An Experimental Study On The Application Of Imaging To Evaluate The Position Of Prosthesis After Unicompartmental Knee Arthro Plasty

BackgroundWith the gradual increase of the elderly population in my country in recent years,knee joint degeneration has gradually become an important disease that plagues middle-aged and elderly people.Osteoarthritis（OA）is an important disease of knee joint degeneration.The rate has remained high and has been increasing year by year.Related epidemiological studies^[1]More than 30%of people over the age of 65 suffer from knee osteoarthritis.Knee osteoarthritis generally has a long course,and its pathological manifestations are that the cartilage wear of the knee joints is increasing year by year^[2],knee joint pain and mobility limitation gradually increase,etc.,which seriously reduce people’s living standards.The early lesions of knee osteoarthritis are mainly concentrated It is located in 1 or 2 compartments of the knee joint,so there are many treatment methods in the early stage of knee osteoarthritis.Hou Junpeng et al.^[3]found through experimental research that the method of patella internal pushing can effectively relieve the pressure between the patellofemoral joint and effectively treat patellofemoral arthritis.In addition,there are conservative treatments such as injection of sodium hyaluronate in the joint cavity and arthroscopic cleanup^[4],high tibial osteotomy（HTO）,unicompartmental knee arthroplasty（UKA）and other surgical methods.With the continuous improvement of unicondylar prosthesis and the continuous improvement of surgical methods,unicondylar replacement is one of the important surgical methods for the treatment of single-compartment knee osteoarthritis.In recent years,a large number of studies have shown that^[5-8]it has small surgical incisions and surgical procedures.After that,the patient recovers quickly and can well retain the proprioception of the patient.Many advantages such as the follow-up of Jennings^[9]unicondyle replacement in the cohort study have a10-year survival rate of>90%.Therefore,it has been recognized by clinicians and the general public.Patients favor it.However,many studies^[10-11]have found objective factors such as individual differences in patients through a large number of postoperative follow-ups.The installation position of the intraoperative unicondylar prosthesis also has a great influence on the postoperative rehabilitation effect of the patient.In clinical practice,it is found that there are individual differences in the actual operation of unicondylar replacement in the actual operation of the unicondylar replacement through the review of the postoperative X-ray.A large number of domestic and foreign literatures have not found that the position of the prosthesis installed during the operation is not the Therefore,this subject uses the method of cadaver specimen experimental research,through the measurement of the postoperative X-ray measurement of the different installation positions of the prosthesis in the unicondylar replacement operation,reverse the application of imaging to the preliminary evaluation of the installation of the unicondylar prosthesis The pros and cons of the location.ObjectiveThis topic is to study the installation position of the femoral prosthesis after unicondylar replacement by applying X-rays of cadaveric knee joint specimens.The unicondylar femoral prosthesis installed in different positions during the operation and the postoperative knee joint standard X-rays Comparative study,using imaging to reversely evaluate the position of the prosthesis after unicondyle replacement,and find the correlation between the internal and external rotation of the femoral prosthesis during unicondyle replacement and the postoperative X-ray.MethodsChoose 4 human knee joint specimens（specifically each age and gender are ominous）,knee joint front and side X-rays to exclude fractures and dysplasia;cut 15cm from the joint line up and down,each knee joint cadaver specimen removes the skin and The subcutaneous tissue is completely preserved with the quadriceps tendon,knee joint capsule,complete bony structure and knee joint ligaments.The completed knee joint specimens are fixed to the special knee joint fixation frame,and the unicondylar prosthesis is placed in the standard position of the femoral prosthesis.The body is rotated at 0°,the tibial prosthesis is placed in 5°backwards,and X-rays are taken after the standard position.Then the unicondylar femoral prosthesis is rotated 3°,6°,9°,12°and external rotation 3°,6°,9°,12°,the tibial prosthesis is tilted back 5°.After the operation,the knee joint X-rays were taken and measured on the e Film DICOM viewing software.The distance from the coronal projection vertex of the femoral prosthesis to the parallel line of the central axis of the femoral prosthesis was measured,and the measurement was taken 3 times.The average value is recorded as the A value;the sagittal projection vertex of the posterior condyle of the femur is drawn on the lateral radiograph to the distal femoral osteotomy surface and the vertical line is measured and its length is measured,and the average value is measured 3 times and recorded as the B value;Femoral prosthesis The internal and external rotation angle is recorded as theθangle.ResultsThe X-rays of standard anteroposterior and lateral positions after unicondyle replacement under different installation positions were measured and analyzed.The data in each group conformed to the normal distribution.The correlation analysis between the rotation angleθand the A value and the B value was P=0.000（P<0.05）,with significant statistical significance.Using nonlinear regression analysis to establish a tangent function model,R²=0.921（R²≥0.900）has good rationality,and the relationship between the intraoperative femoral prosthesis installation rotation angle and the postoperative X-ray measurement A value and B value is as follows:θ=arctan（A/1.362B-0.001）.Conclusion 1.Preliminary evaluation of the position of femoral prosthesis after unicondyle replacement by imaging（X-ray film）.2.According to the X-ray measurement to evaluate the calculation formula of the external rotation angle of the femoral prosthesis after unicondylar replacement of the knee joint:θ=arctan（A/1.362B-0.001）.