Interlaminar versus sublaminar lumbar decompression: a retrospective study on patient satisfaction as measured by PROMIS outcomes.

BackgroundInterlaminar and sublaminar decompressions are evolving alternatives to traditional lumbar laminectomy for managing symptomatic lumbar stenosis, but comparative patient-reported outcomes remain underexplored. This study evaluates differences in Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference and physical function (PF) scores between interlaminar and sublaminar lumbar decompression.MethodsWe conducted a retrospective cohort study of 74 patients (18-85 years) who underwent lumbar decompression without fusion at a Level I Trauma Center from January 2022 to March 2024. Patients were categorized by decompression type per operative reports. PROMIS pain and PF scores were collected preoperatively and at 2 weeks, 4 weeks, 3 months, 6 months, and 1 year postoperatively. Linear mixed-effects models assessed changes from baseline, adjusting for age, body mass index (BMI), surgical levels, and operative time.ResultsSublaminar decompression demonstrated greater improvements from baseline in PROMIS PF scores compared to interlaminar decompression at 2 weeks (mean difference: +7.84), 4 weeks, 3 months, and 6 months. Similarly, PROMIS pain scores improved more in sublaminar patients at 2 weeks and 6 months, with interlaminar patients showing a smaller reduction [mean difference in pain improvement: -4.27; standard error (SE): 1.99; P=0.03]. Absolute PROMIS pain and PF scores, however, did not significantly differ between the two techniques (pain: P=0.93; PF: P=0.23). A significant interaction was observed between BMI and surgical type for pain outcomes: in sublaminar decompression, every 1 kg/m2 increase in BMI above the cohort mean (29.3 kg/m2) was associated with a +0.79-point increase in PROMIS pain score (P=0.002), while interlaminar decompression demonstrated no BMI dependency.ConclusionsSublaminar decompression was associated with greater improvements in PROMIS pain and PF scores compared to interlaminar decompression, although absolute postoperative scores were similar. BMI was a significant modifier of pain outcomes in sublaminar patients. Further prospective studies are warranted to validate these findings.