| Percutaneous vertebroplasty | |
|---|---|
| Intervention | |
| ICD-9-CM | 81.65 |
Vertebroplasty and kyphoplasty are similar medical spinal procedure where bone cement is injected through a small hole in the skin (percutaneously) into a fractured vertebra with the goal of relieving the pain of vertebral compression fractures (VCF). Vertebroplasty was found to be ineffective in treating compression fracture of the spine by each of the only two randomized trials done to study the procedure that used a sham procedure for the control group.
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Vertebroplasty had been performed as an open procedure for many decades to secure pedicle screws and fill tumorous voids. However, the results were not always worth the risk involved with an open procedure, which was the reason for the development of percutaneous vertebroplasty.
The first percutaneous vertebroplasty was performed in 1984 at the University Hospital of Amiens, France to fill a vertebral void left after the removal of a benign spinal tumor. A report of this and 6 other patients was published in 1987 and it was introduced in the United States in the early 1990s. Initially, the treatment was used primarily for tumors in Europe and VCF in the United States, although the distinction has largely gone away since then.[1]
The effectiveness of vertebroplasty is controversial. Two randomized and blinded trials found no benefit however they have been faulted for not looking at people with acute vertebral fractures.[2] Some have suggested that this procedure only be done in those with fractures less than 6 weeks old (which was not the population of these two trials).[3]
Two studies published in The New England Journal of Medicine in 2009 found no benefit to vertebroplasty for compression fractures when compared to a sham procedure :[4]
Several case reports and unblinded studies initially suggested that vertebroplasty provided effective relief of pain.[7][8][9][10] However, none of these studies were comparisons to a placebo.
Nevertheless, many vertebroplasty practitioners and healthcare professional organizations continue to advocate for the procedure.[11][12]
In response to the NEJM articles and a medical record review showing misuse of vertebroplasty and kyphoplasty, US Medicare contractor Noridian Administrative Services (NAS) conducted a literature review and formed a policy regarding reimbursement of the procedures. NAS states that in order to be reimbursable, a procedure must meet a certain criteria, including, 1) a detailed and extensively documented medical record showing pain caused by a fracture, 2) radiographic confirmation of a fracture, 3) that other treatment plans were attempted for a reasonable amount of time, 4) that the procedure is not performed in the emergency department, and 5) that at least 1 year of follow-up is planned for, among others. The policy, as referenced, applies only to the region covered by Noridian and not all of Medicare's coverage area. It became effective on 20 June 2011 and remains current.[13]
An unblinded study published in 2010 compared vertebroplasty to conservative care with 202 patients. The results were consistent with prior unblinded studies; patients who were aware that they had undergone vertebroplasty reported improvement in pain.[14]
Vertebroplasty is typically performed by a spine surgeon or interventional radiologist. It is a minimally invasive procedure and patients usually go home the same or next day as the procedure. Patients are given local anesthesia and light sedation for the procedure, though it can be performed using only local anesthetic for patients with medical problems who cannot tolerate sedatives well.
During the procedure, bone cement is injected with a biopsy needle into the collapsed or fractured vertebra. The needle is placed with fluoroscopic x-ray guidance. The cement (most commonly PMMA, although more modern cements are used as well) quickly hardens and forms a support structure within the vertebra that provide stabilization and strength. The needle makes a small puncture in the patient's skin that is easily covered with a small bandage after the procedure.[15]
Kyphoplasty is a variation of a vertebroplasty that attempts to stop the pain caused by the bone fracture and attempts to restore the height and angle of kyphosis of a fractured vertebra (of certain types), followed by its stabilization using injected bone cement. The procedure typically includes the use of a small balloon that is inflated in the vertebral body to create a void within the cancellous bone prior to cement delivery. Once the void is created, the procedure continues in a similar manner as a vertebroplasty, but the bone cement is typically delivered directly into the newly created void.
In its review of vertebroplasty and vertebral augmentation procedures, Medicare contractor NAS determined that there is no difference between vertebroplasty and kyphoplasty, stating, "No clear evidence demonstrates that one procedure is different from another in terms of short- or long-term efficacy, complications, mortality or any other parameter useful for differentiating coverage."[13]
Several unblinded clinical studies have suggested a benefit of balloon kyphoplasty for patients with spinal fractures. Earlier unblinded studies also suggested a similar benefit to the closely related procedure vertebroplasty, however the only two blinded randomized controlled studies done to assess vertebroplasty failed to demonstrate any benefit as compared to patients who received a sham procedure.[16][17] Although no blinded studies have been performed on kyphoplasty, since the procedure is a derivative of vertebroplasty, the unsuccessful results of these blinded studies have cast doubt upon the benefit of kyphoplasty despite the continued benefit suggested by unblinded studies.[18]
Some of the associated risks that can be produced are from the leak of acrylic cement outside of the vertebral body. Although severe complications are extremely rare, it is important to know that infection, bleeding, numbness, tingling, headache, and paralysis may ensue due to misplacement of the needle or cement. This particular risk is decreased by the use of x-ray or other radiological imaging to ensure proper placement of the cement.[15]