Role of magnetic resonance imaging in assessment of extensor compartment abnormalities of knee joint – A cross-sectional study

INTRODUCTION: The patellofemoral joint (PFJ) is a complex joint structure with high functional and biomechanical requirements. The magnetic resonance imaging (MRI) is an effective tool for definition and characterization of knee pathology as it can accurately detect, localize, and characterize various pathologies of the knee joint. OBJECTIVES: (1) Evaluate MR images to identify different pathologies that are seen in the extensor compartment of the knee joint. (2) Quantitative assessment of patellofemoral measurements to determine predisposing risk factors that contribute to patellofemoral joint instability. METHODOLOGY: A cross-sectional study was conducted from January 2017 to December 2017 with a sample size of 30 in the Department of Radiodiagnosis at The KLE's Dr. Prabhakar Kore Hospital and MRC, Belagavi. The data were collected using a pretested semi-structured questionnaire. The pro forma included sociodemographic profile of the study subjects, clinical presentation MRI to identify different pathologies that are seen in extensor compartment of the knee joint and quantitative assessment of patellofemoral measurements to determine predisposing risk factors that contribute to patellofemoral joint instability. RESULTS: Among the study population majority of people had normal synovium, laterally subluxated/dislocated patella. Among the study population, the majority had normal lateral trochlear inclination angle, normal trochlear facet asymmetry, normal trochlear depth, normal sulcus angle, and trochlear dysplasia. Twenty-four (80%) people had normal Insall–Salvati index, 27 (90%) people had normal lateral patella femoral angle, 25 (83.30%) people had normal lateralization of the patella, 28 (93.30%) people had normal tibial tubercle to trochlear groove distance, majority, i.e., 11 (36.70%) had Hoffa's fat pad edema followed by chondromalacia patella, trochlear dysplasia, medial patellofemoral ligament tear, patella alta, synovial plicae, subluxated/dislocated patella, transient dislocated patella, Osgood–Schlatter disease, and patellar tendonitis. CONCLUSION: MRI has also been useful in identifying extensor compartment pathologies that lead to anterior knee pain.