Outcomes and revision rates in normal, overweight, and obese patients 5 years after lumbar fusion.
Obesity is a growing problem in health care. Studies have demonstrated similar functional outcomes but higher complication rates after spine surgery in obese patients.



This study aimed to compare patient-reported outcomes and revision rates 5 years after instrumented posterior lumbar fusion between normal, overweight, and obese patients.



Propensity matched case control.



Patients who had posterior instrumented lumbar spinal fusion from 2001 to 2008 from a single spine specialty center with complete preoperative and 5-year postoperative outcome measures were identified.



Oswestry Disability Index (ODI), Back Pain (0-10) and Leg Pain (0-10) Numeric Rating Scales, and Short Form-36 Physical Composite Summary Scores (SF-36 PCS).



Three comparison groups, one with body mass index (BMI) ≥20-25 kg/m2(normal), another with ≥25-<30 kg/m2(overweight), and another with ≥30-40 kg/m2(obese) were created using propensity matching techniques based on demographics, baseline clinical outcome measures, and surgical characteristics. Five-year postoperative outcome measures and revision rates in the three groups were compared. One-way analysis of variance was used to compare continuous variables, and Fisher exact test was used to compare categorical variables between the groups. Significance was set at p<.01.



There were 82 cases matched in each cohort. Estimated blood loss (440 cc vs. 702 cc vs. 798 cc, p=.000) and operative time (234 minutes vs. 263 minutes vs. 275 minutes, p=.003) were significantly greater in the overweight and obese patients. Improvements in ODI (14.2 vs. 9.6 vs. 10.4, p=.226), SF-36 PCS (5.9 vs. 2.9 vs. 3.5, p=.361), back pain (3.0 vs. 2.0 vs. 2.1, p=.028), and leg pain (3.0 vs. 2.3 vs. 2.3, p=.311) scores were similar among the groups. Revision rates (14 vs. 15 vs. 13, p=.917), and time between index and revision surgery (p=.990) were similar among the three groups as well.



When considering a subset of patient-reported outcomes and revision surgery after 5 years, patients with an elevated BMI >25 at baseline did not appear to have worse outcomes than those with a normal BMI of 20-25 when undergoing posterior lumbar fusion surgery. Obesity should not be considered a contraindication to surgery in patients with appropriate surgical indications.
Norton Leatherman Spine Center, 210 East Gray St, Suite 900, Louisville, KY 40202, USA; Department of Orthopaedic Surgery, University of Louisville School of Medicine, 550 S. Jackson St, 1st Floor ACB, Louisville, KY 40202, USA.
R Kirk
RK
Owens
Norton Leatherman Spine Center, 210 East Gray St, Suite 900, Louisville, KY 40202, USA; Department of Orthopaedic Surgery, University of Louisville School of Medicine, 550 S. Jackson St, 1st Floor ACB, Louisville, KY 40202, USA.
Mladen
M
Djurasovic
Department of Orthopaedic Surgery, University of Louisville School of Medicine, 550 S. Jackson St, 1st Floor ACB, Louisville, KY 40202, USA.
Ikemefuna
I
Onyekwelu
Norton Leatherman Spine Center, 210 East Gray St, Suite 900, Louisville, KY 40202, USA.
Kelly R
KR
Bratcher
Department of Orthopaedic Surgery, University of Louisville School of Medicine, 550 S. Jackson St, 1st Floor ACB, Louisville, KY 40202, USA; University of Louisville School of Public Health and Information Sciences, 485 East Gray St, Louisville, KY 40202, USA.
Katlyn E
KE
McGraw
Norton Leatherman Spine Center, 210 East Gray St, Suite 900, Louisville, KY 40202, USA. Electronic address: leah.carreon@nortonhealthcare.org.
Leah Y
LY
Carreon
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008161:Lumbosacral Region / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D012086:Reoperation / Q000706:statistics & numerical data; D013123:Spinal Fusion / Q000009:adverse effects*
Adjacent segment degeneration; Complications; Long-term outcomes; Obesity; Posterior lumbar fusion; Revision