ABSTRACT
Objective:To discuss the clinical value of magnetic resonance neurography (MRN) on diagnosis and treatment of lumbosacral nerve injury associated with sacral fractures and analyze the characters of nerve injury which was caused by sacral fractures.Methods:The clinical data of 40 patients who had lumbosacral nerve injury associated with sacral fractures and accepted treatment in Tianjin hospital from August 2018 to December 2020 were collected based on inclusion and exclusion criteria. Twenty-four patients had unilateral sacral fractures (Tile C1) which included 16 Denis II type fractures and 8 Denis III type fractures. Sixteen patients had bilateral sacral fractures which were all Tile C3, U shaped and Denis II type sacral fractures. All patients had symptoms or signs of lumbosacral nerve injury, and accepted contrast-enhanced three-dimensional magnetic resonance neurography (CE-3D MRN) to diagnose the injury part and severity degree. The L 5-S 4 nerves were separated to three parts based on injured side and intraspinal type (IS), intraforaminal type (IF) and extraforaminal type (EF) location, and were judged the mild, medium or severe degree of nerve injury severity. Overall and pairwise Chi-square test was performed on the number of nerve injuries. Eleven patients accepted the operation of nerve dissection and exploration. The nerve injury part and severity were recorded under direct vision, and were statistically analyzed with CE-3D MRN outcome. Results:The outcome of 239 lumbosacral nerve injuries which had different part and severity were found by MRN, and all combined with sacral fractures of the same side. The nerves which ranked from largest to fewest according to injured numbers were L 5, S 1, S 2, S 3 and S 4. The statistical analysis showed that there were significant differences of injured nerve numbers except between S 1 and S 2, S 3 and S 4, and there were no significant difference of nerve injury part and severity degree between the direct visual judgement intraoperatively and preoperative CE-3D MRN examination. Conclusion:MRN can reveal the part and severity degree of lumbosacral nerve injury associated with sacral fracture clearly and accurately, which has important clinical value and should become the preferred examination of such injuries. The lumbosacral nerve injury has the most frequent features of S 1 and S 2, followed by L 5, and the least in S 3 and S 4.
ABSTRACT
Objective:To measure the anatomical parameters of three-dimensional available space of S 1 and S 2 vestibules on Chinese adults by imaging methods, and discuss their clinical values. Methods:Data of 200 cases of pelvic CT with complete posterior ring were collected from January 2015 to January 2021, included 110 males and 90 females. The ages ranged from 21 to 63 years (average, 40.72±10.70 years). Then the parameters of both the left vestibule and the right vestibule of S 1 and S 2 such as vestibular width, vestibular height and vestibular area were measured by the three-dimensional CT reconstructions. Statistical analyses were performed among the groups which were classified according to the gender, side of vestibule to compare the difference of vestibular morphological characteristics among different groups. Results:The average vestibular area of S 1 was 425.71± 45.07 mm 2 (range, 296.3-604.4 mm 2), which was 449.80±28.62 mm 2 (range, 338.3-604.4 mm 2) in males and 388.25±34.01 mm 2 (range, 296.3-498.4 mm 2) in females. The average vestibular width was 28.52±4.34 mm (range, 17.1-36.3 mm), 31.77±2.33 mm (range, 22.46-36.30 mm) in males and 24.55±2.55 mm (range, 17.1-26.1 mm) in females. The mean vestibular height was 21.05±2.29 mm (range, 17.5-32.0 mm), with 21.34±2.37 mm (range, 18.5-32.0 mm) of men and 20.69±1.60 mm (range, 17.5-25.6 mm) of women. The mean S 2 vestibular area was 230.19±35.57 mm 2 (range, 142.5-297.3 mm 2), which was 258.91±28.04 mm 2 (range, 218.3-297.3 mm 2) in males and 205.61±24.12 mm 2 (range, 142.5-258.6 mm 2) in females. The average vestibular width was 15.94±1.72 mm (range, 12.4-20.3 mm), 16.51±1.59 mm (range, 14.4-20.3 mm) in male and 15.25±1.63 mm (range, 12.4-18.1 mm) in female. The mean vestibular height was 14.30±1.20 mm (range, 12.9-17.8 mm), 15.49±1.46 mm (range, 13.6-17.8 mm) in males and 13.73±0.93 mm (range, 12.9-16.1 mm) in females. There were significant differences in vestibular width, height and area between S 1 and S 2 (vestibular width t=3.934, P< 0.001; vestibular height t=3.692, P< 0.001; vestibular area t=4.816, P< 0.001). There were significant differences in S 1 vestibular width, S 1 vestibular height, S 1 and S 2 vestibular area between male groups and female groups (S 1 vestibular width: t=2.969, P=0.003; S 1 vestibular height: t=0.316, P=0.049; S 1 vestibular area: t=1.975, P=0.049; S 2 vestibular area: t=2.023, P=0.044). While there was no significant difference in S 2 vestibular width and height between the two gender groups. There were significant differences in S 1 and S 2 vestibular width, height and area between male and female groups ( P < 0.001). There were no significant difference in parameters between the left and right values of the same vestibular site. Conclusion:The parameters of S 1 sacral vestibule are larger than that of S 2. It implies that S 1 was more feasible to insert iliosacral screws than S 2; lesser diameter iliosacral screws should be selected to insert into S 2. The female S 1 vestibule is smaller than the male, so the iliosacral screws placement has more stringent requirements on the selection of the insertion point and the direction of the screw. And the surgeon can utilize the intact contralateral sacral vestibule as the damaged side to proceed the iliosacral screw inserted simulation.
ABSTRACT
<p><b>OBJECTIVE</b>To synthesize a biodegradable non-viral gene carrier with a high transfection efficiency and a low cytotoxicity.</p><p><b>METHODS</b>Poly(ethylene glycol)-block-(poly(L-glutamic acid)-graft-polyethylenimine) was prepared via ammonolysis of poly(ethylene glycol)-block-poly (γ-benzyl L-glutamate) with the low-molecular-mass polyethylenimine (600 Da). The synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. The polyplex micelle from PEG-b-(PG-g-PEI) and plasmid DNA (pDNA) was studied using dynamic light scattering, zeta-potential measurements, and gel retardation assay. The in vitro cytotoxicity and transfection efficiency of PEG-b-(PG-g-PEI) were tested by MTT assay and luciferase assay in HEK 293T cells using PEI (25 kDa) as the control.</p><p><b>RESULTS</b>PEG-b-(PG-g-PEI) could efficiently condense DNA into nanosized particles with positive surface charges when the N/P ratio of polymer and DNA was above 5:1. The zeta potential of the polyplexes was about 25 mV, and the particle size was 120 nm at a N/P ratio of 10. The cell toxicity and gene transfection evaluations showed a lower cytotoxicity and a higher gene transfection efficiency of the copolymer than PEI 25000 in HEK 293T cells.</p><p><b>CONCLUSIONS</b>The polymer can be used as a potential non-viral gene carrier for gene therapy.</p>