Comparison of the Outcomes between AO Type B2 Thoracolumbar Fracture with and without Disc Injury after Posterior Surgery.

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.

Experiences in managing different consequences of forgotten ureteral stents.

Purpose: We reported the different consequences of forgotten stents and share our managing experiences. Patients and Methods: From July 2011 to August 2019, eight patients (five men and three women) with forgotten encrusted ureteral stents were treated by different endoscopic procedures in our center. Plain-film radiography (kidney, ureter, and bladder [KUB]) and computed tomography were used to evaluate the position of stents, the site of encrustation, and the stone burden. Various sole or combined endoscopic techniques including percutaneous nephrolithotomy, retrograde ureteroscopic lithotripsy, and cystolitholapaxy were used to achieve stent removal. Results: The average age of the patients was 50.9 years (range: 25-72 years). The mean indwelling time of the stents was 32.9 months (range: 12-83 months). Mean stent stone burden was 15 mm × 10 mm. Three patients had stent stone burden larger than 20 mm. Three patients had a preoperative positive urine culture before treatment. The stent was fragmented in two patients. The ureteral stents and related stones were successfully removed without any complications by a sole or combined endoscopic techniques with stone-free status achieved in all patients. There is no complications occurred. Conclusion: Forgotten stents can lead to complicated urinary tract calculi, stent encrustation, urinary tract infection, vesicoureteric reflux, and even ureteral polyps. Various sole or combined endourological techniques can be used to manage the forgotten encrusted ureteral stents.

Enhancement of the bone-implant interface by applying a plasma-sprayed titanium coating on nanohydroxyapatite/polyamide66 implants in a rabbit model.

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.

3D-printed titanium implant-coated polydopamine for repairing femoral condyle defects in rabbits.

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.

An approach to architecture 3D scaffold with interconnective microchannel networks inducing angiogenesis for tissue engineering.

The angiogenesis of 3D scaffold is one of the major current limitations in clinical practice tissue engineering. The new strategy of construction 3D scaffold with microchannel circulation network may improve angiogenesis. In this study, 3D poly(D: ,L: -lactic acid) scaffolds with controllable microchannel structures were fabricated using sacrificial sugar structures. Melt drawing sugar-fiber network produced by a modified filament spiral winding method was used to form the microchannel with adjustable diameters and porosity. This fabrication process was rapid, inexpensive, and highly scalable. The porosity, microchannel diameter, interconnectivity and surface topographies of the scaffold were characterized by scanning electron microscopy. Mechanical properties were evaluated by compression tests. The mean porosity values of the scaffolds were in the 65-78% and the scaffold exhibited microchannel structure with diameter in the 100-200 µm range. The results showed that the scaffolds exhibited an adequate porosity, interconnective microchannel network, and mechanical properties. The cell culture studies with endothelial cells (ECs) demonstrated that the scaffold allowed cells to proliferate and penetrate into the volume of the entire scaffold. Overall, these findings suggest that the fabrication process offers significant advantages and flexibility in generating a variety of non-cytotoxic tissue engineering scaffolds with controllable distributions of porosity and physical properties that could provide the necessary physical cues for ECs and further improve angiogenesis for tissue engineering.

[Clinical and histological features of non-alcoholic fatty liver disease].

