Vertebral Endplate Cyst Formation in Relation to Properties of Interbody Cages.

OBJECTIVE: This retrospective study aimed to compare vertebral endplate cyst formation (VECF), an early predictor for pseudoarthrosis, in different types of interbody cages. METHODS: We reviewed 84 cases treated with single-level posterior/transforaminal lumbar interbody fusion. We utilized a polyetheretherketone cage in 20 cases (group P), a titanium cage in 16 cases (group Ti), a titanium-coating polyetheretherketone cage in 13 cases (group TiP) and a porous tantalum cage in 35 cases (group Tn). VECF was evaluated comparing the computed tomography scans taken at day 0 and 6-month postoperation. We defined VECF (+) as enlargement of a pre-existing cyst or de novo formation of a cyst with the diameter over 2 mm. We calculated the adjusted odds ratio (OR) and 95% confidence intervals (CIs) as an indicator of association between different types of cages and VECF using a logistic regression model. RESULTS: VECF was observed in 13 (65%), 7 (44%), 9 (69%), and 8 (23%) cases in groups P, Ti, TiP and Tn, respectively. VECF correlated with the type of cage (p = 0.04). In comparison with group P, the proportion of VECF (+) cases was lower in group Tn (OR, 0.16; 95% CI, 0.04-0.60) but not different in group Ti (OR, 0.47; 95% CI, 0.10-2.20) and group TiP (OR, 1.06; 95% CI, 0.21-5.28). No patient underwent additional surgery for the fused spinal level during the follow-up periods (average, 37.9 months; range, 6-76 months). CONCLUSION: VECF was the least in the porous Tn cage, suggesting its potential superiority for initial stability.

Early Development of Syringomyelia after Spinal Cord Injury: Case Report and Review of the Literature.

We report a case of post-traumatic syringomyelia (PTS), which developed 2 months after spinal cord injury (SCI). A 20-year-old man who was involved in a motorcycle accident sustained a complete SCI resulting from a burst fracture of the T5 vertebral body. He underwent posterior fixation with decompression at another hospital 2 days after the injury. Postoperative imaging suggested that spinal stenosis endured at the T4 level and swelling of the spinal cord above that level. Two months later, he felt dysesthetic pain in his forearms and hands, but the cause of the pain was not examined in detail. Four months after the injury, he presented with motor weakness in the upper extremities. Magnetic resonance imaging (MRI) showed syringomyelia ascending from the T3 level to the C1 level, and he was referred to our hospital immediately. The imaging studies suggested that PTS was caused by congestion of the cerebrospinal fluid (CSF) at the T3 level. The patient was treated with syringosubarachnoid (SS) shunt at the T1-T2 level, whereby neurological symptoms of the upper extremities were immediately relieved. Postoperative MRI showed shrinkage of the syrinx. At the latest follow-up 2 years postoperatively, there was no sign of recurrence. It is noteworthy that PTS potentially occurs in the early phase after severe SCI. We discuss relevant pathology and surgical treatment through a review of previous literature.

[Analysis of Post-Recurrence Survival of Resected Lung Cancer with Brain Metastasis].

METHODS: We retrospectively evaluated the post-recurrence survival of 37 cases with brain metastases out of 439 consecutive resected cases of primary lung cancer between 2001 and 2017. FINDINGS: There was no difference in survival according to tumor size but survival was significantly shorter in patients with larger numbers of tumors. Patients initially treated with stereotactic radiosurgery(SRS)or surgical resection survived longer than those with whole-brain irradiation(WBI)(median survival: 23 months for SRS, 17 months for surgical resection, and 4 months for WBI: p<0.001 between SRS and WBI). CONCLUSIONS: As SRS is recommended for 1-4 tumors with maximum diameters ofC3 cm and surgical resection is recommended for tumors larger than 3 cm, these effective locoregional therapies should be aggressively adopted for local control of brain metastases with the aim of improved QOL and prolonged survival. Due to the deterioration of neurocognitive function, WBI should be avoided as initial treatment for brain metastases when effective locoregional therapy or systemic chemotherapy is available and reserved for leptomeningeal dissemination or miliary metastases.

Adult Case of Atlantoaxial Rotatory Fixation Treated with In Situ Fixation Using an Unusual Posterior Instrumentation Construct.

Atlantoaxial rotatory fixation (AARF) occurs commonly in children who have undergone trauma. It is usually corrected with conservative therapy. In this report, however, the patient was an adult with AARF who was treated surgically. A 64-year-old woman presented with a 1-year history of spastic gait and hand clumsiness. Imaging studies revealed the presence of AARF, os odontoideum, and severe spinal cord compression at that spinal level. As the AARF had not been responded to head traction with a halo device, we decided to treat the patient with in situ posterior fixation. Because the rigid dislocation was present between the atlas and the axis, we were forced to make an unusual instrumentation construct. Neurological symptoms other than hand numbness diminished after the surgery, and arthrodesis was obtained between the occiput and the axis. It should be noted that surgical planning for posterior instrumentation construct is required when rigid AARF is treated surgically.

Report of a familial case of proatlas segmentation abnormality with late clinical onset.

Although proatlas segmentation abnormalities as developmental remnants around the foramen magnum have been reported in postmortem studies, they are rarely documented in a clinical setting. This report details the clinical and radiological characteristics of a rare case of proatlas segmentation abnormalities with clinical onset during the seventh decade of life. This case was suspected to have a familial factor. We also review the literature regarding this condition.

[Two cases of lung cancer patients with postoperative brain metastases obtaining long-term survival after gamma knife radiosurgery].

We report two cases of lung cancer patients with postoperative solitary brain metastases obtaining long-term survival after gamma knife stereotactic radiosurgery. Both were seventies men and had good performance status without active extracranial disease. In one case, an asymptomatic metastatic brain tumor 1.8 cm in maximum diameter appeared one year and two months after the operation and was irradiated with gamma knife resulting in complete local control for seven years. He is alive with solitary lung metastasis in good performance status. In the other case, gamma knife was employed for a metastatic brain tumor 2.7 cm in maximum diameter that appeared nine months after the operation accompanying incomplete left hemiplegia. Six months later, the tumor was enlarged and gamma knife was repeated, but the tumor growth could not be suppressed. Following deterioration of hemiplegia and appearance of convulsion, he died of neurological disorder three years and two months after the onset of brain metastasis. Gamma knife stereotactic radiosurgery for metastatic brain tumors is less invasive and a repeatable technique, and is expected to provide a good local control and a survival benefit for appropriately selected patients.

Brain herniation into the middle ear following temporal bone fracture.

Otorrhea of leaked cerebrospinal fluid and meningitis in a 33-year-old male originated from an encephalic herniation into the middle ear following traumatic temporal bone fracture. CT demonstrated a mixed-type fracture consisting of a longitudinal fracture and a posterior oblique fracture of the left temporal bone. The left tegmen tympani was broken into a bellows-like shape and a bone splinter from it had stuck in the epitympanum at the level of the incus body. Surgery via a middle cranial fossa approach confirmed penetration of the brain tissue between the incus and lateral semicircular canal. The diagnosis and management of this condition are discussed in the context of a literature review.