【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.
Objective To investigate the epidemiological and clinical characteristics of patients with thoracolumbar osteoporotic vertebral compression fracture (OVCF) treated by percutaneous vertebroplasty (PVP). MethodsThe clinical and imaging data of 681 patients with thoracolumbar OVCF treated with PVP between January 2017 and December 2021 were collected. The epidemiological and clinical characteristics of the patients with thoracolumbar OVCF in single center were summarized from the aspects of demographic distribution (mainly including gender, age), fracture characteristic analysis [including pathological segments, bone mineral density, and body mass index (BMI)], and operation related results (including the distribution of unilateral and bilateral puncture and bone cement injection, postoperative effectiveness analysis and refracture). ResultsOf the 681 patients, 134 (19.68%) were male and 547 (80.32%) were female, with a male-to-female ratio of 1∶4.08. The age ranged from 53 to 105 years, with an average of 75.3 years. The age group of 60-90 years old had the largest number of patients (91.04%); the high incidence age group of men was 70-90 years old (13.95%), and that of women was 60-80 years old (72.98%). A total of 836 vertebrae were involved, and the morbidity of thoracolumbar vertebrae (T11-L1) was the highest (56.34%, 471/836). The main type of fracture was compression fracture (92.58%, 774/836) and Kümmell disease (7.42%, 62/836). There were 489 cases (71.81%) of osteoporosis, including 66 males and 423 females, with a male-to-female ratio of 1∶6.42. There was significant difference in distribution of bone mineral density between male and female groups (Z=–5.810, P<0.001). BMI showed 206 cases (30.25%) of underweight, 347 (50.95%) cases of normal, 58 cases (8.52%) of overweight, 42 cases (6.17%) of obese, and 28 cases (4.11%) of extremely obese. The difference in BMI distribution between male and female groups was significant (Z=–2.220, P=0.026). Of 836 vertebral bodies, 472 (56.46%) were punctured unilaterally and 364 (43.54%) bilaterally. Most of the vertebral bodies (49.88%, 417/836) were injected with 5.0-6.9 mL bone cement, and most of them were distributed in thoracolumbar and lumbar vertebral bodies (T11-L3). The visual analogue scale (VAS) score and Oswestry disability index (ODI) of patients with unilateral puncture and bilateral puncture significantly improved at 6 months after operation (P<0.001), and also the difference was significant between the two groups in the difference of pre- and post-operation (P<0.001). There were 628 cases (92.22%) with the first occurrence of OVCF, and 53 cases (7.78%) with two or more times of OVCF, all of which were female patients, and 26 cases (49.06%) occurred in the adjacent segment of the previous PVP operation. ConclusionFemale were more than male in OVCF patients. Thoracolumbar vertebral body has the highest morbidity. Patients with low BMI are more likely to have osteoporosis, and patients with high BMI have a higher risk of compression fracture. The amount of bone cement injected through bilateral puncture was greater than that through unilateral puncture.
ObjectiveTo evaluate the operability and effectiveness of a self-developed patellar bone canal locator (hereinafter referred to as “locator”) in the reconstruction of the medial patellofemoral ligament (MPFL). Methods A total of 38 patients with recurrent patellar dislocation who met the selection criteria admitted between January 2022 and December 2022 were randomly divided into study group (the patellar canal was established with a locator during MPFL reconstruction) and control group (no locator was used in MPFL reconstruction), with 19 cases in each group. There was no significant difference in baseline data between the two groups (P>0.05), such as gender, age, body mass index, disease duration, patella Wiberg classification, constituent ratio of cartilage injury, Caton index, tibia tubercle-trochlear groove, and preoperative Lysholm score, Kujal score, Tegner score, visual analogue scale (VAS) score, and so on. The Lysholm score, Kujal score, Tegner score, and VAS score were used to evaluate knee joint function before operation and at 3 days,1 month, 3 months, and 6 months after operation. The ideal prepatellar cortical thickness and canal length were measured before operation, and the actual prepatellar cortical thickness and canal length after operation were also measured, and D1 (the distance between the ideal entrance and the actual entrance), D2 (the ideal canal length minus the actual canal length), D3 (the ideal prepatellar cortical thickness minus the actual prepatellar cortical thickness) were calculated.ResultsPatients in both groups were followed up 6-8 months (mean, 6.7 months). The incision length and intraoperative blood loss in the study group were smaller than those in the control group, but the operation time was longer than that in the control group, the differences were significant (P<0.05). There was no complication such as incision infection, effusion, and delayed healing in both groups, and no further dislocation occurred during follow-up. One patient in the study group had persistent pain in the anserine area after operation, and the symptoms were relieved after physiotherapy. The VAS score of the two groups increased significantly at 3 days after operation, and gradually decreased with the extension of time; the change trends of Lysholm score, Kujal score, and Tegner score were opposite to VAS score. Except that the Lysholm score and Kujal score of the study group were higher than those of the control group at 3 days after operation, and the VAS score of the study group was lower than that of the control group at 3 days and 1 month after operation, the differences were significant (P<0.05), there was no significant difference in the scores between the two groups at other time points (P>0.05). Patellar bone canal evaluation showed that there was no significant difference in preoperative simulated ideal canal length, prepatellar cortical thickness, and postoperative actual canal length between the two groups (P>0.05). The postoperative actual prepatellar cortical thickness of the study group was significantly smaller than that of the control group (P<0.05). D1 and D3 in the study group were significantly higher than those in control group (P<0.05), but there was no significant difference in D2 between the two groups (P>0.05). ConclusionThe locator can improve the accuracy of MPFL reconstruction surgery, reduce the possibility of intraoperative damage to the articular surface of patella and postoperative patellar fractures.