Trochleoplasty in major trochlear dysplasia: current concepts

The importance of a dysplastic trochlea as a component of patellar instability (especially recurrent dislocation or habitual dislocation) has been recognized for many years. It is usually combined with other static or dynamic abnormalities such as genu recurvatum, patella alta, patellar tilt, increased Q angle and bone torsional abnormalities.Major trochlear dysplasia is characterized by the combination of a flat and/or prominent trochlea proud of the anterior femoral cortex which offer inadequate tracking during flexion and lead to patella subluxation respetively [1,2].Many surgical techniques have been proposed for the treatment of patellar instability. Trochleoplasty has been described as corrective treatment for bony abnormalities for many years with the goal of restoring normal anatomy. Correcting the trochlear depth abnormality plays a major role to stabilising the patella because it facilitates proper entrance of the patella into the groove of the trochlea. In our experience the restoration of the trochlea groove by trochleoplasty prevents future patellar dislocation and is effective in reducing anterior knee pain.Elevation of the lateral trochlear facet was first described by Albee [3] in 1915, followed by deepening trochleoplasty [2,4-12] which tries to create a new sulcus by removing subchondral bone. Recently Goutallier [13] proposed an easier concept, termed Recession Trochleoplasty, in which the bump is solely corrected with the trochlea remaining flat. This has now been adopted as our preferred technique [14].Trochleoplasty is considered as a demanding technique and frequently may be avoided due to a lack of familiarity. However it can be a useful addition to the surgical armamentarium of the patellofemoral surgeon and has precise indications.Trochleoplasty can be proposed as a primary procedure for primary trochlea dysplasia or as a salvage procedure [13] in case of failure after previous patellar alignment surgery, principally Anterior Tibial Tubercl