Jianxiao Li's research while affiliated with First Affiliated Hospital of China Medical University and other places

Objective: The type AO B2 thoracolumbar fracture is a kind of flexion-distraction injury and the effect of disc injury on treatment results of patients with B2 fracture remains unclear. The objective of the current study was to compare and analyze the outcomes in AO Type B2 thoracolumbar fracture patients with and without disc injuries in terms of the Cobb angle of kyphosis, the incidence of complication, and the rate of implant failure. Methods: This is a retrospective study. Of the 486 patients with thoracolumbar fractures who underwent posterior fixation, 38 patients with AO type B2 injuries were included. All the patients were divided into two groups according to changes in the adjoining discs. Disc injury group A included 17 patients and no disc injury group included 21 patients. Clinical and radiologic parameters were evaluated before surgery, after surgery, and at follow-up. Clinical outcomes included visual analogue scale (VAS) scores, incidence of complications, and incidence of implant failure. Radiologic assessment was accomplished with the Cobb angle (CA), local kyphosis (LK), percentage of anterior vertebral height (AVBH%), intervertebral disc height, and intervertebral disc angle. Fisher's precision probability tests were employed and chi square test were used to compare categorical variables. Paired sample t tests and independent-sample t tests were used to compare continuous data. Results: Disc injury mainly involved the cranial disc (15/19, 78.9%). The mean follow-up period for the patients was 30.2 ± 20.1 months. No neurologic deterioration was reported in the patients at the last follow-up. Radiological outcomes at the last follow-up showed significant differences in the CA (18.59° ± 13.74° vs 8.16° ± 9.99°, P = 0.008), LK (12.74° ± 8.00° vs 6.55° ± 4.89°, P = 0.006), and %AVBH (77.16% vs 90.83%, P = 0.01) between the two groups.Implant failure occurred after posterior fixation in five patients with disc injury who did not undergo interbody fusion during the initial surgery. Additionally, in the subgroup analysis, interbody fusion in the implant failure group were significantly different than in the no implant failure group (0% vs 75%, P = 0.009). Conclusions: AO B2 fracture patients with disc injury have higher risk of complications, especially implant failure after posterior surgery. Interbody fusion should be considered in AO type B2 fracture patients with disc injury.

Background Many types of bone grafting have been reported for successful use in the treatment of lumbar spinal tuberculosis. However, none-structural bone grafting has rarely been studied. This study was aimed to identify the clinical efficacy of nonstructural with structural bone graft for interbody fusion in the surgical treatment of single segment lumbar tuberculosis after one stage posterior debridement. Methods We retrospectively reviewed patients with nonstructural (n=27) and structural (n=22) bone grafting after single-stage posterior debridement and instrumentation for lumbar tuberculosis with at least 24 months of follow-up. Plain radiographs, magnetic resonance imaging, computed tomography scans, and health-related outcomes (e.g., Visual Analog Scale for back pain, the Oswestry Disability Index) were collected and analyzed before and after surgery. Results Both nonstructural and structural bone grafting were associated with significant improvements in the life quality parameters, the laboratory tests, and the Cobb angle of local kyphosis. A slight loss of Cobb angle correction was observed in two groups. Nonstructural bone grafting exhibited the advantages of less operation duration, blood loss and lower bone fusion rate compared with structural bone grafting. There were three complications in the nonstructural bone grafting and four complications in the structural bone grafting group, with no significant difference between two groups. Conclusions In conclusion, nonstructural bone grafting can achieve comparable interbody fusion to structural bone grafting but has less surgical trauma and simpler surgical procedure than structural bone grafting in the treatment of single segment lumbar tuberculosis after one stage posterior debridement and pedicle screws fixation.

