Abstract
Background
There is minimal published data regarding the long-term functional outcome in pyogenic spinal infection. Previous studies have used heterogeneous, unreliable and non-validated measure instruments, or neurological outcome alone, yielding data that is difficult to interpret. We aim to assess long-term adverse outcome using standardised measures, Oswestry disability index (ODI) and MOS short form-36 (SF-36).
Methods
All cases of pyogenic spinal infection presenting to a single institution managed operatively and non-operatively from 1994-2004 were retrospectively identified. Follow-up was by clinical review and standardised questionnaires. Inclusion in each case was on the basis of consistent clinical, imaging and microbiology criteria.
Results
Twenty-nine cases of pyogenic spinal infection were identified. Twenty-eight percent were managed operatively and 72% with antibiotic therapy alone. Nineteen patients (66%) had an adverse outcome at a median follow-up of 61 months, despite only 5 patients (17%) having persistent neurological deficit. A significant difference in SF-36 PF (physical function) scores was observed between patients with adverse outcome and patients who recovered (p=0.003). SF-36 scores of all patients, regardless of management or outcome, failed to reach those of a normative population. A strong correlation was observed between ODI and SF-36 PF scores (rho=0.61, p<0.05). Seventeen percent (n=5) of admissions resulted in acute sepsis-related death. Subgroup analysis revealed delay in diagnosis of spinal infection (p=0.025) and neurological impairment at diagnosis (p<0.001) to be significant predictors of neurological deficit at follow-up. Previous spinal surgery was associated with adverse outcome in patients requiring readmission within 1 year of hospital discharge following first spinal infection (p=0.018). No independent predictors of adverse outcome, persistent neurological impairment, readmission within 1 year or acute death were identified by logistical regression analysis.
Conclusions
High rates of adverse outcome detected using SF-36 and ODI suggest under-reporting of poor outcome when ASIA score alone is used to qualify outcome.
