AOSSM/AANA Specialty Day 2020-Handout 2

Handout 2 - TTO + MPFL_ Worth It!

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This presentation by Dr. Andrew J. Cosgarea at the 2020 AOSSM/AANA Specialty Day discusses patellar stabilization and surgical management options, focusing on Tibial Tuberosity Osteotomy (TTO) and Medial Patellofemoral Ligament (MPFL) reconstruction.<br /><br />Patellar stability depends on dynamic muscle action (notably the vastus medialis oblique, hip external rotators, and core muscles), passive soft tissue restraints (the medial patellofemoral complex including MPFL, MPML, MPTL, MQTFL), and osteochondral geometry (factors like femoral version, patellar height, trochlear morphology, and tibial alignment).<br /><br />Surgical options are divided into femoral-based and tibial-based approaches. Femoral options include soft tissue procedures (VMO advancement, MPFL repair/reconstruction) and osteotomies (femoral derotation, trochleoplasty). Tibial-based options include the Galeazzi procedure and various tuberosity osteotomies (medialization, anteriorization, distalization) as well as tibial derotation osteotomies.<br /><br />Key findings include risk factors for MPFL reconstruction failure such as patella alta, a positive J-sign, and elevated tibial tuberosity–trochlear groove (TT-TG) distance. Elevated TT-TG distances are also associated with higher risk and progression of patellofemoral osteoarthritis. Biomechanical studies show that MPFL graft tension correlates with TT-PCL distance, and that TTO can reduce lateral patellar maltracking and patellofemoral cartilage stress.<br /><br />Pathologically lateralized tibial tuberosities increase stress on MPFL grafts; thus, medializing osteotomies can correct maltracking, optimize contact pressures, and reduce failure risk. Surgical decisions should be tailored to specific anatomical issues including medial soft tissue insufficiency (MPFL reconstruction), malalignment (TTO), patella alta (distalization), trochlear dysplasia (trochleoplasty), femoral anteversion (derotation osteotomy), and genu valgum (distal femoral osteotomy).<br /><br />Overall, combining TTO with MPFL reconstruction when appropriate can improve patellar stability and outcomes.

Keywords

Patellar stabilization

Tibial Tuberosity Osteotomy

Medial Patellofemoral Ligament reconstruction

Patellar stability factors

Femoral-based surgical options

Tibial-based surgical options

MPFL reconstruction failure risk factors

Patellofemoral osteoarthritis

Biomechanical studies MPFL

Surgical decision making patellar instability