The purpose of this study was to evaluate whether
the serum level of interleukin 6 (IL-6) could be used to identify the
persistence of infection after the first stage of a two-stage revision
for periprosthetic joint infection. Between 2010 and 2011, we prospectively studied 55 patients (23
men, 32 women; mean age 69.5 years; 36 to 86) with a periprosthetic
joint infection. Bacteria were identified in two intra-operative
tissue samples during re-implantation in 16 patients. These cases
were classified as representing persistent infection. To calculate a precise cut-off value which could be used in everyday
clinical practice, a 3 x 2 contingency table was constructed and
manually defined. We found that a serum IL-6 ≥ 13 pg/mL can be regarded as indicating
infection: its positive-predictive value is 90.9%. A serum IL-6 ≤ 8
pg/mL can be regarded as indicating an absence of infection: its
negative predictive value is 92.1%. The serum IL-6 level seems to be a reasonable marker for identifying
persistent infection after the first stage of a revision joint arthroplasty
and before attempting re-implantation. Cite this article:
Tumor size and metastases are known risk factors in Ewing tumors. Adequate staging is essential to stratify treatment intensity, but TNM staging is not established. The validity of TNM staging was tested based on tumor volume (T1 ≤200 ml; T2 >
200 ml ≤500 ml; T3, >
500 ml), the presence or absence of lymph node metastases (N0, N1), and distant metastases (M0, no metastases; M1 lung/pleura metastases; M1a ≤5 nodules; M1b >
5 lesions; M2 bone metastases; M2a, 1 lesion; M2b >
1 lesion and/or microscopic bone marrow contamination; M3, multi-system metastases). 1799 Ewing sarcoma patients of the (EI)CESS/EE99 studies entered into the Muenster database from 1981–2008 were analyzed. Ten-year event-free survival (EFS) was 0.46. EFS in patients without metastases (T1-3N0M0) was 0.56 compared to 0.22 in metastatic patients (T1-3N0,1M1-3), p<
.0001. In non-metastatic patients, tumor volume discriminated EFS: T1:0.62; T2:0.43; T3:0.40, p<
.0001. The rare event of lymph node metastases correlated with unfavorable prognosis (N0:0.47, N1:0.12, p<
.0001). The difference in EFS between pulmonary, skeletal and multi-system dissemination was significant: M1:0.29, M2:0.23; M3:0.12, p<
.0001. The discrimination of M1 subgroups (M1a/M1b) was of prognostic relevance (p=.0050); M2 subgroups (M2a/M2b) discriminated outcome less clearly (p=.0457). TNM staging is appropriate in Ewing tumors and should be incorporated in future trials.
