Is It Real False Negative Finding in Motor Evoked Potential Monitoring during Corrective Surgery of Ankylosing Spondylitis? A Case Report

We performed L1 posterior vertebral columnar resection and posterior correction for Andersson's lesion and thoracolumbar kyphosis in an ankylosing spondylitis patient during motor evoked potential (MEP) monitoring. We checked MEP intra-operatively, whenever a dangerous procedure for neural elements was performed, and no abnormal findings were seen during surgery. After the operation, we examined neurologic function in the recovery room; the patient showed a progressive neurologic deficit and no response to MEP. After emergency neural exploration and decompression surgery, the neurologic deficit was recovered. We questioned whether to acknowledge the results of this case as a false negative. We think the possible reason for this result may be delayed development of paralysis. So, we recommend that MEP monitoring should be performed not only after important operative steps but also after all steps, including skin suturing, for final confirmation.

Association of Estrogen Receptor 2(ESR 2) Gene Polymorphisms with Ossification of the Posterior Longitudinal Ligament of the Spine

STUDY DESIGN: Genetic screening of the estrogen receptor 2 (ESR2) genes in patients with ossification of the posterior longitudinal ligament (OPLL). OBJECTIVE: We studied the relationships between ESR2 gene polymorphisms and OPLL to understand the pathophysiology of OPLL. SUMMARY OF LITERATURE REVIEW: The OPLL has a strong genetic component. Several familial surveys and human leukocyte antigen (HLA) haplotype studies reveal that genetic background is an important component in the occurrence of OPLL and a large number of gene analysis studies were utilized to clarify the susceptible gene for OPLL, including COL11A2, BMP-2, TNF-alpha, NPPS, leptin receptor, transforming growth factor (TGF)-beta, Retinoic X receptor, ER, IL-1, PTH, and VDR have been performed. MATERIALS AND METHOD: Genomic deoxyribonucleic acid (DNA) samples obtained from 164 patients (93 men and 71 women) with OPLL and 219 control subjects, without the disease (105 men and 114 women) were amplified by polymerase chain reaction, and polymorphism genotypes were determined by the restriction endonuclease digestion. The distribution of genotypes was compared between the patients with the disease and the control subjects. RESULTS: The polymorphism of ESR2 [rs1256049, exon6, Val328Val, p=0.018, odd ratio (OR)=2.41, 95 confidence interval (CI)=1.15-5.02 in the recessive model] only showed statistically significant association between the control and the OPLL groups. The rest SNPs of ESR2 did not show any significant differences between the control and the OPLL groups. CONCLUSIONS: Estrogen receptor 2 (ESR2) gene polymorphisms (rs 1256049) was associated with OPLL. In future studies, we will perform target SNP chip between OPLL and candidate gene.

Comparative Study of the Clinical Outcomes of Unilateral Transforaminal Lumbar Interbody Fusion(TLIF) with Bilateral TLIF using Wiltse Approach and Conventional Approach

STUDY DESIGN: Comparative study. OBJECTIVES: To compare the outcomes of unilateral TLIF, bilateral TLIF using Wiltse approach and bilateral TLIF using conventional midline approach. SUMMARY OF LITERATURE REVIEW: There are many studies about outcomes of Unilateral TLIF, but few have compared the 3 different fusion procedures. MATERIALS AND METHODS: 60 patients were divided into 3 groups. Each group has enrolled 20 patients (Study group: unilateral TLIF, Control group 1: bilateral TLIF using Wiltse approach, Control group 2: bilateral TLIF using conventional midline approach). For clinical outcomes, we compared operative time, blood loss, time for ambulation and discharge, VAS for back pain and leg pain and ODI among three groups. For radiologic evaluation, disc height and segmental lordosis were examined. RESULTS: The mean operative time was 147 minutes in study group(SG), 172 minutes in control group 1(CG1), 167 minutes in control group 2(CG2). The mean total blood loss was 466ml in SG, 569ml in CG1, 1140ml in CG2 respectively. VAS for back pain at the third postoperative day significantly decreased in SG and CG1 compared with CG2. There was no significant difference in ODI, disc height and segmental lordosis among the groups. CONCLUSION: Using Wiltse approach, there were several advantages in decreasing blood loss, immediate postoperative back pain, hospital stay and early ambulation. Clinical and radiological results of unilateral TLIF were comparable with bilateral TLIF.

