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KNEE ULTRASOUND INTERESTING CASE • • • • • • • Student: Student Number: Email Address: School: Workplace: Lecturer: Due Date: Agnes Kaweme 17324438 [email protected] Science and Engineering My Radiology Centre (MRC) Perth Le-Anne Grimshaw 26/05/2014 • I declare that this assignment is my own work and has not been submitted in any form for another unit, degree or diploma at any university or other institute of tertiary education. Information derived from the published or unpublished work of others has been acknowledged in the text and a list of references is given. I warrant that any disks and or computer files submitted as part of this assignment have been checked for viruses and reported clean. • • Student Signature: akaweme Date: 30/05/2014 INTRODUCTION Ultrasound remains an imaging modality of choice (useful tool) in musculoskeletal investigations of all body parts because it’s readily available, non invasive and economic. The knee is one of the body parts where ultrasound remains useful in assessing pathology. It has a complex anatomy with attachments of numerous tendons, ligaments and bursae. Due to high incidence of over use most injuries occur to the extra articular soft tissues of the joint (Ronald Ptasznik 1999). Patient’s history A 35-year-old man presented for an ultrasound appointment with a request to scan the knee. The patient had a clinical history of swollen knee, and acknowledged that he was a sports man and has spent the past six months renorvating his house, however did not recall any acute injury to the knee. Over a period of three weeks, the swelling had increased and he consulted his General Practitioner. BACKGROUND INFORMATION ON THE KNEE Below is a summary of how the structures relate to one another within the knee: Bony structures The intercondylar notch separates the medial and lateral condyles of the femur articulate with the tibial plateau-and posteriorly The medial and lateral articular surfaces are firmly fitted by the triangular shaped menisci – cartilaginous structures The anterior tibia has a prominent apophysis and tibial tuberosity Proximal metaphysis of the tibia where the patella tendon inserts. The largest body sessamoid bone (patella) lies anteriorly to the femoro-tibial joint The lateral tibia condyle has a small articular surface with the fibula (tibiofibula joint). The medial femoral condyle and the concave part of the medial tibial plateau (Bianchi and Martinoli 2007). Ligament structures Anterior cruciate ligament- strong and thicker-intra and extra capsular synovial –originates from the postero-medial of the lateral femoral condyle- inserting anterior to the tibial spine. Medial collateral ligament (MCL) –is the most commonly injured superficial ligament. It is found in the intermediate layer that blends with the crural fascia to form the medial patellar retinaculum (which originates from the medial femoral epicondyle). The MCL is 5 centimeters above the joint and inserts on the medial aspect of the tibia 6-7centimeters below the knee joint behind the pes anserinus The iliotibial band and the biceps tendon are housed in the most superficial layer. The intermediate layer houses the lateral patellar retinaculum, patellofemoral ligaments and lateral collateral ligament (Bianchi and Martinoli 2007). Quadrants The four quadrants within the knee are known as anterior, medial, lateral and posterior. • Anterior kneeThe quadriceps tendon is made up of the following muscles, whose main action is the extension of the leg and knee joint -The rectus femoris- lies superficially, originates from the anterior inferior iliac spine above the acetabulum and attaches the quadriceps tendon to the base of the patella and onto tibial tuberosity via patella ligament -The vastus lateralis-is located mid and laterally, is the largest of the quadriceps in the anterior compartment, originates from the greater trochanter and upper lateral surface of the linear aspera and inserts on the patella via the quadriceps tendon-on the tibial tuberosity via the patellar ligament -The vastus medialis-located medially, (it’s a medial quadriceps in the anterior compartment)-originates from the intertronchanteric line and medial lip of the linear aspera, inserting on the patella via the