Differences in Functional Treadmill Tests in Patients With Adult Symptomatic Lumbar Scoliosis Treated Operatively and Nonoperatively

Study Design.Prospective longitudinal cohort.Objectives.The aim of this study was to determine whether functional treadmill testing (FTT) demonstrates differences between patients treated operatively and nonoperatively for adult symptomatic lumbar scoliosis (ASLS).Summary of Background Data.ASLS has become increasingly prevalent as the population ages. ASLS can be accompanied by neurogenic claudication, leading to difficulty walking. FTT may provide a functional tool to evaluate patients with ASLS.Methods.One hundred and eighty-seven patients who underwent nonoperative (n = 88) or operative treatment (n = 99) of ASLS with complete baseline and 2-year post-treatment FTTs and concurrent patient-reported outcomes were identified. FTT parameters included maximum speed, time to onset of symptoms, distance ambulated, time ambulated, and Back and Leg pain severity before and after testing.Results.At baseline, patients treated operatively reported worse post-FTT back pain (4.39 vs. 3.45, P = 0.032) than those treated nonoperatively, despite similar ODI, SRS-22 Pain and Activity domain scores. Mean time ambulated (+2.15 vs. -1.20 P = 0.001), pre-FTT back pain (+0.19 vs. -1.60, P < 0.000) and leg pain (+0.25 vs. -0.54, P = 0.024) improved in the operative group but deteriorated in the nonoperative group. On the 2-year follow-up FTT, both groups showed improvement in post-FTT back pain (-0.53 vs. -2.64, P < 0.000) and leg pain (-0.13 vs. -1.54, P = 0.001) severity but the improvement was statistically significantly greater in the operative compared to the nonoperative group.Conclusion.FTT results at baseline were worse in patients treated operatively than those treated non-operatively. FTT may be a useful adjunct to assess treatment outcomes in patients with ASLS and may help surgeons counsel patients regarding expectations 2 years after operative or nonoperative treatment for ASLS. At 2-year follow-up, time ambulated deteriorated in patients treated nonoperatively but improved in patients treated operatively. Although both groups showed improvement in post-FTT Back and Leg pain at 2 years, the improvement was greater in the operative compared to the nonoperative group.Level of Evidence: 2.