Musculoskeletal pathology Flashcards
What is a Baker’s cyst?
A synovial fluid collection in the calf related to a break in the synovial membrane around the joint.
It may mimic deep venous thrombosis.
What are the clinical features of a Baker’s cyst?
Local tenderness that may mimic deep venous thrombosis.
What is the sonographic finding of a Baker’s cyst?
A collection of synovial fluid develops posterior to the knee joint and/or in the calf, with a possible connection to the knee joint.
What is the Achilles tendon?
The strongest and largest tendon in the body, comprising the joined tendons of the gastrocnemius, soleus, and plantaris muscles.
What are the functions of the Achilles tendon?
Connects the gastrocnemius and soleus muscles to the calcaneus, enables plantar flexion and knee flexion, and allows foot movement downward.
What are indications for Achilles tendon sonography?
- Trauma
- Displacement of Kager’s fat pad on a radiograph
- Knot or bulge over proximal tendon
- Audible pop or snap followed by sharp pain
- Inability to stand on toes
- Swelling
- Heel pain >4 weeks
- Decreased strength or mobility
- Postoperative monitoring
What is a full thickness tear in the Achilles tendon?
Characterized by retracted tendons, fiber discontinuity with interposed fluid, and a cleft in the cuff that may appear hypoechoic or anechoic.
What is a partial-thickness tear?
Appears hypoechoic compared to the surrounding rotator cuff, with fluid, blood, and debris collecting in the bursa.
What is tendinitis?
Common tendon inflammation due to age-related elasticity loss, rheumatoid arthritis, overuse, or acute trauma.
What are common symptoms of tendinitis?
- Pain at tendinous insertion into bone
- Palpable mass in area of pain
What are the sonographic features of tendinitis?
- Enlargement of tendon with increased echogenicity
- Calcifications with chronic tendinitis
- Increased vascularity on color Doppler signal in periphery
What is bursitis?
Inflammation of bursa, fibrous pockets of synovial fluid that lie between tendons and bones to reduce friction.
What causes cellulitis?
An infection of the skin and subcutaneous tissue, leading to tenderness and warmth in the skin.
What is the anatomy of the carpal tunnel?
Bounded posteriorly by the lunate and scaphoid bone, laterally by the radial artery and vein, and medially by the ulnar vein and vessels.
What are indications for wrist sonography?
- Masses
- Loss or decrease mobility of digits
- Pain and swelling
- Trauma
- Foreign body location
- Numbness of middle and index fingers
- Weakness or clumsiness of hand
- Tingling with nerve percussion (Tinel’s sign)
- Pain with wrist flexion sustained for a minute or longer (Phalen’s sign)
What is the normal AP diameter of the Achilles tendon?
5 to 6 mm, taken in transverse plane.
What is Thompson’s test?
A test for evaluating the integrity of the Achilles tendon by assessing plantar flexion with calf squeezing.
What is anisotropy in ultrasound imaging?
Occurs when the incident angle is not perpendicular to the structure being imaged, leading to a hypoechoic appearance.
What is the significance of the rotator cuff?
It is made of four shoulder muscles: supraspinatus, subscapularis, infraspinatus, and teres minor, which facilitate arm movement.
What is a common artifact in musculoskeletal ultrasound?
- Anisotropy
- Reverberation
- Speed error
- Refractile shadowing
What is a comet tail artifact?
A type of reverberation artifact caused by the bouncing of sound waves between two closely placed reflectors within the imaged structure.
What is the typical appearance of muscle and soft tissue hematomas on ultrasound?
Fluid collections of varying echogenicity, depending on the age of the bleed.
What is speed error artifact?
Occurs when returning sound waves pass between two tissues with different speeds, affecting the perceived location of structures.
What is the function of the biceps tendon?
Connects the biceps muscle to the humerus and is easily located in the transverse plane.
