Infections of the spine are uncommon but can lead to serious complications like paralysis or instability of the spine if untreated. They are more common in patients with other health problems like diabetes, HIV AIDS, alcoholism, drug abuse or other disease which compromise the immune system (kidney failure). Tuberculosis of the spine is a special type of infection which is increasing in numbers in the UK. Spinal infections can also be caused by any spinal operation or injection. Thankfully, the risks in routine operations is low (2-4%). These usually occur within the first 2-3 weeks after surgery.
In patients with a spinal infection three important questions need to be answered:
Which organism is causing the infection?
In principle, any bacterial infection can be treated with antibiotics. Therefore, it is essential to identify the organism, which is causing it as soon as possible. At the same time, the microbiology lab will be able to test antibiotics and say whether the organism is sensitive or resistant.
Where exactly is the infection?
It is important to know where in the spine the infection has started and has spread to. This has an influence on how long antibiotics are given.
Discitis is an infection of the intervertebral disc. It usually starts at the junction of the vertebral body and disc (so-called endplates) and spreads into the disc. The intervertebral disc has a very poor blood supply. This means that blood cells which form part of the body’s defence system, cannot fight the infection.
An epidural abscess forms if the infection is in the space between the bony parts of the vertebral column and dural sac (see ‘The Spine&Spinal conditions’ -Normal Structure of the Spine’). This is a continuous space from the head to the sacrum (base of the spine). Infections can spread quickly along a number of levels if left untreated.
Osteomyelitis means an infection of the bone. In the spine this occurs in the vertebral body. This can lead to the collapse of the vertebral body.
What damage has been done by the infection?
The infection can destroy the bones or ligaments. This can have an effect on the stability of the spine. It can also cause pressure on the nerves or spinal cord leading to numbness or paralysis. This information will have an important influence on the decision whether surgery is indicated or not.
Patients with spinal infections typically have severe pain in a localised area of the spine, which develops over a short time (days). The pain may radiate down the arm or leg if it effects nerve roots (radiculopathy). Most patients will also have fever and may feels generally unwell. If untreated, the infection will spread and cause pressure on nerves or the spinal cord. This can lead to myelopathy or cauda equina syndrome.
In tuberculosis (TB) of the spine, symptoms often develop slower over weeks and sometimes months. Because of the slower progression, some patients are misdiagnosed by their doctors with musculoskeletal neck or back pain. However, many patients will show other typical signs of tuberculosis like night sweats and unexplained weight loss.
If untreated spinal infections can lead to permanent paralysis and spinal instability or collapse of the vertebral body. A systemic infection, which may have caused the spinal infection or can be the result of it (uncommon) can affect other organs and is life threatening in extreme cases.