Abstract
Background
DAIR is an attractive treatment for PJI. The purpose of this study is to determine predictive factors of failure.
Materials and Methods
We reviewed all DAIR procedures for hip PJI performed between 2002–2017 (n=69). Data recorded included all factors correlated with treatment failure. KLIC score and an adapted McPherson score (sum of three criteria where the lower score is three for 3 A and the higher is 9 for 3 C) were analyzed.
Results
Infection eradication for early PJI (< 4 weeks) was achieved in 68% of patients and was correlated with treatment success (p=0.01). Success rate was only 37.5% in hematogenous infection and 28% in late infection. KLIC score (p=0.036), McPherson adapted score (threshold value 5.5/9) (p=0.01), CRP (with a cut-off value at 73.5 mg%) (p=0.025) and late PJI (p=0.031) were significantly predictive of failure treatment. For the KLIC score, patients with a score of ≤2, >2–3.5, >4–6.5, ≥7, respectively obtained a rate of failure of 33.3%,60%,71% and 100%.
We have established an equation in order to predict failure treatment. This tool predicts treatment failure when Logit P (equation result) is >0.476 with a sensitivity of 80% and a specificity of 83% (p = 0.05).
Conclusions
KLIC and adapted McPherson scores predict outcome of DAIR and should help making the decision in PJI treatment. Tsang et al, demonstrates that symptoms lasting for less than 7 days represent a significant threshold. Despite 80% of our patients operated within 7 days, the analysis wasn't significant. It seems that a DAIR procedure done promptly is not the only condition required for success and some other factors influence the outcome of treatment.
Logit P = 0.376 − (0.0533 ∗ Kidney failure) + (0.933 ∗ Age) + (0.640 ∗ BMI) + (1.111 ∗ Tobacco) + (0.031 ∗ Fistula) + (0.164 ∗ Deep infection) − (0.366 ∗ Revision) − (2.684 ∗ Exchange of the modular component) − (2.685 ∗ Early PJI) + (1.243 ∗ Hematogen PJI) + (0.127 ∗ Polymicrobial PJI) − (0.309 ∗ Staphylococcus aureus) + (0.393 ∗ MRSA) + (0.907 ∗ Resistance to quinolons/rifampicin) + (3.789 ∗ CRP >73,5mg/L) − (2.578 ∗ Onset of symptoms > 7days)
