Spondylodiscitis is a serious infection that affects the spine, specifically targeting the intervertebral discs and the adjacent vertebral bodies. It can lead to significant pain and potential complications if not addressed promptly.
What Spondylodiscitis Is
Spondylodiscitis involves an infection that primarily affects the intervertebral disc, the cushion-like structure between spinal bones, and then spreads to the neighboring vertebral bodies. This condition can be described as a combination of discitis, which is inflammation of the disc space, and spondylitis, which is inflammation of the vertebrae themselves. The infection can occur in any part of the spine, though it is often observed in the lumbar (lower back) or thoracic (mid-back) regions, and less commonly in the cervical (neck) area.
The infection can manifest as either an acute or chronic condition. While many cases are bacterial, caused by common microorganisms like Staphylococcus aureus, other pathogens such as fungi can also be responsible. In adults, the infection usually begins in the vertebral endplate before spreading to the disc, making isolated disc infection rare.
Causes and How It Develops
The infection in spondylodiscitis typically reaches the spine through several routes. The most common pathway is hematogenous spread, where bacteria travel through the bloodstream from an infection located elsewhere in the body. Common sources for this type of spread include urinary tract infections, skin infections, or infective endocarditis.
Another way the spine can become infected is through direct inoculation, which may occur after spinal surgery, injections into the spine, or trauma. Less frequently, the infection can spread from adjacent infected tissues in a process called contiguous spread. Staphylococcus aureus is the most frequently identified causative organism, with Escherichia coli and various Streptococcus species also being common. Risk factors for developing spondylodiscitis include weakened immune systems, intravenous drug use, diabetes, and recent spinal procedures.
Recognizing the Signs
Persistent back pain is a common symptom, and it often worsens with movement and may not be relieved by rest. This pain can be localized to the affected spinal segment and may radiate to the chest or abdomen if the thoracic vertebrae are involved. A general malaise and fatigue can also accompany the condition.
Fever and chills may be present, though fever can sometimes be absent. Weight loss can also occur. Neurological deficits, such as weakness, numbness, radiating pain in the arms or legs, or issues with bowel or bladder function, can develop and signal compression of the spinal cord or nerve roots.
Diagnosis and Treatment Options
The diagnostic process for spondylodiscitis involves a thorough evaluation, beginning with a physical examination to assess pain and spinal stability. Blood tests are routinely performed to check for signs of infection and inflammation, including elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), as well as a complete blood count. Blood cultures are also collected to identify the specific pathogen causing the infection.
Imaging studies are important for visualizing the spinal structures and the extent of the infection. Magnetic resonance imaging (MRI) is the primary imaging method for diagnosing spondylodiscitis, showing changes in the disc space, adjacent vertebral endplates, and surrounding soft tissues. X-rays may appear normal in the early stages, while CT scans can provide detailed views of bone destruction and assist in biopsy guidance or abscess drainage. A biopsy of the disc or vertebral tissue is often performed, typically guided by CT, to definitively identify the pathogen, which is important for tailoring antibiotic therapy.
Treatment for spondylodiscitis primarily involves long-term antibiotic therapy, often initiated intravenously before transitioning to oral medications. The duration of antibiotic treatment ranges from several weeks to several months, depending on the pathogen and patient response. Pain management is also an important part of treatment, along with activity modification and sometimes immobilization with a brace to stabilize the spine and reduce pain. Surgical intervention is considered for specific situations, such as when antibiotic therapy fails, in cases of significant neurological deficits, spinal instability, or the presence of abscesses. The goals of surgery include debridement (removing infected tissue), decompression of neural structures, and stabilization of the spine.
Recovery and Long-Term Outlook
The recovery process from spondylodiscitis can be prolonged, often requiring several months of treatment and rehabilitation. Adherence to the full course of antibiotic therapy is important for a successful outcome and to minimize the risk of recurrence. Regular follow-up appointments with healthcare providers are necessary to monitor progress and adjust treatment as needed.
Physical therapy plays a role in regaining strength, flexibility, and mobility in the spine after the infection has been controlled. While complete recovery is possible, some individuals may experience residual back pain, spinal deformity, or even persistent neurological issues, particularly if diagnosis or treatment was delayed. Early and accurate diagnosis improves the chances of a favorable long-term outcome and reduces the likelihood of complications.