Jenelle Beadle, RDMS

Inland Imaging

November 4th, 2014

Basic Musculoskeletal Ultrasound

• Muscles, tendons, ligaments & bursae

• Histologic anatomy and ultrasound appearance correlation

• Common abnormalities visualized using ultrasound

Muskuloskeletal Sonography

…650 skeletal muscles.

…4000 tendons.

…900 ligaments.

… 160 bursae.

In the human body, there are…

Muscles

• Isoechoic/hypoechoic (compared to fat)

• Linear hypoechoic bundles (fascicles) surrounded by echogenic perimysium

• Epimysium & Fascia: single, hyperechoic line at the muscle boundary (arrows)

• Perimysium: innumerable hyperechoic lines (arrowheads)

• Fascicles: hypoechoic bundles of muscle fibers in between

• Muscles are typically evaluated with ultrasound for pain and/or a palpable abnormality.• Often times with a history of traumatic injury

• Most common abnormal findings include strains/tears and tumors.

Adductor Magnus Muscle Gastrocnemius Rupture Normal

Intramuscular Sarcoma Intramuscular Myxoma

• Muscle strains/tears most commonly occur in the lower extremity• typically near the musculotendinous junction

• severity of muscle strain injuries are graded I, II or III

• Strain (Grade I): pain; resolves in about 2 weeks• normal

• thickened and hyperechoic

• Muscle strains/tears most commonly occur in the lower extremity• typically near the musculotendinous junction

• severity of muscle strain injuries are graded I, II or III

• Strain (Grade I): pain; resolves in about 2 weeks• normal

• thickened and hyperechoic

With a contusion, echogenicity may cross fascial boundaries.

• Tear (Grade II): pain with loss of function; resolves in about 4 weeks• intrasubstance tears; detachment from fascia or aponeurosis

• disruption of striated pattern

• intramuscular fluid collection with hyperechoic halo (hypervascular)

“Tennis Leg”

Trans

Long

• Avulsion (Grade III): pain with loss of function, usually caused by strong contraction against firm resistance• myotendinous (muscle to tendon) or tendoosseous (tendon to

bone)

• complete discontinuity of muscle fibers; hematoma

Musculotendinous junction tear

Tendons (muscle-to-bone)

• Echogenic (compared to muscle)

• Linear fibril bundles of collagen in a

supporting matrix

• Short axis: “finely punctate pattern”

• multiple echogenic dots

• Long axis: “fibrillar architecture”

• multiple, closely spaced parallel lines

Long Patellar Tendon

Trans

Long

Anisotropy artifact

Trans Achilles Tendon

Anisotropy

Tendinopathy

• Sonographic evaluation: size/thickness, contour and echotexture• Dynamic scanning can also be helpful

• Tendinosis• thickened, hypoechoic, hypervascular; may have some loss of fibrillar pattern

• occurs with or without tendon tears

• Acute: strained by traumatic injury

• Chronic: general wear-and-tear (age-related changes, inflammatory disorders)

• may have calcifications present (calcific tendinosis); round or linear in shape

• Chronic tendinosis predisposes a tendon to further injury

• As a result, tendons that typically affected by overuse or degeneration are also the tendons most commonly strained or torn.

• Supraspinatus, achilles, patellar, quadriceps and common extensor (elbow) tendons

• Achilles Tendinosis

• Common Extensor Tendinosis (lateral epicondylitis)• “Tennis Elbow” (although 95% are not in tennis players)

• usually results from repetitive motion injuries (chronic)

Normal Common Extensor Tendon

Our personal favorite form of chronic tendonosis…

Supraspinatus Tendonisis Quadriceps/Patellar Tendinosis

Tendon Tears/Ruptures

• Acute or Chronic• most tendon tears are a result of chronic overuse rather than acute

trauma

• Associated with adjacent tendinosis• makes identifying small partial tears difficult

• Ultrasound Findings (often more easily appreciated with dynamic scanning)• partial/complete nonvisualization

• distinct focal hypoechoic/anechoic defect

• apparent disruption of linear fibrillar architecture

• contour abnormality

• Most commonly torn tendons are supraspinatus and achilles

• Tears are categorized• partial

• full thickness (complete rupture)

• Partial Tear• a portion of the tendon remains intact

• includes “intratendinous” tears

Long Common Extensor Tendon

Long Distal Biceps Tendon

Long Achilles Tendon

Trans Peroneal Longus/Brevis

Tendons

• Partial Tear • with a large partial tear, some retraction of the torn tendon may

be identified

Long Quadriceps Tendon

Trans Achilles Tendon

• Full Thickness Tear• rupture that extends across the

entire width and depth of the tendon

• proximal muscular retraction of the entire tendon

• non-functional tendon distal at insertion

Long Achilles Tendon

Prox Dist

Long Patellar Tendon

Complete achilles rupture with intact plantaris tendon

• absent 7-20%

Trans Achilles Rupture

Long Achilles Rupture

Ligaments (bone-to-bone)

• Isoechoic/hypoechoic (compared to tendons)

• Similar composition as tendons, but fibers are less organized structure; more of an interlaced, woven pattern.• Fibrillar pattern, but slightly changing the orientation of the

tranducer will bring other fibers into view.

