Acute and chronic pyogenic vertebral osteomyelitis: Is there a role for adjunctive internal fixation during surgical management?

Abstract

Pyogenic osteomyelitis is a serious illness and up to 7% of all osteomyelitis cases involve vertebral structures. Major risk factors for pyogenic vertebral osteomyelitis (PVO) include infections at distant sites, which can seed the spine through hematogenous spread, and medically compromised status. The most commonly reported complications associated with PVO include pain, kyphotic deformity and neurological sequelae. While PVO remains rare, the epidemiology is changing with an evolving population risk profile. The most frequently isolated microbe associated with PVO in the general population is S. aureus and post-spinal surgery osteomyelitis is frequently polymicrobial, however the ability to obtain definitive blood cultures is highly variable. Diagnosis of PVO includes laboratory findings consistent with escalating markers for inflammatory response. While MRI remains the imaging method of choice for PVO, plain radiographic changes associated with vertebral body or disk space infection are usually apparent 2–4 weeks following clinical symptoms. Initial medical management for uncomplicated PVO includes antibiotic therapy and immobilization. Approximately 25% of cases fail conservative therapies. Among the most consistently cited factors impacting surgical results regardless of approach are the number of significant co-morbidity factors and the impact of effective medical management. An analysis of the literature suggests that decompression and anterior grafting alone in patients who can tolerate prolonged immobilization is adequate. The use of instrumentation is more strongly indicated in circumferential decompression for anterior/posterior abscess, gross instability after debridement, medical compromise precluding prolonged bed rest or bracing, and in those patients with progressive spinal deformity.