Finkelstein's Test: Understanding, Performance, and Diagnosis of De Quervain's Tenosynovitis

What is a positive Finkelstein's test?

A positive Finkelstein's test is a diagnostic indicator used to identify De Quervain's Tenosynovitis, a painful condition affecting the tendons on the thumb side of the wrist, characterized by a sharp increase in pain when the wrist is forcefully bent towards the little finger while the thumb is tucked into a fist.

Understanding the Finkelstein's Test

The Finkelstein's test is a specific orthopedic assessment used primarily to diagnose De Quervain's Tenosynovitis, also known as "washerwoman's sprain" or "mommy thumb." This condition involves inflammation and irritation of the sheath surrounding two tendons: the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB). These tendons pass through a narrow tunnel, or first dorsal compartment, on the thumb side of the wrist. Repetitive motions involving gripping, pinching, or twisting can cause friction and inflammation within this compartment.

The test's purpose is to provocatively stretch these specific tendons, thereby eliciting pain if they are inflamed or entrapped. It is typically performed by a healthcare professional, such as a physician, physical therapist, or occupational therapist, as part of a comprehensive hand and wrist examination.

How the Test is Performed

The Finkelstein's test is a simple yet effective maneuver. Here's a step-by-step breakdown of its execution:

• Patient Positioning: The patient is typically seated or standing, with their arm relaxed and forearm pronated (palm down).
• Thumb Flexion: The patient is instructed to make a fist with their affected hand, specifically by tucking their thumb into their palm and wrapping their fingers over it. This position places the APL and EPB tendons in a shortened, slightly stretched state.
• Ulnar Deviation: While maintaining this fist, the clinician then gently, or the patient actively, bends the wrist towards the little finger side (ulnar deviation). This action applies a maximal stretch to the APL and EPB tendons as they cross the wrist joint.
• Observation: The clinician observes the patient's reaction and asks about any pain experienced during the maneuver.

Interpreting a Positive Finkelstein's Test

A "positive" Finkelstein's test is characterized by the reproduction of sharp, localized pain along the radial (thumb) side of the wrist, specifically over the first dorsal compartment. This pain is typically felt at the base of the thumb and along the styloid process of the radius (the bony prominence on the thumb side of the wrist).

When the test elicits this characteristic pain, it strongly suggests the presence of De Quervain's Tenosynovitis. The pain results from the inflamed and thickened tendons being forcibly stretched and compressed within their constricted sheath during the ulnar deviation movement. It's important to note that while some mild discomfort might be felt by anyone performing this extreme wrist movement, a positive test involves a distinct, sharp, and often reproducible pain that indicates pathology.

Clinical Significance and Next Steps

A positive Finkelstein's test is a crucial diagnostic clue for De Quervain's Tenosynovitis. While it is highly indicative, it is rarely the sole basis for diagnosis. A thorough clinical assessment, including a detailed history of symptoms, palpation of the affected area, and observation of functional limitations, will accompany the test.

If a positive test is observed, the healthcare professional will likely discuss potential management strategies, which can range from conservative approaches to more invasive interventions:

• Rest and Activity Modification: Avoiding activities that aggravate the condition.
• Splinting: Wearing a thumb spica splint to immobilize the thumb and wrist.
• Anti-inflammatory Medications: Non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation.
• Physical or Occupational Therapy: Exercises to improve range of motion, strength, and provide ergonomic advice.
• Corticosteroid Injections: Injections into the tendon sheath to reduce inflammation.
• Surgery: In chronic or severe cases, a surgical procedure may be performed to release the constricting tendon sheath.

Who is at Risk for De Quervain's Tenosynovitis?

De Quervain's Tenosynovitis is often associated with repetitive activities that involve the thumb and wrist. Risk factors include:

• Repetitive Gripping, Pinching, or Twisting: Activities like knitting, gardening, carpentry, or using hand tools.
• New Parents ("Mommy Thumb"): Lifting and holding infants, especially with improper wrist mechanics.
• Occupational Hazards: Jobs requiring repetitive hand and wrist movements (e.g., assembly line workers, dentists, chefs).
• Hormonal Changes: More common in women, particularly during pregnancy and postpartum due to fluid retention and hormonal fluctuations.
• Underlying Conditions: Conditions like rheumatoid arthritis can predispose individuals to tenosynovitis.

Limitations and Considerations

While the Finkelstein's test is widely used, it's essential to understand its limitations:

• Specificity vs. Sensitivity: The test is generally considered sensitive (good at identifying those with the condition) but can sometimes yield false positives, meaning it might be positive in individuals without De Quervain's due to generalized wrist pain or other conditions.
• Differential Diagnosis: Other conditions can cause pain on the radial side of the wrist, such as osteoarthritis of the thumb carpometacarpal (CMC) joint, intersection syndrome, or radial nerve entrapment. A thorough differential diagnosis is crucial.
• Patient Tolerance: Some individuals may experience significant pain even with mild or no pathology, making interpretation challenging. Conversely, others with mild De Quervain's may not have a strongly positive test.

Ultimately, a positive Finkelstein's test is a valuable piece of the diagnostic puzzle, guiding healthcare professionals toward an accurate diagnosis and appropriate treatment plan for De Quervain's Tenosynovitis.