BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Surgical intervention for malignant bone tumors frequently results in bone defects located at the metaphysis of the long bones in the lower extremities.The morphological heterogeneity of the metaphysis poses significant challenges for conventional treatment methods to adequately conform to the defect area.The utilization of three-dimensional(3D)-printed titanium bone repair scaffolds has emerged as an effective reconstructive approach for metaphyseal bone defects,as these scaffolds offer precise shape conformity and provide adequate mechanical support.However,the current commonly used scaffolds do not adequately replicate the biomechanical environment of bone defects,resulting in suboptimal bone ingrowth within the scaffolds and subsequent prosthesis loosening and failure post-operation.Bone is a highly force-responsive organ,and its fate is regulated by biomechanical signals.Consequently,designing scaffolds with consideration of biomechanical principles to ensure mechanical compatibility between the scaffolds and the bone defect sites is a critical factor influencing the success of bone defects reconstruction.This review primarily introduces the biomechanical factors influencing bone defect repair and the advancements in designing 3D-printed titanium bone repair scaffolds biomechanically matched with bones,offering theoretical guidance for scaffold design and preparation.

Objective To investigate the impacts of intervertebral foramen endoscopic surgery combined with silver needle hyperthermia therapy on lumbar spine function and local tenderness in patients with lumbar disc herniation(LDH).Methods From April 2020 to March 2023,100 LDH patients were randomly devided into a control group(50 cases)and an observation group(50 cases)through random number table method.The control group was treated with intervertebral foramen endoscopic surgery combined with conventional lumbar and dorsal muscle training,while observed group was treated with intervertebral foramen endoscopic surgery combined with silver needle warm therapy.The lumbar function,local tenderness,laboratory indicators,and adverse reactions were compared.Results The Japanese Orthopaedic Association(JOA)score increased in both groups after treatment,and observed group had obviously higher scores,the differences were statistically significant(P<0.05);After treatment,both groups showed a decrease in pain visual analogue scale(VAS)score,and observed group had obviously lower scores,the differences were statistically significant(P<0.05);The levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),prostaglandin E2(PGE2),and 5-hydroxytryptamine(5-HT)in both groups decreased after treatment,and the observed group showed a more obvious decrease in all indicators,the differences were statistically significant(P<0.05);The incidence of adverse reactions was 4.00%(2/50)in observed group and 20.00%(10/50)in the control group,adverse reactions in observed group were obviously fewer,the difference was statistically significant(P<0.05).Conclusion The combination of intervertebral foramen endoscopic surgery and silver needle hyperthermia therapy can effectively improve lumbar spine function and alleviate local tenderness symptoms in patients with LDH.It is worthy clinical application.

BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Objective To investigate the impacts of intervertebral foramen endoscopic surgery combined with silver needle hyperthermia therapy on lumbar spine function and local tenderness in patients with lumbar disc herniation(LDH).Methods From April 2020 to March 2023,100 LDH patients were randomly devided into a control group(50 cases)and an observation group(50 cases)through random number table method.The control group was treated with intervertebral foramen endoscopic surgery combined with conventional lumbar and dorsal muscle training,while observed group was treated with intervertebral foramen endoscopic surgery combined with silver needle warm therapy.The lumbar function,local tenderness,laboratory indicators,and adverse reactions were compared.Results The Japanese Orthopaedic Association(JOA)score increased in both groups after treatment,and observed group had obviously higher scores,the differences were statistically significant(P<0.05);After treatment,both groups showed a decrease in pain visual analogue scale(VAS)score,and observed group had obviously lower scores,the differences were statistically significant(P<0.05);The levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),prostaglandin E2(PGE2),and 5-hydroxytryptamine(5-HT)in both groups decreased after treatment,and the observed group showed a more obvious decrease in all indicators,the differences were statistically significant(P<0.05);The incidence of adverse reactions was 4.00%(2/50)in observed group and 20.00%(10/50)in the control group,adverse reactions in observed group were obviously fewer,the difference was statistically significant(P<0.05).Conclusion The combination of intervertebral foramen endoscopic surgery and silver needle hyperthermia therapy can effectively improve lumbar spine function and alleviate local tenderness symptoms in patients with LDH.It is worthy clinical application.

