1. Pathology Flash Cards Emma Kan
Ultrasound of the Knee
Pathology Flash Cards
Emma Kan

2. 1. Identify and Name the pathologyB C D E
Gilani, 2010; available
Identify the structures indicated.

3. 1. Answer: Joint effusion – fluid within the suprapatellar recessB C D E
Image 1. Anechoic fluid collection within the suprapatellar recess.
(Gilani, 2010; A B C D E
The effusion must be assessed for homogeneity and loose intraarticular bodies, and the suprapatellar plica must be noted if present1-2.
Anechoic fluid collections often indicate acute pathological processes while hyperechoic effusion may be a result of haemorrhage or debris1-2.
Structures: A. Quadriceps femoris tendon. B. Prefemoral fat pad. C. Anechoic joint effusion within the suprapatellar recess. D. Suprapatellar fat pad. E. Patella.

4. 2. Name the abnormality indicated by the arrow
Identify the structures indicated B A
(Geertsma, 2015;

5. 2. answer: Synovial thickening in the suprapatellar recess
The epiphyseal growth plate of the distal femur is indicated by the red arrow. B
Structures: A. Distal femoral shaft. B. Distal femoral epiphysis. A
Image 2. Synovial thickening within the suprapatellar recess (yellow arrow).
(Geertsma, 2015;

6. 3. Identify and Name the pathology indicated by the arrow
Identify the structures indicated B C A
(Geertsma, 2015;

7. 3. Answer: Lipohaemarthrosis
Observe the blood/fat interface within the suprapatellar recess (arrow) indicating cortical breach. In this case, tibial plateau fracture. B C A
Structures: A. Quadriceps tendon. B. Patella. C. Suprapatellar fat pad.
Image 3. Lipohaemarthrosis.
(Geertsma, 2015;

8. 4. Identify and Name the pathology indicated by the arrow
(Geertsma, 2015;

9. 4. answer: Partial tear of distal quadriceps tendon
Rupture of the superficial component of the quadriceps tendon (yellow arrow) results in a hypoechoic defect and discontinuity in tendon fibres3.
Deeper fibres appear in tact and continuous (red arrow).
Partial flexion of the knee may assist in demonstrating the extent of the partial tear4.
Image 4. Partial tear of the distal quadriceps femoris tendon (yellow arrow).
(Geertsma, 2015;

10. 5. Identify and Name the pathology
Identify the structures indicated B A C
(Geertsma, 2015;

11. 5. answer: Prepatellar bursitisC
Image 5. Prepatellar Bursitis.
(Geertsma, 2015;
Thickening of the prepatellar bursa with intrabursal fluid is seen anterior to the patella and patella tendon (arrow).
Use light pressure to avoid displacing fluid4.
Structures: A. Patella. B. Patellar tendon. C. Tibial tuberosity.

12. 6. Identify and name the pathology
Proximal Tibia
(Geertsma, 2015;
(Geertsma, 2015;

13. 6. answer: Distal patellar tendinosis
The distal patellar tendon appears extremely thickened and hypoechoic with loss of fibrillar echotexture4 (yellow arrows).
There is a small amount of fluid within the deep infrapatellar bursa likely representing peri-tendinous fluid1 (red arrow).
Image 6. Tendinosis of the distal patellar tendon.
(Geertsma, 2015;
Characteristic neovascularity may be observed4 (right). Chronic tendinosis may demonstrate calcifications, nodularity and heterogenous scarring1.
Image 7. Neovascularity within the distal patellar tendon. (Geertsma, 2015;

14. 7. Identify and name the pathology indicated by the yellow arrow
Proximal tibia
Medial femoral condyle
(Geertsma, 2015;

15. 7. Answer: Partial rupture of the distal MCL
Observe the hypoechoic defect with loss of normal fibrillar pattern (green dotted line) indicating rupture of the deep layer of the distal MCL4. The superficial layer is intact (red arrow).
Chronic lesions may cause the MCL to appear thickened, heterogenous and hyperechoic due to scarring4.
Image 8. Partial tear of the deep part of the distal medial collateral ligament.
(Geertsma, 2015;

