, and computed tomography scan demonstrated lytic lesions of the vertebral bodies and lateral masses from C3 to C6. Magnetic resonance imaging showed spinal cord compression without myelopathy. Surgical biopsy was inconclusive, and an oncological vertebral instability led to surgical stabilization. Laminectomy and bilateral facetectomy of levels involved was achieved, instrumentation from C1 to T3 and reconstruction with posterolateral fibula bilaterally, and without occipital fixation. A third satellite rod was placed using C1-2-7 translaminar screws. Translaminar screw of C1 is a feasible alternative for increasing the strength of the construct.

Unilateral spacer distraction of the subaxial cervical facet joint for the treatment of fixed coronal malalignment of the craniovertebral junction.

Introduction: The standard treatment for a fixed coronal malalignment of the craniovertebral junction is an anterior and/or posterior column osteotomy (PCO) plus instrumentation. However, the procedure is very challenging, carrying an inherently high risk of complications even in experienced hands. This case series demonstrates the usefulness of an alternative treatment that adds a unilateral spacer distraction (USD) to the subaxial cervical facet joint to promote coronal realignment and fusion. Materials and Methods: A single-center retrospective study of the patients with fixed coronal malalignment of the craniovertebral junction caused by different etiologies treated with USD in the concavity side with PCO in the convexity side of the subaxial cervical spine. Demographic characteristics and radiological parameters were collected with special emphasis on clinical and radiological measurements of coronal alignment of the cervical spine. Results: From 2012 to 2019, four patients were treated with USD of the subaxial cervical spine complementing an asymmetrical PCO at the same level. The causes of coronal imbalance were congenital, tuberculosis, posttraumatic, and ankylosing spondylitis. The level of USD was C2-C3 in three patients and C3-C4 in one patient. A substantial coronal realignment was achieved in all four. One patient had an iatrogenic vertebral artery injury during the dissection and facet distraction and developed Wallenberg's syndrome with partial recovery. Conclusions: USD of the concave side with unilateral PCO of the convexity side in the subaxial cervical spine is a promising alternative treatment for fixed coronal malalignment of the craniovertebral junction from different causes.

Correlation Between Single-Pulse and Pulse-Train Stimulation During Neuromonitoring of Thoracic Pedicle Screws in Scoliosis Surgery.

BACKGROUND: The use of thoracic pedicle screws (TPSs) during scoliosis surgery entails an inherent risk of neurological deficit. Triggered electromyography (t-EMG) is an accurate neuromonitoring test for detection of malpositioned TPSs. However, single-pulse (SP) t-EMG stimulation has shown variable capability for detecting medial pedicle breaches, while pulse-train (PT) t-EMG could be more accurate. The aim of this study was to analyze the correlation between SP t-EMG and PT t-EMG. METHODS: This retrospective study included 20 patients who underwent scoliosis correction with 294 TPSs placed. A total of 588 tests with both SP t-EMG and PT t-EMG were performed, analyzed, and compared. The results of both t-EMG techniques were stratified into 3 different groups according to threshold obtained: group 1 (≤6 mA), group 2 (6.1-11.9 mA), and group 3 (12 mA). A generalized linear model was used to analyze the correlation between the methods. RESULTS: SP t-EMG elicited response in 5 screws (1.7%) at ≤6 mA, 28 screws (9.5%) at 6.1-11.9 mA, and 261 screws (88.8%) at 12 mA. PT t-EMG elicited response in 16 screws (5.4%) at ≤6 mA, 30 screws (10.2%) at 6.1-11.9mA, and 248 screws (84.4%) at 12 mA. There is a strong positive and significant association between SP t-EMG and PT t-EMG with a decrease ratio of 2% (95% confidence interval 1% to 3%). CONCLUSIONS: SP t-EMG and PT t-EMG stimulation techniques had similar results when the stimuli were applied to TPSs, but PT t-EMG may have better efficacy in low-threshold group.