The change in plasma D-dimer does not help to guide the timing of reimplantation in two stage exchange for periprosthetic joint infection

D-dimer has been included in the criteria by the Musculoskeletal Infection Society in 2018 as a novel parameter to diagnose prosthetic joint infection (PJI). However, it is unclear how D-dimer levels change in between stages of a two-stage exchange. We prospectively investigated 30 patients who underwent a two-stage exchange using a spacer for PJI. D-Dimer, CRP and IL-6 were collected before first and second stage surgery and the difference (Delta) in between stages was calculated. The levels of plasma D-Dimer did not change from first to second stage surgery (2770 ng/ml (IQR, 1600-3770 ng/ml) versus 2340 ng/ml (IQR, 1270-4100 ng/ml); p=0.8) while CRP (4.0 mg/dl (IQR, 1.7-5.5 mg/dl) versus 0.6 mg/dl (IQR, 0.5-0.8 mg/dl); p<0.001) and IL-6 (21 pg/ml (IQR, 10-29 pg/ml) versus 6 pg/ml (4-9 pg/ml); p<0.001) decreased. The Delta D-dimer between both stages was 300 ng/ml (range:-2820 to 4280 ng/ml), the median Delta CRP was-3.4 mg/dl (IQR,-1.2 to-4.8 mg/dl) and Delta IL-6 was-13 pg/ml (IQR,-4 to-20 pg/ml). In 15 of 30 cases (50%) the D-dimer level increased between both stages, whereas the level of CRP (93%; 28/30) and IL-6 (96%; 28/29) decreased in most patients. As the level of serum D-dimers varies greatly, lacks a uniform decrease and does not identify persisting infection, surgeons should be cautious when using it at the timing of reimplantation.

Automated summary

A study found that in a two-stage exchange for PJI, D-dimer levels did not change significantly, while CRP and IL-6 levels showed a decreasing trend. Some patients had an increase in D-dimer levels between stages, while most patients had decreasing levels of CRP and IL-6. Surgeons should exercise caution when using D-dimer to identify persisting infection during reimplantation.