Factors associated with intervertebral cage subsidence in posterior lumbar fusion.

BACKGROUND: The interbody fusion apparatus is a key component of the operation and plays a key role in the postoperative efficacy. Cage subsidence is one of the common complications after lumbar fusion and internal fixation. Clinical studies on the risk factors of cage subsidence are incomplete and inaccurate, especially paravertebral muscle atrophy and intervertebral bone fusion time. METHODS: Among the patients who underwent PLIF surgery in our hospital from January 2016 to January 2019, 30 patients with cage subsidence and 30 patients without cage subsidence were randomly selected to be included in this study. The differences between the two groups were compared, and the relevant factors of cage subsidence were explored by single factor comparison and multiple logistic regression analysis. RESULTS: Bone mineral density (T) of the subsidence group [(- 1.84 ± 1.81) g/cm2 vs (- 0.87 ± 1.63) g/cm2, P = 0.018] was significantly lower than that of the normal group. There were 4 patients with end plate injury in the subsidence group (P = 0.038). Preoperative end plate Modic changes [I/II/III, (7/2/2) vs (2/5/8), P = 0.043] were significantly different between the two groups. In the subsidence group, preoperative rCSA of psoas major muscle [(1.43 ± 0.40) vs (1.64 ± 0.41), P = 0.043], CSA of paravertebral muscle [(4530.25 ± 776.55) mm2 vs (4964.75 ± 888.48) mm2, P = 0.047], paravertebral muscle rCSA [(3.03 ± 0.72) vs (3.84 ± 0.73), P < 0.001] and paravertebral muscle rFCSA [(2.29 ± 0.60) vs (2.89 ± 0.66), P < 0.001] were significantly lower than those in normal group. In the subsidence group, the vertebral body area [(1547.81 ± 309.89) mm2 vs (1326.48 ± 297.21) mm2, P = 0.004], the height of the immediately corrected vertebral space [(2.86 ± 1.10) mm vs (1.65 ± 1.02) mm, P = 0.020], immediately SL corrective Angle [(5.81 + 4.71)° vs (3.24 + 3.57) °, P = 0.009), postoperative PI-LL [(11.69 + 6.99)° vs (6.66 + 9.62) °, P = 0.029] and intervertebral fusion time [(5.38 ± 1.85) months vs (4.30 ± 1.49) months, P = 0.023] were significantly higher than those in the normal group. Multivariate logistic regression analysis showed that the time of intervertebral fusion (OR = 1.158, P = 0.045), the height of immediate intervertebral space correction (OR = 1.438, P = 0.038), and the Angle of immediate SL correction (OR = 1.101, P = 0.019) were the risk factors for cage subsidence. Bone mineral density (OR = 0.544, P = 0.016) and preoperative paravertebral muscle rFCSA (OR = 0.525, P = 0.048) were protective factors. CONCLUSION: Intervertebral fusion time, correctable height of intervertebral space, excessive Angle of immediate SL correction, bone mineral density and preoperative paravertebral muscle rFCSA are risk factors for cage subsidence after PLIF.

IRF8 and its related molecules as potential diagnostic biomarkers or therapeutic candidates and immune cell infiltration characteristics in steroid-induced osteonecrosis of the femoral head.

