Magnetic resonance imaging enables precise quantification of patellar height and engagement in patients undergoing
Andrea Pintore1, François Fauré2, Carmela Pizzigallo3
1Department of Trauma and Orthopaedic Surgery, University of Salerno, Ospedale San Giovanni di Dio e Ruggi D'Aragona, Salerno, Italy; Lyon-Ortho-Clinic, Clinique de la Sauvegarde, Ramsay Santé, Lyon, France.
Introduction:
The objective of this study is to evaluate the improvements in patellar height and the amount of correction of Caton-Deschamps index (CDI), patellar height index (PHI), and sagittal patellofemoral engagement (SPE) after surgery of tibial tubercle osteotomy (TTO) and medial patellofemoral ligament (MPFL) reconstruction for objective patella instability (OPI) associated with patella alta.
Methods:
A consecutive series of TTO and MPFL reconstruction between 2021 and 2023 was prospectively enrolled. All patients underwent pre-operative and postoperatively (7 months) X-rays and Magnetic resonance imaging (MRI). Images were reviewed by three independent reviewers to measure CDI, PHI, and SPE.
Results:
A total of 50 patients were enrolled in this study (mean age: 22.2 ± 7.2 years; 48% male). The mean tibial distalization was 6.7 mm ± 2.7. CDI decreased from 1.25 ± 0.2 to 0.97 ± 0.1 (p < 0.001). PHI improved from 1.28 ± 0.2 (mean ± SD) to 1.04 ± 0.19 (p < 0.001), and SPE from 31% ± 18.7-60% ± 13.5 (p < 0.001).
Conclusion:
A standardized MRI protocol allows reproducible quantitative assessment of patellar height and sagittal patellofemoral engagement following distalization TTO.
Level Of Evidence:
IV.
