Abstract
Introduction
To introduce a novel technique of thinning, peeling and carving to remove the ossification ligamentum flavum(OLF) nidus easily, safely and completely for the treatment of thoracic myelopathy caused by OLF. This surgical procedure avoids aggressive irritating the most seriously compressed spinal cord caused by OLF nidus especially. The epidural venous plexus bleeding and the bleeding from the pedicle can be seen clearly and controlled easily during the decompression.
Material and Methods
Thoracic myelopathy caused by OLF was diagnosed in 28 patients using plain radiography, 3D CT, and MRI from January 2009 to January 2012. The lamina, the lower and the upper facet joint of the involved segment were thinned with the bigger neuro drill(diameter 3.5mm) first, The shell was so thin that the feeding blood vessels of the dura can be seen clearly. Second, the thinned shell was peeled off with the curette piece by piece. The upper facet joint and the OLF nidus were carved by the smaller neuro drill (diameter 2.5mm)and the thinned bony nidus compressing the spinal cord was removed finally, Spinal cord monitoring (SEP and MEP)was performed intraoperatively in all cases. The operating time and blood loss were recorded during the operation. The Frankel scoring system was used to assess the neurological status before the operation and in the follow up. The S F-36 were also used to assess the general health status.
Results
Of the 28 cases of OLF,3 were single level, 10 were double level, and 15 were multilevel. Of the 71 ossified segments in this study, 16 (22.5%) were located in the upper thoracic spine (T1–4), 9 (12.7%) were located in the midthoracic spine (T5–8), and 46 (64.8%) were located in the lower thoracic spine (T9-L1). The mean operating time was 145 ±32min. The mean intraoperative blood loss was 280 ± 48.6 ml. The neurological status improved during follow-up (mean 46.1 months) from a preoperative mean mJOA score of 5.39 ± 1.52 to 8.97 ± 1.22 points (t = 18.39, p < 0.05). The neurological function recovery rate ranged from 28.6% to 100%.
Conclusion
Thinning, peeling and carving technique was effective, safe and may be a reasonable choice for the treatment of thoracic myelopath y caused by OLF