Significant Motion Factors Affecting the Outcome of a Medial Branch Block in Patients with Low Back Pain Developing after Trivial Trauma

ABSTRACT

OBJECTIVE: The aim of this study was to analyze significant motion factors that affected the outcome of medial branch blocking(MBB) in patients with low back pain(LBP) after trivial trauma. METHODS: Twenty-four patients(10men and 14 women; 70 vertebrae) complained of LBP after trivial trauma and under went bilateral MBB in the lumbar spine between January 2007 and August 2008. Visual Analogue Scale(VAS) scores of discomfort were measured before and after MBB. The motion factors considered were sitting, standing, flexion, extension and rotation. RESULTS: Sitting-, standing- and rotation-related LBPs were identified in 11 patients(44.5%, 11/24), 10 patients(41.7 %, 10/24) and 8 patients(33.3%, 8/24), respectively. The ratios of flexion- and extension-related LBPs in the enrolled patients were 66.7%(16/24) and 54.2%(13/24), respectively. The reduction in VAS score after treatment in the patients with sitting-related LBP was less than that of patients without sitting-related LBP(3.2+/-2.27 and 5.2+/-2.87, p=0.169). There was no difference between patients with standing-related LBP and those without(4.3+/-2.75 and 4.3+/-2.86). Although the mean VAS score improvement of the patients with extension- and rotation-related LBP(4.4+/-2.99 and 5.4+/-2.67) was higher than that of patients without extension and rotation LBP(4.1+/-2.59 and 3.7+/-2.71), the difference was not significant(p=0.721 and p=0.552, respectively). The mean VAS score improvement of the patients with flexion- related LBP was significantly higher than that of patients without it(6.1+/-1.81 vs 2.8+/-2.59, p=0.042). CONCLUSIONS: In patients with LBP after trivial trauma, flexion- and extension-related LBP was more common than sitting-, standing- and rotation-related LBP. Flexion was a significant motion factor affecting the outcome of MBB after trivial trauma.