ABSTRACT
Objective To study the diagnosis of thoracic myelopathy caused by ossification of ligamenta flava(OLF) and the influence of the improved surgical procedure on clinic effect. Methods From October 1994 to December 1999, 14 patients with thoracic myelopathy secondary to OLF were diagnosed and treated by improved procedure. The chief clinic manifestation of the disease were insidious and progressive onset of numbness, sensory loss of lower extremities or trunk, motor weakness, gait disturbance and imbalance, hyperreflexia and sphincter dysfunction. 41 levels of OLF were found by means of plain radiography,MRI associated with CT or CTM and were resected.There were 4 levels at T 8-9, 10 levels at T 9-10, 11 levels at T 10-11 and 5 levels at T 11-12. OLF were removed by means of improved posterior “floating”procedure that open “window”at cranial and caudal end and cut“bridge”at left and right side of ossified mass. The latest results were assessed according to JOA scale score system and recovery ratio. the preoperative average JOA scale score was 4.1 point (range 1 to 8 points). Results 14 patients were followed up from 6 to57 months with an average of 23 months. The postoperative average JOA scale score was 9.4 point (range 5 to 11), the recovery ratio was 76.8% and the excellent and good results was 85.6%. The average amount of blood loss was 370 ml and the average operative time was 175 minutes. Conclusion Clinic history and neurological examination associated with MRI and CT or CTM was the important means of the diagnosis of OLF, improved surgical technique was more effective and reliable.オ