What it is (overview)

A Tendon USS (tendon ultrasound scan) is a type of diagnostic imaging that uses high-frequency sound waves to create real-time pictures of a tendon and the nearby soft tissues (such as tendon sheaths, bursae, muscles, and small amounts of fluid). Unlike X-rays, ultrasound does not use ionizing radiation. It is commonly used in musculoskeletal care, including sports medicine and orthopedics, to evaluate tendon-related pain, swelling, and suspected injury.

The scan helps the clinician assess:

• Tendon structure: whether the tendon fibers look normal and tightly organized or show wear, thickening, or degeneration.
• Inflammation: signs of tendonitis/tendinitis or tenosynovitis (inflammation around the tendon), often seen as thickening and/or extra fluid.
• Tears: partial-thickness or full-thickness tendon tears, including gaps, retraction, or disrupted fibers.
• Blood flow changes: with Doppler ultrasound, increased blood flow can support active inflammation or healing.
• Dynamic problems: because it’s done in real time, the sonographer can sometimes watch the tendon move to detect snapping, impingement, or subluxation (slipping out of place).

In plain language, normal results generally mean the tendon looks smooth and uniform with no significant thickening, tearing, or surrounding fluid. Abnormal results may show swelling, degeneration (tendinosis), inflammation, fluid around the tendon, calcifications, or a partial/full tear—findings that help guide treatment plans such as rest, physiotherapy, rehabilitation, injections, bracing, or sometimes surgical evaluation.

When & why it's usually done

A doctor may order a tendon ultrasound when symptoms suggest a tendon problem and imaging is needed to confirm the cause, assess severity, or plan treatment. It is especially helpful for people who are active, play sports, perform repetitive work, or are in rehabilitation after an injury.

Common reasons include:

• Persistent or worsening tendon pain that does not improve with rest, activity modification, or initial treatment.
• Swelling, tenderness, warmth, or thickening along a tendon (possible tendonitis/tenosynovitis).
• Sudden pain after a pop or snap, bruising, weakness, or loss of function (possible tendon tear).
• Limited range of motion or pain with movement, such as lifting the arm, walking, gripping, or jumping.
• Sports injuries and overuse problems from running, jumping, throwing, racquet sports, weight training, or repetitive occupational tasks.
• Monitoring healing during rehabilitation after tendon injury or surgery, or checking response to treatments such as physiotherapy or anti-inflammatory care.
• Guidance for procedures (in many clinics): ultrasound can help accurately place injections around a tendon sheath or bursa when appropriate.

Tendon ultrasound is often chosen because it is quick, noninvasive, and can compare the painful side to the other side. It is particularly useful for superficial tendons (for example: Achilles tendon, patellar tendon, rotator cuff tendons in the shoulder, elbow tendons, wrist/hand tendons, and ankle tendons). Your clinician will interpret the findings alongside your symptoms and physical exam, since imaging changes do not always match pain levels.

Common diseases related to it

• Tendinitis (tendonitis) and tendon inflammation
• Tendinosis (chronic tendon degeneration)
• Partial tendon tear
• Full-thickness tendon rupture (e.g., Achilles rupture)
• Tenosynovitis (inflammation of the tendon sheath)
• Rotator cuff disease (supraspinatus/infraspinatus tendinopathy or tear)
• Tennis elbow (lateral epicondylitis) and golfer’s elbow (medial epicondylitis)
• De Quervain’s tenosynovitis (thumb-side wrist pain)
• Trigger finger (stenosing tenosynovitis)
• Patellar tendinopathy (jumper’s knee)
• Plantar fascia-related pain conditions (often assessed alongside nearby tendons)
• Calcific tendinopathy (calcium deposits within a tendon, commonly shoulder)

Health goals where it may help

• Identifying the cause of tendon pain to support faster, safer return to activity
• Confirming or ruling out a tendon tear to guide next steps (rehabilitation vs. surgical referral)
• Tracking recovery and tendon healing progress during a rehabilitation program
• Optimizing sports performance by addressing overuse injuries early (sports medicine screening for recurrent pain)
• Reducing chronic inflammation and preventing progression from tendinitis to long-term tendinosis
• Supporting personalized treatment planning in orthopedics (e.g., bracing, physiotherapy, load management)
• Improving mobility and function for daily activities (walking, lifting, gripping) by accurately diagnosing musculoskeletal soft-tissue problems