OBJECTIVETo study the effect of length of cervical anterior fusion on adjacent levels by Biomechanical test.

METHODSSix fresh-frozen human cervical specimens were used in this study. The specimens were tested in flexion, extension, bending and rotation on a spine 3D test system. The specimens were tested intact and then underwent a single-level anterior cervical discectomy and fusion (ACDF) at the C4-5 first, a double-level fusion at the C4-6, and finally extended to triple-level at the C4-7, Based on a hybrid test method. Changes in overall range of motion (ROM), segmental motion and facet joints pressure during flexion, extension, bending and rotation were measured and statistically analyzed.

RESULTSThe overall ROM of the entire spinal construct decreased progressively as the single-level fixation extending to 2-level and 3-level (P < 0.05). A progressive increase in ROM above (C3-4) the fused motion segment units (MSUs) was found during flexion, extension and bending (P < 0.05). In bending and extension, a same result was recorded on the average pressure and max pressure of C3-4 facet joints (P < 0.05).

CONCLUSIONSThis study has demonstrated that the biomechanics at adjacent levels to a cervical spine fusion are altered and that there was progressively increased adjacent segment motion and stress as a single-level ACDF extended to a 3-level fusion, which might lead to the acceleration of adjacent segment degeneration.

Biomechanical Phenomena ; Cadaver ; Cervical Vertebrae ; surgery ; Diskectomy ; methods ; Humans ; Range of Motion, Articular ; Rotation ; Spinal Fusion ; methods

Background::Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by complex and various clinical manifestations. The study aimed to analyze clinical features and cerebral magnetic resonance imaging (MRI) changes of hyperintense white matter (WM) lesions in SLE patients.Methods::This was a retrospective study based on a consecutive cohort of 1191 SLE patients; 273 patients for whom cerebral MRI data were available were enrolled to assess hyperintense WM lesions associated with SLE. Patients were assigned to two groups, ie, with or without hyperintense WM lesions. The MRI assessment showed that the hyperintense WM lesions could be classified into three categories: type A, periventricular hyperintense WM lesions; type B, subcortical hyperintense WM lesions; and type C, multiple discrete hyperintense WM lesions. The clinical and MRI characteristics were analyzed. Factors related to hyperintense WM lesions were identified by multivariate logistic regression analysis.Results::Among the 273 SLE patients with available cerebral MRI scans, 35.9% (98/273) had hyperintense WM lesions associated with SLE. The proportions of types A, B, and C were 54.1% (53/98), 11.2% (11/98), and 92.9% (91/98), respectively. Fifty-one percents of the patients showed an overlap of two or three types. Type C was the most common subgroup to be combined with other types. Compared with those without hyperintense WM lesions, the patients with hyperintense WM lesions were associated with neuropsychiatric SLE (NPSLE), lupus nephritis (LN), hypertension, and hyperuricemia ( P = 0.002, P = 0.018, P = 0.045, and P = 0.036, respectively). Significantly higher rates of polyserous effusions and cardiac involvement were found in the patients with hyperintense WM lesions ( P = 0.029 and P = 0.027, respectively), and these patients were more likely to present with disease damage ( P < 0.001). In addition, the patients with hyperintense WM lesions exhibited a higher frequency of proteinuria ( P = 0.009) and higher levels of CD8 + T cells ( P = 0.005). In the multivariate logistic analysis, hyperuricemia and higher CD8 + T cells percentages were significantly correlated with hyperintense WM lesions in SLE patients ( P= 0.019; OR 2.129, 95% confidence interval [CI] 1.313-4.006 and P < 0.001; OR 1.056, 95% CI 1.023-1.098, respectively). Conclusions::Hyperintense WM lesions are common in SLE patients and significantly associated with systemic involvement, including NPSLE, LN, polyserous effusions, cardiac involvement, and disease damage. Hyperuricemia and a higher number of CD8 + T cells were independent factors associated with hyperintense WM lesions in SLE.

Carrying out extracurricular research activities for undergraduates in medical colleges and universities can stimulate the creativity of undergraduates. This article analyzes the significance, existing problems, and solutions of extracurricular research activities for clinical medical undergraduates. At the same time, corresponding countermeasures are proposed, including standardized training of research operations for students, time coordination of extracurricular research activities for undergraduates, and reasonable arrangement of teaching tasks for tutors. Medical students need to handle the relationship among study, community, part-time jobs, extracurricular activities, and extracurricular research, and make a rational time arrangement for participation. Young teachers in medical colleges and universities should arrange their time reasonably to undertake the corresponding tasks of research and teaching.