A scoring system for the preoperative evaluation of prognosis in spinal infection: the MSI-20 score

Spinal infection (SI) is a life-threatening condition and its treatment remains challenging. Recent studies have supported early and aggressive surgery, but mortality still reaches 5% to 10% and it remains unclear, if an aggressive surgical strategy also applies for severely sick patients.

The aim of this analysis was to generate an assessment score to predict mortality of SI in order to facilitate decision-making.

Retrospective risk factor analysis.

Two hundred fifty-two patients were retrospectively analyzed.

Physiologic measures, functional measures.

Diagnosis was based on clinical presentation, imaging findings and inflammatory markers. Factors associated with mortality were identified by multivariate analysis, weighted according to their relative risk ratio (RR) and included in the novel assessment score.

Eight parameters were included: (1) BMI, (2) ASA score, (3) presence of sepsis, (4) age-adjusted Charlson Comorbidity Index, (5) presence and degree of renal failure, (6) presence of hepatopathy, (7) neurological deficits and (8) CRP levels at diagnosis. Each parameter was assigned a certain range of points, resulting in a maximum total score of 20. The mortality in spinal infection (MSI-20) score - indicating poorer status with higher values - was obtained for each patient and correlated with mortality.

An MSI-20 score of 11 or more points seems to identify the small group of patients being "too sick to undergo surgery," while early surgery can be recommended in the remainder (MSI-20 ≤10). Our results need to be confirmed in prospective studies, but may give guidance for indicating surgery even in rather sick and comorbid patients.