The Effect of Thoracolumbar Pedicle Isthmus on Pedicle Screw Accuracy.

STUDY DESIGN: Retrospective analysis. OBJECTIVES: Aberrant pedicle screws can cause serious neurovascular complications. We propose that a predominant factor of pedicle screw breach is the vertebral anatomy at a given spinal level. We aim to investigate the inverse correlation between breach incidence and vertebral isthmus width. METHODS: The computed tomography scans of patients undergoing thoracolumbar surgery were retrospectively reviewed. Breaches were categorized as minor (<2 mm) or major (>2 mm). Breach incidence was stratified by spinal level. Average isthmus width was then compared to the collected breach incidences. A regression analysis and Pearson's correlation were performed. RESULTS: A total of 656 pedicle screws were placed in 91 patients with 233 detected breaches. Incidence of major breach was 6.3%. Four patients developed post-operative radiculopathy due to breach. Breach incidence was higher in the thoracic than lumbar spine (Fisher's exact test, P < .0001). The 2 spinal levels with the thinnest isthmus width (T4 and T5) were breached most often (73.7% and 73.9%, respectively). The 2 spinal levels with the thickest isthmus width (L4 and L5) were breached least often (20.5% and 11.8%). Breach incidence and isthmus width were shown to have a significant inverse correlation (Pearson's correlation, R 2 = 0.7, P < .0001). CONCLUSIONS: Thinner vertebral isthmus width increases pedicle screw breach incidence. Image-guided assistance may be most useful where breach incidence is highest and isthmus width is lowest (T2 to T6). Despite high incidence of cortical bone violation, there was little correlation with clinical symptoms. A breach is not automatically a clinical problem, provided the screw is structurally sound and the patient is symptomless.

Spontaneous spinal epidural hematoma management: a case series and literature review.

OBJECTIVE: Spontaneous spinal epidural hematoma (SSEH) manifests from blood accumulating in the epidural space, compressing the spinal cord and leading to acute neurological deficits. Standard therapy is decompressive laminectomy, although spontaneous recoveries have been reported. Sub-optimal therapeutic principles contribute to SSEH's 5.7% mortality-which patient will benefit from surgery remains unclear. This study aims to investigate parameters that affect SSEH's progression, outlining a best-practice therapeutic approach. MATERIALS AND METHODS: Literature review yielded 65 cases from 12 studies. Furthermore, 6 cases were presented from our institution. All data were analyzed under American Spinal Injury Association (ASIA) score guidelines. RESULTS: Fifty percent of SSEH patients do not fully recover. In all, 30% of patients who presented with an ASIA score of A did not improve with surgery, although every SSEH patient who presented at C or D improved. Spontaneous recovery is rare-only 23% of patients were treated conservatively. Seventy-three percent of those made a full recovery, as opposed to the 48% improvement in patients managed surgically. Thirty-three percent of patients managed conservatively had an initial score of A or B, all improving to a score of D or E without surgery. Regardless, conservative management tends toward low-risk presentations. Patients managed conservatively were three times as likely to have an initial score of D than their surgically managed counterparts. DISCUSSION: The degree of pre-operative neural deficit is a major prognostic factor. Conservative management has proven effective, although feasible only if spontaneous recovery is manifested. Decompressive laminectomy should continue to remain readily available, given the inverse correlation between operative interval and recovery.

Nonsurgical management of an extensive spontaneous spinal epidural hematoma causing quadriplegia and respiratory distress in a choledocholithiasis patient: A case report.

RATIONALE: Spontaneous spinal epidural hematoma (SSEH) manifests from blood accumulating in the epidural space, compressing the spinal cord, and leading to acute neurological deficits. The disease's cloudy etiology and rarity contribute to dangerously suboptimal therapeutic principles. These neural deficits can be permanent, even fatal, if the SSEH is not treated in a timely and appropriate manner. Standard therapy is decompressive laminectomy, though nonsurgical management is a viable course of action for patients who meet a criterion that is continuously being refined. PATIENT CONCERNS: A 76-year-old woman on warfarin for a past pulmonary embolism presented to the emergency room with jaundice, myalgia, hematuria, neck pain, and an International Normalized Ratio (INR) of 14. Upon admission, she rapidly developed quadriplegia and respiratory distress that necessitated intubation. DIAGNOSES: T2-weighted magnetic resonance imaging (MRI) revealed an epidural space-occupying hyperintensity from C2 to S5 consistent with a spinal epidural hematoma. An incidental finding of dilated intrahepatic and common bile ducts prompted an endoscopic retrograde cholangiopancreatography, which demonstrated choledocholithiasis. INTERVENTIONS: The patient's INR was normalized with Vitamin K and Beriplex. Upon transfer to the surgical spine team for assessment of a possible intervention, the patient began to demonstrate recovery of neural functions. The ensuing sustained motor improvement motivated the team's preference for close neurologic monitoring and continued medical therapy over surgery. Thirteen hours after the onset of her symptoms, the patient was extubated. A sphincterotomy was later performed, removing 81 common bile duct stones. OUTCOMES: MRI demonstrated complete resorption of the SSEH and the patient maintained full neurological function at final follow-up. LESSONS: Nonsurgical management of SSEH should be considered in the context of early and sustained recovery. Severe initial neural deficit does not necessitate surgical decompression. Choledocholithiasis and subsequent Vitamin K deficiency, particularly when coupled with anticoagulant use, can increase INR and is a novel proposed risk factor for SSEH. Furthermore, coagulopathies should be medically corrected before surgical intervention within a given timeframe, as spontaneous recovery may manifest. This should be favored over surgery in patients demonstrating early and sustained recovery, as nonsurgical management is 25% more effective in achieving full recovery.