Diagnostic validity of space available for the spinal cord at C1 level for cervical myelopathy in patients with rheumatoid arthritis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate diagnostic validity of space available for the spinal cord (SAC) at C1 level for myelopathy in patients with rheumatoid arthritis (RA). SUMMARY OF BACKGROUND DATA: The relationship of SAC at C1 level with myelopathy has been evaluated by relatively small number of the patients, and 2 criteria have been proposed. METHODS: Two cohorts of the patients with RA were established. Group A consisted of 140 patients with myeopathy due to upper cervical involvement selected from the database. Group B consisted of 99 patients with upper cervical subluxation, but not associated with myelopathy selected from the consecutive series of the hospitalized patients. Distributions of SAC at C1 level in both groups were evaluated. Efficacy indexes for screening (sensitivity, specificity, etc.) were calculated for these patients' population by previously demonstrated 2 criteria. In addition, analysis according to receiver operating characteristic (ROC) curve was performed. RESULTS: The average values of SAC were 11.1 mm in Group A and 16.5 mm in Group B. When cut-off point for myelopathy was defined as 13 mm or less, sensitivity and specificity were 82% and 85%, respectively. When it was defined as 14 mm or less, sensitivity increased (88%) while specificity decreased (74%). Accuracies by these 2 criteria were almost the same (83%, 82%). The left upper corner point of ROC curve was located between these 2 cut-off points. CONCLUSION: Distributions of SAC showed that SAC was a reliable parameter for relating myelopathy in patients with upper cervical subluxation in RA. The plots according to ROC curve showed adequacy of previously demonstrated 2 cut-off points. For the purpose to screen the patients with high risk for myelopathy, 14 mm or less was recommended as a cut-off point of SAC.

Surgical strategy for cervical dumbbell tumors based on a three-dimensional classification.

STUDY DESIGN: Forty-two patients with cervical dumbbell tumors were analyzed retrospectively using a new three-dimensional classification. OBJECTIVES: To establish optimal surgical strategies, we considered shapes and three-dimensional locations of cervical dumbbell tumors based on diagnostic images and intraoperative findings. SUMMARY OF BACKGROUND DATA: Eden's classification for dumbbell tumors of the spine, long considered a "gold standard," no longer is sufficient to determine surgical strategy in view of recent advances in computed tomography and magnetic resonance imaging. METHODS: Forty-two cervical dumbbell tumors were characterized according to transverse-section images (Toyama classification; nine types) and craniocaudal extent of intervertebral and transverse foraminal involvement (IF and TF staging; three stages each). RESULTS: Type IIIa tumors, involving dura plus an intervertebral foramen, accounted for 50% of cases. A posterior approach was used in 35 patients; 7 others underwent a combined anterior and posterior approach. A posterior approach was used for all type IIa and IIIa tumors, and for some type IIIb (upper cervical), IV, and VI tumors; a combined posterior and anterior approach was used for type IIb and the remainder of type IV and VI. Reconstruction was performed using spinal instrumentation in 4 patients (9.5%). Resection was subtotal in 6 patients (14.3%) and total in 36 (85.7%). CONCLUSIONS: Systematic, imaging-based three-dimensional characterization of shape and location of cervical dumbbell tumors is essential for planning optimal surgery. The classification used here fulfills this need.

Posterior circumferential decompression for late onset paraparesis caused by kyphotic deformity due to infantile tuberculosis--case report.

A 46-year-old male presented with late onset of paraparesis caused by kyphotic deformity due to infantile tuberculosis. A posterior circumferential decompression was performed from the sixth thoracic to the eighth thoracic levels. His neurological status improved with no evidence of kyphosis progression at the last follow up (2 years 5 months postoperatively). The paraparesis was caused by bony compression following increasing kyphosis above and below the block vertebrae due to growth. Posterior circumferential decompression is a less invasive surgical intervention for this condition.

Local recurrence after S2-3 sacrectomy in sacral chordoma. Report of four cases.

Excision is the treatment of choice in cases of sacral chordoma. Local recurrences, however, have often been observed even after total en bloc resection. The authors assessed outcomes in four cases of tumor recurrence in patients who underwent total en bloc S2-3 resection for sacral chordomas that were located below S-3. The primary recurrences were located at either side of the lateral portion of the remaining sacrum in all patients. In two patients in whom preoperative magnetic resonance imaging indicated no invasion of the tumor into surrounding soft tissues, recurrence in the resected end of the gluteus maximus or piriformis muscle was also observed. The authors therefore recommend that the S2-3 sacrectomy should be performed over an adequate margin, including a part of sacroiliac joints at the bilateral portions of the sacrum and soft tissues such as the gluteus maximus or piriformis muscle.