Upper facet joint en bloc resection for the treatment of thoracic myelopathy caused by ossification of the ligamentum flavum

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The authors introduce a novel technique to treat thoracic myelopathy caused by ossification of the ligamentum flavum (OLF): upper facet joint en bloc resection. This surgical procedure avoids surgery to the most heavily compressed cord surface, contact with the cord, and cord injury. The epidural venous plexus bleeding point can be directly seen and easily controlled during the decompression.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Between January 2007 and January 2009, thoracic myelopathy caused by OLF was diagnosed in 38 patients using plain radiography, CT, and MRI, and diagnoses were confirmed by postoperative pathological examination. All upper facet joint en bloc resection procedures were performed in 2 steps. First, the bony structures above the upper facet joint surfaces were resected and the upper facet joints were isolated. Second, en bloc resection of the upper facet joint was performed by dissection of the junction between the pedicle and upper facet joint. Intraoperative neurological monitoring was performed in all cases. The modified Japanese Orthopaedic Association (mJOA) scoring system was used to assess neurological status. The degree of postoperative expansion of the spinal cord was calculated on axial MR images. The pre- and postdecompression Cobb angle was applied to assess the magnitude of local kyphosis.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Of the 38 cases of OLF, 6 were single level, 12 were double level, and 20 were multilevel. Of the 92 ossified segments in this study, 23 (25.0%) were located in the upper thoracic spine (T1–4), 13 (14.1%) were located in the midthoracic spine (T5–8), and 56 (60.9%) were located in the lower thoracic spine (T9–L1). The mean intraoperative blood loss was 340 ± 54 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 &lt; 0.05). The neurological function recovery rate ranged from 28.6% to 100%. The mean increase in pre- and postoperative kyphosis of the involved vertebrae was only 1.3° ± 1.6°. The increase in the cross-sectional area of the dural sac at the level of maximum compression suggested that decompression was complete.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Upper facet joint en bloc resection is effective and may be a reasonable alternative treatment choice for thoracic myelopathy caused by OLF.</jats:p></jats:sec>

Comparative Effectiveness of Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion

“…Several authors have reported that the most severe ossification tends to be located at the facet joints 14,[16][17][18] . Several authors have reported that the most severe ossification tends to be located at the facet joints 14,[16][17][18] .…”

Circumferential Decompression via a ModifiedCostotransversectomy Approach for the Treatment of Single Level Hard Herniated Disc between T10–L1

“…Traditional laminectomy and its modifications have gradually been abandoned because they do not completely decompress the spinal cord and can have unsatisfactory final outcomes because of the high early complication rate and recurrence of compression in some patients . Additionally, laminectomy involves some manipulation of the HTHD which, while being insufficient to cause mechanical damage, may interfere with blood supply to the cord .…”

“…Upper facet joints en bloc resection was performed as reported previously . In brief, to achieve posterior exposure, the erector spinae were retracted laterally bilaterally, after which posterior decompression was achieved as follows: the spinous processes, inferior facet joints, and laminae of the involved segments were resected, then the bony junction between the pedicle and upper facet joint was detached with a bone rongeur or motor burr via the pedicle‐ossification tunnel.…”

Surgical strategies for thoracic myelopathy due to ossification of ligamentum flavum: a technical note based on radiological type

“…The neurological deterioration rate after surgery has been reported to be as high as 8.4% (10). The most severe narrowing of the spinal canal was found at the middle level of the facet joints (22,25). At this level, the spinal cord was compressed tightly by the OLF.…”