Michel D. Crema MD, Presenter: Shareholder, Boston Imaging Core Lab, LLC

Larissa Garcia de Oliveira Cortinas MD, Abstract Co-Author: Nothing to Disclose

Giovanni L. Bessa, Abstract Co-Author: Nothing to Disclose

Sheila M. Ingham, Abstract Co-Author: Nothing to Disclose

Rene Abdalla MD, PhD, Abstract Co-Author: Nothing to Disclose

Abdalla Y. Skaf MD, Abstract Co-Author: Nothing to Disclose

Proximal patellar tendinopathy (PPT) is one of the most common overuse injuries of the knee. Knee morphology and alignment may play a role in the pathogenesis of PPT. The aim of this study was to assess the differences in morphology and alignment of the knee using MRI, focusing on the patellofemoral (PF) joint, between patients with PPT and controls.

We retrospectively included 35 patients with clinically diagnosed and unequivocal findings of PPT on knee MRI (case group). For the control group, we retrospectively included 70 patients who underwent knee MRI for other reasons, without clinical or MRI findings of PPT. Patients and controls were matched for age and gender, with all subjects reporting frequent physical activity. Knee MRIs were evaluated by two musculoskeletal radiologists, who assessed parameters regarding patellar morphology (subchondral Wiberg index and subchondral Wiberg angle – sWA), trochlear morphology (medial/lateral trochlea length ratio, trochlear sulcus, and lateral trochlear inclination angles), PF alignment (lateral patellar displacement, patellar inclination angle, Insall-Salvati (IS) and Caton-Deschamps ratios, tibial tuberosity-trochlear groove distance), and tibiofemoral (TF) alignment (angle). The differences in parameters between cases and controls were assessed using Student’s t-test. Logistic regression was applied to assess the associations between the parameters measured on MRI and PPT.

The patellar height IS ratio was significantly different between cases and controls (1.37 ± 0.21 and 1.24 ± 0.19 respectively; p=0.003). The sWA was significantly higher in cases vs. controls (136.8 ± 7.4 and 131.7 ± 8.8 respectively, p=0.004). The TF angle was also different between cases and controls (+4.7 ± 2.5 and +2.5 ± 3.7 respectively, p=0.002). After applying logistic regression, patellar morphology (sWA), patellar height (IS ratio), and the TF angle were significantly associated with PPT (odds ratios (95%CI) of 1.1 (1.0, 1.2); 1.3 (1.0, 1.7); and 1.2 (1.1, 1.5); respectively).

Some MRI-based measures of patellar morphology (sWA) and alignment (patellar height and TF angle) were shown to be useful in discriminating between controls and those with PPT.

Assessment of patellar morphology and height, as well as TF angle should be considered in athletes at risk for PPT, as it may help planning their training and potentially avoid PPT development.

Crema, M, Cortinas, L, Bessa, G, Ingham, S, Abdalla, R, Skaf, A, Magnetic Resonance Imaging (MRI)—Based Morphological and Alignment Assessment of the Knee Joint and its Relationship with Proximal Patellar Tendinopathy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011310.html