Clinical Anatomical Study On The Treatment Of Avascular Necrosis Of The Navicular Bone With A New Four Angle Fusion Device

ObjectiveThrough the technique of perfusion of the nutrient vessels in the tarsal navicular bone,using the red lead oxide(Pb3O4)as the contrast agent,micro CT was used to image the nutrient vessels in the tarsal navicular bone,to explore the blood supply pattern in the tarsal navicular bone and to establish the three-dimensional digital model of the blood supply in the tarsal navicular bone,and to simulate the new four foot fusion device(nickel titanium memory alloy)in the three-dimensional model of the blood supply in the tarsal navicular bone The influence of four foot fixator and hollow lag screw on the blood supply of navicular in the treatment of avascular necrosis of navicular,which provides anatomical basis for the selection of internal fixation in the fusion of scaphoid alone.Finally,through the preliminary clinical application of the new four foot fusion cage,to explore the clinical effect of Nitinol memory alloy four foot fixator in the treatment of avascular necrosis of the navicular.MethodsPart I microanatomy of blood supply in navicularSeven fresh adult lower limb specimens were selected,the red lead oxide(Pb3O4)was perfused through popliteal artery,the navicular bone was dissected and scanned under micro-CT,and the distribution pattern of blood supply in the navicular bone was studied by three-dimensional reconstruction with digital technology,and the distribution and diameter of the nutrient vessels in the navicular bone were measured.The blood supply in the navicular of7 fresh adult lower limb specimens was fitted by digital technology,and a three-dimensional visual model of the taloclavicular joint was established to simulate the application of the new four foot fusion device and the hollow tension screw in the fusion of the taloclavicular joint.The part II The clinical analysis of the treatment of avascular necrosis of navicular with a new four foot fusion cageFrom June 2018 to October 2019,19 patients with müller-Weiss disease,6 males and 13 females,aged 27-59 years,with an average age of 34.6 years,with a course of 4-11 years and an average course of 7.5 years,were admitted.According to the maceira staging method,11 patients in stage III and 8 patients in stage IV were treated by distance boat arthrodesis with nickel titanium memory alloy four foot fixator.The evaluation indexes were AOFAS middle foot score and vas to evaluate the clinical effect of preoperative and postoperative follow-up,and X-ray was used to evaluate the image The mean angle,talar angle and calcaneus inclination angle were measured by X-ray film,and the first metatarsal talus angle,coverage angle and talar angle were evaluated by AP film before loading.ResultsPart ? microanatomy of blood supply in navicularThree dimensional reconstruction of the blood supply model of the tarsal navicular with the same digital technology shows that the main nutrient arteries(1-2 branches)run through the dorsal and metatarsal sides,and radiate to the four sides in the form of branches.The distribution of the nutrient arteries on the lateral tarsal side is the least,while the distribution of the small blood supply at the end is more in the central part of the navicular because of the main nutrient arteries.Measurement of anatomic parameters:(1)there was a significant difference in the number of foramen between groups(F = 15.12564,There were significant differences between the dorsal group(9.3 ± 1.8)and the metatarsal group,the lateral tarsal group,the medial group(P < 0.05);the lateral tarsal group(4.1 ± 1.2)and the dorsal group,the metatarsal group and the medial group(P < 0.05).(2)There was no significant difference in the total mean of the diameter of the foramen(F = 0.159676,P > 0.05).(3)There was no significant difference in the total mean of the diameter of nutrient vessels(F = 0.455602,P >0.05).In this study,the blood supply pattern in tarsal navicular bone was constructed,and the areas of blood supply enrichment and lack of blood vessels were fitted.The 3D model of blood supply of tarsal navicular bone was fitted with the new four angle fusion device and hollow screw,which showed that the damage of four foot fixator to blood supply in the fusion of talo navicular joint was smaller than that of screw.The part ? The clinical analysis of the treatment of avascular necrosis of navicular with a new four foot fusion cage19 patients were followed up for 3-19 months,with an average follow-up time of(11.25± 3.90)months,The average healing time was(11.5 ± 3.62)weeks.There was no loosening of internal fixation,infection and degeneration of adjacent joints.Before and at the last follow-up,AOFAS middle foot score,VAS score and related imaging evaluation indexes were significantly improved(P < 0.05).ConclusionsPart ?digital anatomical study on blood supply of navicularThe blood supply of the foot navicular depends on the main nutrient artery which enters from the dorsal or metatarsal side.The damage of the main artery is easy to cause the blood supply of the navicular to be blocked.At the same time,the distribution of the peripheral nutrient vessels is less on the lateral tarsal side.In the case of the damage of the blood supply of the navicular,the lateral tarsal side lacks the vascular anastomosis to compensate,which is more likely to lead to the local osteonecrosis.At the same time,the 3D model of the blood supply of tarsal navicular bone was fitted with the new four angle fusion device and hollow screw,which showed that the damage of the four foot fixator to the blood supply of the fusion was smaller than that of the screw.The part ? The clinical analysis of the treatment of avascular necrosis of navicular with a new four foot fusionNi Ti shape memory alloy four foot fusion device for the treatment of M ü ller Weiss disease has a definite clinical effect,simple operation,obvious improvement of symptoms after operation,which is worth popularizing.