What are the possible causes of rigor in a 77-year-old male patient with a left intertrochanteric fracture, implant failure, and impaired left ventricular function with an ejection fraction of 33%?

Causes of Rigor in a 77-Year-Old Male with Left Intertrochanteric Fracture, Implant Fracture, and Reduced LV Ejection Fraction

Infection, particularly surgical site infection (SSI), is the most likely cause of rigor in this patient with intertrochanteric fracture and implant failure, especially given his cardiac comorbidity.

Primary Causes to Consider

1. Infection-Related Causes

• Surgical Site Infection (SSI)

  • Incidence of SSI after intertrochanteric fracture surgery is approximately 1.3% (1.1% superficial, 0.2% deep) 1
  • Risk factors present in this patient:
    • Advanced age (77 years)
    • Implant failure (creates instability and potential for bacterial colonization)
    • Reduced cardiac function (LVEF 33%, indicating heart failure)
  • Implant failure can create an environment conducive to bacterial growth and biofilm formation 2

• Systemic Infection

  • Urinary tract infection (common in elderly patients with reduced mobility)
  • Pneumonia (particularly in patients with heart failure)
  • Bacteremia secondary to implant-associated infection

2. Cardiac-Related Causes

• Acute Heart Failure Exacerbation

  • Patient has significantly reduced LVEF (33%), indicating pre-existing heart failure 3
  • Surgical stress and fluid shifts can precipitate acute decompensation
  • Heart failure exacerbation can present with rigor, especially with accompanying infection

• Cardiac Device Infection

  • If patient has an implanted cardiac device (pacemaker or ICD)
  • Patients with LVEF ≤35% often have implantable devices per guidelines 3

3. Orthopedic Complications

• Implant-Related Complications
  • Mechanical failure of the implant can cause inflammation 4
  • Poor reduction quality and loss of medial support are independent risk factors for implant failure 4
  • Nonunion of intertrochanteric fractures can lead to inflammatory response 5

Diagnostic Approach

1. Immediate Assessment

   • Complete blood count with differential
   • Blood cultures (at least two sets)
   • Urinalysis and urine culture
   • Chest X-ray
   • Wound assessment and culture if discharge present
   • C-reactive protein and ESR to assess inflammation

2. Orthopedic Evaluation

   • Radiographic assessment of implant position and fracture site
   • Evaluation for signs of implant loosening, migration, or failure
   • Assessment for nonunion or malunion 5

3. Cardiac Assessment

   • ECG to evaluate for new arrhythmias or ischemic changes
   • Echocardiogram to assess for worsening of cardiac function
   • BNP/NT-proBNP to evaluate for heart failure exacerbation

Management Considerations

1. Infection Management

   • Empiric broad-spectrum antibiotics covering gram-positive and gram-negative organisms
   • Adjust antibiotics based on culture results
   • Consider infectious disease consultation

2. Orthopedic Management

   • If implant failure is confirmed, surgical revision may be necessary
   • Consider valgization with dynamic hip screw and bone grafting if nonunion is present 5
   • Assess stability of fracture pattern, as unstable patterns have higher failure rates 6

3. Cardiac Management

   • Optimize heart failure medications
   • Consider cardiology consultation given reduced LVEF
   • Monitor fluid status carefully, especially if infection present

Important Caveats

• The combination of implant failure and heart failure significantly increases perioperative risk
• Patients with LVEF ≤35% have higher perioperative complications and mortality
• Delay in diagnosing and treating infection can lead to sepsis, particularly concerning in a patient with cardiac compromise
• Consider the timing of the implant failure in relation to the original surgery, as early failure suggests technical issues or infection, while late failure may indicate nonunion or mechanical issues

Remember that the patient's reduced cardiac function (LVEF 33%) places him at higher risk for complications from any cause of rigor, and aggressive diagnostic workup and management are warranted.