Sang Hoon Yoon

Minimum 2-year follow-up result of degenerative spinal stenosis treated with interspinous u (coflex).

OBJECTIVE Clinical and radiological results of posterior dynamic stabilization using interspinous U (ISU, Coflex, Paradigm Spine Inc.(R), NY, USA) were analyzed in comparison with posterior lumbar interbody fusion (PLIF) in degenerative lumbar spinal stenosis (LSS). METHODS A retrospective study was conducted for a consecutive series of 61 patients with degenerative LSS between May 2003 and December 2005. We included only the patients completed minimum 24 months follow up evaluation. Among them, 30 patients were treated with implantation of ISU after decompressive laminectomy (Group ISU) and 31 patients were treated with wide decompressive laminectomy and posterior lumbar interbody fusion (PLIF; Group PLIF). We evaluated visual analogue scale (VAS) and Oswestry Disability Index (ODI) for clinical outcomes (VAS, ODI), disc height ratio disc height (DH), disc height/vertebral body length x100), static vertebral slip (VS) and depth of maximal radiolucent gap between ISU and spinous process) in preoperative, immediate postoperative and last follow up. RESULTS The mean age of group ISU (66.2 +/- 6.7 years) was 6.2 years older than the mean age of group PLIF (60.4 +/- 8.1 years; p = 0.003 ). In both groups, clinical measures improved significantly than preoperative values (p < 0.001). Operation time and blood loss was significantly shorter and lower in group ISU than group PLIF (p < 0.001). In group ISU, the DH increased transiently in immediate postoperative period (15.7 +/- 4.5% --> 18.6 +/- 5.9%), however decreased significantly in last follow up (13.8 +/- 6.6%, p = 0.027). Vertebral slip (VS) of spondylolisthesis in group ISU increased during postoperative follow-up (2.3 +/- 3.3 --> 8.7 +/- 6.2, p = 0.040). Meanwhile, the postoperatively improved DH and VS was maintained in group PLIF in last follow up. CONCLUSION According to our result, implantation of ISU after decompressive laminectomy in degenerative LSS is less invasive and provides similar clinical outcome in comparison with the instrumented fusion. However, the device has only transient effect on the postoperative restoration of disc height and reduction of slip in spondylolisthesis. Therefore, in the biomechanical standpoint, it is hard to expect that use of Interspinous U in decompressive laminectomy for degenerative LSS had long term beneficial effect.

Long-term outcomes of surgical resection with or without adjuvant radiation therapy for treatment of spinal ependymoma: a retrospective multicenter study by the Korea Spinal Oncology Research Group

BACKGROUND We sought to determine the surgical treatment and functional outcome and identify the predictors of survival in a retrospective cohort of patients with spinal cord ependymoma using data collected from the Korea Spinal Oncology Research Group database. METHODS The data regarding 88 patients who had been surgically treated for histologically confirmed spinal cord intramedullary and extramedullary ependymoma from January 1989 to December 2009 were retrospectively reviewed. RESULTS Histopathological examination revealed myxopapillary ependymoma in 24 patients, ependymoma in 61 patients, and anaplastic ependymoma in 3 patients. Gross total removal was achieved in 72 patients, subtotal removal in 15 patients, and partial removal in 1 patient. Twenty patients were treated with postoperative radiation. Fifty-two patients had stable or improved postoperative neurological function, while 36 experienced neurological deterioration. A permanent decrease in McCormick classification grade was seen in 17 patients. The progression-free survival rate was 87% for all patients at 5 years and 80% at 10 years. During follow-up, local recurrence/progression was seen in 13 patients. Diffuse meningeal spread developed in 2 anaplastic ependymoma patients. Postoperative radiotherapy after incomplete resection did not significantly correlate with longer times to recurrence. Multivariate analysis revealed histology and surgical extent of resection as independent predictors of longer progression-free survival. CONCLUSIONS Gross total removal alone is a good treatment strategy for spinal ependymomas. Early diagnosis and surgery, before severe paralysis, are important to obtain good functional outcomes. Subtotal resection with radiation therapy for intramedullary lesions appears to offer no advantages over gross total removal.

Comparative analysis of 3 different construct systems for single-level anterior cervical discectomy and fusion: stand-alone cage, iliac graft plus plate augmentation, and cage plus plating.

