286 A. Horikawa et al. Figure 1. Preoperative computed tomography demonstrating marked trochleodysplasia of the femur, with a sulcus angle of 170 . the cartilage by screw as advocated by Donell et al. (2) (Figure 2). Proximal realignment involved medical retinaculum suture (reeﬁng), as described by Insall et al. (3). Distal realignment comprised medialization of the tibial tuberosity according to Fulkerson’s osteot- omy (4), transferring the tuberosity site 15 mm medially. Following surgery, a long leg plaster cast was applied for 2 weeks. Physical therapy including strengthening quadriceps muscle and improvement of range of motion was started after cast removal, by referring to Kobayashi and Ou’s rehabilitation proto- col (5). Partial weight-bearing was allowed from 4 weeks postoperatively. Although no malalignment of patella was seen on plain radiography, the patient complained of joint contracture from 0 extension to 40 ﬂexion. Considering these symptoms, second- look arthroscopy was performed. A second-look arthroscopic examination demon- strated a good-shaped trochlear groove without car- tilage defect. However, ﬁbrous adhesion was seen mainly in the suprapatellar pouch. After arthroscopic Figure 2. Schema of the modiﬁed Dejour technique. After shaving the subchondral bone, an incision from the aspect of the groove was made. A subchondral trench was then cut and the ﬂap undermined, followed by impaction using ﬁnger pressure and screw ﬁxation.