To explore the effects of varus of knee osteoarthritis (OA) on patellar position.
A total of 19 patients (27 knees) underwent the examinations of anterior-posterior, lateral knee and axis of patellar X-ray at 30°, 45°, 60° and each X-ray was measured.
The ratio between length of patellar tendon and length of patellar, vertical distance of lower edge of patellar to tibial plateau and height of patellar, distance of lower edge of medial facet of patellar to anterior angle of tibia and height of patellar were different from normal values. Patellar moved medially during the process of bending from 30°to 60°.
The patellar of knee OA patients with varus moves down and medially.