The CT and intraoperative observation of pedicel-ossification tunnel in 151 cases of thoracic spinal stenosis from ossification of ligamentum flavum.

PURPOSE: The aim of this study is to precisely illustrate the pedicle-ossification tunnel (POT)-a spinal cord-free pathway in upper facet joint en bloc resection, which was reported as a comparatively neurological safer decompression surgery for thoracic ossification of ligamentum flavum (OLF).

METHODS

From 1998 to 2009, 151 patients with thoracic spinal stenosis from OLF were diagnosed by CT, MRI, neurological examinations and confirmed by postoperative pathological examination. The existence and configuration of the POT were observed by interactive CT virtual endoscopic (CTVE) image with multiplanar reconstructions and confirmed by intraoperative observation. Posterior decompression by upper facet joint en bloc resection via POT was conducted in all patients and the advantage of surgery was evaluated by modified Japanese Orthopedic Association scores pre- and post-operatively.

RESULTS

Through CTVE and intraoperative observation, no spinal cord was found present in POTs. OLF bloc divided the foramen into three parts: upper POT, OLF bloc and lower POT. The POT was the epidural space between the lateral border of OLF and its neighboring pedicles inner cortex. The recovery rate of upper facet joint en bloc resection via POT was 75.24 ± 18.01 %.

CONCLUSIONS

POT is a spinal cord-free pathway between OLF bloc and its neighboring pedicles in thoracic spinal stenosis which can be applied in neuron preserved decompression surgery.