Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Regardless of Tibial Tubercle–Trochlear Groove Distance and Patellar Height: Minimum 5-Year Outcomes

• Published in: The American journal of sports medicine 2024-07, Vol.52 (9), p.2196-2204
• Main Authors: Dennis, Elizabeth R., Marmor, William A., Propp, Bennett E., Erickson, Brandon J., Gruber, Simone, Brady, Jacqueline M., Nguyen, Joseph T., Shubin Stein, Beth E.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Female; Humans; Joint Instability - surgery; Knee; Ligaments, Articular - surgery; Male; Patella - surgery; Patellofemoral Joint - surgery; Patient Reported Outcome Measures; Prospective Studies; Recurrence; Return to Sport; Tibia - surgery; Young Adult
• ISSN: 0363-5465; 1552-3365; 1552-3365
• DOI: 10.1177/03635465241260039

Background: It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction. Purpose: To provide midterm results for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial. Study Design: Case series; Level of evidence, 4. Methods: Patients with recurrent patellar instability were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included history of a previous surgery for patellar instability, an off-loadable (inferior/lateral) chondral defect, anterior knee pain ≥50% of their chief complaint, and a “jumping J” sign. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic characteristics. Patient-reported outcome measures (PROMs), episodes of recurrent instability, and ability to return to sport were obtained annually. Radiographic measurements of baseline radiographs and MRI were obtained at baseline. Results: A total of 138 patients underwent isolated MPFL reconstruction between March 2014 and December 2019. The mean radiographic measurements were tibial tubercle–trochlear groove, 15.1 ± 4.9 mm; Caton-Deschamps index, 1.14 ± 0.16; patellar trochlear index, 46.9% ± 15.1%; trochlear depth index, 2.5 ± 1.2 mm; tibial tubercle to lateral trochlear ridge, −8.4 ± 5.7 mm; and patellar tendon to lateral trochlear ridge, 5.7 ± 6.2 mm. Trochlear dysplasia, defined as a trochlear depth index