Removal of posterior longitudinal ligament in anterior decompression for cervical spondylotic myelopathy

J Spinal Disord Tech. 2009 Aug;22(6):404-7. doi: 10.1097/BSD.0b013e318187039f.

Abstract

Study design: The clinical and radiologic results of the patients with removed posterior longitudinal ligament (PLL) were compared with those of the patients with preserved PLL in the treatment of cervical spondylotic myelopathy (CSM).

Objective: To investigate effect of resection of the PLL in anterior decompression for CSM.

Summary of background data: Anterior decompression has been proved to be effective in the treatment of CSM, and the pathogenic matters including herniated disc, proliferative osteophyte, and ossification of posterior longitudinal ligament should be definitely removed. However, it still remains controversial to remove degenerative or hypertrophic PLL, considering the potential risks of dura tears and neurologic injury.

Methods: Between March 1997 and December 2002, 58 patients who underwent anterior decompression for CSM were included in this study. Among them, the PLL was removed in 31 patients (PLL removed group) and that was preserved in the other 27 patients (PLL preserved group). The clinical [Japanese Orthopedic Association (JOA) score] and radiologic (diameter of the spinal cord on magnetic resonance image) results were compared between 2 groups. The risk of complications and reoperation was also evaluated.

Results: With a 12-month follow-up, the mean JOA score increased from 10.4+/-1.8 to 15.2+/-1.2 in PLL removed group and that increased from 10.7+/-1.6 to 14.6+/-1.1 in PLL preserved group. The improvement rate between 2 groups was significantly different (74%+/-23% vs. 63%+/-21%, P<0.01). Radiologic study showed that the increase of diameter of the spinal cord in PLL removed group was significantly greater than that in PLL preserved group (3.78+/-1.25 mm vs. 2.02+/-1.03 mm P<0.01). Only 1 patient with PLL removed developed cerebrospinal fluid leakage after operation, and 8 patients (5 with PLL preserved and 3 with PLL removed) need posterior revision surgery.

Conclusions: Removal of PLL was generally safe and helpful to get more decompression in anterior approach for CSM, although more technically demanding.

MeSH terms

  • Aged
  • Cervical Vertebrae / diagnostic imaging
  • Cervical Vertebrae / pathology
  • Cervical Vertebrae / surgery*
  • Decompression, Surgical / instrumentation
  • Decompression, Surgical / methods
  • Diskectomy / methods
  • Dura Mater / anatomy & histology
  • Dura Mater / injuries
  • Dura Mater / surgery
  • Female
  • Humans
  • Hypertrophy / diagnostic imaging
  • Hypertrophy / pathology
  • Hypertrophy / surgery
  • Intervertebral Disc Displacement / diagnostic imaging
  • Intervertebral Disc Displacement / pathology
  • Longitudinal Ligaments / diagnostic imaging
  • Longitudinal Ligaments / pathology
  • Longitudinal Ligaments / surgery*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neurosurgical Procedures / instrumentation
  • Neurosurgical Procedures / methods*
  • Ossification of Posterior Longitudinal Ligament / diagnostic imaging
  • Ossification of Posterior Longitudinal Ligament / pathology
  • Ossification of Posterior Longitudinal Ligament / surgery
  • Postoperative Complications / etiology
  • Postoperative Complications / physiopathology
  • Postoperative Complications / prevention & control
  • Radiography
  • Retrospective Studies
  • Spinal Canal / diagnostic imaging
  • Spinal Canal / pathology
  • Spinal Canal / surgery
  • Spinal Cord Compression / diagnostic imaging
  • Spinal Cord Compression / pathology
  • Spinal Cord Compression / surgery*
  • Spinal Fusion / instrumentation
  • Spinal Fusion / methods
  • Spondylosis / diagnostic imaging
  • Spondylosis / pathology
  • Spondylosis / surgery*
  • Treatment Outcome