ABSTRACT
Objective To explore a new way assisted by digital technology to establish a quantitative index to assess the matching performance of anatomically contoured plate. Methods We collected the thin-slice CT data of 20 adults with normal tibias who had received 32-slice spiral CT scanning from April 2015 to June 2016. They were 10 males and 10 females, aged from 28 to 52 years (average, 36.2 years). 3D reconstruction of the tibias was performed with Mimics 18.0. Two brands of 8-hole anatomically contoured plate for distal tibia (Kongli versus GE) were digitized. The curve of the plate facing the bone surface was extracted. The operational process of putting the plate curve on the medial surface of the distal tibia was simulated in Rhino 5.0. The volume of the gap between plate curve and bone surface was measured. The mean distance of the gap between plate cure and bone surface was figured out after the volume divided by the plate area. The inverse value of the mean distance of the gap was used as the index for matching performance. The wall thickness analyzing tool in 3-matic Research was used to mark the various thicknesses of the gap with different colors. The matching performances of the 2 brands of plate were assessed and compared according to the matching performance index and nephogram. Results Of the Kongli 8-hole distal tibial plate, the gap volume was 3,834 mm3± 701 mm3, the mean thickness 1.8 mm ± 0.3 mm, and the matching index 0.56 ± 0.10. Of the GE 8-hole tibial plate, the gap volume was 7,690 mm3± 1,503 mm3, the mean thickness 3.0 mm ± 0.6 mm, and the matching index 0.34 ± 0.06. The significant difference in matching performance between the 2 kinds of plate favored the Kongli plate (t=10.402, P <0.01). There were no significant differences in matching per-formance between different genders among the plates of the same brand (P> 0.05). The nephogram showed a large fixed red area at the proximal part in the GE 8-hole tibial plate. Conclusions As this index for matching performance is simple and intuitive, it can be used to assess and compare the matching performances between different kinds of plates. It can be also used before operation to assess the matching performance of a specific plate for a specific patient to avoid mismatch because of individual differences.
ABSTRACT
BACKGROUND:Currently, bone graft is mainly used for repair of bone defects, and tricalcium phosphate is the most used artificial bone material. But the effectiveness of the tricalcium phosphate bone graft is stil controversial, and there is also no detailed report about its function during the healing of bone defect. ＜br> OBJECTIVE:To observe the concentration changes of bone morphogenetic protein-2 and vascular endothelial growth factor as wel as bone healing after tricalcium phosphate graft in bone defects. ＜br> METHODS:Forty-eight C57 mice were randomly divided to experimental group and control group. A 2-mm-long diaphyseal segment and periosteum from the middle of the right femur was cut to prepare unilateral bone defect models. Tricalcium phosphate bone graft was used in the experimental group, and no bone graft in the control group. During the fol owing 4 weeks, X-ray examination was done once a week to observe the bone healing, and then the animals were executed for col ecting samples in the graft area. The concentrations of bone morphogenetic protein-2 and vascular endothelial growth factor in samples which were taken from the bone graft area were determined by using ELISA assay. ＜br> RESULTS AND CONCLUSION:X-ray films showed that 2 weeks later, bone fracture healed mostly in the experimental group except a smal part of cortical bone;3 weeks later, bone fracture was basical y healed, and only a smal amount of tricalcium phosphate remained;4 weeks later, bone fracture was completely healed, and the cal us grew obviously, and the tricalcium phosphate was nearly absorbed. In the control group, the fracture line was stil visible at 1-2 weeks, but it became vague at 3 weeks;then, the fracture was healed at 4 weeks except some of the cortical bone. The levels of bone morphogenetic protein-2 and vascular endothelial growth factor were significantly higher in the experimental group than in the control group at different time points (P＜0.05). These results suggest that tricalcium phosphate bone graft can up-regulate the expression of bone morphogenetic protein-2 and vascular endothelial growth factor and accelerate bone healing.
ABSTRACT
Objective To investigate the clinical application of minimally invagive fixation of complex proximal tibia fractures by uniaxial and polyaxial locking plates. Methods The clinical data of 38 patients with minimally invagive fixation of complex proximal tibia fractures by uniaxial(n=21)and polyaxial(n=17)locking plates from January 2008 to June 2009 were retrospectively analysed,and the union rates and function recovery were compared between groups.Results All patients were followed up for 3 to 20 months,with an average of 12 months.All patients had bone union.The time of fracture union for fixation by uniaxial locking plates was 10 to 20 weeks,with an average of 14 weeks;and that for fixation by polyaxial locking plates was 11 to 18 weeks,with au average of 13 weeks.Evaluated by Johner-Wruhs method, there were 14 "excellent" cases,5 "better" eases,2 "good" cases and 0 "poor" case for fixation by uniaxial locking plates (rate of "excellent and better",90.4%),and there were 11 "excellent" cases,5 "better" cases,1 "good" cage and 0 "poor" case for fixation by polyaxial locking plates (rate of "excellent and better",94.1%). Conclusion Minimally invagive fixation of complex proximal tibia fractures by uniaxial and polyaxial locking plates is stable,has less effects on bone blood supply,high bone union rate and favourable function recovery,and is an effective way in the treatment of complex proximal tibia fractures.Fixation by uniaxial locking plate has a better mechanical intensity,while fixation by polyaxial locking plate can adjust the screw angle according to fracture situation,which can be clinically applied accordingly.