Obesity in lumbar spine surgery

BMI Does Not Affect Complications or Patient Reported Outcomes After Lumbar Decompression Surgery

STUDY DESIGN

This is a retrospective comparative review.

OBJECTIVE

The objective of this study was to identify the influence of body mass index (BMI) on postsurgical complications and patient reported outcomes measures (PROMs) following lumbar decompression surgery.

SUMMARY OF BACKGROUND DATA

Current literature does not accurately identify the impact of BMI on postsurgical complications or outcomes.

MATERIALS AND METHODS

Records from a single-center, academic hospital were used to identify patients undergoing 1 to 3-level lumbar decompression surgery. Patients under 18 years of age, those undergoing surgery for infection, trauma, tumor, or revision, and those with <1-year follow-up were excluded. Patients were split into groups based on preoperative BMI: class I: BMI <25.0 kg/m; class II: BMI 25.0-29.9 kg/m; class III: BMI 30.0-34.9 kg/m; and class IV: BMI >35.0 kg/m. Absolute PROM scores, the recovery ratio and the percent of patients achieving minimum clinically important difference between groups were compared and a multiple linear regression analysis was performed.

RESULTS

A total of 195 patients were included with 34 (17.4%) patients in group I, 80 (41.0%) in group II, 49 (25.1%) in group III, and 32 (16.5%) in group IV. Average age was 60.0 (58.0, 62.0) years and average follow-up was 13.0 (12.6, 13.4) months. All patients improved significantly within each group, except for class III and class IV patients, who did not demonstrate significant improvements in terms of Mental Component Score (MCS-12) scores (P=0.546 and 0.702, respectively). There were no significant differences between BMI groups for baseline or postoperative PROM values, recovery ratio, or the percent of patients reaching minimum clinically important difference. Multiple linear regression analysis revealed that BMI was not a significant predictor for change in outcomes for any measure. The 30-day readmission rate was 6.2% and overall revision rate at final follow-up was 5.1%, with no significant differences between groups.

CONCLUSION

This study's results suggest that BMI may not significantly affect complications or patient outcomes at 1-year in those undergoing lumbar decompression surgery.

LEVEL OF EVIDENCE

Level III.

Complications with Minimally Invasive Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis in the Obese Population

STUDY DESIGN

A level-3 retrospective cohort analysis.

OBJECTIVE

The aim of this study was to describe obesity's effect on complications and outcomes in degenerative spondylolisthesis patients treated by minimally invasive transforaminal lumbar interbody fusion (MI TLIF).

SUMMARY OF BACKGROUND DATA

Obesity is associated with a greater complication rate among lumbar spine surgery patients. Poor clinical outcomes might likewise be supposed, but the association is not well established. Minimally invasive techniques have been developed to reduce complications and improve clinical outcomes in comparison to traditional open techniques.

METHODS

We reviewed 134 consecutive patients with degenerative spondylolisthesis undergoing MI TLIF. Subjects were grouped into nonobese (N = 65) and obese (N = 69) cohorts. The obese group was further subdivided by BMI. Patient demographics, perioperative complications, and outcome scores were collected over a minimum of 24 months. Four periods (intraoperative, postoperative hospitalization, 6-month, and 24-month postoperative) were assessed.

RESULTS

Cohort demographics were not significantly different, but it was noted that obese patients had more major comorbidities than nonobese patients. There was no difference in intraoperative complications between the two groups. The in-hospital complication rate was significantly greater in the obese group. The 6-month postoperative complication rate was not different between cohorts. Wound drainage was most common and noted only in the obese cohort. Complications at 24 months were not different but did trend toward significance in the obese for recurrence of symptoms and total complications. Functional outcome was better among nonobese subjects compared with obese subjects at every interval (significant at 6 and 12 months). Back pain scores were significantly better among nonobese subjects than obese subjects at 24 months, but Leg Pain scores were not different.

CONCLUSIONS

MI TLIF can be safely performed in the obese population despite a higher in-hospital complication rate. Knowledge of common complications will help the treatment team appropriately manage obese patients with degenerative spondylolisthesis.

LEVEL OF EVIDENCE

3.