Fig. 3From: Medial patellofemoral ligament reconstruction using a bone groove and a suture anchor at patellar: a safe and firm fixation technique and 3-year follow-up studyThe safe angle was defined as the angle between the drilling tunnel and the connecting line. Lines connecting the upper-third horizontal plane and the medial and lateral margins of the patella were created on CT scans. The connecting line was divided into four parts. The area representing the medial one fourth of the patella surface was marked as the drilling site. The direction of the drilling referred to the safety angle according to patellar morphologyBack to article page