Solid fusion at the bone-implant interface (BII) is considered one of the indicators of a satisfactory clinical outcome for spine surgery. Although the mechanical and physical properties of nanohydroxyapatite/polyamide66 (n-HA/PA66) offers many advantages, the results of long-term follow-up for BIIs remain limited. This study aimed to improve the BII of n-HA/PA66 by applying plasma-sprayed titanium (PST) and assessing the mechanical and histological properties. After the PST coating was applied to n-HA/PA66 implants, the coating had uneven, porous surfaces. The compression results were not significantly different between the two groups. The micro-CT results demonstrated that at 6 weeks and 12 weeks, the bone volume (BV), BV/tissue volume (TV) and trabecular number (Tb.N) values of the n-HA/PA66-PST group were significantly higher than those of the n-HA/PA66 group. The results of undecalcified bone slicing showed that more new bone appeared to form around n-HA/PA66-PST implant than around n-HA/PA66 implant. The bone-implant contact (BIC) and push-out test results of the n-HA/PA66-PST group were better than those of the n-HA/PA66 group. In conclusion, after PST coating, direct and additional new bone-to-implant bonding could be achieved, improving the BII of n-HA/PA66 implants. The n-HA/PA66-PST implants could be promising for repair purposes.

Spinal fusion cages have been used in spinal fusion surgery for over 20 years. Polyether-ether-ketone (PEEK) cages are one of the most widely used materials. However, an increasing number of clinical and preclinical studies have shown that as a bioinert material the PEEK cage causes implant failure owing to limited osseointegration. The most common complication is a radiolucent zone at the bone-implant interface. Nanohydroxyapatite/polyamide 66 (n-HA/PA66) is a bioactive composite with sufficient load-bearing properties and good osseointegration abilities. However, in the early stage after surgery, a radiolucent gap can also be observed at the margin of the bone-implant interface. To better assess osseointegration performance as a fusion cage and compare the radiolucent gaps between the two materials, PEEK and n-HA/PA66, implants were prepared and implanted into the femoral condyles of adult New Zealand white rabbits to create a line-to-line bone-implant interface model. The interfaces were systematically investigated using X-ray radiography, histological analysis, scanning electron microscopy (SEM), elemental mapping analysis, micro-computed tomography evaluation, and push-out tests at 4, 8, 12, 24, and 52 weeks. Analysis of X-ray films and histological sections indicated a radiolucent gap around the margin of n-HA/PA66 in the early weeks after implantation (4–8 weeks). The gap narrowed and decreased gradually at 24–52 weeks. Histological analysis and SEM suggested that the formed bone could integrate and adhere in some regions of the implant surface. In addition, a better bone-like apatite layer was formed between the bone and the n-HA/PA66 implant interface than with the PEEK implant. Push-out tests conducted at 24 and 52 weeks to evaluate integrated strength showed that the n-HA/PA66 implants have better bonding strength and sufficient stability, whereas PEEK implants possess poor integrated strength. Therefore, the n-HA/PA66 composite exhibits good osseointegration properties and an improved integrated bone-implant interface.

Adequate bone tissue regeneration has been challenging to achieve at critical-sized bone defects caused by disease. Bone tissue engineering using a combination of scaffolds and bioactive factors provides new hope for the treatment of this extreme condition. Icaritin, a herb-derived chemical, has shown its ability to enhance bone formation both in vitro and in vivo , and it has been found that sub-micron surface structure instructs bone formation in calcium phosphate ceramics (CaPs). Here, we evaluated the possibility of using a submicron surface structured CaP ceramic as the carrier of icaritin for bone tissue regeneration in critical-sized bone defects. Icaritin, an herb-derived chemical, was loaded into a submicron surface structured porous calcium phosphate ceramic (Ø12.8 × 3 mm) to get samples with 0, 10, 50, 250, and 1,250 µg icaritin per CaP disc (M0, M10, M50, M250, M1250 groups, respectively). In vitro evaluation with the certain dosages correlated to those released from the samples showed a dose-dependent enhancement of osteogenic differentiation and mineralization of human bone marrow stromal cells with the presence of osteogenic factors in the culture medium, indicating icaritin is an osteopromotive factor. After intramuscular implantation of the samples in dogs for 8 weeks, a dose-dependent of bone formation was seen with enhanced bone formation at the dosage of 50 and 250 µg. To evaluate the in vivo osteogenic potentials of icaritin-containing CaP ceramic scaffolds in the orthopedic site, a 12.8 mm calvarial defect model in rabbits was established. Micro-computed tomography (micro-CT) and histology results at weeks 4, 8 and 12 post-surgery showed more newly formed bone in M250 group, with correspondingly more new vessel ingrowth. The results presented herein suggested that being osteopromotive, icaritin could enhance bone formation initiated by sub-microstructured CaP ceramics and the CaP ceramics scaffold incorporating icaritin is a promising biomaterial for the treatment of critical-sized defect.

