Compare The MRI Parameters Of The Patellar Tilt And Research The Diagnostic Value Of MRI T1-map Technology In Early Chondromalacia Patella Of The Knee

Part Ⅰ MRI measurement of the patellar tilt:Compare the parametersObjective: To explore the clinical value in describing patellofemoraldisorders of the three parameters (patellar tilt angle (PTA), lateralpatellofemoral angle (LPA) and tilt angle (TA)), which reflect for the patellartilt.Methods:84knees suspected patellar tilt selected from51patients (29male and22female, age range14~30years, mean age25.7years) whichclinical confirmed they had anterior knee pain, and conventional MRI haveexcluded the other factors (Such as trauma, patellar or quadriceps tendonitis,bursitis, fat pad syndrome, synovial plicae syndrome, iliotibial band frictionsyndrome, meniscus tear, meniscus cyst, anterior or posterior cruciateligament sprain, osteochondritis dissecans, neuroma, reflex sympatheticdystrophy，bipartite patella) which might cause anterior knee pain.84kneeswere randomly divided into three groups of A (30knees), B (26knees) and C(28knees). MRI scan were performed at degree of knee flexion20°and30°.The three groups (A, B, C) finished the MRI scan of the knee horizontal axissurface centered patellofemoral using the Siemens3.0T or1.5Tsuperconductive MRI scanners. At20°knee flexion, measured PTA and TA forthe A group, measured LPA and TA for the group B, and TA for group C, andthen classified the patellar tilt according to the traditional standards (the angleof PTA opening later is positive, and opening medial is negative, and if theangle is less than or equal to0°we believe the patella have the lateral tilt. Theangle of LPA opening later is positive, and opening medial is negative, and ifthe angle is less than8°we believe the patella have the lateral tilt. The angleof TA opening medial is positive, the normal angle should be less than10°, and if the angle is more than or equal to10°we believe the patella have thelateral tilt.). At knee-flexion angle equal20°, we calculated the detection rateof patellar tilt for A group by measuring PTA, the detection rate of patellar tiltfor B group by measuring LPA, and the detection rate of patellar tilt for Cgroup by measuring TA, and calculated the toat detection rate of patellar tiltfor A, B, C group by measuring TA. In the knee at30°of flexion, wemeasured the TA for A, B and C three groups. The detection rate of patellar tiltwere compared among this three groups by χ2test, and we compared TAwhich measured at knee-flexion angles of20°and30°by t test andχ2test.Results: In the knee at20°of flexion, we measured22knee have patellartilt in group A, the angle were between-9°～0°,the average angle was-3.8°,and the anther8knee of PTA were between5°～14°,and the averageangle was9.5°. The detection rates of the patellar tilt about PTA was73%(22/30). We measured10knee have patellar tilt in group B, the angle werebetween1°～7°,the average angle was4.8°, and the anther16knee of PTAwere between9°～17°,and the average angle was14°. The detection rates ofthe patellar tilt about LPA was38%(10/26). We measured22knee havepatellar tilt in group C, the angle were between11°～18°,the average anglewas15.2°,and the anther6knee of PTA were between3°～9°,and the averageangle was5.6°. The detection rates of the patellar tilt about TA was76%(22/28). The detection rate of this three methods of measuring had significantdifferences (P <0.05). The difference of detection rate between PTA and LPAwas significant (P=0.009), the detection rate of PTA was higher than LPA.The difference of detection rate between TA and LPA was significant (P=0.003), the detection rate of TA was higher than LPA. The difference ofdetection rate between PTA and TA was no significant (P=0.64), It wassimilar about the detection rate between PTA and TA. The TA of the84kneeswas (13±3.7)°which obtain at20°knee flexion, and the detection rate was64%(54/84).At knee-flexion angle of30°, the TA was (14±2.1)°, thedetection rate was49%(41/84). The TA was significant differences (P <0.05)between knee at20°and30°of flexion, the detection rate was higher at20° knee flexion than30°.Conclusion: Detection rate by measuring the PTA and TA is higher thanLPA, but these two methods of PTA and TA are similar. The detection rate ofTA measured at knee-flexion angle of20°is higher than flexion at30°. PartⅡ The diagnostic value of MRI T1-map technology in earlychondromalacia patella of the kneeObjective: To explore the feasibility of MRI T1-map imaging technique toevaluate early chondromalacia patella of the knee.Methods: Combining clinical diagnostic and MRI diagnostic criteria forearly chondromalacia patellae, and finally confirmed the presence ofchondromalacia patella in26patients (11men and15female, the age rangedfrom16to30years, average24.1years) which conventional MRI haveexcluded the other factors (Such as trauma, patellar or quadriceps tendinitis,bursitis, fat pad syndrome, synovial plicae syndrome, iliotibial band frictionsyndrome, meniscal tear, meniscal cyst, anterior cruciate ligament injury,osteochondritis dissecans, neuroma, reflex sympathetic dystrophy, bipartitepatella) cause of anterior knee pain and healthy volunteers14cases (6menand8female, the age ranged from23to28, average25.7years). Knee jointMRI T1-map imaging was performed in both group using Siemeds3.0T MRsuperconducting scanner. Observed the color changes in both case group andthe normal control group, at the same time, we measured their T1values.Applied rank sum test for the T1values data for statistical analysis.Results: The blue region representing the lower T1values in the patellacartilage were uniformed distribution in14cases of the normal control group.In the case group, light green area in the patellar cartilage representing thehigher T1values increased in8cases,16cases’s T1values were obviouslyhigher than the average T1values of the normal control group, but the colorwas still evenly distributed, there were no significant changes of T1values of and the color in the2cases. The T1values about the patellar cartilage were(1188.1±71.4) ms in normal control group, while1272.5ms in case group.There was a significant difference in T1values of the patellar cartilagebetween the case group and the normal control group (p<0.05).Conclusion: MRI T1-map imaging technique could found the componentchanges of the patellar cartilage with or without morphological changes, andhas a high clinical value in diagnosis and surveillance in eary chondromalaciapatella of knee joint.