The degree of instability in forth lumbar could not predict neurogenic intermittent claudication in patients with degenerative lumbar spondylolisthesis

[Purpose] The aim of this study was to investigate the relationship between the degree of instability in the 4th lumbar and neurogenic intermittent claudication (NIC). [Subjects] Patients were 28 females (65.9 ± 7.9 years) with degenerative lumbar spondylolisthesis with instability in the 4th lumbar. [Methods] Instability was measured by radiographic findings in the sagittal plane in three positions: upright, trunk extension, and flexion positions. The difference between maximum anterior deviation of the 4th lumbar to 5th and the minimum in the three positions was defined as instability. We also measured neurological symptoms that limited walking capacity (WC) to evaluate NIC, the finger-floor distance (FFD), and modified functional reach (FR). Furthermore, we used a visual analogue scale (VAS) to evaluate subjective symptom intensity after standing upright for 30 seconds. [Results] The degree of instability was not correlated to WC. Furthermore, FFD, FR and VAS were not also correlated to instability. However, FR (r = 34, p<.01) and VAS (r = -.58, p<.001) were correlated to WC. [Conclusion] These results suggest that radiographic findings expressing lumbar pathology alone cannot explain NIC symptoms or signs.