OBJECTIVE: To investigate the clinical and histological features in Chinese patients with non-alcoholic fatty liver disease (NAFLD). METHODS: 108 patients with biopsy-proven NAFLD were enrolled in this study. Clinical, demographic, and biochemical data were compared between NAFLD patients with abnormal ALT and those with normal ALT. RESULTS: Simple fatty liver, nonalcoholic steatohepatitis(NASH) and cirrhosis were diagnosed in 49 (45.4%), 57(52.7%) and 2 (1.9%) patients, respectively. ALT and AST levels of NASH group were higher than those of simple fatty liver group (t = 2.55, 3.13; P = 0.01, 0.00). Fifty of the 77 patients (64.9%) with abnormal ALT levels were diagnosed as non-alcoholic steatohepatitis (NASH), and twenty-six were diagnosed as simple fatty liver, according to liver histology. Among the 31 patients with normal ALT levels, nine (29%) had NASH and twenty-two had simple fatty liver (P = 0.00). The patients with normal ALT had lower necroinflammatory grade than patients with abnormal ALT (x2 = 10.30, P = 0.01), but they had similar degree of steatosis and fibrosis (x2 = 5.52, 6.12; P = 0.12, 0.01). AST, g-glutamyltransferase, total cholesterol, apolipoprotein A1, apolipoprotein B and systolic blood pressure of patients with normal ALT were all lower than those of patients with abnormal ALT (t = 5.91, 2.00, 2.30, 2.10, 3.14, 2.43; P = 0.00, 0.05, 0.02, 0.04, 0.00, 0.02), while spleen thickness and AST/ALT ratio in patients with normal ALT were higher than those with abnormal ALT significantly (t = 3.70, 2.95; P = 0.00, 0.01). Multivariate analysis revealed that ALT (OR = 2.78, 95% CI 1.06-7.3, P = 0.04) was the only independent predictor of NASH, and ALT had low accuracy in predicting NASH, the area under the receiver operating characteristics curves of ALT to predict NASH was 0.69 (95% CI 0.59-0.8, P = 0.00). CONCLUSION: NAFLD patients have higher ALT level, and elevated serum level of ALT is independent predictor of the degree of inflammation, but not of steatosis and fibrosis.

[Hepatic steatosis: a common reason for elevated alanine aminotransferase levels in HBsAg-positive chronic hepatitis B patients with low HBV DNA loads].

OBJECTIVE: To evaluate the causes of alanine aminotransferase (ALT) level elevation in HBsAg-positive chronic hepatitis B (CHB) patients with low HBV DNA loads. METHODS: One hundred nineteen HBsAg positive CHB patients with both serum HBV DNA loads less than 1000 copies/ml and ALT more than 1.25 upper limits of normal (ULN) lasting for at least 6 months were enrolled in this study. Patients co-infected with hepatitis C virus or HIV or suffering from other liver diseases were not included. HBV DNA loads were assayed by PCR. Serological biochemistry and liver biopsy histopathological changes and clinical characteristics of the patients were analyzed. RESULTS: Of the 119 patients 102 were males and 17 were females. The mean age of the patients was (33.9+/-9.7) years and their body mass index (BMI) was (23.4+/-3.7) kg/m2. Mean ALT levels were (150.0+/-166.6) U/L and AST levels were (102.4+/-193.2) U/L. Liver biopsies showed hepatic steatosis in 26.9 % (32/119) of the cases, chronic hepatitis in 53.8% (64/119), non-specific changes in 12.6% (15/119), and 1 without any change. However, hepatic steatosis was more frequently seen in patients taking nucleoside analogs (56.7%), x2=10.394, Probability value less than 0.01. BMI, apolipoprotein B (APO-B), triglyceride, cholesterol and uric acid were all significantly higher in patients with hepatic steatosis than those without (t values were 5.369, 4.276, 3.216, 4.223 and 2.438 respectively, all P less than 0.05) while ALT, AST and apolipoprotein A were much lower in those with steatosis than those without (t values were -2.234, -3.877 and -2.956 respectively, all P less than 0.05). Obesity, dyslipidemia and hyperuricemia were more frequently seen in patients with steatosis than in patients without it (x2 value 3.829, 7.659, 13.389, 0.549, all P less than 0.05). The severity of inflammation and fibrosis were also more significant in patients with steatosis (x2 value 20.978, 17.550, all P less than 0.05). As compared to those patients without specific changes, serum levels of ALT, AST, GGT in patients with chronic hepatitis were obviously higher, all P less than 0.05. In contrast, there were no significant differences in mean age, BMI, male preference, obesity, diabetes, dyslipidemia or hyperuricemia, and the levels of triglyceride, cholesterol, and fasting plasma glucose between the two groups. CONCLUSION: Our data indicate that hepatic steatosis might be a factor associated with elevated ALT levels in HBsAg-positive CHB patients with low HBV DNA loads, especially in patients treated with nucleoside analogs.