quadriceps tendon-on the tibial tuberosity via the patella ligament -The vastus intermedius-lies deep to the rectus femoris, originates from the upper third of the anterior lateral surfaces of the femur and inserts as a common tendon of the quadriceps enclosing the patella and then inserting on the tibial tuberosity (Bianchi and Martinoli 2007). MEDIAL KNEE • • • The following are found within the medial knee: Medial Collateral Ligament (MCL) Pes anserinus (comprises of the Graciis, Sartorius and Semitendinosus tendons) insertion is onto tibial metaphysis 5-6 centimeters below the knee joint. Anserinus bursa. LATERAL KNEE There are two groups of knee stabilisers found within the lateral knee 1) Anterolateral- Iliotibial tract which extends from the fascia lata and inserts on Gerdy's tubercle on the tibia The anterolateral ligament forms part of the posterior cruciate ligament, originates from the anterior and distal lateral collateral ligamentinserting on the posterior horn of the lateral meniscus and proximal tibia between Gerdy’s tubercle and fibular head. 2) Posterolateral- arcuate ligament complex; there are 6 Ligaments-LCL, Popliteal fibular, Popliteal meniscal, Oblique Popliteal, arcuate and Fabellofibula. 3 muscle group- Popliteus, Biceps, and lateral Gastrocnemius (Bianchi and Martinoli 2007) POSTERIOR KNEE • • • • • Popliteal Fossa- forms a hollow space when the knee is flexed. The posterior knee tendons are flexors of the joint and also help with extension of the hip joint. Medially the following tendons are found: Semitendinosus, semimembranosus, Laterally- Biceps femoris Distally- medial and lateral heads of the Gastrocnemius Posterior compartment-contains - Semimembranosus and Gastrocnemius bursa with neurovascular bundle comprising of the – Popliteal artery, Popliteal vein and Tibial nerve which lies quite superficially. Posterior cruciate ligament COMMON PATHOLOGY Patellofemoral syndrome, patella tendinopathy, patellofemoral instability (Ronald Ptasznik 1999 • Synovial effusions- Baker’s cyst, found at the medial border of the Gastrocnemius muscle and Semimembranosus tendon. Ganglions- could be intra articular located in the cruciate ligament. extra articular found in the superior tibiofibula joint, extra neural causes Peroneal nerve compression, intramural-located within the nerve sheath • Snapping knee syndrome. • • • • • • • • • • • • • • • Bursitis – e.g. Suprapatella, Prepatella ( subcutaneous in location) Deep infrapatella, Superficial infrapatella, Pes anserinus , Semimambranosusgastrocnemius, Os good – Schlatter disease – Knee locking-usually due to meniscal lesions. Jumpers knee Runners knee (Bianchi S, C martinoli Sinding Larsen- Johansson syndrome- juvenile osteochondrosis Degeneration- could be due to-Osteochondrol defects-Articular cartilage injuries-loose bodies-marginal erosions. Rheumatoid arthritis Vascular insufficiency, due to-compression of the popliteal artery secondary to abnormal anatomical relationship of the medial head of the gastrocnemius and popliteus muscle. INDICATIONS FOR THE EXAMINATION Trauma- mainly sport injuries Acute and chronic knee pain-rheumatological disorders Swelling- could be due to-masses and effusion SCANNING TECHNIQUE-ANTERIOR KNEE The patient was examined in a supine position with the left knee flexed and the planter aspect of the foot flat on the couch. A form pad was placed under the knee (in the popliteal space) to support and maintain the position and for patient's comfort as well as avoiding anisotropy. The transducer was placed longitudinally in the midline with the distal end of the transducer over the patella. Scanning the entire anterior knee from medial to the lateral aspect in longitudinal and transverse planes. Assessing the quadriceps in its superficial position to the bursa, then proximally from the muscle bellies to the distal union of the three muscles to a common tendon inserting on the patella and the tibial tuberosity. The quadriceps was assessed for tendinopathy with colour Doppler, enthesopathy, rupture, partial thickness tears or chronic stress tears. The bursa was assessed for possible effusion and loose bodies. Hoffa’s fat pad was also assessed. The prepatella bursa was showed a large fluid collection (Beggs et al 2010) Fluid in the knee joint would be due to