关键词: 关节线, 屈曲角度

Abstract: Objective To explore the correlation between the joint line and the range of knee flexion after condylar knee joint replacement. Methods The range of knee flexion and the change of the joint line in 41 patients(50 knees) with osteoarthritis(OA) were measured and analyzed before and after total knee arthroplasty(TKA). The linear regressive analysis was used to judge the correlation between the two variables. Results The knee joint flexion was linear correlative to the joint line. It was a negative correlation if the joint line was above the anatomical position（r=－0.92,P<0.01）, and it was a positive correlation if the joint line was below the anatomical position(r=0.58，P<0.01). The knee joint could flex to more than 120°averagely if the joint line was elevated no more than 3 mm. If the joint line was elevated 3-6 mm, the joint could still flex to more than 100°.If the joint line was elevated more than 6 mm,the joint could only flex to 90°. The knees can still flex to more than 120°averagely for the patient with lowered joint line even if the lowest one was －6 mm, Conclusion For the primary TKA of OA cases by posterior stabilized implant, the joint line should be placed to the anatomical position as near as possible. The best range of flexion could be accomplished if the joint line is elevated less than 3 mm.

Key words: joint line, range of flexion