Failure modes in conservative and surgical management of infectious spondylodiscitis

We reviewed the management, failure modes, and outcomes of 196 patients treated for infectious spondylodiscitis between January 1, 2000 and December 31, 2010, at the Spinal Unit, Aarhus University Hospital, Aarhus, Denmark. Patients with infectious spondylodiscitis at the site of previous spinal instrumentation, spinal metastases, and tuberculous and fungal spondylodiscitis were excluded.

Mean age at the time of treatment was 59 (range 1-89) years. The most frequently isolated microorganism was Staphylococcus aureus. The lumbosacral spine was affected in 64% of patients and the thoracic in 21%. In 24% of patients, there were neurologic compromise, four had the cauda equina syndrome and ten patients were paraplegic. Ninety-one patients were managed conservatively. Treatment failed in 12 cases, 7 patients required re-admission, 3 in-hospital deaths occurred, and 5 patients died during follow-up. Posterior debridement with pedicle screw instrumentation was performed in 75, without instrumentation in 19 cases. Seven patients underwent anterior debridement alone, and in 16 cases, anterior debridement was combined with pedicle screw instrumentation, one of which was a two-stage procedure. Re-operation took place in 12 patients during the same hospitalization and in a further 12 during follow-up. Two in-hospital deaths occurred, and five patients died during follow-up. Patients were followed for 1 year after treatment. Eight (9%) patients treated conservatively had a mild degree of back pain, and one (1%) patient presented with mild muscular weakness. Among surgically treated patients, 12 (10%) had only mild neurological impairment, one foot drop, one cauda equine dysfunction, but 4 were paraplegic. Twenty-seven (23%) complained of varying degrees of back pain.

Conservative measures are safe and effective for carefully selected patients without spondylodiscitic complications. Failure of conservative therapy requires surgery that can guarantee thorough debridement, decompression, restoration of spinal alignment, and correction of instability. Surgeons should master various techniques to achieve adequate debridement, and pedicle screw instrumentation may safely be used if needed.