Profiles of Spinal Cord Tumors Removed through a Unilateral Hemilaminectomy

OBJECTIVE: To present the profiles of spinal cord tumors that can be removed through a unilateral hemilaminectomy and to demonstrate its usefulness for benign spinal cord tumors that significantly occupy the spinal canal. METHODS: From June 2004 to October 2010, 25 spinal cord tumors were approached with unilateral hemilaminectomy. We calculated the cross-sectional occupying ratio (CSOR) of tumor to spinal canal before and after the operations. RESULTS: The locations of the tumors were intradural extramedullary in 20 cases, extradural in 2, and intramedullary in 3. The levels of the tumors were lumbar in 12, thoracic 9, and cervical 4. In all cases, the tumor was removed grossly and totally without damaging spinal cord or roots. The mean height and width of the lesions we195re 17.64 mm (3-47.5) and 12.62 mm (4-32.7), respectively. The mean CSOR was 69.40% (range, 27.8-96.9%). Postoperative neurological status showed improvement in all patients except one whose neurologic deficit remained unchanged. Postoperative spinal stability was preserved during the follow-up period (mean, 21.5 months) in all cases. Tumor recurrence did not develop during the follow-up period. CONCLUSION: Unilateral hemilaminectomy combined with microsurgical technique provides sufficient space for the removal of diverse spinal cord tumors. The basic profiles of the spinal cord tumors which can be removed through the unilateral hemilaminectomy demonstrate its role for the surgery of the benign spinal cord tumors in various sizes.

Ossification of Spinal Ligaments

This authors reviewed the radiographs of 20,057 patients with spinl radiculomyelopathy from April 1983 August 1990. The incidence and distribtion of the ossification of the spinal ligaments were analized as following. 1) The overall incidence of spinal ligaments ossification was 3.6% among 20,057 patients. 2) The most frequently occurs at lumbar area(67.1%), and then cervical(27.5%) thoracic(0.4%) area as in orders. 3) The OPLL was most common type(2.19%) of these spinal ligaments ossification, and then OALL(0.7%), OLF(0.24%) as in orders. 4) OPLL (1) OPLL was most frequent at lumbar area(58.6%) and then cervical(37.0%), thoracic(0.4%) area as in orders. (2) The cervical OPLL was commonly found at C5 & C6 area and morphologically, the multiple segmented type was most common then continuous type, mixed type and single segmented type in orders. (3) The multiple segmented type was more frequently found at upper cervical area, but the continuous type was more frequent at lower cervical area. 5) OALL (1) OALL was most frequent at lumbar area(86.0%) but thoracic(1.4%) and cervecal area(5.3%) were relatively low in frequency. (2) Of the lumbar OALL, the L4/5 area was most frequent site(37.8%) but the L3/4(25.3%) and L5/S1 area(24.5%) also had relatively high occurance rate. 6) OLF (1) OLF was most frequent at lumbar area(92.7%), but the incidence of OLF was relativerly rare at cervical(2.1%) and thoracic area(5.2%). (2) Of the lumbar OLF, the L4/5 area was most common site(33.1), but L5/S1 area had also high occurance rate(27.2%).