release of the lateral retinaculum and patellar tendon, knee motion normalized. Physical examination more than 2 years after surgery showed a 0–150 range of motion of the knee without pain. The improved Q angle was 10 , and the patient did not complain of patellar dislocation. Postoperative CT demonstrated no malalignment of the patella, and sulcus angle had improved from 170 to 140 (Figure 3). Discussion The treatment of trochlear dysplasia with malalign- ment of the patella needs to achieve realignment of the patella, such as transfer of the tibial tuberosity in patients with open epiphysis, which might lead to remodeling of the trochlear groove (6). Conversely, trochleoplasty should be considered carefully in cases with closed epiphysis in which remodeling following the realignment procedure may not be expected (7–10). Regarding these procedures, Kobayashi and Ou indicated trochleoplasty for cases with sulcus angle >150 with closed epiphysis and patella dislocation or subluxation in the early ﬂexion phase (5). Considering these treatment options, tro- chleoplasty was indicated for the present case with a closed epiphysis. Although trochleoplasty is a good surgical procedure for the treatment of trochlear dysplasia, some problems after this surgery have been reported. Kuroda et al. suggested that raising the lateral surface of the trochlea will further increase joint pressure, and thereby Recurrent dislocation of the patella 287 increase the risk of arthritis developing in the case of trochleoplasty (11). To avoid this eventuality, we chose the Dejour technique (8), which was unaccompanied by elevation of the lateral surface of the trochlea. Furthermore, we performed both proximal and distal realignment to expect to distribute joint pressure equally between the medial and lateral patello- femoral joint. Koeter et al. (12) and Schottle et al. (10) supported proximal realignment such as medial reeﬁng and lateral release, while Donell et al. (2) and Fulkerson (4) supported distal realignment such as tibial transfer when performing trochleoplasty. Another reason why we performed both proximal and distal realignment procedure was because the patient showed severe malalignment of the patella (Q angle 20 ). For proximal realignment, we adopted the medial reeﬁng procedure proposed by Insall et al. (3). We did not add the lateral release because the lack of balance between medial and lateral patellofemoral joint pressure might occur after additional lateral release (13). However, our case showed joint con- tracture similar to arthroﬁbrosis following immobili- zation in the plaster cast, in the same way as described by Donell et al. (2). Ochi (13) suggested that medial reeﬁng and advancement of vastus medialis increased the patellofemoral joint pressure. For distal realign- ment, Utting et al. (14) recommended that mediali- zation of the tibial tubercle should be carried out when the offset of the tuberosity from the trochlear groove exceeds 18 mm, and we followed that methodology. They also suggested reconstruction of the medial Figure 3. Postoperative computed tomography demonstrating no malalignment of the patella and improvement of sulcus angle from 170 to 140 .