Reduced Impact of Obesity on Short-Term Surgical Outcomes, Patient-Reported Pain Scores, and 30-Day Readmission Rates After Complex Spinal Fusion (≥7 Levels) for Adult Deformity Correction

Abstract

Objective: In the past decade, prevalence of obesity in the United States have been soaring at a disparaging rate. Previous spine studies have associated obesity with inferior surgical outcomes, increased complication and 30-day readmission rates, and worsening patient-reported outcomes. However, there is a paucity of data identifying whether the impact of obesity is sustained in patients undergoing complex deformity correction involving 7 levels or greater. The aim of this study was to determine whether obesity impacts surgical outcomes, patient-reported pain scores, and 30-day readmission rates after complex spinal fusions ≥7 levels.

Methods: The medical records of 112 adult patients (≥18 years old) with spine deformity undergoing elective, primary complex spinal fusion (≥7 levels) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. Preoperative body mass index greater than or equal to 30 kg/m² was classified as obese. Patient demographics, comorbidities, and intraoperative and postoperative complication rates were collected for each patient. Inpatient patient-reported pain scores and ambulatory status also were collected. The primary outcomes of this study were surgical outcomes, patient-reported pain scores, and 30-day readmission rates.

Results: Of the 112 patients, 33 (29.5%) were obese (obese: n = 33 vs. non-obese: n = 79). Patient demographics and comorbidities were similar between both cohorts, including age, sex, diabetes, hypertension, and home narcotic use. The median number of fusion levels operated, length of surgery, estimated blood loss, transfusion, and complication rates were similar between both cohorts. Moreover, the postoperative complication profiles between the cohorts also were similar, with a comparable length of hospital stay (obese: 6.5 ± 4.6 days vs. non-obese: 7.0 ± 3.9 days, P = 0.5833) and 30-day readmission rates (obese: 12.1% vs. non-obese: 13.9%, P = 0.7984). Baseline (P = 0.6826), first (P = 0.9691), and last (P = 0.9583) postoperative patient-reported pain scores were similar between cohorts. Analogously, ambulatory status was similar between the cohorts, including days from operating room to ambulation (P = 0.3471) and number of steps on first (P = 0.9173) and last (P = 0.1634) ambulatory day before discharge.

Conclusions: Our study suggests that obesity does not significantly affect surgical outcomes, patient-reported pain scores, and 30-day readmission rates after complex spinal surgery requiring ≥7 levels of fusion. Further studies are necessary to corroborate our findings.

Keywords: 30-day readmission rates; Adult deformity correction; Complex spine fusion; Obesity; Patient-reported pain scores; Postoperative complications; Postoperative pain.