SLR - June 2019 - Stephanie Mita
Reference: Wang H, Pei H, Chen M, and Wang H. Incidence and Predictors of Surgical Site Infection After ORIF in Calcaneus Fractures, A Retrospective Cohort Study. J Orthop Surg Research 2018 Nov;13.
Scientific Literature Review
Reviewed By: Stephanie Mita, DPMResidency Program: Kaiser Permanente Vallejo, North Bay Consortium, Vallejo, CA
Podiatric Relevance: For displaced, depressed intra-articular, or open calcaneus fractures, surgical treatment with open reduction with internal fixation (ORIF) is the standard of care. The incidence of postoperative wound infection is high—2–25 percent in closed calcaneus fractures and 10–39 percent in open calcaneus fractures—with an amputation rate cited at 8–14 percent. The purpose of this study was to determine the incidence of and risk factors associated with postoperative surgical site infection (SSI) after calcaneus fracture ORIF.
Methods: This level III retrospective cohort study included 681 adult patients who underwent acute calcaneus fracture ORIF at a level 1 trauma center in Hebei, China between 2014 and 2017. Data on demographics, injury mechanism, fracture pattern, surgical technique and hospital stay was collected. Follow-up ranged from 1 to 3.5 years. Univariate and multivariate analyses were performed to determine independent predictors for SSI.
Results: The overall incidence of SSI was 9.7 percent (66 patients), with a 2.9 percent incidence of deep SSI and a 6.8 percent incidence of superficial SSI. The most common pathogen isolated was Staphylococcus aureus (in 14 cases of deep SSI, and in six cases of superficial SSI).
Age, male gender, BMI, diabetes and tobacco consumption were not found to be significant risk factors for SSI.
Sanders grade, preoperative stay, extended lateral approach versus minimally invasive approach, fixation type, length of surgical incision, operative duration and preoperative or intraoperative antibiotics use were not found to be significant.
Independent risk factors associated with SSI were open fracture, high-energy injury mechanism (falling from height, traffic accident), ASA score ≥ 3 and intraoperative hypothermia.
- 35 had open fractures (5.1 percent), of which 16 (45.7 percent) developed SSI, with OR of 9.48.
- 357 had high-energy injuries (52.4 percent), of which 47 (13.2 percent) developed SSI, with OR of 2.07.
- 19 had ASA score ≥3 (0.28 percent), of which 5 (26.3 percent) developed SSI, with OR of 3.50.
- 124 had intraoperative hypothermia (<36.0°C) (18.2 percent), of which 21 (31.8 percent) developed SSI, with OR of 1.69.
Conclusions: Limitations to this study include its retrospective nature and selection bias. Additionally, it includes patients who did not return to the center for treatment in the non-SSI group, which likely led to an underestimation of SSI incidence. Lastly, it does not include data about fractures that were managed initially with external fixation, so conclusions cannot be drawn about the advantages of external fixation over ORIF, although the authors allude to this as a possibility.
Foot and ankles surgeons should be aware of the relatively high incidence of SSI after ORIF of calcaneus fractures, which is cited at 9.7 percent in this study, as well as the predictive value of open fracture, high-energy injury, ASA score ≥ 3 and intraoperative hypothermia. Unfortunately, this study found only one modifiable risk factor to decrease risk of SSI—intraoperative hypothermia. The remaining modifiable factors, such as diabetes, tobacco consumption, Sanders grade, extended lateral approach versus minimally invasive approach, operative time and usage of pre- or intraoperative antibiotics, were, interestingly, not found to be significant risk factors for SSI after calcaneus fracture ORIF.