Posterior Dynamic Stabilization with Selective Wide Decompression for Multilevel Lumbar Stenosis: Preliminary Result / 대한척추외과학회지

STUDY DESIGN: A prospective study OBJECTIVES: We wanted to assess the clinical outcomes of posterior dynamic stabilization with selective wide decompression for treating multilevel lumbar stenosis in old age. SUMMARY OF THE LITERATURE REVIEW: Deciding on the segments to be operated on is challenging problem for old age patients with multilevel lumbar stenosis. There have been no reports on posterior dynamic stabilization with selective wide decompression for treating multilevel lumbar stenosis. MATERIALS AND METHODS: We evaluated 18 patients who underwent posterior dynamic stabilization with selective decompression for multilevel disc degeneration and spinal stenosis. The mean age was 70.2 years and mean follow-up was 15.1 months. We evaluated the segmental angle, the range of motion (ROM) and pedicle screw loosening. The clinical results were evaluated according to the operative time, blood loss, the visual analogue scale (VAS) for the back pain and leg pain and and the Oswestry disability index (ODI). RESULTS: The mean number of operated segments was 2.16. The lordosis of the lumbar and operated segments showed no significant difference. However, the ROM of the total lumbar spine and the operation segment was significantly decreased from 36.8 to 24.3 and 22.9 to 13.1, respectively. The ROM for the adjacent segment did not show a significant difference. A radiolucent line around the pedicle screw appeared at 22 screws (19.3%) out of a total 114 screws. The VAS for back and leg pain were improved from 7.5 and 8.6 to 2.3 and 2.1, respectively. The ODI was improved from 41.5 to 13.4. CONCLUSIONS: The initial clinical outcomes were favorable after posterior dynamic stabilization with selective decompression. This procedure could be considered to be a useful option for treating multilevel stenosis in old age patients.

Latarjet Operation for Anterior Shoulder Instability with Glenoid Bone Defect

PURPOSE: We wanted to evaluate the clinical results of the Latarjet procedure for treating anterior shoulder instability combined with a glenoid bone defect. MATERIALS AND METHODS: Between Oct. 2006 and May. 2007, fourteen patients underwent a Latarjet operation to treat their anterior shoulder instability combined with a glenoid bone defect. The mean follow-up period was 15 months (range: 12 to 19 months), and the average age at the time of surgery was 29.9-years-old (range: 19 to 44 years). There were 13 males and 1 female. Eight patients exhibited involvement of the right shoulder. The dominant arm was involved in 8 patients. Six patients had undergone a previous arthroscopic Bankart repair before their Latarjet operation and 2 patients had a history of seizure. RESULTS: The average Rowe score improved from 51.8 to 80.2 with 9 excellent, 4 good, and 1 fair results. The average Korean shoulder score for instability improved from 61.6 to 82.1 postoperatively. The active forward flexion and external rotation at the side of the involved shoulder was an average of 8degrees and 16degrees less than that of the uninvolved shoulder. The muscle strength of the involved shoulder measured 78.7% in forward flexion and 82.5% in external rotation, as compared with that of the uninvolved shoulder. There was 1 case of dislocation, 1 transient subluxation, 2 fibrotic unions, 1 resorption of the transferred coracoid process, 1 intraoperative broken bone, 1 transient musculocutaneous nerve injury and 1 case of stiffness. CONCLUSION: The Latarjet procedure for treating anterior shoulder instability combined with a significant glenoid defect effectively restores function and stability through extending the articular arc at the expense of external rotation. We should be cautious to avoid or detect complications when performing coracoid transfer.