Describing a Small Knot on the Wrist Indicating Bursitis
A small knot on the wrist indicating bursitis typically presents as a localized, palpable swelling or mass overlying a bursa, most commonly appearing as a fluid-filled, fluctuant nodule that may be tender to palpation and associated with pain during wrist movement. 1
Clinical Presentation
The characteristic features of wrist bursitis include:
- Visible or palpable swelling that appears as a discrete mass or "knot" over the affected bursa 2, 3
- Fluctuant consistency on examination, distinguishing it from solid masses 3
- Tenderness with direct pressure over the swelling 2, 3
- Pain with movement of the wrist, particularly with flexion or extension activities 4
- Gradual onset in most cases, often related to chronic microtrauma or repetitive motion 3
Important Distinctions
Bursitis vs. Ganglion Cyst
A critical pitfall is distinguishing bursitis from ganglion cysts, which are far more common in the wrist. Both present as fluid-filled swellings, but ganglion cysts arise from joints, ligaments, or tendon sheaths rather than bursae. 5 The Annals of the Rheumatic Diseases notes that ganglion cysts can develop in tendon sheaths, joints, and ligaments throughout the hand and wrist 1, 5.
Associated Conditions
When bursitis occurs at the wrist, consider:
- Chronic microtrauma from repetitive wrist positioning (e.g., prolonged computer use, manual labor) 3
- Inflammatory arthropathies such as rheumatoid arthritis or gout as underlying causes 3
- Septic bursitis if there are signs of infection (warmth, erythema, systemic symptoms) 3
- Carpal tunnel syndrome may coexist with chronic wrist bursitis, causing additional numbness in the thumb, index, and middle fingers 4
Diagnostic Approach
The American College of Radiology recommends ultrasound as the initial imaging modality to confirm the fluid-filled nature of suspected bursitis or ganglion cysts, with MRI reserved for occult masses or when solid tumors are a concern. 1, 5
Initial Evaluation Steps:
- Clinical examination focusing on location, consistency (fluctuant vs. solid), tenderness, and range of motion 3
- Ultrasound imaging to distinguish fluid-filled bursitis from cellulitis or solid masses 3, 5
- Bursal aspiration if infection is suspected, with fluid sent for Gram stain, culture, cell count, and crystal analysis 3
When to Consider MRI:
- Occult masses not clearly visualized on ultrasound 1, 5
- Concern for solid tumors or other pathology 5
- Associated soft tissue abnormalities such as tendon or ligament pathology 6
- Chronic cases where the diagnosis remains unclear after initial workup 4
Common Pitfalls to Avoid
- Do not assume all wrist "knots" are bursitis—ganglion cysts are far more common at the wrist 5
- Do not aspirate chronic microtraumatic bursitis routinely due to risk of introducing infection 3
- Do not overlook signs of septic bursitis (warmth, erythema, fever), which requires urgent aspiration and antibiotic therapy 3
- Do not inject corticosteroids without first ruling out infection through aspiration if there is any clinical suspicion 3