RESUMEN
BACKGROUND: The effect of lumbar decompression on physical activity (PA) measures (measured as number of steps/day and as moderate to vigorous PA (MVPA)) is poorly understood. The aim of the current study was to compare PA in patients before and after lumbar decompression and to determine the association between change in steps/day and MVPA with change in disability, health-related quality of life (HRQOL) and pain. METHODS: Patients undergoing lumbar decompression surgery were recruited. Steps/day and MVPA MVPA were recorded with an accelerometer. Oswestry Disability Index (ODI), HRQOL (Short Form 36 questionnaire (SF-36)) and pain levels (visual analogue scale (VAS)) were collected prior to surgery and six and twelve weeks postoperatively. Steps/day were compared to the lower bound of steps/day in healthy persons (7,000 steps per day), and the relationship between changes in steps/day, MVPA, ODI, SF-36, and VAS were calculated. RESULTS: Twenty-six patients aged 37 to 75 years met inclusion criteria and were included in the study. Lumbar decompressions were performed for stenosis and/or disc herniation. Preoperatively, patients took an average 5,073±2,621 (mean±standard deviation) steps/day. At 6 weeks postoperatively, patients took 6,131±2,343 steps/day. At 12 weeks postoperatively, patients took 5,683±2,128 steps/day. Postoperative MVPA minutes per week increased compared to preoperative MVPA (preoperative: 94.6±122.9; 6 weeks: 173.9±181.9; 12 weeks: 145.7±132.8). From preoperative to 12 weeks postoperative, change in steps correlated with MVPA (R=0.775; P<0.001), but not with ODI (R=0.069; P=0.739), SF-36 (R=0.138; P=0.371), VAS in the back (R=0.230; P=0.259) or VAS in the leg (R=-0.123; P=0.550). CONCLUSIONS: During the first 12 postoperative weeks, daily steps did not reach the lower bound of normal step activity of 7,000 steps/day, however postoperative steps/day were higher than before surgery. Steps/day and MVPA appear to be independent of ODI and SF-36 and represent additional outcome parameters in patients undergoing lumbar decompression surgery and should be considered e.g., by physiotherapists especially from 6 to 12 weeks postoperatively. LEVEL OF EVIDENCE: 2, prospective cohort study.
RESUMEN
BACKGROUND CONTEXT: We aimed to fully understand the extent of limitations associated with symptomatic lumbar spinal stenosis (LSS) and the functional outcome of its treatment, including not only function during daily activities (eg, using the 6-minute walk test [6MWT]) but also the quality of function that should be objectively assessed. PURPOSE: This study was performed to test the hypothesis that the Oswestry Disability Index (ODI) score, the walking distance during the 6MWT (6-minute walking distance [6MWD]), and gait quality (spatiotemporal parameters and gait asymmetry) will improve postoperatively and achieve normal values; to determine if changes in gait parameters correlate with changes in Oswestry Disability Index (ODI) score; and to ascertain if patients' gait quality will diminish during the 6MWT, reflected by changes in gait parameters during the 6MWT. STUDY DESIGN/SETTING: This is a prospective observational study with intervention. PATIENT SAMPLE: The sample comprised patients with symptomatic LSS. OUTCOME MEASURES: The ODI score, gait quality (spatiotemporal and asymmetry), and walking performance (walking distance during the 6MWT) were the outcome measures. METHODS: Patients with symptomatic LSS were analyzed on the day before surgery and 10 weeks and 12 months postoperatively. Functional disability in daily life was assessed by the ODI. Spatiotemporal and kinematic gait parameters were recorded with an inertial sensor system during the 6MWT, and the 6MWD was determined. Gait asymmetry was defined as 100*|right-left|/(0.5*(|right+left|)). RESULTS: The ODI decreased by 17.9% and 23.9% and 6MWD increased by 21 m and 26 m from baseline to 10-week and 12-month follow-up, respectively. Gait quality did not change during the 6MWT at any assessment or between assessments. Compared with the control group, patients walked less during the 6MWT, and gait quality differed between patients and the control group at baseline and 10-week follow-up but not at 12-month follow-up. Change in gait quality explained 39% and 73% of variance in change in ODI from baseline to 10-week and to 12-month follow-up, respectively. CONCLUSIONS: Changes in gait quality explained a large portion of variance in changes in the ODI, indicating that patients with symptomatic LSS perceive their compromised gait quality as functional limitations. Gait data obtained by instrumented gait analysis contain information on gait quality that can be helpful for evaluating functional limitations in patients with LSS, the outcome of decompression surgery, and the development of patient-specific rehabilitation regimens.