Incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infection in European hospitals: the COMBACTE-NET ARTHR-IS multi-centre study.

BACKGROUND: The aim of this study was to estimate the incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infections (SA-PJI) after primary hip and knee arthroplasty in European centres. METHODS: This study was conducted in patients who underwent primary hip and knee arthroplasty in 19 European hospitals between 2014 and 2016. The global incidence of PJI and SA-PJI was calculated. The associated disease burden was measured indirectly as infection-related mortality plus loss of function. For healthcare utilization, number and duration of hospitalizations, number and type of surgical procedures, duration of antibiotic treatments, and number of outpatient visits were collected. Subgroup and regression analyses were used to evaluate the impact of SA-PJI on healthcare utilization, controlling for confounding variables. RESULTS: The incidence of PJI caused by any micro-organism was 1.41%, and 0.40% for SA-PJI. Among SA-PJI, 20.7% were due to MRSA with substantial regional differences, and were more frequent in partial hip arthroplasty (PHA). Related deaths and loss of function occurred in 7.0% and 10.2% of SA-PJI cases, respectively, and were higher in patients with PHA. Compared with patients without PJI, patients with SA-PJI had a mean of 1.4 more readmissions, 25.1 more days of hospitalization, underwent 1.8 more surgical procedures, and had 5.4 more outpatient visits, controlling for confounding variables. Healthcare utilization was higher in patients who failed surgical treatment of SA-PJI. CONCLUSIONS: This study confirmed that the SA-PJI burden is high, especially in PHA, and provided a solid basis for planning interventions to prevent SA-PJI.

Vertebral osteomyelitis after spine instrumentation surgery: risk factors and management.

BACKGROUND: Vertebral osteomyelitis after spine instrumentation surgery (pVOM) is a rare complication. Most cases of infection occur early after surgery that involve skin and soft tissue and can be managed with debridement, antibiotics, and implant retention (DAIR). AIM: To identify pVOM risk factors and evaluate management strategies. METHODS: From a multicentre cohort of deep infection after spine instrumentation (IASI) cases (2010-2016), pVOM cases were compared with those without vertebral involvement. Early and late infections were defined (<60 days and >60 days after surgery, respectively). Multivariate analysis was used to explore risk factors. FINDINGS: Among 410 IASI cases, 19 (4.6%) presented with pVOM, ranging from 2% (7/347) in early to 19.1% (12/63) in late IASIs. After multivariate analysis, age (adjusted odds ratio (aOR): 1.10; 95% confidence interval (CI): 1.03-1.18), interbody fusion (aOR: 6.96; 95% CI: 2-24.18) and coagulase-negative staphylococci (CoNS) infection (aOR: 3.83; 95% CI: 1.01-14.53) remained independent risk factors for pVOM. Cases with pVOM had worse prognoses than those without (failure rate; 26.3% vs 10.8%; P = 0.038). Material removal was the preferred strategy (57.9%), mainly in early cases, without better outcomes (failure rate; 33.3% vs 50% compared with DAIR). Late cases managed with removal had greater success compared with DAIR (failure rate; 0% vs 40%; P = 0.067). CONCLUSION: Risk factors for pVOM are old age, use of interbody fusion devices and CoNS aetiology. Although the diagnosis leads to a worse prognosis, material withdrawn should be reserved for late cases or when spinal fusion is achieved.