Lower Extremity Amputation in Fracture-Related Infection.

OBJECTIVES

To analyze demographics, comorbidities, fracture characteristics, presenting characteristics, microbiology, and treatment course of patients with fracture-related infections (FRIs) to determine risk factors leading to amputation.

DESIGN

Retrospective cohort.

SETTING

Single Level I Trauma Center (2013-2020).

PATIENT SELECTION CRITERIA

Adults with lower extremity (femur and tibia) FRIs were identified through a review of an institutional database. Inclusion criteria were operatively managed fracture of the femur or tibia with an FRI and adequate documentation present in the electronic medical record. This included patients whose primary injury was managed at this institution and who were referred to this institution after the onset of FRI as long as all characteristics and risk factors assessed in the analysis were documented. Exclusion criteria were infected chronic osteomyelitis from a non-fracture-related pathology and a follow-up of less than 6 months.

OUTCOME MEASURES AND COMPARISONS

Risk factors (demographics, comorbidities, and surgical, injury, and perioperative characteristics) leading to amputation in patients with FRIs were evaluated.

RESULTS

A total of 196 patients were included in this study. The average age of the study group was 44±16 years. Most patients were men (63%) and White (71%). The overall amputation rate was 9.2%. There were significantly higher rates of chronic kidney disease (CKD; P = 0.039), open fractures (P = 0.034), transfusion required during open reduction internal fixation (P = 0.033), Gram-negative infections (P = 0.048), and FRI-related operations (P = 0.001) in the amputation cohort. On multivariate, patients with CKD were 28.8 times more likely to undergo amputation (aOR = 28.8 [2.27 to 366, P = 0.010). A subanalysis of 79 patients with either a methicillin-sensitive Staphylococcus aureus or methicillin-resistant S. aureus (MRSA) infection showed that patients with MRSA were significantly more likely to undergo amputation compared with patients with methicillin-sensitive Staphylococcus aureus (P = 0.031). MRSA was present in all cases of amputation in the Staphylococcal subanalysis.

CONCLUSIONS

Findings from this study highlight CKD as a risk factor of amputation in the tibia and femur with fracture-related infection. In addition, MRSA was present in all cases of Staphylococcal amputation. Identifying patients and infection patterns that carry a higher risk of amputation can assist surgeons in minimizing the burden on these individuals.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.