| Part one Biomechanical analysis of three hollow compression screws in the treatment of transverse patellar fractureObjective:To investigate the biomechanical stability of three hollow screws with three-dimensional inverted triangle structure for the treatment of transverse patellar fracture.Methods:15 knee patella specimens were randomly extracted from 31 human specimens provided by the Anatomy Department of China Medical University,and specimen with inflammatory joint diseases including rheumatism and rheumatoid arthritis were excluded.The quadriceps femoris tendon,patella and patellar ligament were included in the experimental models and then randomized into group A and B.The patella was made into a simple transverse fracture model.Fixation with Kirschner wire 8-shaped tension band(group A,n=6)and fixation with cannulated screw(group B,n=9)were performed on the model respectively.The fixed models were moved by biomechanics machine from extended position to 90 degree knee flexion position to simulate knee joint flexion and extension movement.Upon completion of 1000 movement cycles,the gap of fracture measured 0.77±0.59mm in group A(n6),and 0.31±0.69mm in group B(n=9).The gap in group B was much smaller than that of group A(P=0.012,P<0.05).After 10000 movement cycles,all models in group A failed,with a passing rate of 0%,while 8 cases in group B maintained effective fixation,with a passing rate of 89%,showing better mechanical performance(P=0.69±0.42mm,P=0.05).The difference between the two groups was statistically significant.The data was collected and pooled and statistical software SPSS 25.0 Grouped T-test was used to analyze statistical significance.Result:The model of transverse patellar fracture was subjected to 150 N tension in the flexion and extended position,and movement was carried out by 150±125N sinusoidal force at 1/5Hz frequency.When the gap of fracture reached 1 mm,the number of cycles performed in the cannulated screw group was 1945.54±662.04,while the number of cycles of the Kirschner wire tension band group was 204.10±62.80.At internal fixation failure,defined by fracture gap reaching 2 mm,the number of cycles in the cannulated screw group has completed(2607.37±832.97)is higher than that of tension band group of Kirschner wire(960.00±147.36).The difference between the two groups was statistically significant.Conclusion:In load cycle test,cannulated screw fixation showed superior stability than Kirschner wire tension band fixation.Part two Minimally invasive treatment of transverse patellar fracture with three hollow compression screwsObjective:To explore the clinical effect of three hollow screws with three-dimensional inverted triangle structure in the treatment of transverse patellar fracture.Methods:from September 1,2016 to January 31,2018,46 patients with patellar transverse fracture who needed surgical treatment were enrolled at our hospital,patients with related complications were excluded.The average age of the patients was 43.5 years(19-67 years),including 30 males.A total of 23 cases in group A were treated with AO Kirschner wire tension band fixation and 23 cases in group B were treated with fixation using three modified percutaneous cannulated screw.The recovery time and complication rate were compared after operation.The VSA scores of the two groups were compared at one-month follow-up.The knee joints function of all 46 patients with patellar fracture were evaluated by Bostman patellar injury efficacy score at six months follow-up.Functional evaluations,including range of motion,pain,quadriceps femoris atrophy,stair climbing and daily working activity,were stratified into 30 points.Patient either received satisfactory(28-30 ponts),or unsatisfactory score(<28 points)and the results were compared.Result:The statistical test of the data obtained from this experiment conforms to the normal distribution.There was no significant difference in operation time,hospitalization time and fracture healing time between groups A and B(P>0.05).Postoperative complications occurred in 2 cases in group A and no complications occurred in group B.The Group A has a VSA score of 0.78±0.23 and group B 1.27±0.34(P<0.05).There was significant difference between the two groups.The Bostman score of group B was higher than that of group A at 6 months follow-up,with statistical significance(P<0.05).Conclusion:complications occurred less frequently with cannulated screw fixation,failure of fracture fixation was not observed,and the knee joint recovered quickly after operation.Part three Experimental study of KLF11 on the inhibition of patellofemoral arthritis after patellar fractureObjective:To investigate the effect of KLF11 on oxidative stress,apoptosis and ER stress in patellofemoral arthritis and osteoarthritis(OA)and its mechanismMethods:Used human articular cartilage tissue to study the correlation between KLF11 and OA.Furthermore,human chondrocytes were used to study the effects of KLF11 overexpression and IL-1β,an OA inducer,on oxidative stress,apoptosis and ERS.The p38MAPK signaling pathway agonist P79350 was used to study the effect of KLF11 on the p3 8 MAPK signaling pathway.Result:Articular cartilage tissue in OA patients and IL-1β-induced chondrocytes expressed higher KLF11.Overexpression of KLF11 significantly reduced oxidative stress levels,apoptosis levels,and activity of ERS-related pathways in chondrocytes.The protective effect of KLF11 on chondrocytes is found to be suppressed by P79350 via activation of the p38MAPK signaling pathway.Conclusion:KLF11 protects against OA through inhibition of oxidative stress,apoptosis and ERS in chondrocytes via activation of p38MAPK signaling pathway. |
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