Surgical intervention for malignant bone tumors frequently results in bone defects located at the metaphysis of the long bones in the lower extremities.The morphological heterogeneity of the metaphysis poses significant challenges for conventional treatment methods to adequately conform to the defect area.The utilization of three-dimensional(3D)-printed titanium bone repair scaffolds has emerged as an effective reconstructive approach for metaphyseal bone defects,as these scaffolds offer precise shape conformity and provide adequate mechanical support.However,the current commonly used scaffolds do not adequately replicate the biomechanical environment of bone defects,resulting in suboptimal bone ingrowth within the scaffolds and subsequent prosthesis loosening and failure post-operation.Bone is a highly force-responsive organ,and its fate is regulated by biomechanical signals.Consequently,designing scaffolds with consideration of biomechanical principles to ensure mechanical compatibility between the scaffolds and the bone defect sites is a critical factor influencing the success of bone defects reconstruction.This review primarily introduces the biomechanical factors influencing bone defect repair and the advancements in designing 3D-printed titanium bone repair scaffolds biomechanically matched with bones,offering theoretical guidance for scaffold design and preparation.

Objective:To investigate the effects of mixed probiotics on food allergy and the underlying mechanism.Methods:BALB/c mice on the 15 th day of pregnancy were randomly (random number table method) classified into the control group, food allergy model group and mixed probiotics group.Mice in the food allergy model and mixed pro-biotics group were subjected to ovalbumin (OVA) sensitization after birth, and those in the mixed probiotics group were then given probiotic solution by gavage from day 21 to day 35.Mice in control group were similarly given 9 g/L saline.Twenty-four hours after the last OVA sensitization, intestinal histopathological sections were prepared to observe intestinal pathological changes.Blood smears were prepared to detect eosinophil count.In addition, serum samples were collected to measure cytokine levels and OVA specific antibodies.The number of dendritic cells (DCs) and regulatory T cells (Tregs) in mouse mesenteric lymph nodes was calculated.Differences among 3 groups were compared by the One- Way ANOVA or Kruskal- Wallis H test. Results:Compared with those of food allergy model group, diarrhea score, the ratio of eosinophils and serum levels of interleukin(IL)-4, IL-5, IL-13, mast cell protease 1 (MCPT-1), and OVA specific antibodies IgE and IgG were significantly lower in mixed probiotics group[(2.00±0.71) points vs.(3.22±0.97) points, (2.28±1.61)% vs.(10.99±2.26)%, (413.68±22.81) ng/L vs.(708.78±27.66) ng/L, (36.64±3.74) ng/L vs.(46.05±4.95) ng/L, (201.37±65.61) ng/L vs.(495.22±96.66) ng/L, (31 924.15±1 177.77) ng/L vs.(36 175.77±618.29) ng/L, (9.10±8.08) ng/L vs.(19.69±0.84) ng/L, (30.50±8.81) ng/L vs.(190.32±6.40) ng/L], while IL-10 level was significantly higher[(164.12±3.88) ng/L vs.(123.90±7.31) ng/L] ( t=3.37, 8.72, 16.07, 3.90, 7.40, 7.95, 3.91, 44.00 and 7.76, respectively, all P<0.01). Compared with those of food allergy model group, programmed cell death ligand 1 (PD-L1) level on the surface of CD 103+ DCs and CD 103+ CD 80-CD 40-DCs, the proportion of Tregs in CD4 + T cells, and the level of programmed cell death 1 (PD-1) on the surface of Tregs were significantly higher in mixed probiotics group[(75.59±0.45)% vs.(45.60±4.73)%, (67.56±1.87)% vs.(37.12±6.07)%, (8.24±0.69)% vs.(6.20±0.66)%, (11.25±3.12)% vs.(4.08±2.33)%]( t=7.88, 4.48, 3.63 and 3.71, all P<0.01). Conclusions:Mixed probiotics can alleviate the symptoms of food allergy and inflammatory response of young rats through mediating Tregs via the PD-1/PD-L1 pathway.

