Anatomy and imaging of knee joint

Anatomy and imaging of knee joint. general information about knee imaging. Class room presentation of BPKIHS -Bsc.MIT 2016 batch , first group.

1. Presentor : Ms Kajal Jha Mr Krishna Sarraf Mr Neeraj Kr Chaudhary Mr Prabin Dhaurali Moderator: Mr Ranjit Jha Dpt. of Radiodiagnosis and Imaging Assistant Professor Anatomy and Imaging of KNEE JOINT

2. Knee is the largest and complex articulation characterized by the presence of ligamentous and meniscal structures that play an important role in the stability and mobility . M o r e l i k e l y t o b e d a m a g e d t h a n m o s t o t h e r j o i n t Introduction

3. The complexity is the result of the fusion of more than three joints in one. Why complex????

4. Lateral femorotibial joint - Condylar Jt Medial femorotibial joint- Condylar jt Femoropatellar joint-Saddle Jt ( biaxial,articular surfaces are concavo- convex,some degree of rotation is allowed.) The three joints are-

5. At the glance…

6. SYNOVIAL JOINT Features: ( fig) Bones are away. Articular surfaces of the bones are covered with the hyaline cartilage It has cavity Joint has synovial membrane and synovial fluid Joint divided by an articular disc The type of joint and why??

7. Lower end of femur . Upper end of tibia . Posterior surface of Patella . Bones taking part??

8. Lower end of femur: It presents medial and lateral condyles . Medial condyl is larger than lateral condyl . Anteriorly both condyles are connected tgether and presents an articular area for patella. Patellar articular area is larger over lateral condyle and smaller over medial. Rest of the articular area on medial and lateral condyles , is meant for tibial articulation On posterior aspect , condyles are seperated from each other by the means of a deep and wide notch known as inter condylar notch. The notch presents medial and lateral walls.

9. Upper end of tibia Presence of two condyles -medial and lateral Medial condyl is larger than that of lateral Medial condyl presents a shallow articulation area for the medial condyl of femur. This area is oval Lateral condyl presents the circular articular area, for lateral condyl of femur. Two condylar areas are seperated from each other by the means of ant. And post. Intercondylar areas and the tibial spines.

10. Posterior surface of the patella It presets large oval articular area above and small non articular area below. The articular area of patella is divided into large lateral and the small medial areas by the means of faint ridges.

11. Fibrous Capsule Ligamentum patellae Tibial collateral or medial ligament Fibular collateral or lateral ligament Oblique popliteal ligament Arcuate popliteal ligament Anterior cruciate ligament Posterior cruciate ligament Medial meniscus Lateral meniscus Transverse ligament Ligaments

12. 12 bursae 4 anterior Sub cutaneous prepatellar bursae Sub cutaneous infrapatellar Deep infrapatellar Suprapatellar bursae 4 lateral A bursa deep to the lateral head of gastrocemius Abursa between the fibular collateral ligament and the biceps femoris A bursa between the fibular collateral ligament and the tendon of the popliteus A bursa between the tendon of the popliteus and the lateral condyle of the tibia. Bursae around the knee

13. 4 medial A bursa deep to the medial head of gastrocemius The anserine bursa is a comlicated bursa which seperates the tendon and sartorius , the gracilis and the semitendinosus from one another, from the tibia,and from the tibial colleteral ligament. A bursa deep to the tibial colleteral ligament A bursa deep to the sem memberanousus .

14. Anteriorly Anterior bursa Ligamentum patellae Patellar plexus of nerves Posteriorly At the middle: popliteal vessels,tibial nerve Posterolayerally : lateral head of gastrocnemius,plantaris and common peroneal nerve Posteromedially : Medial head of gastrocnemius , semitendinosus , semimembranosus , gracilis and popliteus at its insertion. Relation of the knee

15. Medially Sartorius,gracilis and semitendinosus Great saphenous vein with saphenous nerve Semimembranosus Laterally Biceps femoris and tendon of origin of popliteus .

16. Supplied by the anastomoses around the knee joint. The major arteries are: Five genicular branches of the popliteal artery The decending genicular branch of the femoral artery The dencending branch of the lateral circumflex femoral artery Two recurrent branches of the anterior tibial artery. The circumflex fibular branch of the posterior tibial artery. Blood Supply

17. Femoral nerve via its branches to tha vasti , especially the vastus medialis . Sciatic nerve via genicular branches of the tibial and common peroneal nerves. Obturator nerve , via its posterior division. Nerve supply

18. S.NO MOVEMENT PRINCIPAL MUSCLES A Extension Quadriceps femoris B Locking(standing in attention) Vastus medialis C Unlocking(standing at ease) Popliteus D Flexion Biceps femoris Semitendinosus Semimemberanosus E Medial rotation of flexed leg Popliteus Semimemberanosus Semitendinous F Lateral rotation of flexed leg Biceps femoris Muscles and movement

