Blunt traumatic posterior cord syndrome.

INTRODUCTION: Posterior cord syndrome (PCS) is rare and insufficiently assessed in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). CASE PRESENTATION: A 39-year-old male was involved in a motorcycle collision and presented with paresthesia of the entire body, neck pain, subjective right arm weakness, and loss of position sense in all extremities. Imaging of the cervical spine revealed fractures of the upper cervical spine including a teardrop fracture and hangman fracture. Patient underwent anterior cervical interbody fusion and plating and halo orthosis. He ultimately regained near full function. Follow-up imaging clearly depicted the traumatic lesion to the level of the posterior spinal cord. DISCUSSION: PCS is uncommon, but may be underdiagnosed. We would like to emphasize the importance of a full neurological exam in order to properly diagnose and manage patients with PCS. Our case is unique since we were able to anatomically delineate the focus of spinal cord injury to the posterior column on follow up MRI at 10 months. Therefore, a delayed MRI obtained sub-acutely may facilitate the anatomical diagnosis of PCS.

Natural History of a Patient with Sacral Chordoma: Case Report and Literature Review.

BACKGROUND: Chordomas are rare, slow-growing, locally aggressive, malignant tumors of the spine. Chordomas are conventionally treated with surgical resection with or without radiation. There is an absence of literature documenting the natural history of a primary sacral chordoma. CASE DESCRIPTION: A 65-year-old man presented with rectal pain, constipation, urinary and fecal incontinence, S1 radiculopathy, and a palpable rectal mass. A needle biopsy confirmed the pathologic diagnosis of sacral chordoma. The patient declined to have surgery because of the surgical risks involved. He was managed conservatively with supportive care only. The patient was routinely followed in clinic and had a subjective and objective excellent quality of life with adequate pain management. Meanwhile, his neurologic status did not deteriorate. During follow-up, some posterolateral aspects of the chordoma regressed. However, the bulk of the lesion continued to slowly progress. The patient survived for 7.5 years. He eventually succumbed to urosepsis and new-onset peritoneal metastasis. CONCLUSIONS: To our knowledge, the patient is the only documented case in the literature of an untreated biopsy-proven sacral chordoma. The patient's tumor was intended for resection, and therefore comparable with data from treated chordomas. The patient's survival is similar to the median survival in treated chordomas. The patient's survival was despite negative prognosticators, such as advanced age of the patient and high sacral location above S2.

Utility of intraoperative electromyography in placing C7 pedicle screws.

OBJECTIVE: The C7 vertebral body is morphometrically unique; it represents the transition from the subaxial cervical spine to the upper thoracic spine. It has larger pedicles but relatively small lateral masses compared to other levels of the subaxial cervical spine. Although the biomechanical properties of C7 pedicle screws are superior to those of lateral mass screws, they are rarely placed due to increased risk of neurological injury. Although pedicle screw stimulation has been shown to be safe and effective in determining satisfactory screw placement in the thoracolumbar spine, there are few studies determining its utility in the cervical spine. Thus, the purpose of this study was to determine the feasibility, clinical reliability, and threshold characteristics of intraoperative evoked electromyographic (EMG) stimulation in determining satisfactory pedicle screw placement at C7. METHODS: The authors retrospectively reviewed a prospectively collected data set. All adult patients who underwent posterior cervical decompression and fusion with placement of C7 pedicle screws at the authors' institution between January 2015 and March 2019 were identified. Demographic, clinical, neurophysiological, operative, and radiographic data were gathered. All patients underwent postoperative CT scanning, and the position of C7 pedicle screws was compared to intraoperative neurophysiological data. RESULTS: Fifty-one consecutive C7 pedicle screws were stimulated and recorded intraoperatively in 25 consecutive patients. Based on EMG findings, 1 patient underwent intraoperative repositioning of a C7 pedicle screw, and 1 underwent removal of a C7 pedicle screw. CT scans demonstrated ideal placement of the C7 pedicle screw in 40 of 43 instances in which EMG stimulation thresholds were > 15 mA. In the remaining 3 cases the trajectories were suboptimal but safe. When the screw stimulation thresholds were between 11 and 15 mA, 5 of 6 screws were suboptimal but safe, and in 1 instance was potentially dangerous. In instances in which the screw stimulated at thresholds ≤ 10 mA, all trajectories were potentially dangerous with neural compression. CONCLUSIONS: Ideal C7 pedicle screw position strongly correlated with EMG stimulation thresholds > 15 mA. In instances, in which the screw stimulates at values between 11 and 15 mA, screw trajectory exploration is recommended. Screws with thresholds ≤ 10 mA should always be explored, and possibly repositioned or removed. In conjunction with other techniques, EMG threshold testing is a useful and safe modality in determining appropriate C7 pedicle screw placement.

Complications of Poor Cervical Alignment in Patients Undergoing Posterior Cervicothoracic Laminectomy and Fusion.

OBJECTIVE: This study sought to determine whether a relationship exists between caudal instrumented level and revision rates, neck disability index scores, and cervical alignment in patients undergoing multilevel posterior cervical fusion. METHODS: This study examined a dataset of all patients undergoing posterior cervical decompression and fusion at ≥3 levels, terminating between C4 and T4, between January 2010 and December 2015, with at least 12 months of clinical follow-up. Patients were separated into cohorts based on caudal level of the fusion: C6 (or more cranial), C7, T1, or T2 (or more caudal). Revision rate, neck disability index score, sagittal vertical axis, T1 slope, and cervical lordosis were recorded. Linear regression and multivariate analysis were performed to identify independent predictors of patient outcomes and disparities between ending constructs in the cervical and the thoracic spine. RESULTS: The overall revision rate was 10.8% (n = 24). No statistically significant difference in the revision rate was identified between fusions terminating at C6 or cranial, C7, T1, or T2 and caudal (P = 0.74). Revision correlated strongly with increased sagittal vertical axis (P = 0.002) and T1 slope (P = 0.04). Increased neck disability index score correlated with revision rate (P = 0.01), cervical kyphosis (P < 0.001), and increased sagittal vertical axis (P = 0.04). CONCLUSIONS: This study suggests that constructs terminating in the proximal thoracic spine have similar revision rates, postoperative neck disability index scores, and radiographic measurements as those terminating in the cervical spine. Poor cervical alignment, as evidenced by increased sagittal vertical axis, cervical kyphosis and T1 slope, predicts need for revision and of poorer clinical outcomes.