title: Balloon kyphoplasty in malignant spinal fractures: a systematic review and meta-analysis.
abstract: BACKGROUND
  Spinal fractures are a common source of morbidity in cancer patients. Balloon Kyphoplasty (BKP) is a minimally invasive procedure designed to stabilize fractures and correct vertebral deformities. We performed a meta-analysis to determine the efficacy and safety of BKP for spinal fractures in cancer patients.
  
  
  METHODS
  We searched several electronic databases up to September 2008 and the reference lists of relevant publications for studies reporting on BKP in patients with spinal fractures secondary to osteolytic metastasis and multiple myeloma. Outcomes sought included pain relief, functional capacity, quality of life, vertebral height, kyphotic angle and adverse events. Studies were assessed for methodological bias, and estimates of effect were calculated using a random-effects model. Potential reasons for heterogeneity were explored.
  
  
  RESULTS
  The literature search revealed seven relevant studies published from 2003 to 2008, none of which were randomized trials. Analysis of those studies indicated that BKP resulted in less pain and better functional outcomes, and that these effects were maintained up to 2 years post-procedure. While BKP also improved early vertebral height loss and spinal deformity, these effects were not long-term. No serious procedure-related complications were described. Clinically asymptomatic cement leakage occurred in 6% of all treated levels, and new vertebral fractures in 10% of patients. While there is a lack of studies comparing BKP to other interventions, some data suggested that BKP provided similar pain relief as vertebroplasty and a lower cement leakage rate.
  
  
  CONCLUSIONS
  It appears that there is level III evidence showing BKP is a well-tolerated, relatively safe and effective technique that provides early pain relief and improved functional outcomes in patients with painful neoplastic spinal fractures. BKP also provided long-term benefits in terms of pain and disability. However, the methodological quality of the original studies prevents definitive conclusions being drawn. Further investigation into the use of BKP for spinal fractures in cancer patients is warranted.
authors.affiliation: Health-Care Technology Assessment Agency, Instituto de Salud Carlos III, Madrid, Spain. cbouza@isciii.es
authors.forename: Carmen
authors.initials: C
authors.lastname: Bouza
authors.forename: Teresa
authors.initials: T
authors.lastname: López-Cuadrado
authors.forename: Patricia
authors.initials: P
authors.lastname: Cediel
authors.forename: Zuleika
authors.initials: Z
authors.lastname: Saz-Parkinson
authors.forename: José María
authors.initials: JM
authors.lastname: Amate