Risk Factors Associated with 90-Day Readmissions Following Occipitocervical Fusion-A Nationwide Readmissions Database Study.

BACKGROUND: Occipitocervical fusion (OCF) procedures are increasing due to an aging population and the prevalence of trauma, rheumatoid arthritis, and tumors. Reoperation rates and readmission risk factors for cervical fusions have been established, but in relation to OCF they have not been explored. This study investigates the patterns of readmissions and complications following OCF using a national database. METHODS: The 2016 U.S. Nationwide Readmissions Database was used for sample collection. Adults (>18 years) who underwent OCF were identified using the 2016 ICD-10 coding system, and we examined the readmission rates (30-day and 90-day) and reoperation rates. RESULTS: Between January and September 2016, a total of 477 patients underwent OCF; the 30-day and 90-day readmission rates were 10.4% and 22.4%, respectively. The 90-day reoperation rate related to the index surgery was 5.7%. Mean age (68.58 years) was significantly greater in the readmitted group versus nonreadmitted group (61.76 years) (P < 0.001). The readmitted group had a significantly higher Charlson Comorbidity Index and Elixhauser Comorbidity Index (5.00 and 2.41, respectively) than the nonreadmitted group (3.25 and 1.15, respectively; P < 0.001). Nonelective OCF showed a higher readmission rate (29.18%) versus elective OCF (12.23%) (P < 0.001). Medicare and Medicaid patients showed the highest rates of readmission (27.27% and 20.41%, respectively). Readmitted patients had higher total health care costs. CONCLUSIONS: Nonelective OCF was found to have a readmission rate of almost 2½× that of elective OCF. Understanding risk factors associated with OCF will help with operative planning and patient optimization.

[Efficacy of halo-vest fixation in the assessment and prediction of the effectiveness of permanent fixation in a patient with basilar invagination with ambiguous vertebral instability].

Basilar invagination is a developmental anomaly of the craniovertebral junction in which the odontoid abnormally prolapses into the foramen magnum. It is also associated with Chiari malformation, syringomyelia, and hydrocephalus. Patients require surgical treatment to prevent progression of neurological symptoms, but assessment of anterior or posterior decompression can be difficult owing to bone instability and ambiguous compression of neural structures. Here, we describe a case of basilar invagination in a young adult. He presented with neurological symptoms, including syringomyelia, 3 months after a traffic trauma that might have led to instability of the bony structures. Since it was unclear whether the instability of the bony structures contributed to the clinical deterioration, the patient was first treated using halo-vest fixation. Significant improvements were observed in both neurological symptoms and magnetic resonance images. These results justified the invasive fixation and the patient was treated further with an occipito-cervical fusion ; good results were achieved in this case. Owing to the invasiveness of the procedure, occipito-cervical fixation should only be adopted following strict indication criteria. Halo-vest fixation was effective in treating the instability of the bony structures and as a trial treatment for permanent fixation.

Assessment of cognitive function before and after surgery for posterior cranial fossa lesions using computerized and conventional tests.

Cognitive function has not been well studied after neurosurgery for posterior fossa lesions despite its potential importance in determining surgical indications and approaches. The present study evaluated changes in cognitive functions after posterior fossa surgery to detect any differences between the middle cranial fossa and lateral suboccipital approaches in 50 patients with posterior fossa lesions such as tumors and vascular diseases. Twenty-five patients underwent surgery via the middle fossa and 25 via the lateral suboccipital approaches. Computerized test battery (CogState) and conventional neuropsychological tests (serial seven-word learning test and mini-mental state examination) were examined before, 1 month after, and 3 months after surgery. All scores of the neuropsychological tests remained within normal limits after surgery. However, the scores of one computerized test battery and serial seven-word learning tests decreased significantly 1 month after surgery and recovered within 3 months, indicating temporary deterioration of short-term memory in the middle fossa group. The computerized tests detected significantly larger numbers of patients with worsened results than the conventional tests. The middle fossa approach and operation time showed correlations with the postoperative neuropsychological declines. The computerized tests could be performed easily and were beneficial for detecting subtle changes of the cognitive function after surgery. Cognitive function, especially short-term memory, may decline temporarily with the middle fossa approach and long operation time.

[Microsurgical anatomy and quantitative assessment of suboccipital median transcerebellomedullary fissure keyhole approach].

OBJECTIVE: To assess the suboccipital median transcerebellomedullary fissure keyhole approach in a cadaver model by using a neuronavigation system and explore its feasibility and operative indications. METHODS: Six 10% formaldehyde-fixed adult cadaveric head and neck specimens injected with colored latex were chosen for the study. First the suboccipital median transcerebellomedullary fissure keyhole approach was performed and the anatomical structures were observed under operative microscope. The exposed floor area of the fourth ventricle and the vertical and transverse angles at the point where the line between the lateral apertures crossing the median sulcus, vertical angle at the apertures of midbrain aqueduct and the obex were measured with the aid of a frameless stereotactic navigation device. Parameters were compared with those when C1 posterior arch was removed, and also with those under conventional approach with or without C1 arch. RESULTS: By means of adjusting specimen positions and the angle of operative microscope, as tela choroidea and inferior medullary velum were dissected gradually, the structures of floor, lateral recesses and lateral apertures of the fourth ventrical, vermian and aperture of midbrain aqueduct were exposed. There were no significant difference in the exposed floor area of the fourth ventricle between the keyhole approach and conventional approach (P = 0.06), and the C1 arch removal can't increase the exposed area (P = 0.84). The conventional approach have wider angles than the keyhole approach (P < 0.01), and the C1 arch removal increased the vertical angle (P < 0.05), but not the horizontal angle (P > 0.05). CONCLUSION: The suboccipital median transcerebellomedullary fissure keyhole approach can expose similar anatomic architectures as that of the conventional approach. Thus it can be used to remove the tumors located in the fourth ventricle, dorsum of pons and medullary oblongata and cerebellar vermis.

Characterization and functional assessment of patients subjected to occipito-cervical fusion for rheumatoid atlanto-axial dislocation.

20 patients with rheumatoid arthritis and atlanto-axial dislocation subjected to occipito-cervical fusion were studied. The patients were evaluated by a rheumatologist before surgery and 6-12 months after the fusion procedure. Joint tenderness was assessed by Ritchie's Index while the functional capacity was evaluated using a health assessment questionnaire and according to the classification by Steinbrocker. Localization and character of the symptoms from the head-neck region were registered. The neck pain was measured on a visual analogue scale. Radiographs of hands and wrists were obtained before surgery and joint destruction was classified according to the Larsen Dale Index. Reduction of pain and neurological symptoms was observed in the majority. There was, however, little evidence of improved functional capacity.