title: Thoracic myelopathy caused by ossification of the yellow ligament in patients with posterior instrumented lumbar fusion.
abstract: OBJECTIVE
  The objective of this study was to investigate thoracic myelopathy caused by ossification of the yellow ligament (OYL) in patients with posterior instrumented lumbar fusion.
  
  
  METHODS
  Seven patients, who had undergone posterior instrumented lumbar fusion, presented with thoracic myelopathy caused by OYL. No patient had a history of thoracic myelopathy at previous surgery. Instrumented fusions were performed from L1-5 in two patients, L2-5 in three patients and L1-S1 and L2-S1 in one patient each, respectively. MRI and CT scans were performed to confirm cord compression by OYL. Of the seven patients, six patients underwent decompressive laminectomy and OYL removal while one was treated conservatively.
  
  
  RESULTS
  The average time to presentation after first surgery was 63.4 months. OYL was located at T9-10 in two patients, T11-12 in three patients, and T10-11 and T9-11 in one patient each, respectively. All patients had a myelopathic gait and the average Japanese Orthopaedic Association (JOA) score was 3.9, preoperatively. The average JOA score improved from 3.7 to 8 and the average recovery rate was 58.9 % in the six patients who underwent surgical intervention. However, the JOA score fell from 5 to 4 in the one patient who was treated conservatively.
  
  
  CONCLUSIONS
  We report seven patients who suffered from thoracic myelopathy after instrumented lumbar fusion. Surgeons must be aware of the possibility of thoracic myelopathy caused by OYL at the thoracolumbar junction, especially in patients with a complaint of gait disturbance after long instrumented lumbar fusion.
authors: Department of Orthopaedic Surgery, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, 505 Banpo-Dong, Seocho-Gu, Seoul 137-701, Korea. kyh@catholic.ac.kr
authors: Kee-Yong
authors: KY
authors: Ha
authors: Jun-Yeong
authors: JY
authors: Seo
authors: Il-Nam
authors: IN
authors: Son
authors: Young-Hoon
authors: YH
authors: Kim
authors: Ki-Won
authors: KW
authors: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology; D013118:Spinal Cord Diseases / Q000209:etiology*; D013123:Spinal Fusion / Q000009:adverse effects*; D013904:Thoracic Vertebrae