Disclosures: Ultrasound of the • Consultant: Bioclinica Jon A. Jacobson, M.D. • Book Royalties: Elsevier • Advisory Board: GE, Philips Professor of Radiology Director, Division of Musculoskeletal Radiology University of Michigan Note: all images from the textbook Fundamentals of Musculoskeletal Ultrasound are copyrighted by Elsevier Inc.

Pathology: Abnormalities • Tendon • Tendinosis: • –Swollen, hypoechoic, no inflammation • Cartilage • Tear: • Fluid collections and cysts –Partial-thickness tear • Peripheral nerves –Full-thickness tear: retraction • Miscellaneous

Quadriceps Tendon: tendinosis • Full-thickness tear – Complete tendon disruption – Tendon retraction: dynamic imaging – fluid extending through tear

La et al. AJR 2001; 22:1323

Long Axis

1 Quadriceps Femoris Tear: Quadriceps Tendon: full-thickness tear dynamic imaging

Patella

Long Axis Sagittal PDw Long Axis

Patellar Tendon: tendinosis Patellar Tendinosis: • Jumper’s knee • Hypoechoic swelling • Mucoid degeneration, possible Long Axis Short Axis interstitial tearing • Hyperemia: neovascularity • No inflammatory cells

color Doppler power Doppler Radiology 1996; 200:821

Patellar Tendon: full-thickness tear Patellar Tendon Tear • Full-thickness tear – Hypoechoic – Posterior shadowing at ends of torn tendon Patella – Tendon retraction – Patellar alta Long Axis Sagittal PDw AJR 2001; 176:1535

2 Patellar Tendon: full thickness tear Pathology: • Tendon Prox Distal • Ligament • Cartilage • Fluid collections and cysts • Peripheral nerves • Miscellaneous

Longitudinal

MCL: full-thickness tear MCL: sprain

m MCL Femur

Femur

Longitudinal Coronal T2w

Short Axis

Lateral Collateral Ligament Injury Pathology: • Tendon Fibula • Ligament P • Cartilage LM Tibia • Fluid collections and cysts Femur • Peripheral nerves • Miscellaneous Longitudinal

3 : Accuracy Meniscus: • 35 patients • Normal: hyperechoic • Sensitivity / Specificity = 86% / 69% • Degeneration: hypoechoic • PPV / NPV = 83% / 75% • Tear: defined hypoechoic cleft to • Most studies: articular surface – US is markedly limited

*Invest Radiol 1986; 21:332 *JBJS-Br 2008; 90-B:1045.

Meniscus: tear PHMM: degeneration

Tibia Femur

Sagittal Sagittal PDw

Meniscus: chondrocalcinosis Pathology: • Tendon • Ligament • Cartilage • Fluid collections and cysts • Peripheral nerves • Miscellaneous

4 Suprapatellar Recess and Gutters Joint Effusion

• Suprapatellar recess – Superior • Prefemoral & quadriceps fat pad separation • Distends with partial knee flexion – Medial and lateral to patella • Distends with knee extension • Transducer pressure displaces joint effusion

From: Miller PJ et al. Am J Sports Med 2001;29:822.

Joint Effusion: transverse plane Joint Effusion: sagittal plane

Patella Patella

Quadriceps Femur Patella Femur *

* Femur Sagittal T2w

Transverse

Knee Bursae

*Suprapatellar Joint Effusion: Patella Recess Baker knee extension Quad Cyst Prepatellar Bursa Semimembranosus -Tibial Collateral Deep Ligament Bursa Infrapatellar Bursa Pes Patella Patella Anserinus Superficial Bursa Infrapatellar Bursa Femur Femur

5 Prepatellar Bursa: aseptic fluid Anterior Knee Bursa: • Prepatellar bursa • Superficial infrapatellar bursa Patella PT PT • Deep infrapatellar bursa

Sagittal Axial

Superficial Infrapatellar Bursa Deep Infrapatellar Bursa

PT PT

PT

Tibia Tibia Tibia

Normal Abnormal Case #1 Case #2

Baker Cyst Baker Cyst: • Semimembranosus-medial gastrocnemius bursa • 50% over age of 50 have Medial communication with knee joint Gastrocnemius • Cyst communication to posterior knee between SM-MG required SM

AJR 2001; 176:373 Axial Axial T2w

6 Baker Cyst Baker Cyst: rupture + hemorrhage

MG SM MG MG SM

Longitudinal Transverse

Transverse Longitudinal

Baker Cyst: intra-articular body Baker Cyst: rupture

Longitudinal Coronal T2w Transverse Sagittal PDw

Baker Cyst: rupture Pes Anserinus

• Pes anserinus: “goose ” – Sartorius – Gracilis – Semitendinosus • Bursa: – Deep to conjoined tendon – Adjacent to proximal tibia

Radiology 1995; 194:525

7 Pes Anerinus: bursal fluid Adventitious Bursae:

• Site of friction G • Myxomatous degeneration of Medial G S Epicondyle T fibrous tissue • Medial epicondyle: – Rider’s bursa: horseback riding – Limbo-dancing Tibia • Trinidadian art form of limbo Longitudinal Transverse dancing

Pathology: Nerve Entrapment • Tendon • US findings: • Ligament – Nerve enlargement proximal to entrapment • Cartilage • Best appreciated transverse to nerve – Abnormally hypoechoic • Fluid collections and cysts • Especially the connective tissue layers • Peripheral nerves – Variable enlargement or flattening at • Miscellaneous entrapment site

Common Fibular Nerve: entrapment Common Fibular Nerve: entrapment

Fibularis Longus

Fibula

Long Axis Long Axis

8 Common Fibular Nerve: entrapment Peroneal Intraneural Ganglion

• Joint fluid from proximal tibiofibular joint – Enters peroneal nerve via articular nerve branches – Shown at MR arthrography after exercise – Extends proximal via epineurial sheath1 • May also form via tibial nerve2 Asymptomatic Atrophy

1Spinner et al. Clin Anatomy 2007; 20:826 Extensor Musculature (Short Axis) 2Spinner et al. Skeletal Radiol 2006; 35:172

Peroneal Intraneural Ganglion Peroneal Intraneural Ganglia

Fibula

From: Spinner et al. From: Spinner et al. Skeletal Radiol 2008;37:1091 Clin Anatomy 2007;20:826

Intraneural Ganglion

Nerve Transection • Neuroma formation: >15 cm – Disorganized and tangled nerve end – Normal response to nerve transection – After amputation: • US important to determine if symptomatic

Atrophy Asymptomatic J Clin Ultrasound 1997; 25:85

9 Stump Neuroma Transection Neuroma: sciatic

Longitudinal Transverse

Deep Venous Thrombosis Pathology: • Hypoechoic thrombus • Tendon • Not compressible • Ligament Tibial Nerve • No flow • Cartilage • Fluid collections and cysts • Peripheral nerves V A • Miscellaneous

Take Home Points: • Common indications: – Fluid, cysts, extensor tendon • Very limited: – Meniscus, cartilage, cruciate • Suprapatellar recess: – Look all around patella • Baker cyst: often communicates with joint See www.jacobsonmskus.com for syllabus

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