Vertebroplasty & Kyphoplasty

Vertebroplasty and kyphoplasty are medical procedures that involve minimal invasion and are utilized for the treatment of spinal fractures and lesions. The primary objective of these techniques is to enhance the strength and stability of the vertebrae.

Physicians from different specialties routinely perform these procedures, and they have proven to be effective in managing conditions such as osteoporotic fractures and spinal metastases.

Indications

Vertebral compression fractures (VCFs), which are often associated with osteoporosis and metastatic disease, pose a considerable health risk for elderly individuals. The likelihood of experiencing VCFs rises with age, particularly among women, while men also face increased risk in their 80s.

Various factors, including menopause, immobilization, steroid therapy, and specific medical conditions, contribute to the development of VCFs. Osteoporosis has a notable economic impact, with estimated costs in the United States amounting to millions of dollars. As the population continues to age, it is anticipated that the prevalence and economic burden of this condition will further escalate.

Millions of Americans are impacted by osteoporosis, which results in gradual bone loss and heightened susceptibility to vertebral compression fractures. These fractures are associated with intense and persistent pain, which may contribute to dependence on narcotics.

Elderly individuals are especially susceptible and may face chronic pain, sleep disturbances, depression, limited mobility, and a loss of independence as a result. Furthermore, compression fractures in the thoracic and lumbar regions can adversely affect lung capacity.

Initially designed for painful vertebral body hemangiomas, vertebroplasty and kyphoplasty have now been extended to address osteoporotic compression fractures and metastatic spinal lesions. Metastatic disease frequently affects the spine, resulting in weakness, fractures, pain, deformity, and neurological impairments.

Breast, lung, and prostate cancers are the primary sources of metastases. These conditions have a significant impact on patients’ quality of life. Vertebroplasty is employed to alleviate symptoms in spinal metastatic disease, multiple myeloma, malignant compression fractures with epidural involvement, and in conjunction with radiotherapy.

Natural History and Conservative Management

VCFs caused by osteoporosis can lead to a cycle of recurring fractures. Research revealed that individuals with low bone mass density or multiple VCFs are at a considerably higher risk of experiencing future fractures. Fortunately, management approaches result in improvement for approximately two-thirds of patients with acute symptomatic fractures.

The conventional conservative approach for treating vertebral compression fractures (VCFs) includes pain medication and bedrest, but this method has limitations. Physical therapy and bracing offer alternative options to mitigate adverse effects.

Multiple medical treatments have yielded inconclusive outcomes. However, a study indicated that vertebroplasty, when compared to medical treatment alone, effectively alleviates pain and enhances physical activity, establishing it as a viable choice for VCFs.

Assessment and Patient Selection

Prior to initiating a spinal procedure, it is essential to conduct a thorough examination of the nervous system to evaluate any potential motor or sensory alterations. Before the procedure, routine blood work, coagulation studies, and relevant investigations for suspected malignancies should be conducted.

Radiological evaluations encompass spinal X-rays, CT scans to assess the structural integrity of the posterior cortex, and MRI scans to examine the degree of cord compression and identify prognostic factors such as the presence of bone marrow or endplate edema. Signal alterations observed on MRI scans, along with substantial collapse of the vertebral body, are indicative of positive outcomes in the treatment process.

Vertebroplasty is primarily employed when conservative approaches fail to alleviate severe pain resulting from vertebral fractures. Typically, patients considered for vertebroplasty have endured pain for more than 6 weeks but less than 1 year, although successful treatment of fractures up to 2 years old has been reported.

Guidelines assist in selecting appropriate candidates, with painful osteoporotic and osteolytic fractures being common indications. Contraindications include severe wedge deformity, significant loss of vertebral height, burst fractures, notable compromise of the spinal canal, myelopathy, and other factors.

The use of vertebroplasty as a preventive measure is subject to debate, but it is generally reserved for patients experiencing symptomatic discomfort. In case of cement extravasation leading to myelopathy, emergency decompressive surgery should be readily available.

Kyphoplasty, which emerged in the late 1990s, is an adapted method that restores vertebral body height and enables the introduction of cement into a cavity with reduced pressure.

The utilization of a balloon mitigates the risk of cement leakage and has demonstrated a decreased occurrence of end plate fractures. The indications for kyphoplasty resemble those of vertebroplasty, although the effectiveness can be influenced by the age of the fracture. To perform the procedure, a minimum remaining vertebral height of 8 mm is necessary.

