Fig. 2From: Comparison of percutaneous endoscopic thoracic decompression and posterior thoracic laminectomy for treating thoracic ossification of the ligamentum flavum: a retrospective studyA Preoperative CT (sagittal). B Mark the cranial boundary of ossification on the surface of the lamina with the trephine. C Mark the caudal boundary of ossification on the surface of the lamina with the trephine. Dotted line; Roughly delimit the removal range of the laminaBack to article page