Two-week post-surgical antibiotic therapy sufficient for septic arthritis

Targeted antibiotic therapy for 2 weeks following initial surgical lavage for septic arthritis – particularly of the hand and wrist – is noninferior to the currently recommended 4-week duration for inducing remission, a study has shown.

“The treatment of septic arthritis requires a combination of at least one lavage/debridement and a long-lasting antibiotic administration … [However,] the optimal duration of post-surgical antibiotic therapy remains unknown,” said the researchers.

“[Our study shows that] total post-surgical antibiotic therapy can be limited to 2 weeks … [thereby limiting] potential adverse events (AEs), costs, complications of parenteral antibiotic therapy … [and] hospital stay,” they continued.

­A total of 154 adults (median age 51 years, 38 percent women) were randomized 1:1 to receive either 2 or 4 weeks of antibiotic therapy* following surgical drainage of septic arthritis. Of these, 99 had episodes in the hand and wrist. [Ann Rheum Dis 2019;78:1114-1121]

There was no difference in the rate of microbiological recurrences between the 2- and 4-week arms in the overall cohort (1 vs 2; p=0.56) and in the hand and wrist subgroup (1 vs 2; p=0.44).

Overall, there were only seven antibiotic-related AEs reported (2 and 5 in the 2- and 4-week arms, respectively; p=0.25).

A total of 60 episodes of mechanical or neurologic noninfectious sequelae was observed (eg, stiffness, flexion incapacity and adhesions, persistent pain, trigger zone, persistent dry wound, scaphoid necrosis, hypoesthesia, and Raynaud’s phenomenon). “Many of these sequelae did not require any specific therapy; however, a minority were severe enough to require corrective actions**,” said the researchers.

Length of hospital stay (LOHS) was significantly shorter with the 2- vs the 4-week regimen, be it in the overall cohort (4 vs 6 days; p=0.01) or the hand and wrist subset (3 vs 4 days; p=0.01).

Against the grain

For nearly four decades, the recommended total duration of post-surgical systemic antibiotic therapy has been 3–6 weeks, with most clinicians prescribing 4 weeks for adults. [Int J Infect Dis 2013;17:e199-205] “[However,] this is based on expert opinion and individual experience rather than on research studies. Furthermore, clinicians often treat bacterial arthritis at all anatomic sites in the same way, with no distinction between small and large joints,” explained the researchers.

Contrary to the current recommendation, the findings support a shorter course of antibiotic therapy for bacterial arthritis. “Given the clinical and economic advantages of shorter antibiotic courses … financial costs, LOHS, and potential intravenous-related complications [may be reduced],” said the researchers.

Nonetheless, certain limitations should be taken into account, noted the researchers. For one, the study may have been underpowered for other anatomical sites given the focus on the hand and wrist. Moreover, the investigators noted that they cannot comment on the potential of other treatment durations as the comparison only centred on 2 and 4 weeks. “While there appears to be little benefit for treating native joint infections longer than 4 weeks, there is almost no data favouring antibiotic courses shorter than 2 weeks.”

Given the paucity of prospective trials, it might be a challenge to convince clinicians who are used to prescribing longer treatment durations about the sufficiency of a shorter antibiotic treatment course in this setting, noted the researchers. “We hope that recent prospective data, including ours, may [help] in revising that [mindset].”