Study Design: A retrospective cohort-nested longitudinal study. Objective: To evaluate radiologic and clinically functional outcomes after single-level anterior cervical discectomy and fusion (ACDF) using 3 different fusion construct systems applying an accurate and reliable methodology. Summary of Background Data: ACDF is an established procedure that uses 3 different fusion construct systems: cage alone (CA), iliac tricortical bone block with plate (IP), and cage with plate construct (CP). The outcome of a previous study is quite different and did not correlate with experimental studies. Methods: ACDF was performed on 158 patients (90 male and 68 female), who were followed up for >12 months. The patients were divided into the following 3 treatment groups: CA, IP, and CP. Factors related to outcome were also evaluated. Fusion rate, subsidence rate, and cervical angles were used to measure radiologic outcome. The Odom criteria and the visual analog scale were used to evaluate the clinical outcome. Results: The fusion rate was higher for patients in the IP (87.1%) and CP (79.5%) groups than for those in the CA group (63.2%) after 12 months of follow-up (P=0.019). The subsidence rate was lower for patients in the IP (28.1%) and CP (38.5%) groups than for those in the CA group (58.6%) (P=0.010). Subsidence occurred for the anterior height regardless of constructs. Radiating arm pain showed greater relief in the CP group than in the CA group (P=0.015). It improved more in the CP group than in the IP group, but the differences were not statistically significant (P=0.388). Other clinical outcomes did not show significant differences. Conclusions: The trend of excellent radiologic outcome was observed for IP≥CP>CA. Plating may play a key role in the support of anterior height. As a result, plating prevents segmental kyphosis and subsidence and promotes bone fusion. Although the overall clinical outcomes were not different among the 3 groups, except for arm pain, more favorable trends regarding clinical outcome were observed for CP≥IP>CA.

The volumetric analysis of cement in vertebroplasty: relationship with clinical outcome and complications.

Study Design. Prospective study. Objective. The aim of this study was to demonstrate the safe range of cement volume during percutaneous vertebroplasty. Summary of Background Data. A few clinical reports have addressed the relationship between cement volume and clinical outcome. However, the weakness of these studies was that subjects included were not homogeneous. No study in the clinical setting has confirmed results from biomechanical and computational studies. Methods. We examined 96 patients with single compression fractures who underwent percutaneous vertebroplasty and postoperative three-dimensional CT scan within a week between June 2006 and April 2009. The volume and fraction were measured by a CT volumetry program. Relationships between predictors and volumetric data, outcome, leakage, intraverterbal vacuum cleft (IVVC), and subsequent fracture were examined. Relationships between volumetric data and outcome, leakage, IVVC, and subsequent fracture were analyzed with stratification by the treated level. Receiver–operator characteristic (ROC) curves were plotted to acquire cut-off values of volumetric data. Results. Seventy-three patients (76%) were female, and the mean age was 76.3 ± 8.4 years (range 53–97). The mean duration of follow-up was 11 months (range 6–21). Locations were as follows: T4–T10 9, T11-L1–L57, and L2–L4 30. Seventy-eight patients (81%) reported a favorable outcome. Fractured body volume (FBV) and the level treated were associated with fraction, which had an influence on outcome. The fraction of the favorable group was significantly higher. Cut-off values to acquire a favorable outcome were 11.64% (P = 0.026) on the T4-L4 level and 3.35 cm3 (P = 0.059), 11.65% (P = 0.059) on the T11-L1 level. Group with intradiscal leakage had a smaller volume than nonleakage group on the L2–L4 level (3.86 cm3 vs. 5.65 cm3, P = 0.002). There were no relationships of volumetric data with epidural leakage and pulmonary embolism. The presence of IVVC increased volume on the T4-L4 and L2–L4 level (P < 0.03). Larger volume increased significantly the incidence of adjacent fracture on the L2–L4 level. The significant cut-off volume to avoid adjacent fracture was 4.90 cm3 on the ROC curve. Conclusion. It is suggested that fraction is superior to volume for predicting outcome on the T11-L1 level and an amount of cement should be determined in terms of FBV and fraction according to the treated level. A lower fraction than required for the restoration of mechanical property was enough to obtain pain relief. Intradiscal leakage on the L2–L4 level may be inevitable to obtain appropriate mechanical properties in the case of severe endplate breakdown connected with the disc space. Smaller volume is needed to avoid an adjacent fracture on the L2–L4 level. Although we did not know the reason why there was a difference among the treated level groups, one thing that is certain is the fact that level-specific approaches may be necessary for good outcome in terms of volume, fraction and FBV.

Inflammatory myofibroblastic tumor in the intradural extramedullary space of the lumbar spine with spondylolisthesis: case report and review of the literature

An inflammatory myofibroblastic tumor (IMT) is a rare disease entity reported to arise in various organs but still thought to be a neoplastic or reactive inflammatory condition controversially. The author reports an extremely rare case of intradural extramedullary IMT of lumbar spine which was presenting radiculopathy and neurogenic intermittent claudication due to concomitant spondylolisthesis.

The Efficacy of Lumbar Hybrid Stabilization Using the DIAM™ to Delay Adjacent Segment Degeneration: An Intervention Comparison Study With a Minimum Two-Year Follow-up.