PURPOSE: Steroid-induced osteonecrosis of the femoral head (SONFH) was a refractory orthopedic hip joint disease in the young and middle-aged people, but the pathogenesis of SONFH remained unclear. We aimed to identify the potential genes and screen potential therapeutic compounds for SONFH. METHODS: The microarray was obtained for blood tissue from the GEO database, and then it identifies differentially expressed genes (DEGs). The DEGs were analyzed to obtain the differences in immune cell infiltration. The gene functional enrichment analysis of SONFH was analyzed. The PPI of DEGs was identified through the STRING database, and the cluster modules and hub genes were ascertained using MCODE and CytoHubba, and the ROC curve of hub genes was analyzed, and the tissues distribution of hub genes was understood by the HPA, Bgee and BioGPS databases. The hub genes and target miRNAs and corresponding upstream lncRNAs were predicted by TargetScan, miRDB and ENCORI database. Subsequently, we used CMap, DGIdb and L1000FWD databases to identify several potential therapeutic molecular compounds for SONFH. Finally, the AutoDockTools Vina, PyMOL and Discovery Studio were employed for molecular docking analyses between compounds and hub genes. RESULTS: The microarray dataset GSE123568 was obtained related to SONFH. There were 372 DEGs including 197 upregulated genes and 175 downregulated genes by adjusted P value < 0.01 and |log2FC|> 1. Several significant GSEA enrichment analysis and biological processes and KEGG pathway associated with SONFH were identified, which were significantly related to cytoskeleton organization, nucleobase-containing compound catabolic process, NOD-like receptor signaling pathway, MAPK signaling pathway, FoxO signaling pathway, neutrophil-mediated immunity, neutrophil degranulation and neutrophil activation involved in immune response. Activated T cells CD4 memory, B cells naïve, B cells memory, T cells CD8 and T cells gamma delta might be involved in the occurrence and development of SONFH. Three cluster modules were identified in the PPI network, and eleven hub genes including FPR2, LILRB2, MNDA, CCR1, IRF8, TYROBP, TLR1, HCK, TLR8, TLR2 and CCR2 were identified by Cytohubba, which were differed in bone marrow, adipose tissue and blood, and which had good diagnostic performance in SONFH. We identified IRF8 and 10 target miRNAs that was utilized including Targetsan, miRDB and ENCORI databases and 8 corresponding upstream lncRNAs that was revealed by ENCORI database. IRF8 was detected with consistent expression by qRT-PCR. Based on the CMap, DGIdb and L1000FWD databases, the 11 small molecular compounds that were most strongly therapeutic correlated with SONFH were estradiol, genistein, domperidone, lovastatin, myricetin, fenbufen, rosiglitazone, sirolimus, phenformin, vorinostat and vinblastine. All of 11 small molecules had good binding affinity with the IRF8 in molecular docking. CONCLUSION: The occurrence of SONFH was associated with a "multi-target" and "multi-pathway" pattern, especially related to immunity, and IRF8 and its noncoding RNA were closely related to the development of SONFH. The CMap, DGIdb and L1000FWD databases could be effectively used in a systematic manner to predict potential drugs for the prevention and treatment of SONFH. However, additional clinical and experimental research is warranted.

Research of a Safe and Simplified Intertransverse Process Approach for the Lower Thoracic Interbody Surgery.

OBJECTIVE: To assess a safe surgical approach for intertransverse process lower thoracic intervertebral body fusion (ITIF) based on measurements from enhanced three-dimensional CT reconstruction, cadaver simulated operation, and patient operation. METHODS: Enhanced three-dimensional CT image reconstruction was performed for 20 healthy volunteers on thoracic segments T8-T12. The length of the transverse process (LTP), distance between the upper and lower transverse processes (DULTP), remote distance of the transverse process (RDTP), height of the extraforaminal intervertebral space (HEIS), and oblique diameter of the intervertebral space (ODIS) were measured and recorded. The blood vessels of the intertransverse lower thoracic region were observed, and their internal diameters were measured. The rib-intervertebral space relationship for T10/11 and T11/12 was measured in 104 patients of the thoracic skeleton. Then, based on the data from the CT measurements, simulated surgery was performed on six human cadavers at the T11/12 level. An ankylosing spondylitis (AS) patient with a fracture of the T10/11 level was eventually operated on with the ITIF technique. RESULTS: No significant difference was found between the lengths of the left and right thoracic transverse processes. The relationship of the values of the LTP and RDTP for the measured vertebrae were found to be as follows:T8 > T9 > T10 > T11 > T12. For HEIS and DULTP, T8-9 < T9-10 < T10-11 < T11-12. The results for the ODIS were as follows: T8-T9 < T9-T10 < T10-T11 < T11-T12. The blood vessel inner diameter of T11-12 was less than that of T10-11, while there was no significant difference between the diameters for T8-9 and T11-12. Almost half of the volunteer's T10/11 intervertebral spaces were covered posteriorly by the 11th rib (45.19% on left and 41.35% on right), while for most patients, the T11/12 intervertebral space was not covered by the 12th rib (98.08%). According to the cadaver experiments, intervertebral bone grafting and ipsilateral pedicle screw fixation were performed to simulate the operation. One patient with a combined AS and T10/11 fracture was then operated on with the ITIF technique and followed up for 3 years with satisfactory results. CONCLUSION: As verified by 3D CT reconstruction measurements, cadaver simulation surgery and patient operation with follow-up, the intertransverse process approach for some T10/T11 and almost all T11/T12 segments is a safe surgical pathway for operations such as ITIF, fracture bone grafting, clearance of focal lesions.

Clinical Observations of Kümmell Disease Treatment Through Percutaneous Fixation Combined with Vertebroplasty.

