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…)