The effect of obesity on inpatient outcomes in lower extremity trauma: A systematic review and meta- analysis

SLR - June 2022 - Madison Ravine, DPM

Reference: Liu Q, Wu M, Orgill DP, Bai X, Panayi AC. The effect of obesity on inpatient outcomes in lower
extremity trauma: A systematic review and meta-analysis. J Trauma Acute Care Surg. 2022 Feb 1;92(2):464-70.

Level of Evidence: Level IV

Scientific Literature Review

Reviewed By: Madison Ravine, DPM
Residency Program: Cambridge Health Alliance — Cambridge, MA

Podiatric Relevance: As the global prevalence of obesity increases, the prevalence of obesity in our respective patient populations will only increase as well. Appropriate management and mitigation of patient comorbidities is essential in medical clearance and optimization for surgery, which may be considered in an elective context. In the acute traumatic context, however, surgical intervention is oftentimes necessitated regardless of medical comorbidities. As such, managing the acute trauma patient with obesity often may result in a lengthy post-operative course with multiple complications which may culminate in proximal amputation or even death.

Methods: The authors carried out a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria for reviewed literature included any prospective observational or retrospective cohort studies and case-control studies reporting on primary outcome (total complications) of patients with acute traumatic, nonpathological lower limb fractures (to include femur, tibia, fibula, knee, ankle, foot) that required internal fixation. Ultimately, 16 studies met inclusion criteria, accounting for 309,263 patients. Obesity was defined as a Body Mass Index (BMI) greater than or equal to 30, per World Health Organization guidelines.

Results: The results of the meta-analysis reported a statistically significant increase in rate of total complications, rate of wound complication, risk of death, and length of hospital stay in the obese groups as opposed to the non-obese. It is noted however that only a portion of the analyzed studies included Injury Severity Score (ISS), and there was found to be a statistically significant increase in ISS in obese patients as opposed to non-obese patients. Therefore, the authors state that the increase in mortality associated with obesity may be due to severity of injury.

Conclusions: In previous literature, obesity has been associated with increased risk of perioperative complications, longer surgical times and longer hospitalization stays. This study notes obese patients are significantly more likely to experience complications, including wound complications, have a longer hospital stay, and a higher mortality rate than non-obese patients with lower-limb trauma who require surgical intervention. This highlights the risk in obese patients following reconstruction in trauma. While certain complications may be unavoidable, surgeons may help mitigate the risk by prioritizing decreased operating room time, minimally invasive techniques, external fixation or use of negative pressure wound therapy where appropriate in this population. Potential weaknesses to this study do include heterogeneity of injury patterns included. Further, underlying comorbidities related to obesity (such as diabetes, metabolic syndrome) may be confounding variables influencing these results.