BACKGROUND: Although posterior lumbar interbody fusion (PLIF) has a successful fusion rate, the long-term outcome of PLIF is occasionally below expectations because of adjacent segment degeneration (ASD). OBJECTIVE: To evaluate the ability of hybrid stabilization using DIAM (Device for Interspinous Assisted Motion) to delay ASD. METHODS: An intervention comparison study of 75 patients (hybrid, 25; PLIF, 50) was performed. The indications for hybrid stabilization were facet joint degeneration, Pfirrmann grade II to III, and stenosis at the rostral adjacent segment. The PLIF group consisted of patients matched for age, sex, and fusion. The hybrid stabilization procedure included traditional PLIF and DIAM installation at a superior adjacent segment. The outcomes were analyzed with a linear mixed model analysis. Conditional logistic regression was performed to calculate the odds ratio for the association of surgical methods. RESULTS: The hybrid group (24%) revealed fewer ASDs than the PLIF group (48%). Among ASDs, spondylolisthesis occurred more frequently in the PLIF group than the hybrid group. Hybrid surgery was significantly associated with ASD; the odds ratio for hybrid surgery was 0.28 compared with PLIF. Foraminal height of the PLIF group decreased more than the hybrid group (P = .01). Segmental mobility showed a greater increase in the PLIF group than the hybrid group (P = .04). However, the clinical outcomes did not show significant differences between the groups. CONCLUSION: Hybrid stabilization with DIAM and pedicle screws can be used for patients with facet degeneration at adjacent segments but should be further investigated. ABBREVIATIONS: ASD, adjacent segment degeneration FH, foraminal height ODI, Oswestry Disability Index PLIF, posterior lumbar interbody fusion VAS, Visual Analog Scale

Anteroposterior spondyloschisis of atlas with incurving of the posterior arch causing compressive myelopathy.

Study Design. A case report of a patient with a combined anterior and posterior arch anomaly of atlas leading to compressive myelopathy. Objective. To describe a rare presentation of cervical stenosis at the atlas where congenital defects of the posterior arch with an incurving portion exists. This report includes a feasible hypothesis for the development of this anomaly on the basis of previous hypotheses and surgical findings. Summary of Background Data. Congenital defects of the posterior arch of atlas are uncommon and congenital symptomatic cervical stenosis is very rarely seen at this level. The congenital midline cleft of the posterior arch of an atlas has been described in patients with progressive motor symptoms and sensory deficit in extremities. Methods. An 11-year-old boy suffered from right side weakness for 1 year. His mother witnessed his awkward walking and clumsiness in using chopsticks and writing. His medical history was unremarkable, and there was no history of significant trauma. Right upper limb weakness of Grade IV/V and difficulty in hopping on right leg was checked on neurologic examination. The magnetic resonance image showed cervical canal stenosis at atlas level and high signal intensity change in the spinal cord. The computed tomography demonstrated partial defect at anterior and posterior arch of the atlas with incurving at defect site leading to cord compression. Suspecting one of craniovertebral junction anomalies, we performed a surgical resection of the posterior arch of the atlas (decompressive laminectomy). Results. The laminectomy was done. The defect site of the posterior arch was substituted with a cartilage and there was no dural adhesion. After surgery, right lower limb weakness was improved and no instability has been observed during 1-year follow-up. Conclusion. We describe the association between compressive myelopathy and combined anteroposterior spondyloschisis of an atlas with incurving of the arch at defect site. Both computed tomography and magnetic resonance image were required to demonstrate the bony configuration and cord compression. And decompressive laminectomy of atlas was effective as a treatment for this compressive myelopathy caused by midline defect in the posterior atlantal arch with bony incurving.

Extraosseous multiple myeloma mimicking spinal epidural metastasis

A 42-year-old man presented with a one-month history of upper back pain and a two-week history of progressive spastic paraparesis. Thoracic spinal MRI showed an epidural mass with spinal cord compression at T6-8 but no bony involvement. The patient underwent T6-8 laminectomy for decompression. Lumbosacral MRI and CT scans revealed bony abnormalities on the sacrum and left posterior iliac bone. Immunohistochemical studies confirmed the diagnosis of multiple myeloma (MM). Thus, this patient suffered from extraosseous MM without adjacent bony involvement or distant skeletal involvement.

An Extensive Intramedullary Epidermoid Cyst with a Longstanding History of Paraplegia: A Case Report

Spinal cord tumors still challenge clinicians because of their neurological deterioration before and after surgery. Epidermoid cyst is one of the rare intramedullary lesions producing neurological deterioration in cervical spine and it has been reported four times in the literature. We report the case of an intramedullary epidermoid cyst showing a longstanding history of paraplegia as well as recent slowly progressive tingling paresthesia extending from C4 to T10 and weakness in both hands.

Adult Spinal Intramedullary Ependymomas: Complete Resection

Achieving gross total resection of the tumor is one of the most important factors in promoting long-term recurrence-free survival in the management of spinal intramedullary ependymomas. Therefore, total resection is primary goal of treatment in the modern era. In this perspective, presence of natural dissection plane between the tumor and the spinal cord is crucial to achieve gross total resection. Some large tumors, often devoid of dissection plane, may preclude gross total resection and increase the risk of postoperative neurological compromise. Moreover, modalities of intraoperative neurophysiological monitoring have evolved recently to avoid additional neurological deficits in resection of these tumors. In this chapter, we describe up-to-date knowledge about spinal intramedullary ependymomas including refined operative techniques for complete resection and surgical outcome.