Diskitis

Diskitis is an infection. It happens in the vertebral disk space. The vertebral disk is a soft cartilage cushion. It lies between the bones of the spine (vertebrae). The soft, inner portion of the disk (nucleus pulposus) can become infected following surgery on the spine. The infection may spread from the inner portion of the disk to the tougher outer portion (annulus fibrosis) and into the vertebral bone. The condition is uncommon. It tends to occur more often in children than in adults.

People at higher risk of developing diskitis include:

  • Elderly patients.

  • People with poor immune systems.

  • People with diabetes.

  • Patients on chemotherapy.

  • Anyone with immune system disorders.

The infection may be mild and may get better without any treatment. More severe cases can result in the formation of a fluid-filled mass (abscess). These cases may require surgery.

CAUSES

  • The exact cause of postsurgical diskitis is not agreed upon.

  • Some specialists believe it may come from getting an infection such as Staphylococcus aureus in the disk space.

  • Others believe that it may be caused by an inflammation of the area operated on.

  • Whatever the cause, once the process begins, it may lead to destruction of the disk. The disk tissue has a poor blood supply. So it has a difficult time fighting infection. When the infection spreads into the vertebrae, the body's ability to fight the infection is better due to the better blood supply.

SYMPTOMS

  • Diskitis following surgery is often not quickly diagnosed. The main symptoms are back pain or spasms. These same problems are common after a spine procedure.

  • The pain of diskitis does not begin right away following the procedure. It appears and gradually worsens within the first 1 to 4 weeks after the procedure.

  • The pain can be moderate to severe. It is worse with movement of the back.

  • The pain can also radiate:

  • From the lower back down to the buttocks and the legs.

  • Into the abdomen and groin.

  • Also making it harder to diagnose, it is unlike other infections. In diskitis after a surgical procedure, the traditional warning signs may not happen. These include:

  • Fever.

  • Chills.

  • Loss of appetite.

DIAGNOSIS

  • Your caregiver may use a number of blood tests to diagnose this. It is sometimes a difficult diagnosis. A number of the blood tests are affected by surgery even when there is no infection.

  • Your surgeon may suggest a needle aspiration or open biopsies as a better diagnostic test. During a needle aspiration, the doctor uses a syringe to remove some of the fluid in the disk. This can then be tested to determine the exact germ causing the infection.

  • An open biopsy is a surgical procedure in which a small portion of the infected disk is removed for study. The advantage to these procedures is that if the exact organism causing the infection is detected, the most effective course of antibiotics can be chosen.

  • Diagnostic imaging such as magnetic resonance imaging (MRI) and computed tomography (CT) scans are useful in diagnosing postsurgical diskitis. MRI is the most highly recommended. Its sensitivity can detect changes in the disk consistent with infection as early as 5 days after the procedure.

TREATMENT

  • Once the diagnosis is made, your surgeon may prescribe antibiotic medicines, immobilization of the spine, or surgery, depending upon how bad the infection is.

  • The usual treatment of antibiotics involves 6 weeks of intravenous (IV) administration. This is followed by an additional 6 weeks of oral antibiotics.

  • Some caregivers advise restricting the movement of the spine in addition to antibiotics. Whether this aids in curing the infection is not certain. It does help with the pain. It may allow you to return to your daily activities more quickly.

  • Surgical treatment is used where there is an abscess, spinal instability or weakness, or tumor involvement. It may also be used in cases where bowel or bladder functions are involved. The surgeon cleans out (debrides) the infected disk space. Debridement can be performed through an open or minimally invasive technique.

  • Once the infected disk material is removed, your surgeon may wish to perform a fusion. This is a procedure in which the vertebrae on each side of the infected disk are joined together (fused). This is to eliminate movement between them.

  • Prognosis following treatment for post-procedural diskitis is good. Most patients are pain-free after the infection is resolved.

PREVENTION

Some surgeons think prophylactic antibiotics may prevent diskitis following surgery. These are antibiotics that are taken before the surgery. Other surgeons believe that it is not good to take antibiotics before an infection develops.

As with all medical procedures, it is important to know and discuss all the risks and benefits of spinal procedures with your physician before you undergo them.