A retrospective study investigated and compared the results of lamina with spinous process (LSP), transverse process strut (TPS) and iliac graft (IG) as bone graft in thoracic single-segment spinal tuberculosis(TB) with the one-stage posterior approach of debridement, fusion and internal instrumentation. 99 patients treated from January 2012 to December 2015 were reviewed. LSP was performed in 35 patients (group A), TPS was undertaken in 33 patients (group B), and IG was carried out in 31 patients (group C). Surgical time, blood loss, hospitalization time, drainage volume, and follow-up (FU) duration were recorded. The visual analog scale (VAS), Oswestry Disability Index (ODI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), American Spinal Injury Association (ASIA) grade, segmental angle, intervertebral height and bone fusion time were compared between preoperative and final FU. All the patients were followed up for a mean 43.90±10.39 months in group A, 45.30±6.20 months in group B, 44.32±7.17 months in group C without difference(P>0.05). The mean age was younger, the blood loss was less, the hospitalization time and the surgical time were shorter in group A than those in group B and C (P<0.05). The drainage volume was less in group A than that in group B and group C. The CRP, ESR, VAS, and ODI were significantly decreased and there were no significant difference among the groups at the final FU. The neurological function after surgery was improved compared with preoperation among the groups. The bony fusion at a mean time 12.90±3.91 months in group A was longer than that in group B (6.75±1.55 months) and group C (5.52±1.64 months) (P<0.05). No significant difference was found at the mean segmental angle, mean intervetebral height of preoperation and final FU among the groups (P>0.05). In conclusion, the LSP and TPS as bone graft are reliable, safe, and effective for single-segment stability reconstruction for surgical management of thoracic TB and TPS could be new bone graft methods.

[Background] Various bone grafting have been reported to achieve anterior column support and bone fusion after one stage posterior debridement in the treatment of lumbar tuberculosis. However, nonstructural bone grafting has been rarely studied. This study aimed to compare the efficacy of nonstructural bone grafting versus structural bone grafting in the treatment of lumbar tuberculosis. [Patients and methods] We retrospectively reviewed patients with nonstructural (n=27) and structural (n=22) bone grafting after single-stage posterior debridement and instrumentation for lumbar tuberculosis with at least 24 months of follow-up. Plain radiographs, magnetic resonance imaging, computed tomography scans, and health-related outcomes (e.g. Visual Analog Scale for back pain, the Oswestry Disability Index) were collected before surgery and at follow-up. [Results] Both nonstructural and structural bone grafting were associated with significant improvements in the quality of life parameters, the laboratory tests and the Cobb angle of local kyphosis. A slight loss of Cobb angle correction was observed in two groups. Nonstructural bone grafting resulted in the significantly less operation duration, blood loss and lower bone fusion rate than structural bone grafting group. There were three complications in the nonstructural bone grafting and four complications in the structural bone grafting group, with no significant difference between two groups. [Conclusions] Nonstructural bone grafting can achieve anterior column support with less surgical trauma and simpler surgical procedure than structural bone grafting, but the lower rate of grafted bone fusion should be taken into consideration when choosing nonstructural bone grafting.

