RESUMEN
Anterior lumbar interbody fusion (ALIF) followed by posterior pedicle screw fixation (PSF) in a second procedure is mostly used to implement lumbar spine fusion. ALIF followed by anterior lumbar screw-plate has a lot of advantages, but its biomechanical stability requires confirmation. This study evaluated the biomechanical stability of a novel anterior lumbar locked screw-plate (ALLSP) by comparison with posterior lumbar PSF. Twelve fresh human cadaveric lumbar specimens (L4-L5) were assigned to four groups: ALIF+PSF group, ALIF+ALLSP (both fixed) group, ALIF group and an untreated control (both non-fixed) group. The first three groups received implantation of a rectangular titanium cage. Tests under axial compression, flexion, extension, lateral bending, or rotation showed that the fixed groups had significantly stronger stability than the non-fixed groups (P=0.000 for all). The ALIF+ALLSP group had significantly greater axial stiffness under applied axial compression and significantly less angular displacement under rotational forces than the ALIF+PSF group. The angular displacement of the ALIF+ALLSP group was less under flexion than that of the ALIF+PSF, and the angular displacement under lateral bending and extension was greater, but these differences were not statistically significant. In summary, the ALLSP conforms to the anterior lumbar spine and has good biomechanical stability. It is a reliable choice for enhancing the stability of ALIF.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Placas Óseas , Tornillos Óseos , Vértebras Lumbares , Patología , Ensayo de MaterialesRESUMEN
Anterior lumbar interbody fusion (ALIF) followed by posterior pedicle screw fixation (PSF) in a second procedure is mostly used to implement lumbar spine fusion. ALIF followed by anterior lumbar screw-plate has a lot of advantages, but its biomechanical stability requires confirmation. This study evaluated the biomechanical stability of a novel anterior lumbar locked screw-plate (ALLSP) by comparison with posterior lumbar PSF. Twelve fresh human cadaveric lumbar specimens (L4-L5) were assigned to four groups: ALIF+PSF group, ALIF+ALLSP (both fixed) group, ALIF group and an untreated control (both non-fixed) group. The first three groups received implantation of a rectangular titanium cage. Tests under axial compression, flexion, extension, lateral bending, or rotation showed that the fixed groups had significantly stronger stability than the non-fixed groups (P=0.000 for all). The ALIF+ALLSP group had significantly greater axial stiffness under applied axial compression and significantly less angular displacement under rotational forces than the ALIF+PSF group. The angular displacement of the ALIF+ALLSP group was less under flexion than that of the ALIF+PSF, and the angular displacement under lateral bending and extension was greater, but these differences were not statistically significant. In summary, the ALLSP conforms to the anterior lumbar spine and has good biomechanical stability. It is a reliable choice for enhancing the stability of ALIF.
RESUMEN
<p><b>OBJECTIVE</b>To investigate the protective effects of recombinant SCR15-18 domain of human soluble complement receptor type 1 (sCR1-SCR-15-18) in rats underwent myocardial ischemia and reperfusion (I/R).</p><p><b>METHODS</b>Sprague-Dawley rats were randomly divided into three groups (n = 12 each group): sham (SO); 30 min ischemia/3h reperfusion (I/R) and I/R plus sCR1-SCR15-18 (15 mg/kg before I/R, sCR1). Serum LDH, CK and cardiac myeloperoxidase (MPO) activity were measured. Infarct size, myocardial histopathological changes and myocardial C3c were also compared among groups.</p><p><b>RESULTS</b>Infarct size [(16.1 +/- 3.3)% vs. (22.9 +/- 3.0)%, infarct zone/left ventricular mass, P < 0. 05] and CK [(2532.5 +/- 597.1) U/L vs. (3400.9 +/- 534.9) U/L, P < 0. 05] and LDH [(5436.2 +/- 611.3) U/L vs. (6572.0 +/- 476.3) U/L, P < 0. 05] as well as MPO activity in infarct zone [(0.81 +/- 0.14) U/g vs. (1.12 +/- 0.13) U/g, P < 0.05] were significantly decreased post sCR1 compared to I/R group. sCR1 also significantly attenuated histological myocardial injury and reduced the deposition of C3c in infarct zone.</p><p><b>CONCLUSION</b>sCR1-SCR15-18 protein exerts cardioprotective effects in this rat I/R model.</p>