SLR - March 2016 - Samantha Baker

Title: Local Injection of Aminoglycosides for Prophylaxis Against Infection in Open Fractures

Reference: Lawing CR, Lin FC, Dahners LE. Local Injection of Aminoglycosides for Prophylaxis Against Infection in Open Fractures. J Bone Joint Surg Am. 2015 Nov 18; 97 (22): 1844-1851.

Scientific Literature Review

Reviewed By: Samantha Baker, DPM
Residency Program: The Christ Hospital, Cincinnati, Ohio

Podiatric Relevance: Open fractures can be common injuries encountered by podiatric surgeons. Infection remains a common complication of open fractures, especially with more severe, higher grade Gustilo-Anderson fracture types. The administration of systemic antibiotics is the conventional treatment in open fractures. An alternative treatment method includes the use of systemic antibiosis and local injection of aminogylcosides (gentamicin or tobramycin) to reduce the prevalence of deep and superficial infections in patients with open fractures.

Methods: A total of 351 open fractures that occurred at a single institution between January 1, 2008 and August 31, 2013 were retrospectively analyzed. Fracture type was retrospectively determined by a single senior level resident to reduce variability. Treatment was provided at the discretion of the attending surgeon. The control group consisted of 183 fractures and received systemic antibiotics only. The intervention group consisted of 168 (48 percent) fractures and received systemic antibiotics and a locally administered aminoglycoside (2 mg/mL) at the time of the procedure. Gustilo-Anderson type I and type II fractures were treated with 1 to 2 g of weight-based cefazolin or 600 mg of clindamycin in penicillin-allergic patients. Type III fractures were treated with weight-based gentamicin (until 2011) and penicillin G for farm-type contaminations. Gentamicin was switched to tobramycin due to the inhibitory effect of gentamicin on osteoblasts. 80 mg of aminoglycoside diluted in 40 mL of normal saline was injected into the wound cavity at the completion of the irrigation and fixation procedure in the intervention group.

Results: The difference between deep and superficial infection rates was statistically significant between the control and intervention groups. In the control group, the deep and superficial infection rate was 19.7 percent (36 of 183 fractures). In the intervention group, the deep and superficial infection rate was 9.5 percent (16 of 168 fractures). The deep infection rate for the control group was 14.2 percent (26 of 186 fractures) versus 6.0% (10 of 168 fractures) for the intervention group. The average time to surgical intervention was longer in the intervention group (14.5 ± 10.7 hours) compared to the control group (11.6 ± 10.3 hours). The type of fixation used had significant impact on infection rates. Closed reduction percutaneous pinning and external fixation resulted in a significantly higher rate of infection. The administration of local antibiotics did not affect nonunion rates.

Conclusions: Open fractures commonly result in infections even when treated with irrigation, debridement and systemic antibiotics. Infection rates vary between the literature for type I, type II, and type III Gustilo-Anderson fractures. This article supports evidence of lower infection rates in open fractures by locally injecting aminoglycosides into open fracture wound cavities in addition to the use of systemic antibiotics. The intervention group in this study received systemic antibiotics in addition to a locally injected aminoglycoside at the completion of the surgical procedure. This group demonstrated a significantly lower infection rate compared with the control group, who received systemic antibiotics only.

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