Indications and contraindications
Percutaneous augmentation is indicated for patients with severe localized back pain strictly along the midline (without radiation). Pain typically worsens with axial load or palpation of the spinous processes. The procedure is prescribed when standard conservative therapy fails to provide relief.
It is important to remember the strict contraindications:
- Spinal cord compression with neurological deficit. In this case, puncture cement injection is strictly prohibited—open surgical decompression and fixation are required.
- Bone sclerosis, indicating successful natural fracture healing.
- Absence of a hyperintense signal on MRI in STIR mode (no active bone marrow edema).
Pre-procedure diagnostic imaging
Preoperative planning is based on radiography, contrast-enhanced CT, and MRI data. The main goal of imaging is to determine the exact level and chronicity of the fracture, assess the degree of destruction (osteolysis), the integrity of the posterior vertebral wall, and rule out the spread of tumor masses into the spinal canal.
MRI semiotics:
- Acute and unhealed fractures show a hypointense signal on T1-weighted images and a hyperintense signal on T2-weighted images.
- The STIR mode (fat suppression) has maximum sensitivity to bone marrow edema, accurately identifying metabolically active foci.
- Hemangiomas typically show high signal on T1 and T2, whereas aggressive (symptomatic) forms are characterized by low signal on T1.
Bone scintigraphy (Bone scan) is used to locate the symptomatic level in multiple adjacent lesions or to diagnose occult pelvic bone stress fractures.
Approaches and technique
The intervention requires strict asepsis, local anesthesia combined with sedation. General anesthesia is rarely used—mainly for kyphoplasty due to the use of larger-diameter instruments.
The patient is placed in the prone position (prone). For the thoracic and lumbar spine, the gold standard is the transpedicular approach (insertion of a 10–15 G puncture needle through the vertebral pedicle). In the cervical spine, an anterolateral approach is used in the supine position, while the neurovascular bundle is manually displaced.
A critically important point during pedicle puncture: it is strictly forbidden to cross its medial and lower borders, otherwise there is a high risk of falling into the spinal canal or intervertebral foramen. All manipulations are performed under continuous high-quality fluoroscopic guidance in the lateral projection. A mandatory condition for safety is preserving at least 1/3 of the height of the fractured vertebra.
Kyphoplasty and osteoplasty
Kyphoplasty is a modification of classical vertebroplasty. The main difference is the use of an inflatable balloon tamp (balloon tamp). The balloon mechanically separates the bone trabeculae, creating a cavity within the vertebral body into which cement is then injected. This not only strengthens the bone but also restores vertebral height (on average by 3–5 mm in the center). Furthermore, a bipedicular approach (insertion of two needles from both sides) is mandatory for this procedure.
Osteoplasty is a conceptually similar technique used for bones subjected primarily to compressive loading (compressive stress). This includes the consolidation of painful fractures of the sacrum, acetabulum, pubic rami, and ischial tuberosities arising against the background of osteolysis or bone insufficiency.
Cement selection: properties and types
Pain relief is achieved through mechanical consolidation of the cancellous bone and the cytotoxic effect during material polymerization. Polymethyl methacrylate (PMMA / PMMA) is traditionally used. It is injected in the pasty phase to reduce the risk of leakage.
| Characteristic | Polymethyl methacrylate (PMMA) | Calcium phosphate cements (CPC) | Composite resins |
|---|---|---|---|
| Reaction properties | Exothermic (heating up to 80–120°C) | Delayed at room temperature | Rapid at low temperature (<58°C) |
| Tissue interaction | Encapsulated by fibrous tissue | Bioresorbable (stimulates bone growth) | Mineralization of surrounding bone |
| Main indications | Osteoporosis, bone metastases | Fresh burst fractures | Early-onset osteoporosis |
Complications and clinical efficacy
The most common complication is cement leakage. Although it is often asymptomatic, the ingress of masses into the epidural space leads to spinal cord compression and requires emergency neurosurgical care. Cement breakthrough into the paravertebral venous plexus can lead to fatal pulmonary cement embolism.
Despite surgical risks, the procedure demonstrates high efficacy: it relieves pain in 90% of patients with osteoporotic fractures, 80% with symptomatic hemangiomas, and 70% with metastases. About a quarter of patients develop new compression fractures in the future, with half of them forming at levels adjacent to the stabilized one.
Briefly: answers to topical questions
What are the absolute contraindications for percutaneous vertebroplasty?
Contraindications to percutaneous vertebral augmentation include:
- bone sclerosis;
- absence of a hyperintense signal on MRI STIR images;
- spinal cord compression with neurological deficit requiring open surgical decompression and posterior spinal stabilization.
The only biomechanical contraindication to vertebroplasty is extensive tumor involvement of the posterior elements of the vertebra.
What anatomical structures are part of the neurovascular bundle displaced during the anterolateral approach to the cervical vertebrae?
During the anterolateral approach to the cervical vertebrae, the neurovascular bundle, which includes the carotid artery and jugular vein, is manually displaced laterally.
Class and exam questions
Why is vertebroplasty contraindicated in spinal cord compression?
When the spinal cord is compressed by bone fragments or tumor masses, high-pressure cement injection can exacerbate compression. In such cases, open surgical decompression is indicated.
What is the effect of high temperature during PMMA hardening?
Heating up to 120°C provides useful local thermocoagulation of metastases and nerve endings (reducing pain), but in the event of cement leakage, it creates a risk of direct thermal injury to nerve roots and the spinal cord.
In which phase should PMMA be injected?
Injection should be performed when the cement has reached a thick, pasty phase. This minimizes the risk of uncontrolled leakage (extravasation) into blood vessels and the spinal canal.
What else to study on this topic
- Osteoplasty of the pelvic bones and sacrum: indications and technique
- Treatment of aggressive vertebral hemangiomas
- Features of the bipedicular approach
- Bioresorbable calcium phosphate cements (CPC)
- MRI semiotics of spinal stress fractures
Master the entire topic in the "Diagnostic Radiology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Percutaneous vertebroplasty and kyphoplasty" and 2,199 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 10 video lessons on the subject
Other topics in the "Interventional radiology" section
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.