Abstract
Aim
Pubic osteomyelitis (PO) is one of less frequent Bone and Joint Infections forms (BJI). Its management is still poorly codified as far as nosological framework is still unclear in medical literature. We aim to describe PO epidemiology and to look for factors associated with management failure.
Method
We performed a retrospective cohort study, carried out in two Reference Centres, including patients with PO in 2010–2016. Treatment failure was defined by: (i) persistence of clinical signs despite treatment; (ii) clinical relapse with same microorganisms; (iii) infection recurrence with one or more different microorganism(s);
(iv) new signs of infection (abscess, sinus tract) in same area, without recourse to get microbiological documentation. Factors associated with management failure were determined by univariate Cox analysis (hazard ratio [HR] and 95% confidence interval calculation). Kaplan-Meier curve were compared between groups by log-rank test.
Results
Twenty-five patients were included over thirteen years (median age 67 years; 19 men, median ASA score 3). Six (24 %) had a PO from haematogenous origin. Those were all monomicrobial infection, due to S.aureus, mostly identified in young patients without comorbidities, especially in athletes. No surgery was required if no abcess or bone sequestrum were found. Nineteen patients (76 %) had a post-operative chronic PO (developed from 1 month to 11 years after a pelvic surgery); 15 of them had history of pelvic cancer (60%); 12 received radiotherapy at the site of infection (48 %). Infection was polymicrobial in 68 % of cases, including 32 % of cases with multidrug-resistant pathogens. A clinical success was recorded in only 14 patients (56%). Treatment failure was always noticed in chronic post-operative forms. Potential risk factors associated with failure management were: pelvic cancer history (HR 3.8; p=0,089); pelvic radiotherapy history (HR 2.9; p=0.122); clinical sinus tract (HR 5.1; p=0,011); infection with multidrug-resistant bacteria (HR 2.8; p=0,116), and polymicrobial infection (HR 70.5; p=0,090).
Conclusions
Our study highlights predominant chronic complex post-operative forms of PO. They are mostly plurimicrobial, sometimes associated with multi-drug resistance, occurring in fragile patients with pelvic cancer. It frequently leads to complex antibiotherapy, with important risk of relapse. Aggressive surgical procedure with large bone resection is frequently required in patients who underwent pelvic radiotherapy.
