No Difference in Lumbar Disk Height between Operated and Nonoperated Patients at 9-Year Follow-Up
Authors: Froholdt A. , Brox J. I. , Leivseth G. , Reikerås O. 
Published: June 2012

Introduction

Degeneration of the lumbar spine is a common and age-related finding in the normal population (1;2). Several factors may contribute to lumbar disk degeneration, such as ageing, genetic, and fusion (3). Patients treated for disk degeneration and CLBP may be more prone to further degeneration than the rest of the population. We hypothesized that degeneration of the disks will proceed independent of fusion, also within the fused segments.

Materials and Methods

A total of 124 patients were included in the original two studies (4–6). At 9-year follow-up, baseline and long-term radiographs were available in 48 patients, 23 had lumbar fusion, and 25 had no lumbar fusion. Measurements of disk height were performed with Distortion Compensated Roentgen Analysis (DCRA) (7). Three levels were examined; one operated level (L4/L5), and two nonoperated levels (L2/L3 and L3/L4). The Norwegian version (1.0) of the Oswestry disability index (ODI) (8;9) was used to evaluate condition-specific disability and pain. Back pain was measured on a vertical visual analogue scale from 0 to 100 wherein 100 reflected the worst pain imaginable. Maximum pain, minimum pain, and current pain were scored on three different scales. The mean of the three scores provided the pain index for back pain (10)

Results

Disk height was reduced in both groups at levels L3/L4, and L4/L5, but not formally significant ( p = 0.06) at L2/L3 with no disk height differences between the operated and nonoperated group at any level at 9-year follow-up. ODI and back pain were improved in both groups from baseline to 9-year follow-up, but ODI and back pain correlated poorly with disk degeneration at 9-year follow-up.

Conclusion

Disk height was decreased from baseline to 9-year follow-up with no differences between groups and no association between pain and back disability and disk height. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared Carragee EJ, Paragioudakis SJ, Khurana S. 2000 Volvo Award winner in clinical studies: Lumbar high-intensity zone and discography in subjects without low back problems. Spine (Phila Pa 1976 ) 2000;25(23):2987–2992 Kanayama M, Togawa D, Takahashi C, Terai T, Hashimoto T. Cross-sectional magnetic resonance imaging study of lumbar disk degeneration in 200 healthy individuals. Journal of Neurosurgery Spine 2009;11(4):501–507 Battie MC, Videman T, Parent E. Lumbar disk degeneration: epidemiology and genetic influences. Spine (Phila Pa 1976 ) 2004;29(23):2679–2690 Brox JI, Sorensen R, Friis A, Nygaard O, Indahl A, Keller A, et al. Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disk degeneration. Spine (Phila Pa 1976 ) 2003;28(17):1913–1921 Brox JI, Reikeras O, Nygaard O, Sorensen R, Indahl A, Holm I, et al. Lumbar instrumented fusion compared with cognitive intervention and exercises in patients with chronic back pain after previous surgery for disk herniation: a prospective randomized controlled study. Pain 2006;122(1–2):145–55 Brox JI, Nygaard OP, Holm I, Keller A, Ingebrigtsen T, Reikeras O. Four-year follow-up of surgical versus non-surgical therapy for chronic low back pain. Ann Rheum Dis 2010;69(9):1643–1648 Frobin W, Brinckmann P, Biggemann M, Tillotson M, Burton K. Precision measurement of disk height, vertebral height and sagittal plane displacement from lateral radiographic views of the lumbar spine. Clin Biomech (Bristol, Avon ) 1997;12(1):S1-S63 Fairbank JC, Couper J, Davies JB, O'Brien JP. The Oswestry low back pain disability questionnaire. Physiotherapy 1980; 66(8):271–273 Holm I, Friis A, Storheim K, Brox JI. Measuring self-reported functional status and pain in patients with chronic low back pain by postal questionnaires: a reliability study. Spine 2003;28(8):828–833 Fritzell P, Hagg O, Wessberg P, Nordwall A. 2001 Volvo Award Winner in Clinical Studies: Lumbar fusion versus nonsurgical treatment for chronic low back pain: a multicenter randomized controlled trial from the Swedish Lumbar Spine Study Group. Spine (Phila Pa 1976 ) 2001;26(23):2521–2532