Patellofemoral Joint Reconstruction for Patellar Instability: Medial Patellofemoral Ligament Reconstruction, Trochleoplasty, and Tibial Tubercle Osteotomy

Abstract

Recurrent patellar instability can be very debilitating and may require surgical intervention. A thorough workup must be completed in this subset of patients. Risk factors for recurrent instability include patella alta, trochlear dysplasia, an increased tibial tubercle-trochlear groove distance, and insufficiencies in the medial retinacular structures. Necessary treatment of these risk factors, once identified, should be addressed surgically. Patellofemoral reconstruction must be individually tailored to each patient's anatomy and may necessitate medial patellofemoral ligament reconstruction, tibial tubercle osteotomy, or trochleoplasty in any combination or as a standalone procedure. This article details our technique for surgical treatment of recurrent patellar instability with a medial patellofemoral ligament reconstruction, an open trochleoplasty, and a tibial tubercle osteotomy for patients with severe trochlear dysplasia, an increased tibial tubercle-trochlear groove distance, or patella alta.

Fig 1

Dejour classification system for trochlear dysplasia represented by lateral radiographic views and axial cross sections. (A) In type A dysplasia, the trochlea is shallow but still symmetrical and concave, with the crossing sign on the lateral radiograph. (B) In type B dysplasia, the trochlea is flat or convex, with the crossing sign and a trochlear spur on the lateral radiograph. (C) In type C dysplasia, the lateral facet is convex and the medial facet is hypoplastic, with the crossing sign and double contour sign (subchondral sclerosis of the medial hypoplastic facet) on the lateral radiograph. (D) In type D dysplasia, the cliff pattern is present on the axial view; the crossing sign, a supratrochlear spur, and the double contour sign can all be seen on the lateral radiograph. Reprinted with permission.

Fig 2

Cadaveric photograph of a right knee showing the relation of the patella, vastus medialis obliquus (VMO), and adductor tubercle (AT) relative to the medial patellofemoral ligament (MPFL). A needle holder is under the MPFL, and the scissors are pointing to the femoral insertion of the MPFL. (sMCL, superficial medial collateral ligament.)

Fig 3

Intraoperative photograph of a right knee with the tibial tubercle (TT) and patellar tendon reflected superiorly. A second cut is being made in the tibia at the level at which the tubercle will undergo distalization.

Fig 4

Intraoperative photograph of a right knee with the patella reflected laterally during trochleoplasty. A high-speed reamer is being used to remove subchondral bone. (DMTF, distal medial trochlear facet; TG, trochlear groove.)

Fig 5

Intraoperative photograph of a right knee with the cartilage flap secured with 3 × 26–mm cannulated Bio-Compression screws. (DLTF, distal lateral trochlear facet; DMTF, distal medial trochlear facet; TG, trochlear groove.)

Fig 6

Intraoperative photographs of a right knee with the tibial tubercle (TT) being pulled distally, secured with two K-wires (A) and then fully threaded 4.5-mm cannulated screws with washers (B), and checked with fluoroscopy.

Fig 7

Intraoperative photograph sequence of a right knee undergoing medial patellofemoral ligament reconstruction with semitendinosus autograft. (A) The graft is pulled through the patella and secured laterally with a button, (B) a channel beneath the medial retinaculum is created, and (C) the graft is passed and (D) secured to the anchor in its anatomic position.