OBJECTIVE: To explore the safety and efficacy of percutaneous pedicle screw fixation combined with vertebroplasty for the treatment of stage III Kümmell disease. METHODS: The clinical data and follow-up results of 22 patients with Kümmell disease who were admitted to our department from 2014 to 2018 were analyzed. There were 14 females and eight males, and the Age range was 58-81 years. All patients were followed up for 24 months. The treatment method was percutaneous pedicle screw fixation combined with vertebroplasty. The patient general information such as age, gender, bedrest time and location of fracture vertebrae were recorded. The clinical symptoms and imaging data of visual analogue scale (VAS), bone cement leakage, Oswestry Disability Index (ODI), Cobb angle, anterior, middle and posterior height of the diseased vertebral body, and complications were recorded before operation and during follow-up. RESULTS: For patients enrolled, no bone cement leakage was observed during the operation; no patients developed infections after operation. The operation was safe and resulted in a short bedrest time. The VAS score and ODI index at 3 and 24 months postoperative (2.86 ± 0.83, 31.68% ± 6.21%; 3.0 ± 0.82, 32.78% ± 6.05%) were significantly lower than that recoded preoperatively (7.59 ± 0.59, 71.5% ± 8.84%) (P < 0.05). Additionally, there was no significant difference between the records at 3 and 24 months after operation (P > 0.05). Imaging data showed that the bone cement and screws were in good position and did not move during postoperative and follow-up. The anterior, middle and posterior height of the diseased vertebral body measured 2 days after surgery (23.46 ± 4.72, 23.12 ± 3.05, 25.81 ± 2.22) and at last follow-up (20.83 ± 4.48, 21.78 ± 2.74, 24.74 ± 1.93) were higher than that recorded preoperatively (13.08 ± 4.49, 12.93 ± 3.53, 19.32 ± 2.73) (P < 0.05), and the Cobb angle measured 2 days and 24 months after operation (9.57 ± 4.63, 10.68 ± 3.97) were lower than that recorded preoperatively (28.24 ± 8.95) (P < 0.05), and no significant difference was found between the values recorded at 2 days and 24 months after operation (P > 0.05). Follow-up for 24 months, there was no re-fracture of the diseased vertebrae and internal fixation loosening, but two cases of adjacent vertebral refracture complications occurred, and the effect was good after PVP treatment. CONCLUSION: Short-segment percutaneous pedicle screw fixation combined with vertebroplasty in the treatment of stage III Kümmel disease can effectively restore the height of the diseased vertebrae, kyphosis correction, reduce trauma, prevent the diseased vertebral body from collapsing again, and effectively improves clinical symptoms.

[Naringin reduced polymethylmethacrylate-induced osteolysis in the mouse air sacs model].

OBJECTIVE: To evaluate the influence of naringin on PMMA-induced osteoclastic bone resorption using the mouse air sacs model. METHODS: Total 48 female Balb/c mices with the age of 8 to 10 weeks were chosen in the study. Air were injected into the back in 32 mices and formed the air sacs, 6 d later, the skulls (originated from other 16 mices) were implanted to the air sacs. Thirty-two animals were divided into naringin treatment group (with 2 concentrations of 150 mg/kg and 30 mg/ kg) , DMSO group and PBS blank group, 8 animals in each group. Polymethylmethacrylate (PMMA) particles were injected into the air sacs in naringin treatment groups and DMSO group so as to irritate inflammatory reaction. Naringin with 2 concentrations of 150 mg/kg and 30 mg/kg were dissolved in DMSO of 0.2 ml, and were injected into air sacs, respectively. In PBS black group, no stimulation with PMMA particles, only injected PBS, and in DMSO group, injected DMSO without naringin. Tartrate resistant acid phosphatase (TRAP), Ca2+ release, modified Masson stain and histological analysis were performed on the 7th day after stimulation. RESULTS: Compared with DMSO group, naringin treatment group's cellular infiltration decreased (P < 0.01); concentration of 150 mg/kg was better than that of concentrations of 30 mg/kg (8.90 ± 1.75 vs 15.23 ± 1.86). Naringin can decrease calcium release in the lavage of the air sacs bone resorption model, especially obvious in naringin with concentration of 150 mg/kg. Naringin can ameliorate the inflammatory reaction and the subsequent bone resorption (including bone collagen loss, TRAP positive cells amount and so on) in air sacs with bone implant and PMMA particles. Naringin with concentration of 150 mg/kg appeared to be an optimal dosage to deliver the therapeutic effects. CONCLUSION: Naringin inhibits PMMA-induced osteoclastogenesis and ameliorates the PMMA-associated inflammatory reaction and the subsequent bone resorption.