Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage.

OBJECTIVE: The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. METHODS: A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. RESULTS: During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (≥7mm) (p=0.037) were significantly associated with subsidence. CONCLUSION: The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (≥7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.

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.

Early significant tumor volume reduction after radiosurgery in brain metastases from renal cell carcinoma results in long-term survival.

PURPOSE: To retrospectively evaluate survival of patients with brain metastasis from renal cell carcinoma (RCC) after radiosurgery. PATIENTS AND METHODS: Between 1998 and 2010, 46 patients were treated with radiosurgery, and the total number of lesions was 99. The mean age was 58.9 years (range, 33-78 years). Twenty-six patients (56.5%) had a single brain metastasis. The mean tumor volume was 3.0 cm(3) (range, 0.01-35.1 cm(3)), and the mean marginal dose prescribed was 20.8 Gy (range, 12-25 Gy) at the 50% isodose line. A patient was classified into the good-response group when the sum of the volume of the brain metastases decreased to less than 75% of the original volume at a 1-month follow-up evaluation using MRI. RESULTS: As of December 28, 2010, 39 patients (84.8%) had died, and 7 (15.2%) survived. The overall median survival time was 10.0 ± 0.4 months (95% confidence interval, 9.1-10.8). After treatment, local tumor control was achieved in 72 (84.7%) of the 85 tumors assessed using MRI after radiosurgery. The good-response group survived significantly longer than the poor-response group (median survival times of 18.0 and 9.0 months, respectively; p = 0.025). In a multivariate analysis, classification in the good-response group was the only independent prognostic factor for longer survival (p = 0.037; hazard ratio = 0.447; 95% confidence interval, 0.209-0.953). CONCLUSIONS: Radiosurgery seems to be an effective treatment modality for patients with brain metastases from RCC. The early significant tumor volume reduction observed after radiosurgery seems to result in long-term survival in RCC patients with brain metastases.

Changes in the cross-sectional area of multifidus and psoas in unilateral sciatica caused by lumbar disc herniation.

OBJECTIVE: To quantitatively evaluate the asymmetry of the multifidus and psoas muscles in unilateral sciatica caused by lumbar disc herniation using magnetic resonance imaging (MRI). METHODS: Seventy-six patients who underwent open microdiscectomy for unilateral L5 radiculopathy caused by disc herniation at the L4-5 level were enrolled, of which 39 patients (51.3%) had a symptom duration of 1 month or less (group A), and 37 (48.7%) had a symptom duration of 3 months or more (group B). The cross-sectional areas (CSAs) of the multifidus and psoas muscles were measured at the mid-portion of the L4-5 disc level on axial MRI, and compared between the diseased and normal sides in each group. RESULTS: The mean symptom duration was 0.6±0.4 months and 5.4±2.7 months for groups A and B, respectively (p<0.001). There were no differences in the demographics between the 2 groups. There was a significant difference in the CSA of the multifidus muscle between the diseased and normal sides (p<0.01) in group B. In contrast, no significant multifidus muscle asymmetry was found in group A. The CSA of the psoas muscle was not affected by disc herniation in either group. CONCLUSION: The CSA of the multifidus muscle was reduced by lumbar disc herniation when symptom duration was 3 months or more.

Clinical analysis of thoracic ossified ligamentum flavum without ventral compressive lesion.

The aim of this study was to analyze the clinical characteristics of thoracic ossified ligamentum flavum (OLF) and to elucidate prognostic factors as well as effective surgical treatment modality. The authors analyzed 106 thoracic OLF cases retrospectively from January 1999 to December 2008. The operative (n = 40) and the non-operative group (n = 66) were diagnosed by magnetic resonance imaging (MRI) and/or computed tomography (CT) imaging. We excluded cases exhibiting ventral compressive lesions causing subarachnoid space effacement in thoracic vertebrae as well as those with a coexisting cervical compressive myelopathy. Those in the operative group were treated with decompressive laminectomy as well as resection of OLF. The preoperative neurologic status and postoperative outcomes of patients, as indicated by their modified Japanese Orthopedic Association (mJOA) scores and recovery rate (RR), Modic changes, the axial (fused or non-fused) and sagittal (omega or beak) configurations of OLF, and the ratios of the cross-sectional area (CSA) and anteroposterior diameter (APD) of the most compressed level were studied. The most commonly affected segment was the T10-11 vertebral body level (n = 49, 27.1%) and the least affected segment was the T7-8 level (n = 1, 0.6%). The ratios of the CSA in non-fused and fused types were 77.3 and 59.3% (p < 0.001). When Modic changes were present with OLF, initial mJOA score was found to be significantly lower than those without Modic change (7.62 vs. 9.09, p = 0.033). Neurological status improved after decompressive laminectomy without fusion (preoperative vs. last mJOA; 7.1 ± 2.01 vs. 8.57 ± 1.91, p < 0.001). However, one patient exhibited transient deterioration of her neurological status after surgery. In the axial configuration, fused-type OLF revealed a significant risk for a decreased postoperative mJOA score (0-7, severe and moderate) (Odds ratio: 5.54, χ (2) = 4.41, p = 0.036, 95% CI: 1.014-30.256). The results indicated that the new categorization of axial-type of OLF is a helpful predictor of postoperative patient outcome and fused type was related with poor prognosis. In OLF cases free from ventral lesions compressing the spinal cord, decompressive laminectomy is enough for successful surgical outcome. Therefore, early surgical treatment will be considered in cases with fused-type OLF compressing spinal cord even though they do not have myelopathic symptoms.

Temozolomide for malignant primary spinal cord glioma: an experience of six cases and a literature review.

Malignant primary spinal cord gliomas (PSCGs) are rare, and the optimal treatment for these lesions remains controversial. We report herein treatment outcomes of six malignant PSCGs managed with temozolomide (TMZ)-based multidisciplinary treatment. TMZ was administered concomitantly with fractionated radiotherapy for two newly diagnosed primary spinal cord glioblastoma multiforme (GBM), followed by adjuvant chemotherapy with TMZ. For one anaplastic astrocytoma (AA) and one anaplastic ependymoma (AEPN), TMZ was given as adjuvant therapy at first recurrence. One malignantly transformed ependymoma (EPN) and one malignantly transformed diffuse astrocytoma (DA) were treated with TMZ after radiotherapy at second recurrence. Two patients with newly diagnosed GBM died, 12 and 16 months, respectively, after being treated with TMZ, during and after radiation therapy. One patient with AA and one with malignantly transformed EPN showed good response to salvage therapy with TMZ and had stable disease 21 and 20 months, respectively, after TMZ treatment. One patient with recurrent AEPN and one with malignantly transformed DA died from uncontrolled progression of the lesions despite TMZ chemotherapy. Three patients developed grade 1 or 2 neutropenia, anemia, and infection. Nonhematologic toxicities occurred in all patients; however, they were below grade 3 in severity. TMZ treatment may have a positive effect on control of malignant PSCGs and survival for some patients. Specifically, treatment with TMZ during and after radiation therapy might provide survival benefit to patients with primary spinal cord GBM. A multicenter cooperative investigation for a large-scale study on malignant PSCGs may be required.