title: Intravertebral clefts in osteoporotic compression fractures of the spine: incidence, characteristics, and therapeutic efficacy.
abstract: OBJECTIVE
  To determine the pathogenesis and characteristics and to assess the long-term effectiveness of polymethylmethacry late (PMMA) vertebroplasty treatment in patients with intravertebral cleft (IVC) in osteoporotic compression fractures.
  
  
  METHODS
  A retrospective analysis of radiological and clinical parameters was performed on 388 patients who underwent percutaneous vertebroplasty or kyphoplasty to treat osteoporotic compression fractures from January 2010 to October 2012. IVC sign was observed in the MRI of 47 patients. Postoperative follow-ups were conducted for at least 2 years after surgery.
  
  
  RESULTS
  IVC incidence was associated with older age and lower bone mineral density. Other baseline measurements, such as preoperative visual analogue scale and Oswestry Disability Index (ODI), showed no significant difference between IVC and non-IVC fracture patients. Vertebral height and kyphotic angle were corrected after percutaneous vertebroplasty or kyphoplasty with no significant difference in outcome between the two procedures. Restored vertebral height collapsed and the kyphotic angle became aggravated during the 2 years following surgery in patients with IVC. Similarly, initial improvements in visual analogue scale and ODI decreased over time. Non-IVC patients' had a slight recurrence of compression and kyphosis that began to normalize after 1 year. Visual analogue scale and ODI at 2 years' post-surgery was also significantly lower in non-IVC than IVC patients.
  
  
  CONCLUSIONS
  Polymethylmethacrylate vertebroplasty treatment of osteoporotic compression fractures is initially effective for patients with signs of IVC, but compression and kyphosis gradually reoccur. Therefore, we strongly recommend strict observation and follow-up after vertebroplasty.
authors.affiliation: Department of Orthopaedics, Beijing Shijitan Hospital, Capital Medical University Beijing 100038, China.
authors.forename: Xiutong
authors.initials: X
authors.lastname: Fang
authors.affiliation: Department of Orthopaedics, Beijing Shijitan Hospital, Capital Medical University Beijing 100038, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.affiliation: Department of Orthopaedics, Beijing Shijitan Hospital, Capital Medical University Beijing 100038, China.
authors.forename: Shengliang
authors.initials: S
authors.lastname: Fu
authors.affiliation: Department of Orthopaedics, Beijing Shijitan Hospital, Capital Medical University Beijing 100038, China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Song
keywords: Avascular osteonecrosis; intravertebral vacuum cleft; osteoporosis; spinal fracture; vertebroplasty