Fig. 1　Preoperative clinical symptoms in each group. VAS score (leg pain) and JOA score were significantly higher in LSS than in TSS (p = 0.007 and 0.016, respectively). VAS, visual analogue scale; VAS (LBP) : VAS (Low Back Pain) ; JOA, Japanese Orthopaedic Association; RDQ, Roland-Morris Disability Questionnaire; ODI, Oswestry Disability Index; TSS, Tandem spinal stenosis; LSS, lumbar spinal canal stenosis.