Study on effectiveness of treating femoral neck fractures based on theory of "positive support" / 中国修复重建外科杂志

OBJECTIVE@#To explore effectiveness of positive support reduction and internal fixation in the treatment of femoral neck fractures.@*METHODS@#A clinical data of 74 patients with femoral neck fractures treated with hollow screw internal fixation between September 2017 and September 2021 was retrospectively analyzed. Based on the quality of fracture reduction, they were divided into positive support reduction group (group A, n=25), negative support reduction group (group B, n=21), and anatomical reduction group (group C, n=28). There was no significant difference in baseline data such as gender, age, cause of injury, disease duration, fracture side, Garden classification, and fracture line position classification between groups (P>0.05). The occurrence of complications such as early fixation failure, femoral neck shortening, non-union of fractures, and femoral head necrosis in three groups, as well as the Harris score of the hip joint were recorded and compared.@*RESULTS@#All patients had primary healing of incisions after operation and were followed up more than 12 months. The follow-up time for groups A, B, and C was (21.1±5.7), (22.6±4.3), and (21.9±4.1) months, respectively; there was no significant difference between groups (P>0.05). There was no significant difference in the incidences of non-union of fractures, early internal fixation failure, and the femoral head necrosis between groups (P>0.05). The incidence and length of femoral neck shortening, and the hip Harris score at last follow-up in groups A and C were all superior to those in the group B, with significant difference (P<0.05). There was no significant difference in the above indicators between groups A and C (P>0.05).@*CONCLUSION@#Positive support reduction can provide a good biomechanical environment for the healing of femoral neck fractures, thereby achieving a higher fracture healing rate, reducing the occurrence of femoral neck shortening, minimizing the function of hip joint, and achieving effectiveness similar to anatomical reduction.

Preparation of silk fibroin/chitosan/nano-hydroxyapatite scaffold for sustained release of bone morphogenetic protein-2 / 中国组织工程研究

BACKGROUND:Bone morphogenetic protein-2 (BMP-2) is a key to bone formation and repair.However,it has some disadvantages such as easy to lose and degrade and difficult to sustain continuous effect.OBJECTIVE:To study the preparation and properties of silk fibroin/chitosan/nano-hydroxyapatite (SF/CS/nHA) scaffold loading BMP-2.METHODS:After silk degumming,dissolution and purification,2％ SF solution was obtained.BMP-2 was dissolved in 2％ CS solution,and then fully mixed with equal volume of SF solution and proper amount of nHA.At last,the SF/CS/nHA scaffold loading BMP-2 was prepared using freeze-drying method as experimental group.The SF/CS/nHA scaffold was soaked in the BMP-2 solution as control group.The scaffold porosity was measured by Archimedes method,the surface morphology of the scaffold was observed by scanning electron microscope,the compressive strength was measured by universal testing machine.Scaffolds in the two groups were soaked in PBS,and the release of BMP-2 was measured by ELISA method at different time points.RESULTS AND CONCLUSION:(1) The scaffolds in the two groups had irregular porous structure,interconnected pores and uneven pore wall.There was no significant difference between the two groups in mean pore diameter,porosity and maximum compressive strength.(2) On the 1st day,the release rate of BMP-2 was 4.63％ in the experimental group,and the release curve increased slowly.After 28 days,the release curve of BMP-2 was transferred to the plateau stage.But in the control group,the release rate of BMP-2 on the 1stday was 58.84％,and it was a significant initial burst release.The release curve increased rapidly,and was transferred to the platform stage on the 10th day.The release rate of BMP-2 release was significantly different between the two groups at days 1,2,4,10 (P ＜ 0.05).These results show that the SF/CS/nHA scaffold loading BMP-2 could sustainably and slowly release BMP-2.