Spondylodiscitis

In one minute

Spondylodiscitis is an infection of a disc and the vertebrae on either side of it, also called vertebral osteomyelitis or discitis. It mostly affects people over 50, people with diabetes, kidney failure or a weak immune system, and people who have recently had an infection elsewhere or a spinal procedure. It feels like constant back or neck pain that does not ease with rest and often wakes you at night, sometimes with fever, sweats or weight loss. MRI (magnetic resonance imaging) shows it; blood cultures or a needle biopsy identify the organism. Most cases are cured with weeks to months of antibiotics, and in this region tuberculosis and brucellosis of the spine must always be considered. Surgery is for nerve pressure, an unstable spine, or infection that antibiotics cannot control.

What it is

The disc has no blood supply of its own in adults, but the bony endplates next to it do. Bacteria travelling in the blood from another site lodge in the endplate, cross into the disc and spread to the neighbouring vertebra. The infection can then form an abscess in front of the spine, in the psoas muscle, or in the epidural space behind the vertebra, where it presses on the spinal cord or nerve roots.

The Infectious Diseases Society of America (IDSA) guideline gives the scale: about 2.4 cases per 100,000 people a year, rising to 6.5 per 100,000 between ages 50 and 70. Staphylococcus aureus, a common skin bacterium, is the leading cause. Two other organisms matter in Central Asia. Tuberculosis of the spine, also called Pott disease, is the most common form of tuberculosis in bone and accounts for about 1 to 2% of all tuberculosis cases. Brucellosis, caught from unpasteurised milk and cheese or from contact with sheep, goats and cattle, involves the spine in between 2 and 60% of cases in published series.

Causes and risk factors

The IDSA guideline names the settings in which spondylodiscitis should be suspected: new or worsening back or neck pain with fever, with raised inflammation markers in the blood, or with a known bloodstream infection or infected heart valve. The people at risk are older adults, people with diabetes, kidney or liver disease, cancer or long-term steroid treatment, people who inject drugs, people with a recent urinary, skin or dental infection or an intravenous line, and people who have had spinal surgery or an injection near the spine.

Tuberculosis reaches the spine from a lung or lymph node focus, often years later. Uzbekistan is on the World Health Organization (WHO) list of the 30 countries with the highest burden of multidrug-resistant tuberculosis for 2021 to 2025, which makes drug resistance a practical question here. Brucella spondylitis is a disease of farming families and of anyone who drinks raw milk; it is most common in men between 50 and 60 and most often affects the lumbar spine.

How it develops

Bacterial infection destroys the disc and the adjacent endplates within weeks, so the disc space narrows and the vertebrae erode toward each other. Tuberculosis behaves differently: it spreads under the ligaments along the front of the spine, destroys the vertebral bodies slowly, tends to spare the disc until late, and produces large cold abscesses and, when the front of several vertebrae collapse, a sharp forward angulation called a gibbus. Brucellosis is the least destructive of the three and often looks like ordinary wear on X-ray until an MRI is done.

Pain comes from the inflamed bone and from instability as the bone gives way. Neurological damage comes from an abscess or collapsed bone pressing on the cord or nerve roots, and it is the complication that turns a medical illness into a surgical one.

Symptoms

The typical story is back or neck pain that has been building for weeks, is constant rather than positional, is worse at night, and is not explained by an injury. Fever is present in fewer than half of bacterial cases in the IDSA data, so its absence does not rule the diagnosis out. Tuberculosis is slower still: in the StatPearls review, chronic local back pain is often the only symptom, general symptoms such as weight loss and sweats appear in only 20 to 30%, and a visible hump is a late sign. Brucellosis adds fevers, joint pains, fatigue and sweats that come and go.

Because the pain is so easily blamed on a disc, diagnosis is often late. The IDSA guideline cites an average delay of two to four months and a series in which 34% of patients were first given the wrong diagnosis. Persistent pain with raised inflammation markers should always raise the question.

Diagnosis

The examination looks for tenderness over the spine, restricted movement, a hump, and the strength, sensation and reflexes of the limbs. The IDSA guideline recommends two sets of blood cultures and the inflammation markers ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) in everyone with suspected spondylodiscitis; blood cultures identify the organism in up to half of the cases caused by Staphylococcus aureus.

MRI is the standard imaging test, with a sensitivity of 97% and a specificity of 93% in the IDSA review. It shows fluid signal in the disc and bone, endplate erosion, and any abscess in front of the spine, in the psoas muscle or in the epidural space. Words in the report: endplate destruction, disc space narrowing, paravertebral or epidural collection, and, for tuberculosis, subligamentous spread and vertebral collapse. CT (computed tomography) helps plan a biopsy and shows bone destruction. Because tuberculosis and brucellosis are both common here, the IDSA advice for endemic areas applies: Brucella antibody tests alongside the blood cultures, and tuberculosis and Brucella cultures on any biopsy.

When blood cultures are negative, the guideline recommends an image-guided needle biopsy of the disc or bone before antibiotics are started, so that the sample can be cultured, tested for tuberculosis by microscopy, culture and molecular tests, and examined under the microscope. Tuberculosis cultures are slow and often negative, which is why tissue for histology matters. For our opinion, send the MRI images, the written report, your blood results and any tuberculosis or Brucella test results.

