What is the management for a patient with rigors 14 days post-operative from a Transforaminal Lumbar Interbody Fusion (TLIF) surgery?

Management of Rigors 14 Days Post-TLIF

Rigors occurring 14 days after TLIF surgery represent a surgical site infection until proven otherwise and require immediate evaluation with inflammatory markers (CRP, ESR, CBC), blood cultures, and consideration for advanced imaging (MRI with contrast) to assess for deep wound infection, epidural abscess, or discitis. 1

Immediate Diagnostic Workup

Laboratory Assessment

• Obtain inflammatory markers immediately: CRP and ESR are elevated in postoperative infections and should be measured urgently 2
• Complete blood count with differential: Leukocytosis supports infectious etiology 2
• Blood cultures: Draw at least two sets during febrile episodes before initiating antibiotics 1
• Creatine kinase (CK): While typically elevated early postoperatively, persistently elevated or rising CK at 14 days suggests ongoing muscle inflammation or infection 2

Imaging Studies

• MRI with gadolinium contrast: This is the gold standard for detecting epidural abscess, discitis, or osteomyelitis at the surgical site 1
• Consider CT if MRI contraindicated: Can identify hardware complications, though less sensitive for soft tissue infection 3

Common Infectious Complications Post-TLIF

Surgical Site Infection Risk

• Overall complication rates for TLIF range from 8.7% to 33.6%, with infection being a significant concern in the early postoperative period 4, 5
• Deep wound infections can present with delayed fever and rigors, typically occurring 7-21 days postoperatively 1
• Pin tract infections and wound complications occur in up to 18-25% of instrumented cases 3

Specific Infection Patterns

• Discitis/osteomyelitis: Presents with fever, rigors, and worsening back pain at the fusion site 6
• Epidural abscess: Medical emergency requiring urgent decompression if neurological deficits develop 1
• Hardware-related infection: May require removal of instrumentation if infection cannot be cleared with antibiotics alone 3

Management Algorithm

If Infection Confirmed

1. Initiate broad-spectrum IV antibiotics immediately after cultures obtained, covering Staphylococcus aureus (including MRSA) and gram-negative organisms 1
2. Surgical debridement is indicated for deep wound infections, epidural abscess, or failure of antibiotic therapy within 48-72 hours 1
3. Hardware retention should be attempted if possible, but removal may be necessary if infection persists 3
4. Prolonged antibiotic course: Typically 6-12 weeks for discitis/osteomyelitis, guided by infectious disease consultation 1

If Infection Ruled Out

• Consider alternative diagnoses: Pulmonary embolism, deep vein thrombosis, urinary tract infection, or pneumonia 5
• Evaluate for hardware complications: Cage migration (occurred in 2% of cases in one series), endplate fracture, or nerve root irritation 6
• Assess for BMP-related complications: If bone morphogenic protein was used, postoperative radiculitis occurs in 14-20% of cases and can present with systemic symptoms 1

Critical Pitfalls to Avoid

Delayed Recognition

• Do not attribute rigors to "normal postoperative course" at 14 days—this timing is highly suspicious for infection 1
• Do not delay imaging if clinical suspicion is high, even if initial inflammatory markers are equivocal 2
• Do not start empiric antibiotics before obtaining blood cultures unless patient is hemodynamically unstable 1

Inadequate Source Control

• Superficial wound drainage alone is insufficient if deep infection is present—formal surgical debridement is required 1
• Do not assume hardware can remain if infection is confirmed around instrumentation—early consultation with spine surgery is essential 3

Monitoring and Follow-up

Inpatient Management

• Admit for IV antibiotics and monitoring given the 14-day postoperative timeframe and systemic symptoms 7
• Serial neurological examinations every 4-6 hours to detect evolving epidural abscess or cord compression 1
• Trend inflammatory markers (CRP, ESR) every 48-72 hours to assess treatment response 2

Expected Outcomes

• With appropriate treatment, infection-related complications can be managed successfully in most cases, though fusion rates may be compromised 6
• Mortality risk exists with untreated epidural abscess or sepsis—aggressive management is warranted 1
• Long-term functional outcomes are generally preserved if infection is controlled and fusion proceeds 4