Prevalence of venous thromboembolic events after elective major thoracolumbar degenerative spine surgery.

STUDY DESIGN: A case-control study. OBJECTIVE: The purposes of this study were to establish the prevalence of venous thromboembolic disease in patients undergoing elective major thoracolumbar degenerative spine surgery and identify risk factors. SUMMARY OF BACKGROUND DATA: Venous thromboembolic events (VTE) are a serious complication of orthopedic surgery, but the prevalence of VTE after elective thoracolumbar degenerative spine surgery is not well known. METHODS: This was a case-control study of 5766 consecutive elective thoracolumbar degenerative spine surgeries. Symptomatic pulmonary emboli (PE) were diagnosed by spiral chest CT scans, nuclear scintigraphic ventilation-perfusion, and angiography. Deep vein thromboses (DVT) were diagnosed by venous duplex scans. The prevalence of VTE was analyzed according to patient demographic variables and type of surgery performed. RESULTS: The prevalence of developing a VTE was 1.5% (89/5766), with a prevalence of symptomatic PE of 0.88% (51/5766) and DVT of 0.66% (38/5766). There were 47% males and 53% females with a mean age of 60.3 years. In patients undergoing 5-segment fusions the prevalence of PE was 3.1% (P=0.022). Patients who had ≥4 segments fused had a prevalence of PE of 1.7% (P=0.014). The odds of having a PE in those above 65 years at the time of surgery were 2.196 times as large as for those below 65 years. Noncontributory factors included sex, instrumentation, and revision surgery. CONCLUSIONS: This case-control study of 5766 patients who underwent elective thoracolumbar degenerative spine surgery revealed a prevalence of VTE of 1.5%, with a prevalence of PE of 0.88% and DVT of 0.66%. Patients with increasingly extensive surgery had a higher risk of PE, specifically those undergoing fusion of ≥5 segments.

Surgical approach to the cervicothoracic junction: can a standard Smith-Robinson approach be utilized?

STUDY DESIGN: Retrospective case series study. OBJECTIVES: To determine when the standard Smith-Robinson approach can be used successfully to approach the cervicothoracic junction (CTJ). SUMMARY OF BACKGROUND DATA: Most of techniques for exposing the anterior CTJ are associated with significant morbidity. To our knowledge, there is no reliable technique, which described to determine when the standard Smith-Robinson approach is adequate and when a more invasive approach, such as a sternal splitting approach, is necessary to approach the CTJ anteriorly. METHODS: We evaluated the ability of the following technique to preoperatively determine whether a standard Smith-Robinson approach can be used to approach the CTJ: on the lateral plain radiograph, a line was drawn from the intended skin incision site to the top of the manubrium (at the suprasternal notch) to the level of the disc space. If it appeared that this trajectory would allow adequate exposure of the CTJ, then the operation was performed through the standard Smith-Robinson approach. The records and radiographs of all patients who had undergone anterior cervicothoracic arthrodesis to T1 or below were evaluated. RESULTS: A total of 99 patients who underwent an anterior cervicothoracic fusion using the standard Smith-Robinson approach were identifed. Using the proposed technique, there were no cases in which the planned lowest instrumented vertebra could not be safely reached through the standard Smith-Robinson approach. No procedure was abandoned or converted to a sternotomy approach. CONCLUSIONS: Our results suggest that if the lowest instrumented vertebra can be seen on a lateral radiograph and a line passing from the intended skin incision site to this level lies on top of the manubrium, a routine Smith-Robinson approach can be used to expose the level. To our knowledge, this is the largest series outlining a simple guideline for approaching the anterior CTJ.

Cervical spinal cord dimensions and clinical outcomes in adults with klippel-feil syndrome: a comparison with matched controls.

Study Design Retrospective case-control study. Objectives To confirm the fact that spinal cord dimensions are smaller in adults with Klippel-Feil syndrome (KFS) than in pediatric patients with KFS and to compare the clinical characteristics and outcomes of neurologic complications in patients with KFS with matched controls. Methods We performed an independent 1:2 case-control retrospective radiographic and chart review of a consecutive series of adults with KFS who underwent surgical intervention. The control group consisted of consecutive non-KFS surgical patients. Patients were matched in 1:2 case-control manner. Their charts were reviewed and the clinical characteristics were compared. Axial T2-weighted magnetic resonance imaging (MRI) was used to measure the anteroposterior and mediolateral axial spinal cord and spinal canal at the operative levels and measurements were compared. Results A total of 22 patients with KFS and 44 controls were identified. The KFS group had a tendency of more myeloradiculopathy, and the control group had a tendency toward more radiculopathy. Both tendencies, however, were not significantly different. MRIs of 10 patients from the KFS group and 22 controls were available. There was no difference in the area of both spinal cord and canal at the operative levels. Conclusion Contrary to the finding in previous reports on pediatric patients, there were no differences between KFS and well-matched control groups in terms of age of onset, presentation, revision rate, complication rate, surgical outcome, and cross-sectional spinal cord and canal dimensions at the operative level.

The incidence of bifid c7 spinous processes.

For posterior cervical surgery, if the operation only involves the lower cervical area, counting from C2 is impractical and the level may not be visible on X-rays. In such cases, we usually place a marker at the top of the incision and also rely on the size and monofid shape of the C7 spinous process. Relying on the C7 morphology, however, we initially instrumented the wrong levels in a case where the patient had a bifid C7 spinous process. We therefore sought to determine the frequency of bifid cervicothoracic spinous processes. Computed tomography axial images of C6, C7, and T1 from 516 patients were evaluated. The spinous processes were classified into three categories: "bifid," "partially bifid," and "monofid." C6 spinous process was monofid in 47.9% of cases, partially bifid in 4.2% of cases, and bifid in 47.9% of cases. C7 spinous process was monofid in 99.2% of cases, partially bifid in 0.5% of cases, and bifid in 0.3% of cases. T1 was monofid in all cases. A truly bifid C7 spinous process occurs 0.3% of the time and therefore is not a reliable landmark for choosing fusion levels. This knowledge hopefully helps prevent the type of wrong-level instrumentation that we performed.