Treatment without surgery

Antibiotics are the treatment, and most patients need nothing else. The IDSA guideline makes two points that patients often find surprising. First, in a stable patient without neurological symptoms, antibiotics should be held until the organism is known, because starting them blind makes cultures negative and can commit someone to months of guessed treatment. Second, once the organism is known, most bacterial infections need six weeks of intravenous or highly absorbable oral antibiotics, and brucellosis needs three months of combination therapy. Antibiotics are started at once in sepsis or a neurological deficit.

Tuberculosis of the spine is treated with the same combination drugs as lung tuberculosis. The WHO scheme is two months of four drugs followed by four months of two, six months in all, but the WHO guideline excludes bone and joint tuberculosis from that six-month recommendation because some expert groups suggest longer therapy. The StatPearls review cites a trial in which six months performed as well as courses of nine to eighteen months, and a 2018 review quotes an older WHO recommendation of nine months, so the honest summary is six months or longer. Drug-resistant tuberculosis needs a different, longer regimen chosen from the sensitivity results. All of this is run with the tuberculosis service, not by a spine surgeon alone.

Pain control, a short rest followed by mobilisation, and a brace for comfort complete the medical treatment. The guideline recommends rechecking ESR and CRP after about four weeks and advises against routine repeat MRI in patients who are improving, because the pictures lag behind the patient.

When surgery is considered

The IDSA indications for surgery are a progressive neurological deficit, progressive deformity or spinal instability despite antibiotics, infection that persists in the blood without another source, and worsening pain despite correct treatment. An epidural abscess with neurological signs is an emergency. For tuberculosis there is no guideline-level list. Two reviews, StatPearls and a 2018 Global Spine Journal review, give neurological deficit, instability, incapacitating deformity or pain, large abscesses, and failure to respond to or recurrence after drug treatment, and StatPearls notes that the decision to operate is not standardised.

Timing follows the nerves. A deficit that is worsening is decompressed urgently, because recovery depends on how long the cord has been compressed. Instability and deformity can be planned. Pain alone is a reason for surgery only when the antibiotics have been correct and the pain is still worsening, because an infected spine that is being cured usually stops hurting on its own.

Surgical options

Image-guided needle biopsy and drainage is the smallest procedure: a needle under CT guidance takes tissue for diagnosis and can drain an abscess. Percutaneous and endoscopic drainage and debridement, in which the infected disc is cleaned out through a small channel, have been reported in small series; the brucellosis review notes that Brucella spondylitis is less destructive than pyogenic or tuberculous infection and prefers minimally invasive procedures when surgery is needed at all.

Open debridement and decompression removes infected bone and abscess and frees the cord or nerve roots, from the front, the back or both, depending on where the destruction is. Stabilisation with screws and a cage or bone graft is added when bone has been destroyed or the spine has collapsed; the fear that metal implants would keep the infection alive has not been borne out: the brucellosis review states that instrumentation in the presence of infection is safe and does not compromise clearing the organism. See the spinal fusion page.

How we treat it at spine.uz

Spondylodiscitis is not treated by a surgeon alone, and not every case is a surgical case. We work with infectious disease specialists, microbiologists and the tuberculosis service; the surgeon's role is diagnosis when a biopsy is needed and surgery when the spine is unstable or the nerves are threatened. Most patients are cured by their antibiotics and never need an operation.

We are Tashkent's first endoscopic spine team, five surgeons operating as one, and the team treats the full range of surgical spine pathology, including the debridement, decompression and stabilisation that infection sometimes needs. Not every case suits the endoscope: a collapsed, unstable spine needs open surgery and fixation, and we will say so. For an opinion on whether your MRI shows an infection and what the next step should be, send the images through Telegram or WhatsApp and a doctor from the team replies by voice within 48 hours. The in-person consultation and any operation are paid, and after the consultation you receive a written conclusion from the team. Across the team's 27,600+ endoscopic and spine operations, our complication rate is well below 1%.

Recovery and outcomes

With the right antibiotic, pain begins to settle within weeks and inflammation markers fall; the guideline uses the four-week ESR and CRP check as the sign that treatment is working. Bone heals over months, and the infected disc space often fuses on its own, which leaves the segment stiff but stable. Some residual back pain and some loss of height at the level are common.

Neurological outcome depends on how much deficit there was and for how long. In the StatPearls review of spinal tuberculosis, weakness or paralysis was present at diagnosis in 20 to 75% of patients across series; much of it recovers with treatment and, where needed, decompression, but late presentations recover less. Brucella spondylitis usually responds to combination antibiotics: the IDSA guideline recommends three months, the brucellosis review reports three to six months and often longer in practice, and surgery was needed in 3 to 29% of patients in the review series. Relapse is more likely when treatment is stopped early, which is why the full course matters more than any operation.

Living with it and prevention

Finish every course of antibiotics and attend every tuberculosis follow-up. Boil or pasteurise milk and do not eat fresh cheese made from raw milk. Control diabetes, stop smoking and treat skin, urinary and dental infections promptly. After the infection has healed, ordinary activity and exercise are safe; a spine that has fused itself is a stable spine.