Medtronic, Inc. announced yesterday the results of a retrospective claims-based data analysis suggesting that a patient group of those over 65 in the U.S. whose spinal fractures were treated with minimally invasive surgery had a higher survival rate up to four years after treatment than a patient group that did not have surgery. The evaluation is pending U.S. Food and Drug Administration (FDA) review of the claims.

The data further suggested that of the patient group treated with one of the two minimally invasive surgical procedures available, a sub-group treated with balloon kyphoplasty had higher survival rate up to four years after treatment than a sub-group that was treated with vertebroplasty. During the evaluation period, Kyphon® Balloon Kyphoplasty was the only balloon kyphoplasty treatment for spinal fractures cleared by the FDA in the U.S.

This first longitudinal, population-based comparison of mortality risk between operated and non-operated patient groups with spinal fractures and between balloon kyphoplasty and vertebroplasty patient sub-groups was published online recently in The Journal of Bone and Mineral Research.i

In the evaluation, researchers looked at data from the U.S. Medicare dataset including a population of 1 million patients that suffered vertebral compression fractures from 2005 through 2008. After inclusion criteria were applied, a population of 858,978 spinal fracture patients was analyzed. The population included 119,253 or 13.9% treated with balloon kyphoplasty, 63,693 or 7.4% treated with vertebroplasty and the remaining treated only with non-surgical care such as pain medication, bed rest, physiotherapy or bracing.

While an estimated 1.4 millionii debilitating and painful spinal fractures are suffered annually worldwide, prior to this evaluation the association between surgical treatment for these painful fractures and survivorship was unknown.

The evaluation was jointly carried out by Exponent, Inc., a scientific and engineering consulting firm and Medtronic, the balloon kyphoplasty market leader with over 900,000 spinal fractures worldwide treated with Kyphon Balloon Kyphoplasty.

Among the findings of the evaluation at up to four years follow-up were:

The patient group whose spinal fractures were treated surgically with either balloon kyphoplasty or vertebroplasty had a statistically significant higher adjusted survival rate of 60.8% compared to 50.0% for the patient group undergoing conservative or non-surgical care (p<0.001). The surgical group was 37% less likely to die than the non-surgical group (p<0.001).

The patient sub-group that received balloon kyphoplasty had a statistically significant higher survival rate of 62.8% compared to the 57.3% survival rate of the sub-group treated with vertebroplasty (p<0.001). The relative risk of mortality for the kyphoplasty sub-group was 23% lower than that for vertebroplasty sub-group (p<0.001).

The improved survivor rate of the group treated with minimally invasive surgery was confirmed by an analysis of a sub-group of these patients who were alive one year after their initial diagnosis of a spinal fracture. This group was 18% less likely to die by the end of the study than those in the non-surgical group (p<0.001). When separated by the type of surgery received, those in the balloon kyphoplasty group were 24% less likely to die by the end of the study, and those in the vertebroplasty group were 7% less likely to die (both p<0.001).

Certain demographics such as gender, age and lower socio-economic status were found to be statistically significant mortality risk factors for patients with spinal fractures regardless of treatment method. Men had a higher mortality risk than women , those 75 and older had a higher mortality risk than those 65-69 , and those with lower socio-economic status based on Medicare buy-in status had a higher mortality risk than those with higher socio-economic status (all p<0.001).

Analyses of treatment effects strongly suggested that the mortality differences between the three groups studied cannot be explained by patient characteristics such as their health status or comorbidities.

"We are very pleased that this evaluation suggested significantly improved survivorship in the patient sub-group whose vertebral compression fractures were treated with balloon kyphoplasty compared with vertebroplasty," said Av Edidin, Ph.D., one of the evaluation's authors and vice president, science and technology, for the Spinal and Biologics Division of Medtronic. "Our hope is that this evaluation will shed light on this important public health issue, open scientific discussion and lead to future studies on the reasons for the improved survivorship in patient groups treated surgically for spinal fractures compared with groups that received non-surgical treatment."

While both balloon kyphoplasty and vertebroplasty are minimally invasive procedures to treat spinal fractures, the procedures are very different. Vertebroplasty only stabilizes the fracture. Balloon kyphoplasty is designed to not only stabilize the fracture, but also attempts to correct vertebral body deformity with the inflation and removal of orthopaedic balloons prior to injection of a more viscous bone cement under low manual pressure. Balloon kyphoplasty products manufactured by Medtronic are indicated throughout the world for treatment of fractures in the spine, hand, tibia, radius and calcaneus caused by osteoporosis, some forms of cancer, benign lesions and trauma. In the U.S., trauma is not an indication.

There are risks associated with Kyphon Balloon Kyphoplasty (e.g., cement leakage), including serious complications, though rare, some of which may be fatal. This procedure is not for everyone. A prescription is required. Patients should consult their physicians for a complete list of indications, contraindications, benefits, and risks. Only patients and their physicians can determine whether this procedure is right for a particular patient. For more information on Kyphon Balloon Kyphoplasty, go to www.balloonkyphoplasty.com.

Limitations

Due to its retrospective, observational nature, this evaluation did not and could not investigate causal relationships between surgical treatment, non-surgical treatment and improved patient survival. Also, while patients in the non-surgical treatment group had greater mortality rates than those in the surgical group, the evaluation did not look into the events that lead to their deaths.

Source
Medtronic