Effectiveness of Doppler Image of the Vertebral Artery as an Anatomical Landmark for Identification of Ultrasound-Guided Target Level in Cervical Spine.

STUDY DESIGN: A prospective sonographic study. PURPOSE: To verify the effectiveness of simultaneous application of two landmarks, Doppler image of the vertebral artery and shape of the transverse tubercle of the seventh cervical (C7) vertebra. OVERVIEW OF LITERATURE: Counting upwards from the C7 vertebra which only has a posterior tubercle of the transverse process is a commonly used method for ultrasound-guided cervical nerve root block. However, each transverse process has a different shape. METHODS: Sonograms of 20 volunteers were examined. At first, we identified the C7 transverse process based on the presence of the vertebral artery without the anterior tubercle. The C5 and C6 transverse processes were identified based on the presence of anterior tubercle without the vertebral artery. Subsequently, we placed needles on the C5, C6, and C7 transverse processes and the location and direction of needles were confirmed by fluoroscopy. RESULTS: In the 120 segments, 93.3% of needles were placed correctly as desired; 97.5% of needles were placed on the 5C transverse process; 97.5% of needles were placed on the C6 transverse process; and 85.0% of needles were placed on the C7 transverse process, respectively. Both sides showed the same accuracy of 93.3%. CONCLUSIONS: Simultaneous application of Doppler image of the vertebral artery and shape of the C7 transverse tubercle showed 93.3% accuracy in identifying the target cervical level. Therefore, Doppler image of the vertebral artery can be considered to be a useful landmark for ultrasound-guided cervical nerve root block.

The effectiveness of bone mineral density as supplementary tool for evaluation of the osteogenic potential in patients with spinal fusion.

STUDY DESIGN: Retrospective study. PURPOSE: This study was designed to determine the effectiveness of bone mineral density measurement as a supplementary tool for evaluation of osteogenic potential in patients with spinal fusion. To this end, we correlated bone mineral density (BMD) with osteogenic potential from cultured mesenchymal stem cells (MSCs). OVERVIEW OF LITERATURE: Many studies have correlated osteogenic potential of in vitro cultured MSCs with aging or osteoporosis. METHODS: We studied twenty-five individuals with harvested bone marrow from the ilium during lumbar spinal surgery. The BMD of the femoral neck was measured using dual energy X-ray absorptiometry prior to bone marrow aspiration, and the osteoporotic group was classified as those with T-scores below-2.5. After MSCs were isolated from bone marrow, in vitro induction of osteogenesis was performed. We analyzed the patient's osteogenic potential from cultured MSCs such as mineral deposition stain, bone alkaline phosphatase (ALP) activity and osteoblast-specific gene expression in RT-PCR. RESULTS: On mineral staining, the osteoporotic group had a scanty matrix mineral deposition in contrast to the non-osteoporotic group. The expression of osteocalcin in the osteoporotic group was 1.5 to 3 times less than in the non-osteoporotic group. At the 3(rd) week after the induction of osteogenesis, the activity of ALP of cultured MSCs in the osteoporotic group was lower than in the control group (mean, 45+/-19 u/L, in osteoporotic group vs 136+/-7 u/L in non-osteoporotic), and there was a statistically significant and positive correlation between BMD & ALP (r=0.487, p=0.013). CONCLUSIONS: There is a positive correlation between BMD and osteogenic potential derived from MSCs. The measurement of BMD can provide supplementary data for evaluating osteogenic potential clinically.