Two-Staged Circumferential Decompression and Fusion Surgery for Upper Thoracic Myelopathy Caused by Concurrent Beak-type Ossification of the Posterior Longitudinal Ligament and Ligamentum Flavum at T1-2 level: A Case Report.

BACKGROUND: Upper thoracic myelopathy caused by combined ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) is relatively rare. This clinical condition is difficult to treat, and a surgical method has not been fully established. We report an extremely rare case of severe thoracic myelopathy caused by concurrent beak-type OPLL and OLF at T1-2.

CASE DESCRIPTION: A 53-year-old woman with paresthesia of both legs and inability to hold a standing position presented to our hospital. Radiological images showed a large beak-type OPLL at T1-2 and OLF at T1-7; the spinal cord was severely compressed at T1-2. First, posterior decompression and instrumentation fusion at C6-T4 was performed, with T1-2 bilateral parallel gutter-making along the dural tube into the vertebral bodies covering the extent of OPLL. Second, anterior decompression of OPLL with corpectomy of T1-2 and fusion using iliac bone grafting was performed following the sternal manubrium splitting approach. In the deep operating field of the second surgery, the gutters made during the first surgery were helpful for judging the width and thickness of OPLL during the anterior decompression procedure. Postoperatively, neurological symptoms greatly improved, the patient could walk independently, and the Japanese Orthopaedic Association score improved from 3 preoperatively to 8 at final postoperative follow-up at 16 months.

CONCLUSIONS: Two-staged circumferential decompression and fusion surgery is considered an effective surgical method for upper thoracic concurrent OPLL and OLF. The bilateral gutters made during the first surgery improved the safety and feasibility of this difficult operation.