髌骨矢状面截骨术对髌骨倾斜病理应力分布的生物力学影响

目的：研究髌骨矢状面截骨术对髌骨倾斜病理应力分布的影响。方法：采用手术方法将七具新鲜人尸体膝关节标本的髌骨外侧支持带紧缩，造成髌骨过度外侧倾斜，然后进行四个不同截骨角的髌骨矢状面截骨术。股四头肌腱加载200N。分别于正常状态、髌骨倾斜、截骨5°、10°、15°、20°六种工况下，应用压敏片测量髌股关节接触压力与面积。摄屈膝45°Merchant髌骨轴位片，测量髌骨倾斜角，了解髌骨倾斜程度。结果与结论：髌骨倾斜后，髌骨内侧接触面积与压力均减少，外例接触面积与压力均增加，屈膝30°时最显著。截骨10°以上，明显改善了髌骨倾斜的应力分布，其中截骨15°改善较为理想。本实验结果为临床上髌骨矢状面截骨术中截骨角的选择提供了可靠依据。

BIOMECHANICAL EFFECT OF SAGITTAL PATELLAR OSTEOTOMY ON THE CONTACT PRESSURE DISTRIBUTION OF PATELLOFEMORAL JOINT OF THE PATELLAR TILT

Seven fresh corpse knee joint were used to simulate excessive lateral patellar tilt by tighting thelateral patellar retinaculum, then the sagittal patellar osteotomy was performed at four differentosteotomy angles. The load was 200N. The contact area and pressure was measured at normalstatus, patellar tilting, 5 degree, 10 degree, 15 degree, 20 degree of osteotomy angle using Fujipressure sensitive film. The patellar tilt angle was gauged on patellar axial film of 45 degree of kneeflexion.The results showed that the contact area and pressure decreased in medial patellar surface,and increased in lateral patellar surface while patel1ar tilt occured. This alteration was mostprominent at 30 degree of knee flexion. After patellar sagittal osteotomy,the contact pressuredistribution of patellar tilt was improved markedly at more than 10 degree of sagittal patellarosteotomy angle. The 15 degree of osteotomy angle was the best to improve the distribution ofcontact pressue while patellar tilt existed. The results offered a reliable evidence for application ofsagittal patellar osteotomy and the selection of osteotomy angle.