DOS 2017

DOS Kongressen 2017 ·

The perioperative infection rate in total knee arthro-

plasty may be dependent on season

Hannes Torngren, Sara Kamilla Clausen, Anders Odgaard, Thomas Lind

Orthopaedic department, Gentofte Hospital

Background:

Total knee arthroplasty (TKA) is a surgical procedure routinely

performed, primarily as end-stage treatment for osteoarthritis, resulting in ap-

proximately 8000 primary procedures every year in Denmark. While many as-

pects of causes and risk factors for infections and TKAs have been extensively

examined, none have, to the authors’ knowledge, sufficiently explored\r\nthe

relationship between seasonality and risk of perioperative infections

Purpose / Aim of Study:

We performed a retrospective study to determine

the rate of revision due to deep infection, defined as those revised within the

first 2 year, for each month of the year . The aim of the study was to investi-

gate wether there is a variation in infection rate after primary TKA based on the

month the primary surgery was done

Materials and Methods:

The study was based on a large dataset from the na-

tional Danish Knee Arthroplasty Registry (DKR). We received data on a total of

124.484 procedures and set out to identify all patients who, between January

1st 1997 and December 31st 2014, had undergone primary TKA resulting in

revision surgery due to infection. The revision rate and relative risk for infection

for each month were calculated and analyzed with Pearsons chi-square test.

Findings / Results:

The revision rate due to infection was calculated for each

season. Of procedures performed during summer, 1,02% ended in revision due

to infection. In comparison, the remainder of the seasons had revision rates of

0,73% (fall), 0,82% (winter) and 0,80% (spring) (P = 0.013) The relative risiko

between summer vs the rest was 1.31 [95% CI, 1.10 - 1.55]

Conclusions:

The relative risk of revision surgery due to infection is 1.31 times

higher if the primary TKA surgery is performed during the summer months

compared to the remainder of the year. The reason for the increased infection

rate is yet to be determined

No conflicts of interest reported

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