Vertebroplasty Technique

Once medical clearance and informed consent are obtained, the patient is transported to the interventional radiology suite. Typically, a surgeon and a radiologist are present during the procedure, although some centers may have a single operator.

The patient is positioned in a prone position with comfortable padding and their arms elevated above the head. Mild sedation and pain relief may be administered, and vital signs are continuously monitored. To minimize the risk of infection, the targeted area is meticulously prepared and draped in a sterile manner.

After positioning the patient, the fracture site is identified using biplanar fluoroscopy. CT guidance is seldom necessary, unless there are unique anatomical limitations that make needle placement difficult. A mark is placed on the skin over the designated pedicle, and the area is infiltrated with a buffered anesthetic solution that reaches down to the periosteum.

A variety of needles and cement options are available for percutaneous vertebroplasty, and there is no standardized technique for needle placement. The preferred approach is the parapedicular approach, but the transpedicular approach is also used. Biplanar fluoroscopy confirms the correct trajectory. A small incision is made, and a Jamshidi needle is inserted.

In the transpedicular approach, the needle is advanced to the pedicle, preferably targeting the upper and outer quadrant to avoid nerve root complications. Fluoroscopy guides the needle placement into the vertebral body. The procedure is then repeated for the opposite pedicle.

Using the parapedicular approach in vertebroplasty eliminates the need for bilateral cannulization, thanks to the lateral positioning that enables more precise needle direction. The Jamshidi needle is inserted onto the transverse process and advanced downward, with entry points determined by fluoroscopic images.

Biplanar fluoroscopy ensures accurate needle alignment with the vertebral body. While the parapedicular approach carries a theoretical risk of pneumothorax and bleeding, our experience suggests that complication rates are comparable to those of the transpedicular approach.

Regardless of the approach employed, it is essential to position the needle tip in the anterior half of the vertebral body on lateral views and in the medial third on AP views. To reduce radiation exposure to the operator’s hand, a clamp can be utilized to stabilize the needle during imaging. When treating multiple vertebral levels, it is preferable to cannulate all the levels before initiating cement injection.

Although some centers previously recommended intraosseous venography, it has been determined that it does not provide additional safety benefits during cement injection. Consequently, we have discontinued the routine use of venography before the procedure. To prevent the introduction of air, the needle is filled with sterile saline once proper placement has been confirmed.

A variety of cement products are available for vertebroplasty, and the selection depends on the practitioner’s expertise. Polymethylmethacrylate (PMMA) is a commonly used cement that combines a powder and liquid to form a solid compound.

The injection is performed when the PMMA reaches a toothpaste-like consistency. Radiopaque markers are used to assist with visualization during the injection process. Typically, 5 to 10 cc of PMMA is injected into each treated vertebral body. If cement leakage occurs, the injection should be halted.

The optimal volume of cement needed for pain relief and the exact mechanism behind its effectiveness are still not fully understood, but it is believed to involve mechanical stabilization and neural thermal necrosis.

After completing the injection, the needle is removed and minor bleeding is controlled. Patients rest for 2 hours before sitting and walking with assistance. A postoperative CT scan is obtained to assess vertebral body filling and rule out spinal cord compression. Patients are discharged on the same day with NSAIDs and muscle relaxants, encouraged to be active in daily life.

Vertebroplasty Technique

Kyphoplasty involves the use of an inflatable bone tamp or balloon to restore the height of the vertebral body, creating a cavity that can be filled with cement. However, it is important to note that restoring vertebral body height does not necessarily result in pain relief or improved quality of life. Radiographic images are used with contrast medium to confirm the expansion of the vertebral body.

In kyphoplasty, a bone tamp is inserted using either a transpedicular or parapedicular approach. The tamp is inflated to create a cavity, and then PMMA cement is injected into the cavity until it reaches two-thirds of the way to the posterior cortex of the vertebral body.

Outcomes

Vertebroplasty demonstrates a 90% to 95% success rate in pain reduction for osteoporotic fractures, enhancing mobility and daily activities. Kyphoplasty achieves an average restoration of 47% of lost vertebral body height, providing pain relief and improved function for osteoporotic fractures. However, the lack of comparative studies and reliance on retrospective and observational data limit conclusive evidence.

Percutaneous vertebroplasty and kyphoplasty offer effective and minimally invasive options for managing osteoporotic and osteolytic vertebral compression fractures. These procedures provide pain relief and improved quality of life in selected patients, with proper technique and patient selection minimizing complications. Further research is needed to compare different approaches and assess cost-effectiveness.