AOSSM/AANA Specialty Day 2020-MPFL Only

MPFL Only - TTO Not Worth Morbidity

Pdf Summary

This debate focuses on whether isolated medial patellofemoral ligament reconstruction (MPFL-r) suffices in treating lateral patellar instability without addressing bony abnormalities through tibial tubercle osteotomy (TTO). Lateral patellar instability primarily affects young individuals, with risk factors including trochlear dysplasia, patella alta, increased tibial tuberosity–trochlear groove distance (TT-TG), and malrotation.<br /><br />MPFL reconstruction is the preferred surgical treatment, showing low recurrence (1.2%) and reoperation rates (3.1%) when performed in isolation. Though TTO can address bony factors like elevated TT-TG and patella alta, it presents notable complication risks (4-8%, up to 46% when including hardware pain or delayed bone healing) and prolongs recovery due to weight-bearing restrictions.<br /><br />Critically, there is no consensus on the TT-TG threshold necessitating TTO; values range between 15-20 mm, but dynamic studies demonstrate that some patients with high static TT-TG maintain normal patellar tracking, risking overtreatment. Studies by Erickson et al and Sappey-Marinier et al show that isolated MPFL-r yields low failure rates even in patients with elevated TT-TG and patella alta, suggesting many patients do not require additional bony procedures.<br /><br />In summary, while bony anomalies are linked to risk of MPFL-r failure, most patients with these risk factors do well after isolated MPFL reconstruction. Given the increased morbidity, longer rehabilitation, and complication potential of combined bony procedures, the recommendation is to perform isolated MPFL-r as a reliable, low-risk treatment for lateral patellar instability without pain, carefully discussing with patients the benefits and risks of adding TTO.

Keywords

medial patellofemoral ligament reconstruction

MPFL-r

lateral patellar instability

tibial tubercle osteotomy

TTO

trochlear dysplasia

patella alta

tibial tuberosity–trochlear groove distance

TT-TG threshold

surgical complications