1. Yoichi Iizuka Haku Iizuka, Atsushi Yamamoto Masahiro Nishinome, Kenji Takagishi Department of Orthopaedic Surgery Gunma University Graduate School of Medicine EUROSPINE 2010 15 — 17 September 2010 Vienna, Austria Associations between low back pain and lumbar spinal stenosis and sagittal spinal alignment among elderly populations

2. PURPOSE  Lower back pain and lumbar spinal stenosis are responsible for decreased quality of life among the elderly population, and a thorough understanding of those pathologic conditions is very important.  The purpose of this study was to investigate the association between lower back pain and lumbar spinal stenosis and sagittal spinal alignment among elderly subjects. Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

3. MATERIALS  A medical check-up survey was performed for residents of a mountainous region in Japan. A questionnaire regarding lower back pain (LBP) and lumbar spinal stenosis (LSS) was administered to 124 elderly Japanese subjects over 65 years of age.  Sex: Male 49 cases Female 75 cases  Average age: 73.5 yrs Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

4. METHODS  Participants were asked about their two-week experience of LBP, and the subjects we divided in to the LBP group (LP group) and the non-LBP group (NLP group).  The self-reporting Kyusyu-Okinawa instrument and the tree model were used to identify the subjects suspected of having LSS, and the subjects we divided into the LSS group (LS group) and the non-LSS group (NLS group). Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

5.  Symptoms induced by walking  Exacerbation of symptoms when standing up  Symptoms relieved by having patients bend forward  Symptoms induced by having patients bend forward  Symptoms induced by having patients bend backward Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

6. TREE MODEL LS group Sato K et al. J. Lumbar Spine Disord 2008 Symptoms relieved by having patients bend forward yesno yes Symptoms induced by walking no Exacerbation of symptoms when standing up or Over 60 years Symptoms induced by having patients bend backward yes no NLS group Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

7. SpinalMouse® ( Idiag, Vplkerswill, Switzerland) Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

8. 1 : Thoracic Kyphosis angle (TKA) 2 : Lumbar Lordotic Angle (LLA) 3 : Sacral/Hip Angle (SHA) 4 : Spinal Inclination (INC) 1 2 3 4 DEFINITION OF SHA, TKA, LLA AND INC Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

9. * * * p<0.05 n.p. One hundred seven of the 124 subjects were had LBP. 9.38 12.1 39.5 37.9 15.5 21.7 6.02 3.23 RESULT 1 (LP group vs NLP group) ■LP group ■NLP group Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

10. * p<0.05 * n.p. Forty six of 124 subjects had suspected LSS, based on the results of the Kyusyu-Okinawa self-reporting instrument. 9.19 10.0 38.3 39.8 13.4 18.1 7.19 4.73 RESULT 2 (LS group vs NLS group) ■LS group ■NLS group Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

11. DISCUSSION  Some authors have suggested that sagittal malalignment of the spine including loss of lumbar lordosis is one of causative factors of lower back pain. Jackson RP et al. Spine 1994, Jang JS et al. Neurosurgery 2009, Smith A et al. Spine 2008  Recently, Suzuki et al. demonstrated that patients with lumbar spinal stenosis revealed forward bending of the trunk with poor sagittal spinal alignment based on x-ray examination. Suzuki H et al. Spine 2010 The current study found that lumbar lordosis in the LP group was significantly smaller than in the NLP group and the forward bending of the trunk in the LP group was significantly larger than in the NLBP group, and INC in the LS group was significantly larger than in the NLS group. However, it was not possible to conclude that LBP or LSS induces the alignment change of spine or the reverse is true. Further longitudinal studies are needed to answer to this question. Department of Orthopaedic Surgery Gunma University Graduate School of Medicine

12. CONCLUSIONS  This study investigated the association between LBP and LSS and the spinal sagittal alignment using the SpinalMouse system.  A significant association was found between LLA-LBP, INC-LBP, and INC-LSS, respectively.  These results provide a powerful lens thorough which to view the treatment strategy for lumbar disease in elderly populations. Department of Orthopaedic Surgery Gunma University Graduate School of Medicine None of the authors has any potential conflict of interest.