Treatment of Pyogenic Vertebral Osteomyelitis with Anterior Debridement and Fusion Followed by Delayed Posterior Stabilization and Fusion

Purpose: The treatment of pyogenic osteomyelitis of the spine remains a serious challenge for clinicians. The results of surgical treatment of complicated osteomyelitis with anterior debridement and fusion followed by a staged posterior stabilization and fusion are presented.

Material and Methods: Forty-eight patients with vertebral osteomyelitis were treated between 1990 and 2000. The sites of infection included 3 cervical, 9 thoracic, 7 thoracolumbar and 28 lumbar and 1 sacral. Although back pain was the most frequent presenting complaint, other symptoms included fever, chills, generalized malaise and neurologic deficits. The most common source appeared to be hematogenous or iatrogenic. The most frequently identified organism were staphylococcus aureus and epidermitis. Most of the patients had significant comorbidities including diabetes or were immunocompromised. Ninety percent of the patients had elevated erythrocyte sedimentation rates (ESR) or C-reactive protein while the white blood cell counts were less reliably elevated. Radiographic assessment consisted of plain radiographs, fine cut reconstructive CT scans, nuclear bone scans, and MRIs. MRI scanning was the most sensitive for diagnosis. Surgical indications included failure of medical management (most common), epidural abscess, neurologic compromise, anterior extraspinal abscess (psoas abscess), or the development of severe kyphotic deformity. All patients in the study were initially treated with anterior debridement and strut grafting following 10-14 days of appropriate IV antibiotics, subsequent instrumented posterior fusions were done. All patients were treated with 6 weeks of IV antibiotics postoperatively.

Results: All patients survived surgery except two, who suffered pulmonary failure and a massive CVA. Significant neurological deficits resolved in all patients. All patients had resolution of their infections with no recurrence as yet identified. Although the patients initial severe back pain resolved, most patients still had mild back pain. At least one pseudoarthrosis developed and continues to have significant back pain. No patients had collapse of the anterior strut grafts. No recurrent psoas abscesses nor epidural abscesses occurred. All patients continued to have postoperative ESR, C-reactive protein and serial radiographs.

Discussion: Pyogenic osteomyelitis continues to increase due to the aging population and resultant increase in comorbidities. Its diagnosis is frequently delayed and as a result may present a significant surgical challenge. The indications for surgical debridement in this series were failed medical treatment (antibiotics), neurologic compromise, soft tissue extension (i.e. psoas abscesses), extensive vertebral body and disc space destruction and progressive deformity. Many of these patients are severely ill at presentation and require urgent treatment as with time their medical condition will only continue to deteriorate. Anterior debridement and fusion followed by intravenous antibiotics allows for restoration of anterior column support and control of the infection, potentially decreasing the chance of septic seeding during posterior instrumentation and fusion.

Conclusion: This study demonstrates that anterior surgical debridement with fusion, followed by a period of intravenous antibiotics, and delayed instrumented posterior fusion is highly effective for the treatment of recalcitrant pyogenic osteomyelitis that has failed conservative medical management.