Objectives: To determine whether morbidity and mortality were increased in morbidly obese patients who had reamed intramedullary nailing of closed femoral shaft fractures compared with similar patients of normal weight.
Design: Retrospective case-control study.
Setting: Level I trauma center.
Patients/participants: All patients with closed femoral shaft fractures treated with reamed intramedullary nailing over a 5-year period were identified. Normal-weight patients (BMI < 25) were compared with overweight (25 ≤ BMI < 30), obese (30 ≤ BMI < 40), and morbidly obese patients (BMI ≥ 40).
Intervention: Reamed intramedullary nailing.
Main outcome measurements: Occurrence of postoperative complications.
Results: Of 507 patients with 526 femoral shaft fractures (AO/OTA-32), 184 (36.3%) were of normal weight, 170 (33.5%) were overweight, 114 (22.5%) were obese, and 39 (7.7%) were morbidly obese. There were no significant differences in complications when comparing normal-weight patients with overweight and obese patients. Systemic complications occurred in 23% of morbidly obese and 9% of normal-weight patients [odds ratio (OR) = 3.15, P = 0.013]. Morbid obesity increased odds of adult respiratory distress syndrome (OR = 35.38, P = 0.019) and sepsis (OR = 6.49, P = 0.0015). Overall, morbidly obese patients with a femoral fracture had a mortality rate of 10%, but a subset of polytraumatized patients (Injury Severity Score > 17) had a mortality rate of 20%. Morbid obesity significantly increased the odds of mortality (OR = 46.77, P = 0.01). Body mass index was found to be an independent predictor of adult respiratory distress syndrome, sepsis, and death.
Conclusions: Morbid obesity is a significant risk factor for systemic complications in patients with closed femoral shaft fractures, especially in polytraumatized patients. Patients and their families need to be counseled regarding the high risk of morbidity and mortality.
Level of evidence: Prognostic level II. See Instructions for Authors for a complete description of levels of evidence.