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 (> or =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 (> or =7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages.

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.

Eosinophilic Granuloma in an Adult Thoracic Spine: A Case Report

In adults, eosinophilic granuloma of the spine is a rare, benign osteolytic lesion. In a case of a 33-year-old man with neurologic deterioration, magnetic resonance imaging (MRI) showed an osteolytic lesion of the T4 vertebra with spinal cord compression. Involvement of the left pedicle of T4 and paravertebral soft tissue was also observed. On the second day after a fluoroscopic percutaneous needle biopsy, the patient abruptly developed paraplegia. He underwent an emer- gency operation with posterior decompression, followed by anterior stabilization and corpectomy several days later. Histological examination of the tissue, including the paravertebral soft tissue, showed features of eosinophilic granuloma. After surgery, the patient returned to full activity. Eosinophilic granuloma of the spine is a rare disease in adults and may affect all the vertebral structures. Surgical treatment seems necessary for cases specifically involving progressive neurologic deficits.

Management of Recurrent Vestibular Schwannomas

OBJECTIVE: Management of recurrent vestibular schwannomas(VS) after microsurgery or radiosurgery is a complicated subject. However, few studies have documented the outcome of recurrent VS. The authors review clinical experience of recurrent VS management and analyzed the efficacy of treatment modalities. METHODS: Between 1990 and 2002, 293 patients harboring unilateral VS underwent, microsurgery, radiosurgery, microsurgery followed by radiosurgery. Of these, 26 procedures (in 20 patients) were performed to treat recurrent VS. Recurrence was assessed from an increased tumor size by magnetic resonance imaging(MRI). The mean age of patients with recurred VS was 46.9 years and the mean follow-up period was 68 months. Radiological characteristics were investigated and growth rates of recurred tumors were calculated by measuring changes in tumor diameter on MRI after treatment. RESULTS: MRI characteristics revealed a lobulated contour in 75% and a cyst in 60% of the patients. Only 1 patient showed neither lobulation nor a cyst. The average diameter of the recurrent tumors were 36.9 mm. The overall tumor control rate for initial management was 87.4%, 94.7%, and 98.5% for microsurgery, radiosurgery, and microsurgery plus radiosurgery, respectively. However, control rates for recurrent tumors were lower at 85%, 63%, and 80%, respectively. CONCLUSION: A cystic nature and a lobulated tumor contour are frequent clinical characteristics of recurrent VS. Microsurgery or microsurgery followed by radiosurgery shows little difference in tumor control rate for primary and recurrent VS. However, radiosurgery alone appears to be less beneficial for recurrent VS.

Brain Metastasis from Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans(DFSP) is an uncommon fibrohistiocytic tumor characterized by aggressive local invasion and consequent local recurrence rather than distant metastasis. We present a case of a 51-year-old male patient with a typical cutaneous DFSP, which showed local recurrences and distant metastasis to the central nervous system(CNS) and the lung after 15 years from the initial diagnosis. CNS metastatic lesions recurred in 5 months after surgical resection of the first CNS lesion. These metastatic tumors were treated by open surgery and gamma-knife radiosurgery. Despite continuous medication of oral chemotherapeutic agent, the patient died during 1-year follow-up period.