Evidence & Methods
Using the NIS, the authors aimed to examine vertebroplasty (VP) and kyphoplasty (KP) regarding complications, costs, and the impact of the two RCTs published in 2009.
They found that KP was associated with lower complications, shorter LOS, and higher costs than VP. They also found procedure rates decreased after 2009.
There are limitations to these data. The database does not include a number of potentially important confounding variables. The KP and VP groups were different at baseline, the latter being older and sicker, which can influence the measured outcomes. It is unclear whether the change in procedure rates were the result of practitioners' interpretation of the literature or changes in reimbursement. That said, the information provides a useful overview of the current landscape and can serve as a baseline for future assessments in trends.
—The Editors
Although most VCFs heal within a few months with conservative therapy, a significant portion fail to improve and require long-term care, surgical intervention, or both [8]. Fractures that fail conservative therapy are often treated with vertebral augmentation procedures (VAPs) such as vertebroplasty (VP) or kyphoplasty (KP).
Vertebroplasty involves the percutaneous injection of polymethylmethcrylate into the fractured vertebral body. Polymethylmethcrylate cement provides structural integrity to the vertebral body preventing further compression and potentially alleviating painful symptoms. Kyphoplasty is a modified VAP that involves creating a cavity in vertebral body by inflating a balloon before injection [9]. The additional balloon inflation step is intended to restore vertebral height and create a space for the polymethylmethcrylate, thereby reducing injection pressure [10], [11].
A number of past case series and small trials suggested that VP is an effective treatment of VCFs [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22]. The strongest evidence for the efficacy of VP came from a small nonblinded randomized trial of 34 patients [21]. Similarly, small studies have suggested that KP is an effective alternative to VP [23], [24], [25]. An open, randomized trial of KP was published that supported its efficacy [26]. Weaknesses in methodology of these studies have brought efficacy of VAPs into question. Specifically, the lack of blinding in the trials and lack of a sham controls predispose the results of the trials to be impacted by placebo. The response to placebo has been noted to be more significant for invasive interventions [27].
Two double-blind randomized controlled trials (RCTs) investigating the efficacy of VP in the treatment of VCFs set out to provide strong evidence for the issue [28], [29]. Both trials found no statistically significant difference in outcomes between VP and a sham procedure. These findings have lead to questioning of the efficacy of VAPs, changes in recommendations by professional societies regarding the use of VP, and changes in reimbursement patterns for both procedures.
In a previous study, we investigated the trends in utilization of VAPs between 2005 and 2008 using inpatient and ambulatory state-specific databases from New York, New Jersey, and California [30]. The study noted a significantly greater use of KP comparing with VP and an overall trend of increasing utilization of VAPs. Other studies have noted similar increases in VAP use [31], [32]. These studies were done before the publication of the two RCTs on the topic.
This study aimed to investigate trends in utilization of VP and KP using a large national administrative database to capture the impact of the 2009 literature on utilization of VAPs. The present study also compares patient characteristics and perioperative outcomes between VP and KP to further delineate the risks of each procedure.