• This less regular structure is what makes ligaments slightly less echogenic than tendons.

• Injury is often associated with joint derangement (acute).• Sprain: stretching or tearing of a ligament (“strain”- tendon)

• Range from invisible “micro-tears” to complete rupture

• Most commonly injured ligaments are in the knee and ankle

• Ankle Ligaments• Anterior Talofibular Ligament (most commonly injured)

• anterior lateral malleolus to anterior talus

• best seen in w/ tendon stressed (plantar flexion)

• injured with supination (lateral rotation of the ankle)

• iIsolated, or associated with Calcaneofibular Ligament (up to 70%)

peroneal tendons

• Ligament Sprain/Rupture• Thickened & hypoechoic with surrounding fluid

• Evidence of tear may be seen (hypoechoic area that interrupts fibers)

“a”: anterior talofibular ligament“b”: calcaneofibular ligamentCurved lines: peroneal tendons

Ruptured Anterior Talofibular Ligament

Normal

• Knee• ACL: Anterior Cruciate

Ligament (can’t be seen well enough with ultrasound)

• PCL: Posterior Cruciate Ligament (not commonly injured)

• Lateral Collateral Ligament (not commonly injured)

• Medial Collateral Ligament

Medial Meniscus (purple) & Medial Collateral Ligament (green)

Bursae

• Thin layer of anechoic fluid (synovial) surrounded by hyperechoic walls.

• Not typically visualized unless abnormal.

• Synovial-lined sac overlying bony surfaces at areas of tendon friction.• Some communicate with the joint space (ex:

semimembranosus bursa)

• Baker’s Cyst (Popliteal Cyst) typically communicates with the joint capsule via the semimembranosus bursa.

• Bursitis: • Repetitive motion and overuse

• Inflammatory disorders (rheumatoid arthritis, gout, etc.)

• Shoulder, elbow , hip & knee

• Most common site: Subacromial Bursa (shoulder)

• Does not normal communicate with the joint space, but can if there is a full thickness tear.

Subacromial Bursitis

• Other common sites of bursitis…• Prepatellar Bursa (“housemaid’s knee”)

• Infrapatellar Bursa (“clergyman’s knee”)

Prepatellar Bursitis

Deep Infrapatellar BursitisInfrapetellar Bursitis

• Other common sites of bursitis…• Trochanteric (lateral hip)

Trochanteric Bursitis (Deep)• Between the greater trochanter

and the gluteus medius muscle insertion.

Trochanteric Bursitis

Gluteus Medius Insertion

• Other common sites of bursitis…• Iliopsoas Bursa

Long Iliopsoas Bursitis

Trans Iliopsoas Bursitis

• Other common sites of bursitis…• Olecranon Bursa (“student’s elbow”)

Triceps Tendon

Long Olecranon Bursitis

Trans Olecranon Bursitis

• “Skeletal Muscle Ultrasound” European Journal Translational Myology 2010; 1 (4): 145-155

• “Ultrasonographic Findings of Musculoskeletal Tissues” J Korean Orthop Assoc. 2013 Oct;48(5):334-341

• “Sonography of Common Tendon Injuries” American Journal of Roentgenology. 2009;193: 607-618

• “Tendon and Ligament Imaging” Br J Radiol. Aug 2012; 85(1016): 1157–1172

• “Imaging of the Bursae” J Clin Imaging Sci 2011; 1:22

• “Ultrasonography of tendon abnormalities” OA Musculoskeletal Medicine 2013 Jun 01;1(2):12

• “Sonography of Lower Limb Muscle Injury” American Journal of Roentgenology. 2004;182: 341-351

• “Full Thickness and Partial Thickness Supraspinatus Tendon Tears” Radiology 2004; 230:234–242

• “Long Head of Biceps Brachii Tendon Evaluation...” AJR 2011; 197:942–948

• “Ultrasound of the Shoulder” JBR–BTR, 2007, 90: 325-337

• Gaitini D. “Shoulder Ultrasonography: Performance and Common Findings” J Clin Imaging Sci 2012; 2: 38-38

• Read J, Perko M. “Ultrasound Diagnosis of Subacromial Impingement for Lesions of the Rotator Cuff” AJUM May 2010; 13 (2): 11-15

References

• http://www.sonoguide.com/soft_tissue.html

• http://www.dynamicultrasound.org/dugphysics.html

• http://www.ultrasoundcases.info/Slide-View.aspx?cat=405&case=1858

• http://www.shoulderdoc.co.uk/article.asp?section=904

• http://www.radiologyassistant.nl/en/p50cf8392cbd97/us-guided-injection-of-joints.html

• http://radiopaedia.org/articles/posterosuperior-impingement-of-th-shoulder

References (continued…)