2021 ISAKOS Biennial Congress ePoster
Influence of Patellofemoral Anatomy on Outcomes of Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability
Robert A Magnussen, MD, MPH, Worthington, OH UNITED STATES
Nicholas Pappa, BS, Columbus, Ohio UNITED STATES
Joseph M Long, BS, Columbus, OH UNITED STATES
Robert A. Duerr, MD, St Louis, MO UNITED STATES
Alex C. Dibartola, MD, MPH, Columbus, OH UNITED STATES
Christopher C. Kaeding, MD, Columbus, OH UNITED STATES
David C. Flanigan, MD, Columbus, OH UNITED STATES
The Ohio State University, Columbus, Ohio, UNITED STATES
FDA Status Cleared
Summary
In patients without a large j-sign, neither moderately elevated TT-TG distance nor patellar alta are associated with poorer patient-reported outcomes following isolated MPFL reconstruction for patellar instability
ePosters will be available shortly before Congress
Abstract
Introduction
Patella alta and elevated tibial tubercle-trochlear groove (TT-TG) distance are known to predispose patients to lateral patellar dislocations and recurrent instability. The purpose of this study was to evaluate the influence of these risk factors on patient-reported outcomes following isolated medial patellofemoral ligament (MPFL) reconstruction.
Methods
A all patients who underwent isolated MPFL reconstruction at a single institution between 2008 and 2016 were identified. Performance of an isolated MPFL reconstruction was at the discretion of the operating surgeon with the primary indication for tubercle osteotomy being a large j-sign with patella alta or elevated TT-TG distance. Patient demographics and surgical details were collected via chart review, and patients were contacted to collect patient-reported outcomes including the Norwich Patellar Instability Score (NPI), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and Marx Activity Score. Preoperative imaging was reviewed, and patellar height (Caton-Deschamps Index [CDI]) and TT-TG distance were measured. Patient-reported outcomes were compared based on CDI > 1.20 versus CDI < 1.20 and TT-TG > 20mm versus TT-TG < 20mm.
Results
During the study period, 165 patients underwent isolated MPFL reconstruction. 125 patients (76%) with minimum one year follow-up were contacted at a mean of 5.2 years. following surgery. Mean CDI was 1.13, and 35% had a CDI > 1.20. Mean TT-TG distance was 17.5mm, and 26% had a TT-TG distance greater than 20mm. No significant differences in patient-reported outcomes were noted based on patella alta or elevated TT-TG distance. Recurrent dislocation occurred in 5 patients (4%).
Conclusion
In patients without a large j-sign, neither moderately elevated TT-TG distance nor patellar alta are associated with poorer patient-reported outcomes following isolated MPFL reconstruction for patellar instability.