19. Locking is the mechanism that allows the knee to remain in the positionn of full extension as in standing without much muscular effort. The anterioposterio diameter of the lateral condyle is less than that of medial condyle . When lateral condyle is fully used up by extension the part of medial condylar surface remains unused. The medial rotation of femur occurs and remaining part of medial condyle surface is taken up. This movement locks the joint ( action of vastus medialis part) The reverse occurs for unlocking the knee i.e , reverse of medial rotation- lateral rotatin of femur ( action of popliteus ) Locking and unlocking of the knee

20. X ray CT MRI MR arthography Imaging modality

21. Soft tissue discrimination with MR imaging is excellent and differentiation can be made among cortex, marrow, ligaments, tendons, muscles, synovium , vascular and cartilage elements. MR is the recommended imaging modality than CT for the evaluation of bone contusions and occult knee fractures including tibial plateau fractures of the knee.

22. PATIENT POSITIONING Supine, with the leg in full extension. The knee is placed in 10 to 15° of external rotation ( esp for sagittal image) Slice thickness: 1-2 mm for cartilage sequence 3-4 mm for rest of the sequences Slice interval: nill for cartilage sequence and 0.5 mm for the rest of the sequenses . MRI OF KNEE

23. Axial plane From the mid condylar region of the femur to the midcondylar region of the tibia. Coronal plane From the anteriot to the posterior aspect of the femorotibial joint including the popliteal fossa in the coronal lane Sagittal plane From the lateral aspect of the lateral meniscus to the medial aspect of the medial meniscus . Scan range

24. During the positioning a small cushion under the ankle should be kept which helps to keep the leg straight. The space between the knee and the coil should be filled with the cotton to keep the knee motionless.

25. PD FSE in the axial , saggital and coronal planes. ( sagittal plane is taken slightly oblique to the intercondylar notch and the coronal plane is obliquely perpendicular to the sagittal plane) STIR/T2FSE fat saturated in the axial , saggital and coronal plane Dynamic 2D or 3D Gd MRA(in case of suspecius cancerous mass) Postcontrast T1 with fat supression in the axial and sagittal or coronal plane(in the case of mass). GRE in the sagittal or coronal plane (for the hemophillic ) 3D SPGR with fat supression in the sagittal plane(cartilage sequence). Pulse sequences

26. localiser Loc Transverse Coronal small FOV T2 TIRM(turbo inversion recovery magnitude) FS COR T1 SE Coronal T2 sagittal TSE RST(restore) T1 SE sagittal PD TSE RST Sagittal T2 TSE TRA( transverseaxial ) T1 SE Transverse Pulse sequence used in our department

27. An axial acquisition through the patellofemoral joint is used as the initial localiser for subsequent sagittal and coronal plane images. Menisci and cruciate ligaments are best evaluated on sagittal images with coronal views for secondary visualisation and confirmation of pathology. The medial and lateral collateral ligaments are best displayed on coronal images.

28. The articular cartilage surfaces of medial and lateral compartments are assessed in both coronal and sagittal planes. The patellofemoral joint including patellar facet and trochlear groove is best seen on axial images.

29. Short echo time (TE) conventional spin echo (CSE) images generally provide the best contrast for anatomical evaluation. The more rapidly acquired, fast spin echo (FSE) pulse sequences with short echo train length have no significant disadvantages compared to conventional spin echo techniques in the evaluation of the knee. STIR and fat saturated FSE pulse sequences are best for the evaluation of bone contusions and other marrow abnormalities.

30. A knee protocol that works well includes fast spin echo PD and T2W in the sagittal plane, a STIR sequence in the coronal plane, T1W coronal images, T2W axial images and a sequence for articular cartilage. Intravenous gadolinium is useful in assessment of inflammatory arthritides as it causes enhancement of the pannus . Summary

31. An MR imaging of the knee includes evaluation of the menisci, the anterior and posterior cruciate ligaments, the medial and lateral collateral ligaments, the extensor mechanism of the knee, the articular cartilage and the evaluation of bone marrow. What to look for in knee MRI?

32. How to report???

33. Anterior cruciate ligament Posterior cruciate ligament Medial meniscus Lateral meniscus Transverse ligament Intracapsular Ligaments

34. BD Chaurasiya Human Anatomy Volume 2 Berry Diagnostic radiology Musculoskeletal and Breast Imaging-2 nd Edition. CT and MRI Protocol – a pratical approach, 3 rd edition. Gray’s atlas of anatomy. Imaging Atlas of Human Anatomy-4 th Edition Kadasne’s Textbook of Anatomy-Upper and lower extremities Mollers atlas of crossectional anatomy – spine,extrimities and joint. Reference