title: Changes of paraspinal muscles in postmenopausal osteoporotic spinal compression fractures: magnetic resonance imaging study.
abstract: BACKGROUND
  To investigate the changes of cross sectional area (CSA) in paraspinal muscles upon magnetic resonance imaging (MRI) and bone mineral density (BMD) in postmenopausal osteoporotic spinal compression fractures.
  
  
  METHODS
  We reviewed 81 postmenopausal women with osteoporosis, who had underwent MRI examination. The patients were divided into 51 patients who had osteoporotic spinal compression fractures (group I), and 30 patients who without fractures (group II). Group I were subdivided into IA and IB, based on whether they were younger (IA) of older (IB) than 70 years of age. We additionally measured body mass index and BMD. The CSA of multifidus, erector spinae, paraspinal muscles, psoas major (PT), and intervertebral (IV) discs were measured. The degree of fatty atrophy was estimated using three grades.
  
  
  RESULTS
  The BMD and T-score of group I were significantly lower than those of group II. The CSA of erector spinae, paraspinal muscles, and PT in the group I was significantly smaller than that of group II. The CSA of paraspinal muscles in group IB were significantly smaller than those of group IA. The CSA of erector spinae, mutifidus, and PT in group IB were smaller than those of group IA, but the difference was not statistically significant. Group 1 exhibited greater fat infiltration in the paraspinal muscle than group II.
  
  
  CONCLUSIONS
  Postmenopausal osteoporotic spinal compression fracture is associated with profound changes of the lumbar paraspinal muscle, reduction of CSA, increased CSA of IV disc, and increased intramuscular fat infiltration.
authors: Department of Orthopedic Surgery, School of Medicine, Wonkwang University Hospital, Iksan, Korea.
authors: Jong Yun
authors: JY
authors: Kim
authors: Department of Orthopedic Surgery, School of Medicine, Wonkwang University Hospital, Iksan, Korea.
authors: Soo Uk
authors: SU
authors: Chae
authors: Department of Radiology, School of Medicine, Wonkwang University Hospital, Iksan, Korea.
authors: Gang Deuk
authors: GD
authors: Kim
authors: Department of Orthopedic Surgery, School of Medicine, Wonkwang University Hospital, Iksan, Korea.
authors: Myoung Soo
authors: MS
authors: Cha
keywords: Cross-sectional area; Fractures compression; Paraspinal muscles; Postmenopause