16. 8. Identify and name the pathology
(Wildman, 2014;

17. 8. answer: Lateral meniscal cyst
Note the cystic lesion immediately superficial to the echogenic lateral meniscus (white dotted line).
Meniscal cysts most commonly occur at the lateral meniscus and are often associated with meniscal tears4.
Image 9. Lateral meniscal cyst seen at the lateral margin of the knee joint. (Wildman, 2014;

18. 9. Identify and name this pathology of the posterior knee
(Radiopaedia, 2015;

19. 9. answer: Baker’s cyst Image 10. Baker’s cyst.
Fluid can be seen distending the gastrocnemius-semimembranosus bursa forming a Baker’s cyst (yellow arrows).
The neck is clearly visible tracking from the joint (blue arrow) between the medial head of the gastrocnemius muscle (X) and the semimembranosus tendon (red arrow)4.
Note the hyperechoic debris within the cyst.
In longitudinal section, the cyst should appear to have rounded margins. If the inferior margins appear angular and pointed, rupture may be suspected3.
Image 10. Baker’s cyst.
(Radiopaedia, 2015;

20. 10. Identify and name the pathology indicated by the arrow
Tibial tuberosity
(Geertsma, 2015;

21. 10. answer: Osgood-schlatter disease
Osgood Schlatter disease demonstrated by cartilage swelling and fragmentation (yellow arrow) at the tibial tuberosity.
The distal patellar tendon also appears hypoechoic and there is an effusion of the deep infrapatellar bursa (red arrow).
Image 11. Osgood-Schlatter disease in an infant.
(Geertsma, 2015;

22. References
1. Friedman, L., K. Finlay and E. Jurrians “Ultrasound of the Knee”. Skeletal Radiology. 30:
2. Court-Payen, Michel “Sonography of the Knee: Intra-articular Pathology”. Journal of Clinical Ultrasound. 32:
3. Bianchi, Stefano and Carlos Martinoli Ultrasound of the Musculoskeletal System. Berlin: Springer.
4. Paczesny Lukasz and Jacek Kruczynski “Ultrasound of the Knee”. Seminars in Ultrasound, CT and MRI. 32:

23. Images
Gilani, Syed Knee joint effusion. American Institute of Ultrasound in Medicine. Available at
Geertsma, T.S.A Effusion in the suprapatellar recess with synovial thickening in a child. Ultrasoundcases-info. Accessed May 17. Available:
Geertsma, T.S.A Lipohaemarthrosis in the superior recess in a child with a tibia fracture. Ultrasoundcases-info. Accessed May 17. Available:
Geertsma, T.S.A Rupture of the superficial part of the distal quadriceps tendon. Ultrasoundcases-info. Accessed May 17. Available:
Geertsma, T.S.A Prepatellar bursitis with thickened fluid-filled bursa anterior to the patellar tendon. Ultrasoundcases-info. Accessed May 17. Available:
Geertsma, T.S.A Tendinosis of the distal patellar tendon with a thickened hypoechoic patellar tendon with neovascularity. Ultrasoundcases-info. Accessed May 17. Available:
Geertsma, T.S.A Partial rupture of the deep layer of the distal part of the medial collateral ligament. Ultrasoundcases-info. Accessed May 17. Available:
Wildman, Stuart Lateral Meniscal Cyst. The Ultrasound Site. Accessed May 17. Available: meniscal-cyst/
Stephenson, Susan Baker’s cyst aspiration. Radiopaedia.org. Accessed May 17. Available: cyst-aspiration
Geertsma, T.S.A Osgood Schlatter on both sides with cartilage swelling and fragmentation of the apophysis. Ultrasoundcases- info. Accessed May 17. Available: