Clinical Results And Prognostic Factors for Thoracic Myelopathy Caused by Ossification of Yellow Ligament after Surgical Treatment

STUDY DESIGN: Retrospective study. OBJECTIVES: We analyzed the clinical results of thoracic myelopathy caused by ossification of yellow ligament (OYL) and to explore prognostic factors after surgical treatment. SUMMARY OF LITERATURE REVIEW: Thoracic myelopathy due to OYL is difficult to treat; surgery is considered as treatment of choice. However, studies of the clinical results and prognostic factors are few due to its rare presentation. MATERIALS AND METHODS: Twenty six patients who had surgery for thoracic myelopathy caused by OYL were evaluated from February 2002 to April 2012. We describe the analysis of the clinical results after surgery and prognostic factors. RESULTS: Modified Japanese orthopedic association (JOA) score was recorded in all patients by 5.7+/-1.3 points (range, 2-9 points) preoperatively, 7.8+/-1.7 points (range, 4-10 points) postoperatively, and 8.4+/-2.1 points (range, 5-11 points) at final follow-up. Hirabayashi recovery rate was recorded by 60.2+/-20.2% (range, 45.5-72.0%) postoperatively, 64.5+/-17.3% (range, 50.2-75.1%) at final follow-up. The Visual Analogue Scale (VAS) score was also improved by 7.6+/-1.8 points (range, 7-10 points) preoperatively, 4.5+/-1.3 points (range, 3-6 points) postoperatively, and 3.8+/-1.6 points (range, 2-5 points) at final follow-up. Both modified JOA score and VAS score improved significantly (p<0.05). In prognostic factor analysis, OYL type on CT axial image, duration of symptom, and preoperative severity of myelopathy was significant (p<0.05). CONCLUSION: We showed the effectiveness of surgery on patients who suffer from thoracic myelopathy caused by OYL and that OYL type identified by CT axial image, duration of symptom, and preoperative severity of myelopathy were significant prognostic factors.

Changes of Spinopelvic Parameter using Iliac Screw In Surgical Correction of Sagittal Imbalance Patients

STUDY DESIGN: A retrospective-based study. OBJECTIVES: To evaluate the usefulness of iliac screws in the surgical correction of sagittal imbalance by changes of spinopelvic parameters. SUMMARY OF LITERATURE REVIEW: Although reports exist regarding the fusion rates on lumbosacral fusion by iliac screws, no previous studies address the issue of changes of spinopelvic parameters on surgical correction of sagittal imbalance by iliac screws. MATERIALS AND METHODS: We analyzed a total of 23 patients who were operated on by pedicle subtraction osteotomy and posterior fusion on sagittal imbalance. Patients were divided into two groups: 1) non-iliac screw fixation and; 2) iliac screw fixation. The two groups were compared during the preoperative and postoperative stages, and the last follow-up spinopelvic parameters of two groups. RESULTS: Spinopelvic parameters, except for pelvic incidence, were corrected after surgery; some corrected values of spinopelvic parameters were lost during follow-up. There was a statistically significant difference in the last follow-up period between lumbar lordosis and pelvic tilt. Values of postoperative lumbar lordosis and pelvic tilt was similar to each other; however, during the follow-up period corrected values of spinopelvic parameters of non-iliac screw fixation group were more lost. There were no statistically significant changes in postoperative and last follow-up sacral slope and pelvic incidence. CONCLUSIONS: Sagittal imbalance could be corrected by pedicle subtraction osteotomy, and corrected values of lumbar lordosis and pelvic tilt of iliac screw fixation group could be maintained well compared to non-iliac screw fixation. Iliac screw fixation could be useful for maintenance of corrected values of spinopelvic parameters in surgical correction of sagittal imbalance.

Proximal Junctional Problems in Surgical Treatment of Lumbar Degenerative Sagittal Imbalance Patients and Relevant Risk Factors

STUDY DESIGN: Retrospective study. OBJECTIVES: As we analyze the incidence and the risk factor for proximal junctional problem after surgical treatment of lumbar degenerative sagittal imbalance, we want to contribute to reducing the junctional problem of surgical treatment of lumbar degenerative sagittal imbalance. SUMMARY OF LITERATURE REVIEW: Surgical treatment of degenerative spinal deformity has increased. Rigid fixation was a risk factor for degenerative change of adjacent segment and failure, and it remains a big challenge for the junctional problem of surgical treatment. However, research on the correlation with risk factors is rare. MATERIALS AND METHODS: Forty four patients (mean age 66.5; range, 50-74) who had surgery due to lumbar degenerative sagittal imbalance were evaluated by the risk factor associated with junctional problems from January, 2005 to December, 2011. The risk factors were analyzed by surgical factor (proximal fusion level, using iliac screw, correction or undercorrection of lumbar lordosis compared with pelvic incidence) and patient factor (age, bone marrow density, body mass index). RESULTS: Junctional problems occurred in 18 patients (41%) out of 44 patients. Among these problems, there were 10 cases of fractures, 8 cases of junctional kyphosis, and 4 cases of proximal screw pull out. . Among the risk factors, only the correction or undercorrection of lumbar lordosis compared with pelvic incidence in surgical factor was statistically significant. Other surgical factors and patient factors were not statistically significant. CONCLUSIONS: Junctional problems after a surgical treatment of lumbar degenerative sagittal imbalance were common. However, we could not know the exact risk factor of junctional problems except the degree of correction of lumbar lordosis compared with pelvic incidence, because most of the risk factors were not statistically significant. So, further evaluations of the risk factor of lumbar degenerative sagittal imbalance are required.

Complications of Iliac Screw in Spinopelvic Fixation With Adult Spinal Deformity: Complications of Iliac Screw in Spinopelvic Fixation

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate clinical & radiologic significance about complications of spinopelvic fixation with iliac screw in patients with adult spinal deformity. SUMMARY OF LITERATURE REVIEW: Complications of iliac screw fixation in adult spinal deformity patients was obscure in spite of the good results of iliac screw fixation. MATERIALS AND METHODS: We analyzed 27 patients, followed over 1-year, with adult spinal deformity (lumbar degenerative kyphosis, degenerative lumbar scoliosis, flat back syndrome). The study was done for complications of iliac screw fixation by clinical and radiological evaluations. RESULTS: Post-operative iliac screw prominence were 15 cases (55.5%), iliac screw breakage was 1 case (3.7%), bursitis was 1 case (3.7%), sacroiliac joint pain were 5 cases (18.5%), halo sign around iliac screw were 23 cases (85.1%), and 3 cases (11.1%) were performed reoperation. There was no significance between halo sign and sacroiliac joint pain. CONCLUSIONS: Iliac screw fixation is a very useful operative method without severe complications on spinopelvic fixation. There are some complications of iliac screw fixation and iliac screw prominence is a most common problem, but few counterplan exits. So, further studies about reducing complication method, management protocols of iliac screw complication were needed.

Clinical Characteristics and Surgical Results of Spinal Intradural Tumor

STUDY DESIGN: A retrospective study about spinal intradural tumor. OBJECTIVES: We analyzed clinical symptom, findings of MRI, and surgical outcome of spinal intradural tumor. SUMMARY OF LITERATURE REVIEW: Intradural tumors are not commonly reported and they show non-specific clinical features. MATERIALS AND METHODS: In this study, 18 patients who underwent surgical treatment and radiologically and pathologically diagnosed as spinal intradural tumor from 1997 to 2009 were reviewed. We evaluated pain, neurological symptoms, location of tumor as well as degrees of signal intensity and its enhancement of MRI(T1 and T2). And clinical outcomes were analyzed according to Klekamp-Samii scoring system and Visual Analogue Scale(VAS). RESULTS: All patients were clinically suffered from back pain and radiating pain of lower extremity including 3 patients with neurological symptoms. We radiologically found single tumor in 16 cases and masses more than two lesion in 2 cases. 1 case was located on cord level(T7), 14 cases cauda equine level, and 3 cases sacral level. We performed laminectomy in 18 cases and posterior instrumentation was applied to 8 cases. In clinical features, mean Klekamp-Samii score was improved from 21.6 to 23.5(p<0.05) and VAS was recovered from 5.2 to 3.0 (p<0.05). CONCLUSIONS: Spinal intradural tumor has non-specific clinical symptoms. Therefore we should perform MRI to find intradural tumor and active management including surgical treatment should be performed due to clinically good results.