Postoperative infections

Infection after surgery is uncommon, but knowing the warning signs and calling early is the most important thing you can do. Most infections caught early clear completely.

What Is a Postoperative Infection?

A postoperative infection is an infection at or near the site of surgery. After spine or brain surgery, it can be superficial (in the skin and tissue just under the incision) or deep (around the spine, implants, disc, or the coverings of the brain and spinal cord). Most appear within the first few weeks after surgery, though some show up months later, especially when implants such as screws or rods are involved.

Every surgical team takes steps to lower the risk, including antibiotics at the time of surgery, careful sterile technique and wound care instructions. Even so, a small percentage of patients develop an infection, and quick treatment leads to the best results.

Warning Signs

At the incision

• Redness that spreads or gets darker
• Increasing swelling, warmth or tenderness
• Drainage that is cloudy, yellow or green, foul-smelling, or that starts after the wound had been dry
• The incision opening up

In your body

• Fever over 101°F, chills or sweats
• Pain that is getting worse instead of better
• Feeling generally unwell or unusually tired

After brain surgery or with a shunt

• Worsening headache, stiff neck or sensitivity to light
• Confusion, unusual sleepiness, vomiting or a seizure

When it’s an emergency: Fever with new weakness or numbness, bladder or bowel changes, confusion, a stiff neck with severe headache, or a seizure needs emergency care. Call 911 or go to the nearest emergency room.

Risk Factors

• Diabetes, especially when blood sugar is poorly controlled
• Smoking or nicotine use
• Obesity
• Older age and a weakened immune system, including from steroids or cancer treatment
• Longer or more complex operations, implants, revision surgery and surgery after trauma
• Poor nutrition

Lowering your risk

• Stop smoking and nicotine before and after surgery
• Keep blood sugar well controlled
• Follow your incision care instructions and keep the wound clean and dry
• Wash your hands before touching the area, and don’t soak the incision in a bath, pool or hot tub until cleared

How It’s Diagnosed

• Examining the incision
• Blood tests: white blood cell count, ESR and CRP (inflammation markers) and blood cultures
• Imaging: MRI with contrast or CT to look for deeper infection or a fluid collection
• Cultures: a sample of drainage or tissue to identify the germ and choose the right antibiotic

Treatment

Superficial infections

These are often treated with oral antibiotics and wound care, with close follow-up.

Deep infections

Deeper infections usually need a return to the operating room to wash out the wound and remove infected tissue (irrigation and debridement), followed by IV antibiotics for several weeks, coordinated with infectious disease specialists. In many cases, spinal implants can stay in place. Some patients need more than one washout, and a wound vacuum may be used to help healing. Rarely, hardware needs to be removed or replaced once the infection is controlled, sometimes with revision surgery.

Related infections are described on our pages for discitis, spinal osteomyelitis, epidural abscess and meningitis after surgery.

What to Expect

Superficial infections typically heal over a few weeks. With a deep infection, expect a short hospital stay, several weeks of antibiotics, often through a home IV line, and regular blood tests and wound checks. Most patients go on to heal and get the benefit of their original surgery.

Frequently Asked Questions

Is some drainage normal after surgery?

A small amount of clear or pink fluid in the first few days can be normal. Cloudy, foul-smelling or increasing drainage, or drainage that starts after the wound was dry, should be checked.

When do infections usually appear?

Most appear within the first two to four weeks, but deep infections around implants can show up later.

Will my screws or rods need to come out?

Often not. Many infections are cured with washout and antibiotics while the implants stay in place to keep the spine stable.

Did something go wrong in my surgery?

Not necessarily. Infection is a known risk of any operation, even when everything is done correctly. What matters most is catching it early and treating it fully.

Who should I call if I’m worried?

Call the surgeon who performed your operation. Don’t wait for your next scheduled appointment if you notice warning signs. If you can’t reach them or your symptoms are severe, go to the nearest emergency room.

Concerned About an Infection After Surgery?

If you’ve had spine or brain surgery and notice fever, chills, redness, swelling or drainage from your incision, or pain that is getting worse instead of better, call the surgeon who performed your operation right away. If you can’t reach them, or you have new weakness or numbness, confusion, a stiff neck with severe headache, or bladder or bowel changes, go to the nearest emergency room or call 911.

This page is for educational purposes only and is not a substitute for medical advice. If you have fever with severe back or neck pain, sudden weakness, numbness in the groin, or bladder or bowel changes, call 911 or go to the nearest emergency room.