P141. Do age adjusted parameters influence patient reported outcomes after lumbar decompression?

Abstract

<h3>BACKGROUND CONTEXT</h3> The impact of sagittal malalignment after lumbar fusion has been well described. However, few studies have examined the impact of sagittal alignment on outcomes after lumbar decompression. The existing literature has focused exclusively on normative measures of alignment (e.g., pelvic incidence lumbar lordosis mismatch [PI-LL] > 10) but has not considered age-adjusted alignment. <h3>PURPOSE</h3> To determine if age-adjusted sagittal malalignment (PI-LL or pelvic tilt [PT]), influences postoperative patient reported outcomes (PROs) after lumbar decompression surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of 62 patients who underwent lumbar decompression. <h3>PATIENT SAMPLE</h3> A total of 62 patients. <h3>OUTCOME MEASURES</h3> Oswestry disability index (ODI), Visual analog scale (VAS) Back, VAS leg <h3>METHODS</h3> Patients with >3 months follow-up who underwent one to four level lumbar decompression at a single institution were included. Patients were stratified into three groups based on achievement of age-adjusted thresholds in PI-LL and PT postoperatively. The first group included patients within the age-adjusted threshold ±10 years (MATCHED), and the other groups included those who were outside of the age-adjusted threshold ±10 years as over corrected (OVER), and under corrected (UNDER). The equations used to determine their age-adjusted sagittal parameters included: PT = [(Age-55)/3] + 20, and PI-LL = [(Age-55)/2] +3. Oswestry Disability Index (ODI), Visual Analog Scale (VAS) Back, and VAS Leg were evaluated. The percent of patients achieving MCID at final follow-up was calculated. <h3>RESULTS</h3> A total of 62 patients (mean 66 years, 50% female) were included with a mean follow-up of 368 days (range, 40 to 1,401). Groups for postoperative age-adjusted PI-LL included 12 MATCHED patients, 30 OVER patients and 20 UNDER patients. Groups for postoperative age-adjusted PT included 16 MATCHED patients, 27 OVER patients and 19 UNDER patients. For the entire cohort, there was a significant decrease in PI-LL (preop 8.7° vs postop 5.5°, p=0.001). There was no significant change in PT for the entire group (preop 22.5° vs postop 23.1°, p=0.39). There was no significant preoperative to postoperative PI-LL difference in the MATCHED (10.5° vs 7.9°, p=0.08) or UNDER patients (22.2° vs 19.3°, p=0.08), but PI-LL significantly decreased in the OVER group (preop -0.9°vs postop -4.7°, p=0.02). There were no significant differences in the preoperative to postoperative PT in the MATCHED (22.0° vs 22.8°, p=0.22), UNDER (28.4° vs 31.3°, p=0.11) or OVER groups (18.7° vs 17.5°, p=0.12). All groups exhibited significant improvements postoperatively for VAS Back, VAS Leg, and ODI scores (p<0.05). With respect to preoperative PROs, postoperative PROs and improvement in PROs, there was no difference between the MATCHED, UNDER or OVER groups. There were no significant differences between the groups in the percent that met MCID for ODI, VAS Back or VAS Leg scores. However, there was a trend towards increased PI-LL mismatch and increased ODI (p=0.09) and VAS-back scores (p=0.07). <h3>CONCLUSIONS</h3> Patients with postoperative age-adjusted spinopelvic abnormalities after lumbar decompression surgery had similar PROs when compared to patients without age-adjusted spinopelvic abnormalities. Therefore, isolated decompression is a viable treatment strategy in patients with sagittal malalignment. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.