Spondylodiscitis due to Stenotrophomonas maltophilia after endoscopic spine surgery: a case report

Spine surgery has changed dramatically in recent decades. Instead of large incisions that cut through thick layers of muscle, surgeons now use tiny tubes and cameras to reach the spine through small openings. This endoscopic approach causes less pain, less blood loss, and allows patients to walk again much sooner. Because the technique is so gentle, complications are rare. However, when an infection does take hold inside the spine, it can be a silent and destructive force. The spine is made of bones and discs that cushion them, and when bacteria invade this space, they can eat away at the bone, causing it to crumble and the spine to become unstable. The most common germs that cause these infections are well-known, but some bacteria are harder to catch and harder to kill. One such germ is Stenotrophomonas maltophilia, a tough, multi-drug-resistant bacterium that usually lives in water and on medical equipment but almost never causes spine infections.

This story follows a 54-year-old woman who underwent a routine endoscopic procedure to remove a slipped disc in her lower back. The surgery went smoothly, and for the first two days, she felt better than she had in months. But on the third day, a dull ache returned to her lower back. It was not the sharp, shooting pain of a nerve being pinched, but a deep, mechanical soreness that grew worse when she moved. She had no fever, and her blood tests showed no signs of a raging infection. Because she felt so well otherwise, the pain was initially dismissed as a normal part of healing. Over the next few weeks, the pain worsened, and doctors finally saw the truth on a magnetic resonance image: the bone and disc at the site of the surgery were inflamed and beginning to break down.

The medical team faced a difficult puzzle. The patient had tested positive for a blood marker often associated with tuberculosis, a serious bacterial infection that is common in her region. Without taking a tissue sample to confirm the diagnosis, the doctors started her on a standard regimen of four drugs used to treat tuberculosis. Two weeks later, she was in more pain, not less. The infection was not responding. They switched to powerful, broad-spectrum antibiotics meant to kill almost any common bacteria, but again, there was no improvement. By the time she had been in pain for nearly three months, scans showed that half of the bottom edge of her fourth lumbar vertebra had been eaten away by the infection. The bone was so weakened that her spine was at risk of collapsing.

The only way forward was to go back into the spine. Surgeons performed a second operation, this time from the back, to remove the infected tissue and stabilize the spine with metal rods and screws. Crucially, they took samples of the fluid and tissue inside the disc to identify the exact germ causing the trouble. When the lab results came back, they revealed a surprise. The patient did not have tuberculosis. The infection was caused by Stenotrophomonas maltophilia, a bacterium that is naturally resistant to many common antibiotics, including the powerful carbapenems she had received earlier. The lab found that this specific strain could be killed by a combination of two different antibiotics: levofloxacin and a drug called trimethoprim-sulfamethoxazole.

Once the correct medication was started, the patient's recovery was swift. She was able to sit up and walk within three days of the second surgery. She took the new combination of antibiotics for six weeks, switching from intravenous infusions to pills once she was stable. Over the next year and a half, her pain disappeared completely. The inflammation in her spine settled, and the bone stopped breaking down. The metal rods that held her spine together were eventually removed, and she returned to her normal life with a stable, pain-free back.

This case is significant because it is the first time this specific bacterium has been found to cause a spine infection after an endoscopic procedure. It highlights a dangerous trap in modern medicine: when a patient feels well enough to walk and has no fever, doctors might assume an infection is not present or is something common. In this case, the lack of fever and normal blood counts masked a deep, destructive infection. The patient's initial treatment failed because the doctors treated for a disease they suspected based on a blood test, rather than waiting to identify the actual germ with a tissue sample. The infection likely entered through the water used to rinse the surgical tools or the instruments themselves, as this bacterium is known to thrive in hospital water systems.

The lesson for surgeons and patients is clear. If a patient feels a new, deep ache in their back shortly after a minimally invasive spine surgery, it should be treated as a warning sign, even if they have no fever. The most important step is to take a sample of the infected tissue before starting any new antibiotics, so the treatment can be targeted exactly at the germ that is causing the problem. Without that step, powerful drugs may be wasted on the wrong enemy while the infection silently destroys the bone. This case shows that even in the most advanced, gentle surgeries, the body can harbor a tough, hidden enemy that requires a very specific key to unlock the cure.