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Ankle Steroid Shots Tied to Post-Op Infections

— Study showed doubled rate of infections with intra-articular injections

MedpageToday

ORLANDO -- The use of intra-articular corticosteroid injections during ankle arthroscopy was associated with an increased rate of postoperative infections, a researcher reported here.

During the 6 months following the arthroscopy, the incidence of infection among patients who had a steroid injection was 3.9% compared with an incidence of 1.8% among controls, according to of the Hospital for Special Surgery in New York City.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

That resulted in an odds ratio of 2.2 (95% CI 1.4-3.7, P=0.002) for infection within 6 months, he said at the American Academy of Orthopaedic Surgeons annual meeting.

Intra-articular steroid injections are intended to reduce postoperative inflammation and pain. The practice has been studied for the knee and some other joints, but literature addressing the safety and efficacy for ankle arthroscopy is sparse.

To address this knowledge gap, Werner and his colleagues used the nationwide PearlDiver database, looking for Medicare patients who had intraoperative corticosteroids during ankle arthroscopy in the years 2005 to 2012. They looked at specific CPT codes for debridement or arthritis procedures likely to include a steroid injection, and used laterality modifiers to ensure that the injection was given in the same ankle as the arthroscopy.

They identified 459 patients who had the steroid injections and 9,327 who had ankle arthroscopy without the injection.

Demographic characteristics including age, gender, obesity, and smoking had no differences between the steroid injection group and controls. There also were no statistically significant differences between the two groups in comorbidities or types of procedures performed.

Almost two-thirds were women, about 20% were obese, and fewer than one-third were smokers.

A total of 18 patients in the steroid group and 168 controls developed infections within 6 months of the surgery.

"We also attempted to do a subgroup analysis breaking it down by age, but this was very challenging to do because of small numbers of infections in the steroid group," Werner noted.

One has looked at intra-articular steroid injections during ankle arthroscopy. This was a randomized trial that included 36 patients, 18 of whom had the injections and 18 who were controls. There was one infection in the steroid group and none in the control group, and the authors concluded that there was no statistically significant difference in steroid injections predisposing to infections, he said.

"But I would argue that it was a relatively underpowered study for this endpoint. So using a large database like we did was probably a better indicator of the association," Werner commented.

Other advantages of his group's study was the use of CPT codes, because if ICD9 codes are used it can be difficult to determine what type of ankle arthroscopic procedure was done, and laterality cannot be confirmed.

Limitations were the inclusion of only Medicare patients, so the results may not apply to a population of younger patients, and causality cannot be be assumed.

"In conclusion, the use of intra-articular steroid injections at the time of arthroscopy in a Medicare population is associated with significantly increased rates of postoperative infections," he said.

Disclosures

Werner disclosed no relevant relationships with industry.

Primary Source

American Academy or Orthopaedic Surgeons

Werner B, et al "Intra-articular steroid injection during ankle arthroscopy leads to increased rates of postoperative infection" AAOS 2016; Paper 847.