Percutaneous vertebroplasty (PV) is a minimally invasive procedure consisting of the injection of an acrylic cement into the spongy portion of a partially collapsed vertebral body that is performed in order to provide pain relief and prevent vertebral collapse and pseudoarthrosis in patients with osteoporotic vertebral fractures by increasing mechanical stability.
Using sterile technique, skin and periosteum infiltrates with local anesthetic; with fluoroscopic guidance in an anteroposterior (AP) and lateral position, the entry point is marked on the skin and a needle is inserted into the vertebral body, either transpedicular or parapedicular, until the union of the second with the third part of the body. If the transpedicular approach was chosen, a second needle can be placed in the contralateral pedicle to continuously aspirate the tissue displaced by the cement injection, thus avoiding its possible displacement towards the canal or foramina that could compress the medulla or a root, especially in cases of tumor pathology. Under careful fluoroscopic visualization and alternating AP and lateral projection, the injection of the opacified bone cement begins, observing that it diffuses through the intertrabecular space of the bone marrow. The injection of the cement through the contralateral pedicle can be repeated unless sufficient filling of the vertebral body is demonstrated from the initial injection. It is not necessary to completely fill the vertebral body since there is no relationship between the amount of filling and the subsequent pain relief. Care should be taken to avoid cement extrusion beyond the confines of the vertebral body, as well as the inadvertent filling of the spinal canal, foramina, the intervertebral disc space or the vertebral venous plexuses. To allow the cement to be managed for a longer period of time and achieve infusion of multiple levels, an ice bath is used to prolong the polymerization time of the PMMA, the appropriate time to start the infusion of the cement is when its consistency is similar to that of the toothpaste. The total volume of cement injected varies from 3 to 15 cm3 with an average of 7 ml3. The cement consolidates in less than an hour and must stabilize the vertebra forming a hard internal support.
After the procedure, the patient is instructed to remain completely reclined in the supine position for a minimum of one hour to allow the cement to fully consolidate. It must be kept in hospital surveillance for at least 3 to 6 hours, after which the patient can stand and walk with little or no pain. During this time, a column CT scan can be performed as a post-procedure control. Before being discharged, patients should be evaluated to quantify pain relief, determine whether or not there is a focal neurological deficit or new-onset chest pain. In some patients, NSAIDs will be prescribed to relieve the pain associated with the procedure. Although it is usually immediate, pain relief can take up to 72 hours. The patient can be maintained with an orthosis for a period of 4 weeks as a precautionary measure in order to avoid injury to the adjacent vertebrae.