bubble_chart Overview

Pyogenic spondylitis is not uncommon, but only about 50% of cases present with acute onset, while half of the patients experience a subacute or chronic course. Due to varying clinical manifestations, different affected sites, and diverse symptoms and signs, it is often misdiagnosed or mistaken for fistula disease. Common causative bacteria include Staphylococcus aureus, Staphylococcus albus, Streptococcus, and Pseudomonas aeruginosa. The infection is most frequently hematogenous in origin. Other routes include spinal surgery, lumbar puncture, or local open injuries that directly introduce infection to the spine. A minority of cases result from the spread of adjacent infections, such as abscesses or bedsores. The condition predominantly affects young adults aged 20 to 40, with males being about four times more likely to be affected than females.

bubble_chart Pathological Changes

The most common site of infection is the lumbar spine, followed by the thoracic and cervical vertebrae. The disease initially invades the center of the vertebral body, where red marrow is concentrated, and then spreads to the intervertebral disc or vertebral arch. It rarely first affects the vertebral arch. Due to the rich blood supply of the vertebrae, large sequestra are seldom formed. In typical cases, the initial changes involve bone destruction and resorption, resulting in a mottled or moth-eaten appearance of osteoporosis. Once the cartilage plate or cortex is destroyed, a paravertebral abscess forms, which can spread along soft tissue spaces and rupture through the skin, forming a sinus. Since pyogenic spondylitis involves simultaneous bone destruction and new bone formation, as the disease progresses, bone gradually proliferates, bone density increases, and sclerosis occurs. Therefore, vertebral collapse, wedging, or kyphotic deformity are rare in pyogenic spondylitis. In advanced stages, extensive new bone formation, bony bridging, or intervertebral fusion may occur.

bubble_chart Clinical Manifestations

Pyogenic spondylitis, characterized by systemic toxic symptoms such as persistent high fever, shivering, rapid pulse, dysphoria, and confusion, along with local severe pain, paravertebral muscle spasms, limited spinal movement, spinous process tenderness, and obvious percussion pain, accounts for only about 20% of typical courses and clinical manifestations. Most cases primarily present with clinical manifestations such as acute abdominal pain, radicular pain, hip arthralgia, or severe sepsis. Only after systemic symptoms improve do local symptoms and signs become more apparent. Some cases even begin with subacute or chronic manifestations and are misdiagnosed as subcutaneous nodules.

bubble_chart Auxiliary Examination

Laboratory tests: In the early stage, leukocyte count is elevated with a notable left shift, erythrocyte sedimentation rate (ESR) is increased, and blood culture may be positive. Under CT guidance, perform local puncture aspiration and biopsy. Smear and bacterial culture should be conducted on the aspirated pus, and pathological examination should be performed on the obtained tissue to establish a direct diagnosis.

Isotope scanning: In the early stage of acute pyogenic spondylitis, isotope concentration may be observed in the affected vertebra. Although isotope scanning is a non-specific examination, it can assist in locating the lesion and determining the affected area.

X-ray and CT examination: Within the first two weeks of onset, conventional X-ray films may show no abnormalities. Tomography or CT scanning may occasionally reveal localized bone resorption or spotty bone destruction. As the disease progresses, destruction of the cartilage plate may occur, with vertebral edges appearing blurred and brush-like. Subsequently, paravertebral soft tissue swelling, narrowing of the intervertebral space, increased bone density, bone sclerosis, and bone bridge formation may be observed. When early imaging cannot provide a definitive diagnosis, diagnostic puncture under CT guidance should be performed promptly.

bubble_chart Treatment Measures

The early diagnosis of acute suppurative spondylitis is often challenging and can easily be confused with sepsis or purulent infections of the lumbar soft tissues. For any suspected case of suppurative spondylitis, treatment should be initiated as early as possible while further examinations are conducted to avoid delaying effective treatment.

1. Antibiotic Therapy When acute suppurative spondylitis is confirmed or suspected, broad-spectrum antibiotics should be administered promptly. Adjustments should be made based on bacterial culture results and sensitivity tests. If the bacterial culture is negative and no significant improvement is observed after three days of treatment, the antibiotics should be changed. The course of treatment should continue until the body temperature normalizes and systemic symptoms disappear, followed by approximately two additional weeks. Stopping antibiotics too early may lead to recurrence of inflammation or progression of local lesions into chronic inflammation.

2. Systemic Supportive Therapy While high-dose effective antibiotics are administered early, patients should strictly adhere to bed rest and receive enhanced nutrition, including a high-protein, high-vitamin diet. Intravenous fluids may be given to correct dehydration and prevent or maintain electrolyte balance. If necessary, small, frequent blood transfusions may be administered, along with appropriate sedatives, analgesics, or antipyretics. For patients with severe toxic symptoms or critical conditions, hormone therapy should be combined.

3. Surgical Treatment

(1) Paravertebral Abscess Drainage For suppurative spondylitis, if pus is aspirated via paravertebral puncture or CT scans reveal a paravertebral abscess, timely incision and drainage of the abscess should be performed to control disease progression and alleviate systemic toxic symptoms.

(2) Laminectomy and Epidural Abscess Drainage For acute suppurative spondylitis, once symptoms of spinal cord compression appear—such as lower limb weakness, sensory changes, or urinary retention—an emergency CT scan should be performed. If an epidural abscess compressing the spinal cord is detected, immediate laminectomy and epidural abscess drainage should be performed to prevent worsening paralysis, spinal cord vascular embolism, softening, or necrosis. Postoperatively, tube drainage with negative pressure or irrigation-suction therapy is often maintained until body temperature normalizes, symptoms improve, and drainage fluid clears before removal.

(3) Sinus Excision and Lesion Debridement For chronic suppurative spondylitis with persistent sinus formation unresponsive to conservative treatment, different surgical approaches should be adopted based on the lesion location. First, the sinus and surrounding scar tissue are excised, followed by exposure of the lesion, enlargement of the bone fistula, removal of sclerotic bone, and thorough debridement of pus, sequestra, granulation tissue, necrotic tissue, and fibrous membranes. After complete debridement, the lesion is repeatedly irrigated with saline. A drainage tube may be placed within the lesion for closed irrigation-suction therapy. Postoperative antibiotic therapy should be continued.