Background: Large segmental bone defects are still one of the challenges for orthopaedic surgeons. Although 3D-printed porous titanium is a potential bone substitute material because of its porous structure simulating natural bone, the titanium surface has low bioactivity, integrates with bone tissue through the simple mechanical interlock. The study aims to investigate the capability and osteogenesis of 3D-printed porous titanium (3D PPT)-coated polydopamine (PDA) for repairing bone defects. Methods: Fifteen 6-month New Zealand white rabbits were implanted with PDA-3D PPT to repair 6 mm × 10 mm defects on the femoral condyle compared with the group of 3D PPT and comparing with the blank group. After 6 weeks and 12 weeks, micro-CT and histological examination were performed to observe bone growth. Results: All the PDA-3D PPT group, the 3D PPT group and the blank group recovered in good condition. The images showed that the boundaries between the implant area and the surrounding area were obscure in the three groups. The results of micro-CT demonstrated that at 6 weeks and 12 weeks, the bone volume (BV) values of PDA-3D PPT implants group were significantly higher than those of the 3D PPT implants group and blank group (P < 0.05), the BV/tissue volume (TV) and the trabecular number (Tb.N) of PDA-3D PPT implants were significantly higher than those of the 3D PPT group and blank group (P < 0.05). The results of un-decalcified bone slicing showed that ore new bone appeared to form around the PDA-3D PPT than that of 3D PPT and blank group. The bone-implant contact (BIC) of PDA-3D PPT was better (P < 0.05) than that of 3D PPT group. Conclusion: PDA-3D PPT could improve the bioactivity and promote the growth and healing of bone tissue and can be a promising repairing material.

Photodynamic therapy (PDT) is a promising treatment for osteosarcoma, and pyropheophorbide‑α methyl ester (MPPa) is a second‑generation photosensitizer for tumor treatment. The present study aimed to determine the efficacy and possible mechanisms of MPPa‑PDT in the treatment of osteosarcoma MG‑63 cells. Flow cytometry and western blotting were used to detect cell cycle‑related indicators Cyclin D1, Cyclin E, Cyclin A and Cyclin B1. Cell migration and invasion abilities were detected using wound‑healing and Transwell chamber assays. Cellular endoplasmic reticulum stress (ERS), autophagy and apoptosis‑related indicators were detected by flow cytometry and western blotting. The results demonstrated that MPPa‑PDT blocked the MG‑63 cell cycle and inhibited cell migration and invasion. Additionally, MPPa‑PDT inhibited the activation of the Akt/mammalian target of rapamycin (mTOR) pathway. MG‑63 cells underwent ERS‑induced apoptosis following MPPa‑PDT treatment. Pretreatment with the mTOR phosphorylation inhibitor rapamycin affected the autophagy of MPPa‑PDT‑induced osteosarcoma MG‑63 cells and enhanced apoptosis through targeting mTOR.

Background Many types of bone grafting have been reported for successful use in achieving anterior column support and bone fusion after one stage posterior debridement in the treatment of lumbar spinal tuberculosis. However, none-structural bone grafting has rarely been studied. This study was aimed to identify the feasibility of none-structural bone grafting from comparing the advantages and disadvantages with structural bone grafting in the treatment of lumbar spinal tuberculosis. Patients and methods We retrospectively reviewed patients with lumbar spinal tuberculosis who had undergone none-structural (n=27) and structural (n=22) bone grafting after single-stage posterior debridement and instrumentation with at least 24 months of follow-up. Plain radiographs, magnetic resonance imaging, and computed tomography scans, as well as health-related outcomes, including Visual Analog Scale for back pain, the Oswestry Disability Index were collated before surgery and at follow-up. Results Both none-structural and structural bone grafting were associated with significant improvements in quality of life parameters, the laboratory tests and the Cobb angle of local kyphosis. A slight loss of Cobb angle correction was in both two groups, without any associated complications. The operation duration and blood loss in none-structural bone grafting group was significantly less. The bone fusion rate was higher in structural bone grafting group. There were three complications in the none-structural bone grafting and four complications in the structural bone grafting group; the incidence of complications between the two groups was not significantly different. Conclusions Based on single-stage posterior debridement and pedicle screws fixation, none-structural bone grafting can achieve anterior column support with reducing surgical trauma, simplifying surgical procedure and decreasing intraoperative hemorrhage, but the lower rate of grafted bone fusion should be taken into consideration when choosing the aforementioned method. Key words Lumbar spinal tuberculous; Single-stage posterior debridement; Anterior column support; Bone fusion; None-structural bone grafting; Structural bone grafting