Fatal outcome after insufficient spine fixation for pyogenic thoracic spondylodiscitis: an imperative for 360 degrees fusion of the infected spine

Abstract

Background: Pyogenic spondylodiscitis represents a potentially life-threatening condition. Due to the low incidence, evidence-based surgical recommendations in the literature are equivocal, and the treatment modalities remain controversial.

Case presentation: A 59 year-old patient presented with a history of thoracic spondylodiscitis resistant to antibiotic treatment for 6 weeks, progressive severe back pain, and a new onset of bilateral lower extremity weakness. Clinically, the patient showed a deteriorating spastic paraparesis of her lower extremities. An emergent MRI revealed a kyphotic wedge compression fracture at T7/T8 with significant spinal cord compression, paravertebral and epidural abscess, and signs of myelopathy. The patient underwent surgical debridement with stabilization of the anterior column from T6-T9 using an expandable titanium cage, autologous bone graft, and an anterolateral locking plate. The patient recovered well under adjunctive antibiotic treatment. She presented again to the emergency department 6 months later, secondary to a repeat fall, with acute paraplegia of the lower extremities and radiographic evidence of failure of fixation of the anterior T-spine. She underwent antero-posterior revision fixation with hardware removal, correction of kyphotic malunion, evacuation of a recurrent epidural abscess, decompression of the spinal canal, and 360 degrees fusion from T2-T11. Despite the successful salvage procedure, the patient deteriorated in the postoperative phase, when she developed multiple complications including pneumonia, acute respiratory distress syndrome, bacterial meningitis, abdominal compartment syndrome, followed by septic shock with multiple organ failure and a lethal outcome within two weeks after revision surgery.

Conclusion: This catastrophic example of a lethal outcome secondary to failure of anterior column fixation for pyogenic thoracic spondylodiscitis underlines the notion that surgical strategies for the infected spine must be aimed at achieving absolute stability by a 360 degrees fusion. This aggressive - albeit controversial - concept allows for an adequate infection control by adjunctive antibiotics and reduces the imminent risk of a secondary loss of fixation due to compromises in initial fixation techniques.

Figure 1

Initial MRI obtained on the first day in the emergency department. STIR sagittal views show the extent of kyphosis at T7/T8 with vertebral body destruction due to pyogenic thoracic spondylodiscitis, spinal canal compression, anterior paravertebral and epidural abscess, and evidence of myelopathy at the T7/T8 level.

Figure 2

Status post anterior debridement through a right-side anterolateral thoracotomy, T7 and T8 corpectomy, anterior spinal canal decompression, and anterior fusion T6 through T9 by expandable cage, autologous bone graft, and anterolateral locking plate. Panel A shows the adequate restoration of the sagittal profile of the thoracic spine, on plain X-rays. The axial CT views demonstrate the adequate locking head screw placement of the anterolateral plate (panels B, F) and adequate expandable cage placement with spinal canal clearance (panels C, D, E).

Figure 3

Failure of the initial anterior fixation at 6 months after surgery, secondary to repeat falls. Conventional anteroposterior X-ray (panel A) and coronal CT reconstruction (panel B) demonstrate the loss of fixation of the anterolateral locking plate and of the expandable cage, which are pulled out at the upper segment in T6. The sagittal CT reconstruction (panel C) demonstrates the kyphotic malunion cephalad to the expandabale cage. The axial CT views (panels D-F) shows the laterally pulled out locking head screws (D, E) and cage (F) at T6.

Figure 4

Postoperative CT scout (A) and chest X-ray (B) after 360° revision fixation by posterior instrumentation T2–T11 and anterior PMMA/Tobramycin mesh cage placement.