The Influence of Sex on Clinical Outcomes in Minimally Invasive Lumbar Decompression

Background Research focused on postoperative outcomes among men and women undergoing minimally invasive lumbar decompression (MIS LD) spine surgery is sparse. This study aims to assess the influence of sex on postoperative patient-reported outcome measure (PROM) evaluations and achievement of a minimum clinically important difference (MCID).

Methods A prospectively maintained surgical database was retrospectively queried for patients undergoing primary or revision, single or multilevel LD procedures from 2011 to 2019. Patients with incomplete visual analog scale (VAS) leg or back surveys were excluded. Demographic and operative variables were recorded, and a chi-squared analysis or t tests were used to compare by sex. PROMs were evaluated from preoperative to postoperative time points. PROM score differences and postoperative improvement were evaluated between sexes by a t test. Achievement of MCID by sex was compared using chi-squared analysis.

Results The study cohort (n = 572) was 70% male (n = 398), had an average age of 47 years, and 42% were obese. Sexes differed in preoperative VAS leg, Oswestry Disability Index (ODI), and 12-item short form (SF-12)-physical composite score (PCS) scores (all P < .05) and in ODI at 6 and 12 weeks (P = .048; P = .001) and VAS back and leg scores at 6 months (P = .039; P = .019). Both sexes significantly improved (P < .050) all PROMs at all time points except for VAS back at 1 year for women and ODI at 6 weeks and 6 months for men. The only significant difference in achievement of MCID was for ODI at 6 months (P = .008).

Conclusions Significant preoperative differences were observed among sexes with ODI, SF-12-PCS, and VAS leg scores. By 1 year, there were no significant sex differences for any PROM or for achievement of MCID. MIS LD has an equivalent role for both sexes in achieving MCID.

Level of Evidence 3.

Clinical Relevance Results demonstrate no sex difference in PROMs following LD.