the presence of intra-articular pathology, an MRI is useful in the investigation of such. Prepatellar bursa- It is a thin synovial lining, located in the subcutaneous tissue between the skin and bone (patella), anterior to the lower half of the patella and proximal patellar tendon. The bursa is also known as popeye knee, house maid’s knee, carpet layer’s knee, coal miner’s knee nun’s knee. The function is to reduce friction between the skin and the patella. Superficial infrapatella bursa- It is a small fluid filled sac , located between the tibial tuberosity and the skin- reduces friction between the skin and tibial tuberosity Deep Infrapatellar bursa- It is a mall fluid filled sac, lies deep to the patella – located between the deep boundary of the distal patellar tendon and the anterior tibia. The function of the bursa is to reduce friction between the distal patellar tendon and the anterior aspect of the tibia. Causes of bursitis: Pressure from kneeling, trauma, bacterial inflammation,, complications from osteoarthritis, knee gout. Risk factors: Osteoarthritis and obesity, sport activities such as wrestling , runners, football and volley ball . LEFT KNEE- MEDIAL • The medial aspect of the knee was assessed in the same position as anterior knee with a slight external rotation. Displaying the medial meniscus, medial collateral ligament assessing these structures in long and axial planes for possible tears and any other pathology such as cysts. LATERAL KNEE • • The patient’s knee was slightly medially rotated-maintaining the flexed position, the lateral aspect of the knee was examined in longitudinal and lateral planes Assessing the Iliotibial band, the lateral meniscus and the lateral collateral ligament POSTERIOR KNEE • The patient was asked to roll over into a prone position, with the knee extended • • • With the transducer in transverse position- postero-medial aspect-the sartorius muscle , the graciis, the semitendinosus and semmembranosus tendons were assessed, carefully looking for possible baker’s cyst. Sliding the transducer towards the mid and postero lateral the medial and lateral head of the gastrocnemius, the posterior cruciate ligament were assessed in long and transverse planes. Moving the transducer up and down in the popliteal fossa the neurovascular bundle was assessed –the tibial nerve, popliteal artery, popliteal vein checking for patency and compressibility to rule out deep vein thrombosis Image 1:Left knee shows normal quadriceps tendon at its insertion Image 2:Left knee shows normal quadriceps in transverse view Image 3:Left knee- shows prepatellar effusion in longitudinal Image 4: Left knee- shows- shows prepatellar effusion in transverse view Image 5: shows normal patella tendon at insertion on the tibial tuberosity note fluid collection in that superficial-infrapatella bursa Image 6:Left knee shows patella tendon inserting on the tibial tubercle Image 7: Left knee –shows superficial infrapatellar bursa Image 8: Left knee –shows the medial-meniscus (medial collateral ligament) LEFT KNEE- PES ANSERINUS Image 9: shows –normal pes anserinus Image 10: Left knee shows fluid in the lateral meniscus recess Image 11:Left knee shows lateral meniscus with Image 12: Left knee –shows normal lateral iliotibial band Image 13: Left knee shows Left Collateral ligament Image 14: Left knee Image 15:Left knee shows posterior knee in transverse with the medial head of gastrocnemius Image 16 left knee shows –posterior knee ganglion Image 17 Left Knee shows compressible popliteal vein Image 18-Left posterior knee –shows a normal artery REFERENCES Bianchi,S., and C. Martinoli. 2007. Ultrasound of the Musculoskeletal System: New York: Springer http://www.curtin.eblib.com.au.dbgw.lis.curtin.edu.au/patron /SearchResults.aspx?q=Bianchi%2CS.%2C+and+C.+Martinoli.+ 2007+ultrasound+of+the+musculoskeletal+system%3ASpring er&t=quick Ptasznik, Ronald.1999. “Ultrasound in acute and chronic knee injury” Radiologic Clinics of North America 37(4):797-830. Beggs Ian Stefano, Bianchi Michel Cohen, Michel Court-Payen, Andrew Grainger, Franz Kainberger, Andrea Klauser, Carlo Martinoli, Eugene McNally, Philip J. O’Connor, Monique Reijnierse Philip and Remplik Enzo Silvestri.2010. “Musculoskeletal Ultrasound: Technical Guidelines” Insights into Imaging 1:99-141.