[Surgical treatment of spinal infections]

Although great advances have been made in both radiological diagnosis and antibiotic therapy of microbial infections, the treatment of spinal infections remains a major clinical challenge. Many of the patients affected are referred to spinal units with long delays. The general population is ageing and the number of immunocompromised patients, as well as the number of operative procedures for spinal disorders are increasing. The aim of our study was to evaluate the clinical presentations of spinal infections, options for their diagnosis, indications for treatment and their risk factors and the results of surgery.

The group of 112 patients evaluated after the treatment of spinal infection comprised 63 men and 49 women at an average age of 59.4 years (range, 17 to 84). The average follow-up was 3.2 years (range, 6 months to 8 years). Of these, 82 patients had primary hematogenous infection, 29 had post-operative infection,and one had an infected gun shot wound. Thirty-six patients showed neurological deficit and six were paraplegic. The diagnostic methods included FBC, CRP and EST tests, examination of blood cultures, aspirates and biopsy samples from the infected site, bone scintigraphy, MRI and CT scanning. Indications for surgery included an infection not responding to conservative treatment,with existing or impending spinal instability, and with or without neurological deficit. The surgical management involved transpedicular drainage of the abscess, wound debridement from the posterior approach and instrumented spondylodesis. Surgery which included spinal decompression with radical excision of infected tissue was augmented with posterolateral instrumented fusion and/or anterior stabilization, as indicated.

Of the 112 patients treated, seven died of uncontrollable sepsis after surgery; the remaining 105 were followed up. Another four patients died of causes unrelated to the spinal problem treated within 12 months. All patients recovered except for two in whom the infection persisted, but 13 required more than one surgical procedure. One patient with CSF leakage failed to heal after five interventions. The most frequently isolated infectious agents were Staphylococus aureus, Staphylococus epidermidis and E. coli. Of the 33 patients with neurological deficit, 24 improved by one or two Frankel grades. The neurological status of six paraplegic patients did not improve, but their functional findings did after stabilization of the spine. Clinical evaluation showed 47 (44.7 %) very good, 40 (38 %) good, eight (7.6 %) unchanged and 10 (9.5 %) poor outcomes.

Early diagnosis is a prerequisite for good treatment outcomes. Clinical examination, results of laboratory tests, and scintigraphy and MRI findings play the key role. When progressing osteolysis is suspected, a CT scan is necessary. Debridement should be as radical as possible, but always in compliance with the patient's health state. At an advanced stage of disease, spinal stabilization is important because it allows us to remove infected tissue. Intravenous and then oral antibiotic therapy at 2 to 4 and 6 to 12 weeks of follow-up is mandatory. The management of spinal infections is a complex process requiring good multidisciplinary cooperation.