Spinal osteomyelitis is an infection of the bones of the spine. It usually starts in or next to a disc and spreads to the neighbouring vertebrae, which is why it is also called spondylodiscitis. Bacteria most often reach the spine through the bloodstream from an infection elsewhere in the body.
At a glance
- Staphylococcus aureus is the most common cause.
- Typical symptom: severe, constant back pain that is worse at night, often with fever, although fever is absent in about half of patients.
- Diagnosis is often delayed because back pain is so common, so blood tests and MRI are key.
- Most patients are cured with about 6 weeks of targeted antibiotics. Surgery is needed for abscesses, nerve compression, instability or failed treatment.
Symptoms
- Gradually worsening, constant back or neck pain that is not relieved by rest and is often worse at night.
- Fever, sweats, chills or feeling generally unwell.
- Weight loss and loss of appetite.
- Tenderness over the spine and difficulty moving.
- Leg or arm weakness, numbness, or bladder or bowel problems if an abscess compresses the spinal cord or nerves. This is an emergency.
Risk factors
- Diabetes.
- Recent infection elsewhere, such as skin, urinary tract, dental or heart valve infection (endocarditis).
- Intravenous drug use.
- Immune suppression: HIV, chemotherapy, steroids or organ transplant.
- Kidney failure and dialysis.
- Recent spinal surgery or injection.
- Older age.
How is it diagnosed?
- Blood tests: raised white cell count and inflammatory markers (CRP and ESR). Blood cultures are taken before antibiotics whenever possible.
- MRI with contrast is the most sensitive scan and shows the infected disc, the bone involvement and any abscess.
- Biopsy: if blood cultures do not identify the organism, a CT-guided needle biopsy or an endoscopic biopsy identifies the bacteria so that the right antibiotic can be chosen. Tuberculosis must always be considered, particularly in South Africa.
- An echocardiogram may be needed to check for heart valve infection.
Non-surgical treatment
- Targeted antibiotics: usually started intravenously and then changed to tablets, for a total of about 6 weeks in most cases, guided by the organism and the response in blood tests.
- Rest and bracing: a brace can relieve pain and support the spine during healing.
- Treatment of underlying conditions, such as diabetes control and nutrition.
- Regular monitoring with blood tests and clinical review, and repeat MRI if the response is not as expected.
What the evidence says: How long should antibiotics be given?
A French randomised trial (Bernard and colleagues, Lancet 2015) of 359 patients with bacterial spondylodiscitis found that 6 weeks of antibiotic treatment was as effective as 12 weeks, with similar cure rates at one year. Longer courses may still be needed for abscesses that are not drained, implant-related infection or certain organisms.
Surgical options
Surgery is needed in a minority of patients, for:
- spinal cord or nerve compression from an abscess, especially with neurological deficit;
- spinal instability or progressive deformity from bone destruction;
- infection that does not respond to antibiotics;
- the need to obtain tissue when a biopsy has not given an answer.
Example: infection of the L3/4 disc
This L3/4 spondylodiscitis followed a previous procedure (iatrogenic infection). It was managed with posterior debridement, removing the infected disc and bone, and instrumented fusion.
Endoscopic and minimally invasive debridement
Using an endoscope through small incisions, the infected disc can be washed out and removed, and samples taken for culture. This approach is useful in selected patients without major bone destruction or instability.
Open decompression and debridement
Pus and infected tissue are removed to relieve pressure on the spinal cord or nerves.
Stabilisation and fusion
Where bone destruction has made the spine unstable, the infected tissue is removed and the spine is stabilised with screws, rods and sometimes a cage or bone graft. Modern evidence shows that titanium implants can safely be used in the presence of active infection when combined with thorough debridement and antibiotics. Minimally invasive percutaneous screws are increasingly used.
Outlook
With early diagnosis and treatment, most patients recover well. Pain can take weeks to months to settle, and the infected segment often fuses naturally as it heals. Delayed diagnosis increases the risk of permanent nerve damage, which is why persistent, severe back pain with fever or risk factors should always be investigated.
Talk to Prof Kruger
If you are living with this condition and would like an opinion on your options, you are welcome to book a consultation. Please bring any recent scans and reports.
References and key studies
- Bernard L, et al. Antibiotic treatment for 6 weeks versus 12 weeks in patients with pyogenic vertebral osteomyelitis: an open-label, non-inferiority, randomised, controlled trial. Lancet. 2015;385(9971):875–882.
- Berbari EF, et al. 2015 Infectious Diseases Society of America (IDSA) clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults. Clin Infect Dis. 2015;61(6):e26–e46.
- Zimmerli W. Vertebral osteomyelitis. N Engl J Med. 2010;362(11):1022–1029.
This page is general patient education based on published research and is not a substitute for a personal consultation. Treatment is always tailored to the individual.