VERTEBROPLASTY

Vertebroplasty – a surgical procedure performed to reinforce the damaged body of your vertebra by injecting bone cement—a special plastic material. In most cases, this surgery is performed for uncomplicated vertebral compression fractures without compression of nerve structures. This type of fracture is most commonly seen in osteoporosis, hemangioma, traumatic back injury, vertebral metastases, and other spinal tumors.

Bone cement is injected into the vertebral body using a special needle, and the manipulation is controlled by x-rays. Recently, surgical methods based on the use of bone cement (polymethylmethacrylate) are increasingly being used in various pathologies affecting the spine.

Originally, in 1984, the percutaneous vertebroplasty technique was proposed to treat aggressive vertebral hemangiomas. Currently, this method is a minimally invasive approach to surgically treat primary and metastatic tumors with an existing threat of pathological fracture. In addition, this method is widely used for osteoporosis and vertebral compression fractures associated with this pathology.

The core of the method is that the surgeon inserts a metal needle (under CT and fluoroscopic control) into the body of the damaged vertebra, through which a special mixture is injected. The mixture contains bone cement based on polymethylmethacrylate, a contrast agent, and antibiotics. The insertion of the specified needle into the vertebral body is transpedicular in lumbar and thoracic pathology, whereas cervical level pathologies use an anterolateral approach.

The solidification rate of polymethylmethacrylate and the duration of its paste-like state are the most important properties of bone cement—because during this period (6-11 minutes), the surgeon must inject the substance and fill the fracture/pathological cavity. The solidification of the bone cement releases heat up to 70 °C, providing support to the injured vertebral body and exerting a cytotoxic effect on pathological neoplasm cells. When hardened, the injected cement reinforces the spine, which not only effectively treats the effects of spinal compression fractures caused by osteoporosis, but is also used to treat pain caused by tumor metastases in the spine or vertebral hemangioma.

Most of the time, vertebral hemangiomas with signs of aggressiveness require vertebroplasty. The criteria for assessing the aggressiveness of this pathology include intense back pain aggravated by physical activity, along with involvement of a large part of the vertebral body and a cellular structure detected by MRI or CT.

The primary indications for surgery are traditionally back pain localized at the level of the lesion. In addition, percutaneous vertebroplasty is often required when there is a pathological fracture of the spine or a threat of its formation, which occurs in the absence of compression of the spinal cord nerve roots due to metastases or osteoporosis, and when the body height of the affected vertebra is preserved by more than 1/3. Along with pain reduction and restoration of supportive functions, the application of bone cement to secondary metastatic lesions of the spine has a cytotoxic effect.

CONTRAINDICATIONS

The CONTRAINDICATIONS for vertebroplasty are divided into two categories: absolute and relative.

Absolute CONTRAINDICATIONS are:

• Active osteomyelitis of the vertebrae (an inflammatory process affecting the bone tissue of the vertebral body);
• Asymptomatic vertebral body fracture;
• Uncorrected coagulopathy (pathological disorder of blood clotting);
• Allergic reaction to contrast agents or the cementing agent.

Relative CONTRAINDICATIONS are:

• Active systemic infection;
• Significant narrowing of the central canal resulting from retropulsion of an epidural tumor or bone fragment;
• Radiculopathy or myelopathy originating from the site of the compression fracture.

RESULTS AND EFFICACY

The procedure is characterized by a high degree of efficacy. Authors of a statistical study claim that in 38 patients suffering from aggressive hemangiomas, pain was relieved in approximately 90% of cases as a result of percutaneous vertebroplasty. The same research team published the results of percutaneous treatment in 100 patients suffering from metastatic spinal lesions—pain regressed in 80% of cases. In addition to low invasiveness and the feasibility of using local anesthesia during surgery, this intervention method allows the activation of patients just two hours after the surgical procedure—hospital stay can be reduced to up to one day. The reduction of pain intensity alongside the preservation of motor activity significantly improves the quality of life of patients undergoing surgery. Therefore, the technique is increasingly used in the treatment of spinal compression fractures.

SURGICAL INTERVENTION

Vertebroplasty is performed under local anesthesia and a mild sedative effect. To prevent possible complications, the patient is administered antibiotics. The patient is positioned on their stomach (prone position). After applying local anesthesia to the projection area of the affected vertebra, a guide wire (or needle) is inserted into the body through a small incision—this manipulation is performed under X-ray control. Through this guide to the surgical site, a needle is introduced, through which the surgeon retrieves a small section of the bone tissue of the vertebral body.

After obtaining the bone sample, vertebroplasty is performed. As part of this technique, a tube is introduced over the inserted wire, through which the cavity is filled with the cementing agent. In some cases, the application of the specified substance from both sides of the vertebral body is recommended. After the completion of the cement injection, the tube is removed, and the surgical wound is then closed and bandaged.

After vertebroplasty, the patient remains on bed rest for 1-2 hours. Our professor initiates the necessary analgesics to prevent pain that may occur after the local anesthesia wears off.

If the compression fracture of the spine is caused by osteoporosis, addressing this pathological condition is a prerequisite for successful treatment, as a recurrent fracture of the spine develops in 20% of patients in its absence.

ADVANTAGES OF THE OPERATION

The benefits of percutaneous vertebroplasty include the following points:

• High efficacy. The targeted and carefully controlled delivery of bone cement directly into the site of the fracture or the affected vertebral body ensures effective reinforcement of the vertebrae and restores the integrity of the damaged bone;
• Low invasiveness. This ensures the minimal invasiveness of the procedure, since surgical manipulations do not require large-scale surgical incisions;
• Use of local anesthesia. This makes the procedure available for patients of any age and any health condition, since local anesthesia does not place a heavy burden on the body, as general anesthesia does;
• Low rate of complications. This point is a result of using modern instruments and techniques to avoid damage to structures adjacent to the vertebrae by the inserted needle. The minimal incision length (a few millimeters) significantly reduces the risk of infection, the volume of blood loss, and the degree of muscle and other soft tissue damage;
• Early activation of patients. Modern vertebroplasty allows patients to move actively just a few hours after surgery. The solidification of the material takes only a few minutes, which means that mobility does not need to be restricted for a long period;
• Reduced hospital stay. After the surgery, the patient stays in the hospital for only one day—they arrive at the hospital in the morning on an empty stomach, undergo surgery, and can go home and return to normal life a few hours later.

COMPLICATIONS

Researchers have noted that the most common complications in vertebroplasty are associated with oncological lesions of the vertebrae (10%) and vertebral hemangioma (2-5%), and correlate less with the probability of osteoporosis (1-3%).

Major complications were detected in less than 1% of patients with osteoporotic vertebral fractures; minor complications in this patient group occurred in less than 2% of cases. In patients suffering from localized neoplasms in the spine, major complications occur in less than 5% of cases, and minor complications occur in up to 10%.

The main complication occurring during vertebroplasty is the leakage of bone cement into the spinal canal. If a small amount of polymethylmethacrylate enters the spinal canal and no symptoms of complications are observed, treatment is not required. If the volume of bone cement entering the spinal canal is sufficiently large, this complication can cause compression of nerve structures, resulting in pain or weakness in the extremities. In this case, repeat surgery aimed at removing the excess cement from the spinal canal must be performed.

Since surgical manipulations are performed through a small puncture and the bone cement heats up to a temperature of 65-70 °C during polymerization, infectious contamination of the wound during such procedures is relatively rare.