Objective:To investigate the clinical efficacy of different grade transoral atlantoaxial release for the treatment of irreducible atlantoaxial dislocation.Methods:From January 2010 to December 2019, 297 patients with irreducible atlantoaxial dislocation treated by different grade releases were retrospectively analyzed, including 132 males and 165 females, aged 42.3±12.14 years (range, 10-63 years). All cases were treated by different grade releases, Grade I (196, 66.0%), Grade II (54, 18.2%), Grade III (28, 9.4%) and Grade IV (19, 6.4%). The American Spinal Injury Association (ASIA) grade and Japanese Orthopedic Association (JOA) score were recorded as the clinical evaluation index. The clivus-canal angle (CCA) and cervico-medullary angle (CMA) were measured to evaluate the reduction. The surgery time, blood loss, duration of bony fusion and complications were also analyzed.Results:The follow-up time was 14.8±10.2 months (range, 9-36 months). The surgery time of Grade I-IV were 2.02±0.35 min, 3.00±0.36 min, 4.07±0.96 min and 5.24±0.83 min, respectively ( F=385.43, P<0.001), blood loss was 84.08±27.21 ml, 153.61±31.36 ml, 268.93±48.94 ml and 444.21±109.51 ml, respectively ( F=582.39, P<0.001). The preoperative ASIA motor score of Grade I-IV were 83.85±6.68, 84.06±5.47, 84.07±5.99 and 85.00±4.11, respectively. The last follow-up were 98.34±2.38, 98.67±1.79, 98.86±1.58 and 98.32±2.11, respectively, with statistically significant differences from preoperative ( P<0.05). The preoperative JOA score of Grade I-IV were 11.44±1.73, 11.59±1.72, 11.61±1.47 and 11.32±1.80, respectively. The last follow-up were 16.22±1.00, 16.28±1.02, 16.14±1.04 and 16.16±1.07, respectively, with statistically significant differences from preoperative ( P<0.05). The preoperative CCA of Grade I-IV were 110.19°±8.76°, 112.48°±7.66°, 106.61°±6.54° and 109.05°±7.79°, respectively. The last follow-up were 140.22°±8.04°, 141.86°±7.04°, 142.35°±8.62° and 140.15°±6.49°, respectively, with statistically significant differences from preoperative ( P<0.05). The preoperative CMA of Grade I-IV were 113.48°±9.54°, 116.03°±8.38°, 109.55°±7.13°, and 112.46°±8.33°, respectively. The last follow-up were 144.28°±7.75°, 146.40°±6.98°, 145.81°±8.27° and 143.24°±6.36°, respectively, with statistically significant differences from preoperative ( P<0.05). Solid bony fusion was obtained except for 3 cases, the fusion time was 9.71±2.55 months (range 3-14 months). Altogether 33 complications occurred in all cases (11.1%), including 3 fusion failure, 3 cerebrospinal leak, 3 wound infection, 2 death (1 case caused by cerebrospinal leak), 11 pharyngeal discomfort, 4 postoperative pain surrounding iliac crest, and 8 malunion of iliac crest. Conclusion:Transoral stepped atlantoaxial release theory could provide guidelines for atlantoaxial dislocation treatment, and make the transoral release technique more effective and safer.

Objective:To report our experience in diagnosis and treatment of posterior atlantoaxial dislocation with odontoid retrolisthesis.Methods:A retrospective study was conducted of the 5 patients who had been treated from July 2012 to August 2018 at Department of Orthopaedics, General Hospital of Southern Theater Command for posterior atlantoaxial dislocation. They were 4 men and one woman, aged from 34 to 67 years (average, 47 years). All of them had a history of trauma. Of them, 4 were complicated with odontoid fracture and one with congenital free os odontoideum. Their posterior atlantoaxial dislocation ranged from 3 to 9 mm (average, 6 mm). By the American Spinal Injury Association (ASIA) grading system, their preoperative spinal injury was rated as grade B in one, as grade C in 3 cases and as grade D in one. All the 5 patients underwent skull traction at 10° flexion. Surgical trans-oralpharyngeal atlantoaxial reduction and internal fixation was performed for the one patient whose reduction had not been achieved by traction while posterior atlantoaxial screw-rod fixation or anterior odontoid screwing was conducted for the 4 patients whose reduction had been achieved by traction. The distance of posterior atlantoaxial dislocation was measured to evaluate their reduction and ASIA grade system was used to assess their spinal function after operation.Results:The postoperative distance of posterior atlantoaxial dislocation was 0 mm, showing a reduction rate of 100%. The 5 patients were followed up for 6 to 36 months (average, 15 months). By the ASIA grade system, the postoperative functional recovery of the spine was grade D in 4 cases and grade C in one. No implant loosening or breakage occurred.Conclusion:As a kind of high-energy hyperextension injury, posterior atlantoaxial dislocation is rare in clinic, but an appropriate treatment can be adopted to deal with its different clinical types to achieve good outcomes.

Objective: To investigate the risk factors of poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe aplastic anemia (SAA) . Methods: Clinical data from 111 SAA patients who received allo-HSCT were analyzed retrospectively. Factors including age, gender, interval to transplantation, the level of serum ferritin before transplantation were analyzed by Cox multivariate regression analysis. Results: Among the 111 patients who underwent allo-HSCT, 16 developed PGF (14.4%) . Multivariate analysis showed donor type (HR=2.656, 95%CI 1.204-5.858, P= 0.016) and the level of serum ferritin before tansplantation (HR=3.170, 95%CI 1.400-7.180, P=0.006) were significant risk factors for PGF. Conclusion Unrelated donor transplantation and the high level of serum ferritin before transplantation are risk factors for PGF.