title: Restoration of the spinal canal volume in stenosis dependent on pedicle-lengthening distance in pedicle-lengthening osteotomy: A three dimensional simulation.
abstract: OBJECTIVE
  This study aimed to determine the relationship between pedicle-lengthening distance and bulge-canal volume ratio in cases of lumbar spinal stenosis, to provide a theoretical basis for the extent of lengthening in pedicle-lengthening osteotomies.
  
  
  METHODS
  Three-dimensional reconstructions of CT images were performed for 69 patients (33 men and 36 women) (mean age 49.96 years; 24 to 81). Simulated pedicle-lengthening osteotomies and disc bulge and spinal canal volume calculations were performed using Mimics software.
  
  
  RESULTS
  The mean spinal canal volume of the two groups, L4 and L5, were 14 646.81 mm(3) (5918.60 to 22 717.77) and 16 408.47 mm(3) (8678.21 to 31 204.79), respectively. The mean lengthening distance was 2.17 mm (0.5 to 4.8) and the mean bulge-canal volume ratio was 0.23 (0.05 to 0.48). The pedicle-lengthening distance of the two groups were very strongly correlated with disc bulge volume and bulge-canal volume ratio (p < 0.001); the predictive equation was established as L = 0.06 + 9.06R (where L equals the pedicle-lengthening distance and R represents the bulge-canal volume ratio).
  
  
  CONCLUSIONS
  Our findings indicated that lumbar pedicle-lengthening distance strongly correlates with bulge-canal volume ratio, which can be estimated before surgery from CT images.
  
  
  CONCLUSIONS
  The predictive equation could help surgeons to decide the pedicle lengthening distance according to individual's condition and guide the surgery effectively.
authors: Southern Medical University, 1023 Shatai South Road, Guangzhou, 510515 P.R., China.
authors: L
authors: L
authors: Qian
authors: Department of Orthopedic Surgery, Guzhen People's Hospital of Zhongshan City, 15 Dongxing Middle Road, Zhongshan, 528421, P.R., China.
authors: P
authors: P
authors: Li
authors: Wuzhou Red Cross Hospital, 3-1 Xinxing First Road, Wuzhou, 543000, P.R., China.
authors: W
authors: W
authors: Wu
authors: Zhengzhou University, 288 Zhongzhou Middle Road, Luoyang, 471009, P.R., China.
authors: Y
authors: Y
authors: Fang
authors: Southern Medical University, 1023 Shatai South Road, Guangzhou, 510515 P.R., China.
authors: J
authors: J
authors: Zhang
authors: Southern Medical University, 1023 Shatai South Road, Guangzhou, 510515 P.R., China.
authors: J
authors: J
authors: Ouyang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010027:Osteotomy / Q000379:methods*; D013115:Spinal Canal / Q000473:pathology*; D013130:Spinal Stenosis / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Pedicle-lengthening distance; Spinal canal volume; Spinal stenosis; 3D reconstruction