The ODI (Oswestry Disability Index) score was 27.4 (+/−13) preoperatively and 42.2 (+/−10.9) post operatively (p=0.004). The scores for SF-36 (Short Form-36) were 34.0 (+/−10.9) preoperatively and 29.7 (+/−6.3) post-operatively (physical component summary; p=0.3); 39.2 (+/−7.9) preoperative and 40.6 (+/− 14.9) postoperative (mental component summary; p=0.85). There were 6 major complications (1- wound break-down, 3 – required extended respiratory support of which 1 required thoracotomy for lung re-expansion, 1- developed severe distal junctional kyphosis requiring revision, 1 – recurrent laryngeal palsy needing thoraco-plasty) and 3 minor (2- dural tears, 1-chyle leak). The survival in the ‘curative’ group was 10/15 (67%) with a mean follow-up of 27.3 months; five patients died at a mean of 115 days (86–129 days) due to respiratory complications. All ten surviving patients reported that they were satisfied/very satisfied with surgery. The survival in the ‘palliative’ group was 192 days (48–360).
To determine the range of in-vivo magnification error in lateral spinal digital radiographs, and determine the effect of BMI on this error. An analysis of two hundred and fifty patients with digital radiographs and CT/MRIs was performed. Digital imaging software was used to measure the antero-posterior vertebral body dimensions (VBD) at C2, C5, L1, and L4. Magnification values were determined in comparison to CT/MRI. CT measurements were also compared to MRI. BMI for each patient was obtained by chart review. The difference between the mean VBD as measured on CT and MRI was <
0.1mm (n=130, p<
0.2514, paired t-test). Mean magnification at the cervical spine was 21% (1.21 ± 0.01; range = 1.06–1.57 (n=177)) and 31% at the lumbar spine (1.31 ± 0.01; range = 1.09–1.63 (n=284)). Linear regression showed a significant positive correlation between BMI and magnification at both the cervical and lumbar spine (Cervical: n=96; p=0.0019; Lumbar: n=144; p<
0.0001). There was a significant difference in magnification between non-obese and obese patients at both the cervical and lumbar levels. Cervical: 1.19 ± 0.01 magnification for non-obese (n=136), versus 1.26 ± 0.01 for obese (n=39) (p<
0.0001). Lumbar: 1.28 ± 0.01 (n=207), versus 1.38 ± 0.01 (n=71) (p<
0.0001), respectively. Linear in-vivo measurements obtained on digital radiographs are subject to magnification errors at both cervical and lumbar spine. This error correlates to the patient’s BMI. Consequently, clinical-decision making, regardless of the anatomical area, that is based on linear measurements obtained from radiographs that do not account for this error are invalid. In the scenario that this measurement is crucial (e.g. dynamic radiographs), this error can be corrected by comparison to morphometric data from CT/MRI.