Long-term functional and radiologic outcomes following MPFL reconstruction: a 10-year retrospective study

Medial patellofemoral ligament (MPFL) reconstruction has become a popular treatment option for recurrent patellofemoral instability. At the fifth-year follow-up, patients reported a high satisfaction rate and experienced few episodes of instability. The literature is scarce regarding the long-term outcomes after MPFL reconstruction. Therefore, a retrospective study was conducted, covering the period between 2008 and 2013.

Demographic and clinical data, including age, gender, number of dislocations, and revision surgery, were collected. Radiologic measurements included patellar height, tilt, maltracking, and trochlear dysplasia. Radiologic assessment was made with computed tomography (CT) preoperatively and magnetic resonance imaging (MRI) postoperatively, contributing to the further identification of chondral lesions. Functional evaluation was based on the Kujala and Lysholm scores.

In this study, 32 patients (62.5% female and 37.5% male, mean age 18 ± 5 years) underwent MPFL reconstruction. There was an increase in the tibial tubercle-trochlear groove (TT-TG) distance in the postoperative (16.2 [IQR 13.8-18.3] vs. 20 [IQR 18-21] mm). Patellar tilt improved both in 0º extension (24 [IQR 15-29.5]° vs. 15 [IQR 6.5-26.8]°; p > 0.05) and with quadriceps contraction (32 [IQR 26-41]° vs. 22.5 [IQR 9.25-37.5]°; p > 0.05). Among patients with lateral release (40%), postoperative tilt reduction was significant (p < 0.005). Two patients experienced re-dislocation, with one requiring revision surgery. More than half showed grade III/IV chondral lesions, mainly on the lateral patellar facet, with an association between a higher patellar tilt and chondral damage (p < 0.05). Median Kujala and Lysholm scores were 89 (IQR 81.25-96.75) and 86 (IQR 76.75-94.75), respectively.

This study suggests that MPFL reconstruction yields good long-term clinical outcomes, though it is insufficient to fully correct a TT-TG offset. Increased preoperative patellar tilt was significantly linked to patellofemoral chondropathy; adjunct lateral release might be a preventive procedure since it helps by reducing lateral facet contact pressures.

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