The Surgical Treatment of Ossification of Ligamentum Flavum of Thoracic and Thoracolumbar Spine / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: The authors reviewed 14 patients with neurologic deficits caused by ossification of ligamentum flavum(OLF) of thoracic and thoracolumbar spine. OBJECTIVE: To evaluate the clinical and roentgenographic characteristics and suggest the treatment method of the OLF in the thoracic and thoracolumbar spine. SUMMARY OF LITERATURE REVIEW The reported OLF mainly developed at the thoracolumbar area. It compressed the spinal cord and resulted to the symptoms of thoracic myelopathy. The methods of treatment were posterior decompression including laminectomy or laminoplasty, and sometimes anterior and posterior decompression, with or without fusion. The OLF was not common disease yet and many surgeons have met a problem in making the decision of the extent of posterior decompression multiple or selective. METHODS: The authors reviewed 14 patients with the OLF using clinical reports and roentgenographic studies. We checked the plain roentgenograms, computed tomograms, and magnetic resonance imagings. We performed the posterior decompression using total laminectomy without fusion. We divided three groups according to the operative methods. Group I included the patients with one or two levels of OLF treated with posterior extensive laminectomy. Group II included the patients with OLF in three or more levels, or combined other cord-compressing diseases. They had been treated with multiple posterior or anterior decompression for the entire cord-compressing levels. Group III included the patients with same conditions as group II but they had been treated with selective decompression for the mainly symptomatic levels of OLF. RESULTS: We found the OLF at 54 segments of 14 patients. The involvement of OLF was 29 segments(53.7%) in thoracolumbar and 25 segments(46.3%) in thoracic area. The most commonly involved segment was T10-11(16.7%) and the second was T11-12(14.8%). Clinically the most common neurologic deficit was motor weakness and sensory deficit. The most symptomatic level of OLF was T10-11 and T12-Ll segment(28.6% at each) and the next was T11-12 segment(21.4%). We got the favorable results in group I and group III. But the final results of group II were not good. CONCLUSION: The OLF was most common at the thoracolumbar area and the symptoms and signs were revealed same as those of the thoracic myelopathy. We obtained favorable clinical results after posterior laminectomy without fusion in cases with the OLF in 1-2 segments. In the cases with multiple OLF in three or more segments, or the cases with other cord-compressing diseases, we could get more favorable results in the patients with the selective decompression than the patients with multiple decompression for the entire cord-compressing diseases.