Evaluation of Knee Pain in Athletes: A Radiologist's Perspective Umer Salati, MBChB, BAO, MRCP(UK), FFR RCSI, Orla Doody, MBChb, BAO, MRCPI, FFR RCSI, Peter L. Munk, MD, CM, FRCPC, FSIR, William Torreggiani, MBBCh, LRCPSI, BAO, MRCPI, FRCR, FFRRCSI  Canadian Association of Radiologists Journal  Volume 68, Issue 1, Pages 27-40 (February 2017) DOI: 10.1016/j.carj.2016.04.003 Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 1 Sagittal fat-suppressed T2-weighted magnetic resonance imaging (T2W MRI) in a 17-year-old field hockey player demonstrates high signal and expansion in the midsubstance of the anterior cruciate ligament (arrows) consistent with a partial tear. Fat-suppressed sagittal T2W MRI depicts oedema in the lateral femoral and tibial condyles (arrowheads) indicating a pivot shift injury. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 2 Frontal radiograph in a 22-year-old soccer player demonstrates a lateral capsular avulsion or Segond fracture (arrow). Subsequent magnetic resonance demonstrated a complete anterior cruciate ligament tear (arrowheads) with nonvisualization of the midsubstance fibers. Note the laxity of the posterior cruciate ligament indicating translation of the femur on the tibia (asterisk). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 3 Sagittal fat-suppressed T2-weighted (T2W) image demonstrating oedema at the anterior aspects of the femoral and tibial condyles due to a hyperextension injury in a 24-year-old soccer player (arrows). Sagittal T2W MRI in an 18-year-old triathlete with a hyperextension injury showing oedema at the anterior aspects of the femoral and tibial condyles (curved arrows), high signal and fraying of the posterior cruciate ligament near its femoral attachment site indicating a tear (arrowheads) and a small joint effusion (asterisk). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 4 Frontal radiograph in a 20-year-old soccer player with a minor hyperextension injury demonstrating the arcuate sign, a proximal fibular avulsion fracture (arrow). Subsequent sagittal T2-weighted magnetic resonance imaging showed oedema at the anterior femoral condyle (curved arrows) and a partial posterior cruciate ligament tear (arrowheads). The patient also had a high grade anterior cruciate ligament tear (not shown). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 5 Axial fat-suppressed T2-weighted image from a 19-year-old runner demonstrates oedema at the medial patellar facet (arrow) and posterolateral femoral condyle (arrowheads) and disruption of the medial patellofemoral ligament (curved arrows), due to lateral patellar dislocation. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 6 Sagittal and coronal fat-suppressed T2-weighted study in a 38-year-old amateur rugby player demonstrating high grade anterior cruciate ligament tear (arrows), suprapatellar effusion (asterisk), grade 2 medial collateral ligament, and grade 3 lateral collateral ligament tears, as part of a “terrible triad” spectrum of injuries (see Figure 7). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 7 Sagittal fat-suppressed T2-weighted magnetic resonance imaging demonstrating the “terrible triad” spectrum of injuries in a 38-year-old rugby player; depicted is bone oedema in the lateral femoral and tibial condyles (asterisks), avulsion fracture of posterolateral tibial condyle (arrow), tear of the posterior horn of the lateral (curved arrow) and the medial menisci (arrowhead). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 8 Sagittal T2 fat saturated image demonstrates a bucket handle tear of the medial meniscus (straight arrow), anterior to a normal low signal intensity posterior cruciate ligament (PCL) (curved arrow), known as the double PCL sign. Note a large suprapatellar effusion (asterisk). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 9 Coronal and sagittal T2-weighted images demonstrates an unusual bucket handle tear of the lateral meniscus, with the displaced fragment noted in the intercondylar notch (straight arrow), adjacent to a normal anterior cruciate ligament (curved arrow). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 10 Sagittal T2-weighted magnetic resonance imaging in a rugby player demonstrating oedema in the anterior tibia (arrows) and a high grade tear of the posterior cruciate ligament (arrowheads) as a result of a tackle and anterior force to the tibia in mild hyperextension. There is no oedema of the femoral condyle in this case. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 11 Sagittal T2-weighted fat saturated magnetic resonance imaging demonstrating thickening and oedema of the posterolateral capsule (arrowheads) and oedema near the popliteus tendon (arrows). Bone marrow oedema is also demonstrated in the posterolateral femoral condyle (asterisk). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 12 Axial and sagittal T2-weighted magnetic resonance imaging demonstrates focal high signal intensity within the proximal patellar tendon (arrows) in keeping with a focal full thickness tear. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 13 Axial and sagittal T2-weighted magnetic resonance imaging demonstrates high signal within and fraying of the distal quadriceps tendon (arrows) as well as oedema in the superior patellar pole, consistent with a partial quadriceps tear. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 14 Axial and sagittal T2-weighted magnetic resonance imaging in 34-year-old basketball player demonstrates a markedly oedematous and thickened patellar tendon (arrows) in keeping with a severe tendinitis. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 15 Axial proton density magnetic resonance in a 25-year-old runner demonstrates fissuring in the patellar articular cartilage (arrows), consistent with chondromalacia patella (confirmed on arthroscopy). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 16 Axial and sagittal T2-weighted magnetic resonance imaging in a 37-year-old amateur marathon runner demonstrates an osteochondral defect at the medial aspect of the lateral femoral condyle (arrows). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 17 Sagittal and coronal T2-weighted magnetic resonance imaging in a 16-year-old cross country runner demonstrates high signal intensity and fragmentation of the inferior pole of the patella (arrows), near the tendon insertion, consistent with Sinding-Larsen-Johansson disease. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 18 Sagittal T1-weighted magnetic resonance imaging demonstrates the presence of cortical bone (arrow) at the inferior aspect of the patellar tendon in a 20-year-old soccer player with chronic Osgood-Schlatter disease. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 19 Sagittal and axial fat-suppressed T2-weighted images in a runner with lateral knee pain demonstrate high signal intensity surrounding the iliotibial band (arrows). This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 20 Coronal and sagittal fat-suppressed T2-weighted magnetic resonance imaging demonstrates a high grade articular surface tear of the posterior horn of the medial meniscus (arrow) associated with a 4 mm meniscal cyst (curved arrow), in a 28-year-old Gaelic football player with chronic medial knee pain. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 21 Axial T2-weighted magnetic resonance imaging depicts a thickened cord-like medial plica (arrow) in a runner with recurrent medial knee pain. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions

Figure 22 Axial T2-weighted magnetic resonance imaging in a runner demonstrates fluid intensity signal (arrows) surrounding the pes anserine tendons (sartorius [S], gracilis [G], semitendinosis [St]), due to bursitis. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2017 68, 27-40DOI: (10.1016/j.carj.2016.04.003) Copyright © 2016 Canadian Association of Radiologists Terms and Conditions