Related Study Of Kyphoplasty And Design & Application Of Percutaneously Guiding Instrument

Part ⅠRelated morphological study of Kyphoplasty Objective: To measure the dry spine specimen and to afford reference data to kyphoplasty. Methods: A variety of data were gotten from 13 spine specimen. They were : distance between entry points on both sides; distance between medial and lateral cortex of transitional parts of pedicle of vertebral arch to vertebral body; distance between medial and lateral cortex of the isthmus of pedicles of vertebral arch; distance between medial and lateral arch of transitional parts of pedicle of vertebral arch to lamina of vertebral arch; distance between entry points to the central tip of spinous processes; width of transitional parts of pedicle to vertebral body, of pedicle to lamina as well as the isthmus of pedicles; height of the isthmus of pedicles; width of superior /inferior 1/4 parts of pedicles; width of the central parts of spinous processes; height of the tip of spinous processes; width of the narrowest parts of spinous processes; distance between the central parts of spinous processes to the anterior lateral parts of superior and inferior endplates. Results: Distance of lateral cortex of pedicles achieved the largest at the transitional parts of pedicle to lamina. The largest distance between the medial cortex of pedicles was at the isthmus of pedicles. For the same vertebra, width became the smallest at the isthmus of pedicle and became the largest at the transitional part of pedicle to vertebral body. Height of isthmus of pedicle increased from cervical vertebrae to thoracolumbar vertebrae, L5 was the largest. The largest distance between entry points was in cervical and lumbar vertebrae, the smallest in thoracic vertebrae. Distance from entry points to anterior –lateral parts of two endplates became larger from cervical to thoracolumbar vertebrae, then decreased. Width of the tip of spinous process from T3 to T9 was less than 5mm, width of the narrowest parts of spinous processes from T1 to T12 was less than 5mm. Length of the tip of spinous process became larger from C5 to L3 and then decreased. Distance from the tip of spinous process to the anterior margin of lamina became larger from C4, became the largest at T1, decreased from L3. Except data of several vertebrae had significant difference between gender groups or sides groups, there were no significant difference between the gender groups and the sides groups among data of the other vertebrae(P>0.05). Conclusion: The areas and height of pedicle were important reference data in puncturing. Different screws could be used according to the data of spinous process in the operations. Part ⅡRelated radiological study of kyphoplasty Objective: To measure the laterally oblique angles and superiorly oblique angles. To define the entry points on the vertebrae. To measure the distance from the entry point to anterior-inferior part of the vertebral body. And to afford reference data for kyphoplasty and design of percutaneously guiding instrument. Methods: Projecting image and standard laterally image of every vertebra from 10 thoracic and lumbar vertebrae were taken. Every laterally oblique angle and superiorly oblique angle were measured and puncturing approach method were analyzed for kyphoplasty in thoracic and lumbar vertebrae. Five specimen were punctured from T11 to L5 according to the angles. The puncturing effect were analyzed. Result: The laterally oblique angle and superior oblique angle diminished from T1 to T7 and enlarged from T7 to T12 in male group, it was the smallest in T7 and the largest in T12. In female group, it diminished from T6 to T12, the smallest was in T6 and the largest was in T12. The superiorly oblique angles varied from 20°to 25°in male group and from 19°to 26°in female group. The total thoracic vertebrae were divided into three groups, namely T1 to T4, T5 to T8, T9 to T12 groups, and the mean angles were compared among the groups. There were significant difference only between T1 to T4 and T5 to T8 groups. The entry point was at the superior-lateral 1/4 quadrant of the cross by a line passed the mid-point of two transverse process roots and a line passed the back edge of the superior articular process. The depth in the vertebral body varied from 35mm to 43mm from T11 to L5. Thelargest mean depth on both sides was in L1, 41mm. The shortest depth on both sides was in T11, 36.4mm and 36.2mm respectively. There was no significant difference between two sides for the same vertebrae. In standard anterior posterior image, the entry points were at 10 o'clock on the left pedicle shadow and 2 o'clock on the right pedicle shadow respectively. Conclusion: In thoracic vertebrae, transpedicular and extrapedicular approach could be chosen from T1 to T4 as well as from T9 to T12. Extrapedicular approach could be chosen from T5 to T8. Transpedicular approach could totally be chosen from L1 to L5. Ideal position could be arrived in puncturing according to the angles measured, the exact entry points, and the depth measured. Part ⅢThe design of percutaneously guiding instrument Objective: To invent the percutaneously guiding instrument and to afford help to kyphoplasty. Methods: Percutaneously guiding instrument was designed according to the character of two pedicle angles and entry point could be used in operation as well as the morphological data of spinous process and the posterior superior iliac spine. Results: The percutaneously guiding instrument was not large in size and could be fixed smoothly and firmly. The angles could be measured exactly. Conclusion: The percutaneously guiding instrument could be used for the experiment of Kyphoplasty to evalute it's effect. Part ⅣThe experimental study of percutaneously guiding instrument Objective: To evaluate the effect of facilitating the operation and the effect of decreasing X-ray exposure of using percutaneously guiding instrument on vertebral specimen. Methods: CT scan and standard lateral image of 3 vertebrae specimen from T11 to L5 were got. Every laterally and superiorly oblique angles were got. The instrument was fixed on the specimen and the entry point was defined. Percutaneously guiding instrument was only used on the left sides. Puncturing was supervised under C-arm fluoroscopy and the effect was analyzed and the exposure times were compared between the left and the right sides. Result: The puncturing were succeed on both sides. The exposure times were 12.61±1.69 on the left and 23.19±1.60 on the right. There was significant difference between both sides(P<0.05). Conclusion: Theinstrument could be fixed firmly and the operation could be done easily. Use of percutaneously guiding instrument significantly diminished exposure times. Part ⅤClinical experimental application of percutaneously guiding instrument Objective: To evaluate the effect of percutaneously guiding instrment in clinical application. Methods: Percutaneously guiding instrument was used on 2 patients with L1 osteoporotic vertebrae compressive fractures and 1 with L2 fracture, 2 of which were male and the other was femle. All vertebral body were compressed more than 1/2 and the age varied from 62 to 76 years old. Results: The mean exposure times were 10. The instrument could shorten the operating time and significantly decrease the X-ray exposure times. Conclusion: The percutaneously guiding instrument could do much help in Kyphoplasty.