Patellofemoral (PF) instability arises from a constellation of biomechanical and anatomical factors, of which trochlear dysplasia is recognized as one of the most important.1, 2, 3 The abnormal trochlear morphology results in changes in kinematics, contact area, and contact pressures, compromising the stability of the PF joint.4,5 Trochleoplasty was developed to address the osseous foundation of instability in these patients, and has further evolved into three distinct techniques: sulcus or groove deepening, recession wedge, and bumpectomy. Two variations of the sulcus deepening trochleoplasty exist: the Lyon or “thick shell” technique developed by Masse6 and further standardized by Dejour7,8, and the “thin flap” technique pioneered by Bereiter and Gautier9, later refined by Schöttle10. Goutallier et al11 introduced the recession wedge technique, which was further modified by Yanke21, to avoid damage to the native cartilage. Peterson et al12 described the proximal entrance grooveplasty, considered a type of bumpectomy, to address the supratrochlear spur in isolation. This chapter will discuss the nuances of these three techniques and synthesize the latest literature on the subject, providing a valuable update to previous chapters3.