title: The effect of postural correction and subsequent balloon inflation in deformity correction of acute osteoporotic vertebral fractures.
abstract: OBJECTIVE
  To determine deformity correction by postural correction and subsequent balloon inflation in acute vertebral compression fractures (OVCFs) and to examine the effect of bone mineral density on deformity correction.
  
  
  METHODS
  A totol of 50 acute OVCFs received balloon kyphoplasty. Lateral radiographs were taken and analyzed at five different time points : 1) preoperative, 2) after placing the patient in prone hyperextended position, 3) after balloon inflation, 4) after deposition of the cement, and 5) postoperative. All fractures were analyzed for height restoration of anterior (Ha), middle (Hm) and posterior (Hp) vertebra as well as Cobb angle and Kyphotic angle. The bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry. According to the T-score, the patients were divided into two groups which were osteoporosis group and osteopenia group.
  
  
  RESULTS
  Postoperative measurements of Ha, Hm and the Cobb angle demonstrated significant reduction of 4.62 mm, 3.66 mm and 5.34° compared with the preoperative measurements, respectively (each p<0.05). Postural correction significantly increased Ha by 5.51 mm, Hm by 4.35 mm and improved the Cobb angle by 8.32° (each p<0.05). Balloon inflation did not demonstrate a significant improvement of Ha, Hm or the Cobb angle compared with baseline prone hyperextended. Postural correction led to greater improvements of Ha, Hm and Cobb angle in osteoporosis group than osteopenia group (each p<0.05).
  
  
  CONCLUSIONS
  In acute OVCFs, the height restoration was mainly attributed to postural correction rather than deformity correction by balloon inflation. BMD affected deformity correction in the process of postural correction.
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Hai-Xiao
authors.initials: HX
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Rehabilitation, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Shang
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Hua-Zi
authors.initials: HZ
authors.lastname: Xu
keywords: Balloon kyphoplasty; Bone mineral density; Height restoration; Osteoporosis; Vertebral fracture