An Algorithmic Approach to the Management of Recurrent Lateral Patellar Dislocation

Abstract

High-level evidence supports nonoperative treatment for first-time lateral acute patellar dislocations. Surgical intervention is often indicated for recurrent dislocations. Recurrent instability is often multifactorial and can be the result of a combination of coronal limb malalignment, patella alta, malrotation secondary to internal femoral or external tibial torsion, a dysplastic trochlea, or disrupted and weakened medial soft tissue, including the medial patellofemoral ligament (MPFL) and the vastus medialis obliquus. MPFL reconstruction requires precise graft placement for restoration of anatomy and minimal graft tension. MPFL reconstruction is safe to perform in skeletally immature patients and in revision surgical settings. Distal realignment procedures should be implemented in recurrent instability associated with patella alta, increased tibial tubercle-trochlear groove distances, and lateral and distal patellar chondrosis. Groove-deepening trochleoplasty for Dejour type-B and type-D dysplasia or a lateral elevation or proximal recession trochleoplasty for Dejour type-C dysplasia may be a component of the treatment algorithm; however, clinical outcome data are lacking. In addition, trochleoplasty is technically challenging and has a risk of substantial complications.

Medial patellofemoral ligament reconstruction with gracilis autograft for recurrent patellar instability: a case report

“…As anatomic knowledge and radiographic capabilities have improved, criteria have been developed to aid in the operative decision-making process and identify patients who may be candidates for an isolated MPFL reconstruction. 19 Multiple procedures have been proposed to treat patellar instability including lateral release, medial imbrication, medial patellofemoral ligament repair, and a number of distal realignment procedures. Reconstruction of the medial patellofemoral ligament can be used as a successful primary procedure or as a salvage procedure.…”

Patellar instability: Traditional surgical interventions and a robotic approach

“…The surgeon has to redefine the trochlear groove in order to perform a new groove to stabilize the patella in the sulcus. This is a complex surgery that depends of surgeon's experience [10].…”

Demystifying Tibial-Tuberosity Trochlear Groove Distance, the J-Sign and Trochlear Dysplasia: An Imaging Encomium

“…In skeletally mature patients, the anterior knee pain and the value of the TTTG distance #20 mm could imply surgical treatment [8], namely medialization of the tibial tuberosity [6]. The purpose of our study was to examine the association of the clinical J-sign with trochlear dysplasia and TTTG distance in patients with symptomatic patellofemoral instability.…”

“…It is a straight forward clinical sign, sometimes shortly referred to as "dislocation in extension" [4]. A positive J-sign might suggest patellar maltracking [5], and potentially a need for trochleoplasty [6]. Yet, the underlying anatomical features and its actual diagnostic value are somewhat cryptic [7].…”

“…Yet, the underlying anatomical features and its actual diagnostic value are somewhat cryptic [7]. On the contrary, both trochlear dysplasia and the tibial tuberosity-trochlear groove (TTTG) distance, as a measure of lateralization of the extensor mechanism of the knee, are well-known phenomena with regard to recurrent patellofemoral instability [6].…”