Vertebroplasty and kyphoplasty: biomechanics, outcomes, and complications

Purpose of review: The purpose of this review is to provide a summary of the past year’s published literature involving the increasingly popular percutaneous vertebral augmentation procedures (vertebroplasty and kyphoplasty). Recent findings: There is ample literature in the form of short-term, retrospective reviews with small numbers of patients undergoing vertebroplasty. There is much less, but similar quality, literature for the newer kyphoplasty procedure. The reported clinical results from both procedures appear to be excellent and suggest that percutaneous cement augmentation of fractured osteoporotic vertebra can consistently produce significant pain relief, increased mobility, and improved quality of life in 70 to 95% of selected patients. To date, the literature lacks a prospective, case-controlled study comparing the efficacy of kyphoplasty and vertebroplasty. It appears that kyphoplasty may offer greater potential for reversal of vertebral deformity as well as a reduced risk of extravasation since the bone cement is injected under lower pressure than for vertebroplasty alone. It is still unknown whether the incidence of adjacent level fractures is higher with the deformity-reducing kyphoplasty procedure. Complications are relatively rare with both procedures. However, some studies reported a higher incidence of clinically insignificant leakage of bone cement into paravertebral tissues with vertebroplasty. Definitive patient selection criteria for these procedures have not been established. However, there is evidence that cement augmentation may be an appropriate option for patients with vertebral lesions resulting from osteolytic vertebral metastasis and myeloma, vertebral hemangioma, and osteoporotic compression fracture if the following criteria have been met: 1. Pain is severe and debilitating and cannot be relieved by correct medical therapy. 2. Other causes of pain, such as herniated intervertebral disc, have been ruled out. 3. The affected vertebra has not been extensively destroyed and is at least one third of its original height. Cement augmentation is contraindicated in patients with spinal infections, unstable vertebral fractures, fractures with retropulsed bone fragments in the spinal canal, and in patients with coagulation disorders. Some authors consider destruction of the posterior wall of the vertebral body to be a relative contraindication and suggest that extreme caution must be used in these patients to prevent cement leakage into the spinal canal. Summary: There is evidence from a number of uncontrolled studies that most patients with pain unresponsive to standard medical treatment will experience significant pain relief, increased function and quality of life following vertebral cement augmentation, with few serious complications. While early results are promising, more research is needed to better understand the long-term effects of cement augmentation on the human spine. The most recent literature is summarized in this review.