Durable patellar stability and high patient-reported success at minimum 5-year follow-up after isolated suture tape...

To evaluate the mid-to- long-term clinical and radiological outcomes of isolated medial patellofemoral ligament reconstruction (MPFL-R) using a high-strength suture tape (HSST) construct in patients with recurrent patellar instability and no major osseous risk factors.

Patients treated with isolated MPFL-R using HSST and a single knotless femoral anchor between 2015 and 2021 were retrospectively reviewed. Inclusion criteria were recurrent lateral patellar instability (≥2 dislocations or symptomatic subluxations) refractory to nonoperative treatment and a minimum postoperative follow-up of 60 months. Patients requiring concomitant bony realignment or presenting with major anatomic risk factors (e.g., high-grade trochlear dysplasia, severe patella alta, tibial tubercle-trochlear groove distance >20 mm) were excluded. Clinical outcomes were assessed with the International Knee Documentation Committee (IKDC) subjective score, Kujala score and visual analogue scale (VAS) for pain. Patellar tilt was measured on axial magnetic resonance imaging (MRI). Postoperative instability events, complications and reoperations were recorded. Clinically meaningful improvements were assessed using minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) thresholds. Kaplan-Meier survival analysis was performed to estimate 5-year survivorship free from redislocation (primary endpoint) and any postoperative instability (secondary endpoint). Postoperative instability was defined as clinically documented redislocation or symptomatic subluxation.

Eighty-one patients (mean age 20.8 years; 31.4% female) were included. At a mean follow-up of 79.4 ± 14.3 months, one redislocation (1.2%) and two subluxations (2.5%) occurred. Five-year survivorship free from redislocation was 98.8% (95% confidence interval [CI], 96.4%-100%), and survivorship free from any postoperative instability was 96.3% (95% CI, 92.2%-100%). All patient-reported outcome measures improved significantly from baseline to final follow-up (all p < 0.001). Ninety-six percent of patients achieved the PASS threshold for IKDC (95% CI, 89.7%-98.7%), whereas PASS attainment for the Kujala score ranged from 74% to 86% depending on the applied cut-off. Radiologically, patellar tilt improved substantially on MRI (p < 0.001). Postoperative complications were infrequent and manageable, including five cases of arthrofibrosis (requiring manipulation under anaesthesia), one deep infection (treated with arthroscopic debridement) and three cases of implant-related bursitis at the femoral fixation site.

Isolated MPFL reconstruction using an HSST construct provided durable patellar stability and significant functional improvement at a minimum 5-year follow-up. This technique represents a reliable mid-to-long-term option for isolated MPFL-R in appropriately selected patients, especially when graft harvest morbidity and patellar bone preservation are concerns.

Level IV, retrospective cohort study.