Background Vertebral osteomyelitis is considered as a rare but severe disease: previous works have estimated that neurological complications occurred in up to 59% cases. However, these works are mainly surgical studies, so neurological complications might have been overestimated.

Objectives The aim of our study was to evaluate the frequency of neurological deficit (ASIA grade A to D) in a non-selected population of patients with pyogenic vertebral osteomyelitis and to find MRI pattern associated with these complications.

Methods We reviewed medical charts of all patients with spondylodiscitis from 2007 to 2012 in Nantes University Hospital and we included patients aged 18 years or older with infectious spondylodiscitis confirmed by MRI. Were excluded patients who had no microbiological identification of the causative agent or no MRI at baseline.

Results 86 patients were included. Mean age was 63.7±15.3 years, mostly men (67%, n=58). Lombo-sacral spine was the most frequently affected (58.1%, n=50), followed by thoracic (31.4%, n=27) and cervical spine (23.3%, n=20). It was multifocal in 24.4% cases (n=21). Overall, we found that 20.9% of the patients had a motor deficit (n=18), 8.1% had also sphincter dysfunction (n=7) and 14% (n=12) had surgical therapy for spinal or root nerve decompression. Neurological involvement was present at the time of admission for all patients. On MRI, 73.3% of patients (n=63) had an epidural inflammation and 40.7% (n=35) had an epidural abscess. We found that several MRI patterns were associated with the presence of a neurological deficit: Cervical spine lesions (OR 5.7, p=0.017), dural compression (OR 8.9, p=0.003), cerebro-spinal fluid interruption (OR 13.1 p<0,001) and signal changes of the spinal cord (OR 4.9, p=0,027). Destruction of more than 50% of the sus-jacent vertebrae volume was also associated with higher risk of motor deficit: OR 7.4, p=0.006. Interestingly, epidural abscess was not associated with neurological deficit, but was associated with higher frequency of surgical treatment (OR 3.9, p=0,048). Finally, neither multifocal lesions, loss of disk height, roots nerve compression nor posterior arch inflammation were associated with a higher risk of neurological deficit.

Conclusions Neurological deficit occurred in 20% of our patients. It was always present at the time of diagnosis: none of the patients developed a neurological deficit during the treatment course. Patient with a cervical involvement, major vertebrae destruction, dural compression, cerebro-spinal fluid interruption and signal changes of the spinal cord on MRI were at risk of neurological deficit. In contrast, epidural abscesses or nerve roots compression were not significantly associated with such complications.

References

1. Mylona E. Samarkos M. Kakalou E. Pyogenic vertebral osteomyelitis: a systematic review of clinical characteristics. Semin Arthritis Rheum. 2008

2. Uchida K et al. Epidural abcess associated with pyogenic spondylodiscitis of the lumbar spine; evaluation of a new MRI staging classification and imaging findings as indicators of surgical management: a retrospective study of 37 patients. Arch orthop trauma Surg. 2009.

3. Leone A. et al. Imaging of spondylodiscitis. Eur Rev Med Pharmacol Sci. 2012

Disclosure of Interest None declared