Foot & Ankle

Routine perioperative antibiotic prophylaxis is common practice, but the evidence in support of this practice is generally lacking and somewhat inconclusive. There are controversies not only regarding the timing, duration, no of doses, and microbial coverage during the pre-, intra-, and postoperative periods but also regarding the necessity of any perioperative antibiotic administration.

 

It is well documented that skin preparation does not eliminate surgical site bacteria in most elective foot operation. More than 70 percent of patients have a positive culture at the hallux following skin preparation, and even at the ankle more than 15 percent patients still have contaminated skin after routine preparation.

 

Some studies indicate that preoperative antibiotics have a positive effect on the prevention of postoperative wound infections in certain high risk foot procedures, while other studies failed to indicate an advantage for antibiotic prophylaxis. The patient factors may more strongly drive the decision to use antibiotic prophylaxis than type of procedure performed.

 

Although the incidence of postoperative wound infection is low in elective Foot and Ankle surgery, but if an infection does occur, the final outcome can lead to unfortunate consequences. The incidence of infection rate in clean orthopaedic surgery is between 0.5% to 9.2%, depending on the procedure and the reported studies. A drawback of antibiotic prophylaxis might be the generation of highly antibiotic resistant bacteria and thus routine antibiotic prophylaxis in low infection risk patients has been questioned.

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Recently a taskforce was appointed by the American College of Foot and Ankle Surgeons (ACFAS) to provide a clinical consensus on this topic. The panel members performed a literature search and identified 6 studies that met the inclusion criteria. They explored 4 categories: indications for antibiotic prophylaxis relative to surgical procedure; antibiotic prophylaxis in high-risk patients; antibiotic selection; and timing of antibiotic prophylaxis.

 

The panel members found that studies pertaining specifically to elective foot and ankle surgeries that were not level I evidence generally did not recommend prophylaxis. Regarding indications of antibiotics, the panel reached consensus that it was appropriate for antibiotic prophylaxis to be routinely utilised in surgeries involving bone, hardware, and prosthetic joints.

 

With regards to soft tissue surgery, the panel reached consensus that it was uncertain whether antibiotic prophylaxis should be utilised and would be considered procedure dependent. With regards to prophylaxis in high-risk patients, the panel reached consensus that antibiotic prophylaxis was appropriate in patients who may be at increased risk for infection including those with diabetes, immunocompromised, and those at risk for endocarditis.

 

With regards to antibiotic selection, the panel reached consensus that narrow spectrum antibiotics covering Staphylococcus aureus should be utilised for prophylaxis in patients without a history of resistant infection. It was not considered appropriate to routinely perform preoperative nasal swabs to check for methicillin-resistant Staphylococcus aureus (MRSA) colonization.

 

With regards to the timing of antibiotic administration, the panel reached a consensus that in cases where prophylaxis is used it is appropriate for the antibiotics to be administered within 60 minutes prior to surgery, discontinued within 24 hours after surgery and given prior to tourniquet inflation. It was considered uncertain whether prophylaxis should be performed more than once in prolonged foot and ankle surgery cases.

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A recently published retrospective review of 4890 patients undergoing Foot and Ankle surgery showed that the routine use of antibiotic prophylaxis did not reduce the incidence of infection. Interestingly the incidence of infection was found significantly higher in patients receiving prophylactic antibiotics; however this could have been influenced by the complexity of the cases and patients’ co-morbidities in this study.

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A retrospective review of 1933 foot and ankle procedures in 1632 patients over 56 months showed that 91.8% of the risk of a surgical site infection could be predicted by ASA score and length of surgery alone and the timing of administration of the antibiotics did not seem to play any major role in the prevention of infection.

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Results of a systematic review by Modha et al. stated that in clean, uncomplicated and elective soft tissue and bony surgery of the foot and ankle, antibiotic prophylaxis is not routinely warranted. Where the use of metallic hardware is necessitated, the decision to provide prophylaxis must be agreed locally as a conclusive recommendation cannot be made due to the paucity of the literature. The decision should ultimately be based upon surgeon preference, patient and surgical risk factors with pertinence to the amount and type of hardware and the surgery required. Where the use of joint replacement prostheses are necessitated, antibiotic prophylaxis is recommended due to their propensity to form biofilms. Antibiotic prophylaxis should be delivered to the patient within 60 min of inflation of pneumatic tourniquet to allow sufficient plasma concentrations of the drug to be utilised.

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References

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• Dayton et al.,American College of Foot and Ankle Surgeons’ Clinical Consensus Statement: Perioperative Prophylactic Antibiotic Use in Clean Elective Foot Surgery, The Journal of Foot and Ankle Surgery, 2015 (1-7).

• Ostrander RV, Brage ME, Botte MJ. Bacterial skin contamination after surgical preparation in foot and ankle surgery. Clin Orthop Relat Res. 2003: 246-252

• Robinson et al. The Efficacy of Prophylactic Single Dose Intravenous Antibiotics vs. Multi Dose Intravenous/Oral Antibiotics in Elective Foot and Ankle Surgery, JSM Foot and Ankle, 2016; 1(3), 1017.

• Greisberg et al., Timing of antibiotic prophylaxis for preventing surgical site infections in foot and ankle surgery; http://dx.doi.org/10.1016/j.fas.2016.05.141.

• Modha, M.R.K., Morriss-Roberts, C., Smither, M. et al. Antibiotic prophylaxis in foot and ankle surgery: a systematic review of the literature. J Foot Ankle Res 11, 61 (2018).