R T Loder

Shriners Hospitals for Children, Tampa, Florida, United States

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Publications (3)3.77 Total impact

  • Randall T Loder
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    ABSTRACT: The effect of pelvic osteotomy on birth canal size at skeletal maturity is unknown. This information would be useful to counsel women of reproductive age who have undergone pelvic osteotomy. It was the purpose of this study to answer that question. A retrospective review of girls who had undergone pelvic osteotomy in the period 1980-1999 was performed. Transverse plane birth canal dimensions (inlet, mid-pelvis, and outlet) were measured from radiographs before and after osteotomy and at final follow-up. Final follow-up diameters were compared to threshold values (obstetric pelvimetry and clinical guidelines). There were 37 patients (40 osteotomies: 31 Salter, 5 Steel, 2 Chiari, and 2 Ganz). The average age at osteotomy was 7.5 +/- 5.3 years (range 2.0-21.3 years), and at final follow-up was 16.0 +/- 4.7 years (range 2.9-25.7 years); the average follow-up was 8.5 +/- 5.2 years (range 0.5-17.6 years). The effect of osteotomy at skeletal maturity was investigated by analyzing the 30 children > or = 14 years of age at the final follow-up. The pelvic inlet was above the threshold for all 30 children. The mid-pelvis was below the low normal threshold (9.5 cm) in 3 of 21 Salter, 2 of 5 Steel, and 1 of 2 Chiari osteotomies. The pelvic outlet was below the threshold in 2 of 21 Salter and 2 of 5 Steel osteotomies. The mid-pelvis dimensions were narrower in those who underwent osteotomy when older: 7.1 +/- 4.9 years (n = 24) and 11.9 +/- 7.9 years (n = 6) (p = 0.06) for those above and below the 9.5 cm mid-pelvis threshold, respectively. In conclusion, 6 of the 30 cases had a mid-pelvis which was below threshold at skeletal maturity. If the transverse mid-pelvis diameter at skeletal maturity is < 9.5 cm, then the likelihood of Cesarean section is increased, and this information should be given to the patient.
    Archives of Orthopaedic and Trauma Surgery 02/2002; 122(1):29-34. · 1.36 Impact Factor
  • R T Loder
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    ABSTRACT: The sagittal and frontal profiles of the entire spine are poorly studied in lumbosacral spondylolisthesis. It was the purpose of this study to further investigate these profiles. Standing posterior-anterior and lateral radiographs in 24 children with lumbosacral spondylolisthesis were reviewed (18 isthmic, 6 congenital). Cervical lordosis, lumbar lordosis, thoracic kyphosis, sagittal vertebral axis, sacral inclination, slip magnitude, slip angle, and sagittal rotation were measured. Cobb magnitude, Risser sign, curve location, and direction were noted for those with scoliosis. Relationships between sagittal variables were explored (Pearson correlation). The average age of patients was 14.7 +/- 2.5 years, slip magnitude was 38 +/- 38%, slip angle was 5 +/- 31 degrees, sagittal rotation was -6 +/- 31 degrees, thoracic kyphosis was 29 +/- 16 degrees, cervical lordosis was -1 +/- 12 degrees, and lumbar lordosis was 62 +/- 22 degrees. Correlations were noted between thoracic kyphosis and sacral inclination, percent slip, slip angle, and sagittal rotation. Sacral inclination decreased as the slip increased. Scoliosis was present in 10 children, with an average curve of 19 +/- 6 degrees. Thoracic kyphosis was less in those with scoliosis (21 +/- 25 degrees versus 33 +/- 25 degrees, p = 0.033). In children with lumbosacral spondylolisthesis, the sacrum becomes more vertical as the slip worsens. As the sacrum becomes more vertical, the thoracic spine becomes more lordotic, which is likely an adaptive mechanism used by the body to maintain forward visual gaze.
    Journal of Spinal Disorders 01/2002; 14(6):465-71. · 1.21 Impact Factor
  • R T Loder
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    ABSTRACT: The sagittal profiles of the cervical and lumbar spine have not been studied in Scheuermann kyphosis. The purpose of this study was to investigate these profiles. Standing lateral radiographs of the spine in 34 children with Scheuermann kyphosis were reviewed. Cervical lordosis, lumbar lordosis, thoracic kyphosis, sagittal vertebral axis, and sacral inclination were measured. The relations between these variables were explored using the Pearson correlation. The average patient age was 15.5 +/- 1.8 years, thoracic kyphosis was 65 degrees +/- 12 degrees, lumbar lordosis 71 degrees +/- 13 degrees, and cervical lordosis 4 degrees +/- 15 degrees (Cobb angle), and 9 degrees +/- 14 degrees (posterior vertebral body angle [PVBA]). No correlations were noted between cervical lordosis and thoracic kyphosis. Correlations were noted between cervical lordosis and lumbar lordosis (r2 = 0.17, Cobb angle; r2 = 0.16, PVBA) and between cervical lordosis and the residual sagittal difference (thoracic kyphosis minus lumbar lordosis; r2 = 0.32, p = 0.001 [Cobb angle], and r2 = 0.19, p = 0.01 [PVBA]). In Scheuermann kyphosis, the flexible cervical and lumbar spine is linked by the intermediate rigid thoracic segment. As the residual sagittal difference becomes more kyphotic, lordosis of the cervical spine increases as the patient strives to maintain a forward visual gaze.
    Journal of Spinal Disorders 07/2001; 14(3):226-31. · 1.21 Impact Factor

Publication Stats

14 Citations
3.77 Total Impact Points


  • 2002
    • Shriners Hospitals for Children
      Tampa, Florida, United States