Objective To compare the clinical outcomes of posterior lumbar interbody fusion（PLIF） using simple cage alone fusion with pedicle screw fixationand autogenous bone grafting and cage fusion with pedicle screw fixation in adult spondylolisthesis. Methods From March 2003 to March 2004，Twenty-seven patients with lumbar spondylolisthesis were divided in two groups. In group A, 15 patients were treated by PLIF using simple cage alone fusion with pedicle screw fixation, including 4 males and 11 females, aging 53-68 years. Isthmic defectswere located at L4 in 9 cases, at L5 in 6 cases. Four patients were smokers.Thepreoperative mean disc space height was 5.4±2.3 mm, the mean percentage of slip was 36.8％±7.2%. In group B, 12 patients were treated by PLIF using autogenous bone grafting and cage fusion with pedicle screw fixation, including 3 males and 9 females, aging 56 years. Isthmic defects were located at L4 in 8 cases, atL5 in 4 cases. Five patients were smokers. The preoperative mean disc space height was 5.7±2.5 mm, the mean percentage of slip was 37.8%±6.2%. Two groupswere compared in the amount of blood loss, duration of hospitalization, back pain, radiating pain, fusion rate, the intervertebral disc space height, the postoperative degree of slip and the fusion rate. Results All patientswere followed up for 24-38 months. The mean follow-up was 29(24-36) months in group A and26(24-38) months in group B. There were no statistically significant differences infollow-up period, age,sex, the location of isthmic defects, smoking, the preoperative disc space height and the percentage of slip between two groups (Pgt;0.05).There were no statistically significant differences in the amount of blood loss, the duration of hospitalization, the fusion time between two groups(Pgt;0.05). But there were statistically significant differences in the back pain score, the radiating pain score and the fusion rate between two groups(Plt;0.05).Thepo stoperative disc space height and the degree of slip of the last follow-up were5.8±2.2 mm and 25.6％±7.2% in group A, 6.2±2.5 mm and 24.1％±7.4 % ingroupB, showing statistically significant difference (Plt;0.05). Conclusion The PLIF using autogenous bone grafting and cage fusion with pedicle screw fixations ismore beneficial to improving the fusion rate and preventing longterm instabilities than simple cage alone fusion with pedicle screw fixation in adult spondylolisthesis.
【Abstract】 Objective To produce a new bone tissue engineered carrier through combination of xenograft bone (X)and sodium alginate (A) and to investigate the biological character of the cells in the carrier and the abil ity of bone-forming in vivo, so as to provide experimental evidence for a more effective carrier. Methods BMSCs were extracted from 2-week-old New Zealand rabbits and the BMSCs were induced by rhBMP-2 (1 × 10-8mol/L). The second generation of the induced BMSCs was combined with 1% (V/W) A by final concentration of 1 × 105/mL. After 4-day culture, cells in gel were investigated by HE staining. The second generation of the induced BMSCs was divided into the DMEM gel group and the DMEM containing 1% A group. They were seeded into 48 well-cultivated cell clusters by final concentration of 1 × 105/mL. Seven days later, the BMP-2 expressions of BMSCs in A and in commonly-cultivated cells were compared. The second generation of the induced BMSCs was mixed with 2% A DMEM at a final concentration of 1 × 1010/mL. Then it was compounded with the no antigen X under negativepressure. After 4 days, cells growth was observed under SEM. Twenty-four nude mice were randomly divided into 2 group s (n=12).The compound of BMSCs-A-X (experimental group) and BMSCs-X (control group) with BMSCs whose final concentrat ion was 1 × 1010/mL was implanted in muscles of nude mice. Bone formation of the compound was histologically evaluated by Image Analysis System 2 and 4 weeks after the operation, respectively. Results Cells suspended in A and grew plump. Cell division and nuclear fission were found. Under the microscope, normal prol iferation, many forming processes, larger nucleus, clear nucleolus and more nuclear fission could be seen. BMP-2 expression in the DMEM gel group was 44.10% ± 3.02% and in the DMEM containing 1% A group was 42.40% ± 4.83%. There was no statistically significant difference between the two groups (P gt; 0.05). A was compounded evenly in the micropore of X and cells suspended in A 3-dimensionally with matrix secretion. At 2 weeks after the implantation, according to Image Analysis System, the compound of BMSCs-A-X was 5.26% ± 0.24% of the totalarea and the cartilage-l ike tissue was 7.31% ± 0.32% in the experimental group; the compound of BMSCs-X was 2.16% ± 0.22% of the total area and the cartilage-l ike tissue was 2.31% ± 0.21% in the control group. There was statistically significant difference between the two groups (P lt; 0.05). At 4 weeks after the operation, the compound of BMSCs-A-X was 7.26% ± 0.26% of the total area and the cartilage-l ike tissue was 9.31% ± 0.31% in the experimental group; the compound of BMSCs-X was 2.26% ± 0.28% of the total area and the cartilage-l ike tissue was 3.31% ± 0.26% in the control group. There was statistically significant difference between the two groups (P lt; 0.05). Conclusion The new carrier compounding A and no antigen X conforms to the superstructural principle of tissue engineering, with maximum cells load. BMSCs behave well in the compound carrier with efficient bone formation in vivo.