Watson Test

What is a Watson Test?

The Watson Test is a pivotal tool in clinical examinations. It primarily aids in diagnosing the instability of the scapholunate ligament (SL) within the wrist, between the scaphoid and lunate bones. This test owes its name to David Watson, who introduced it to the medical world in 1988.

The Watson Test is a hands-on physical examination technique. It involves exerting pressure on the scaphoid bone from a specific wrist position. If the ligament is damaged or unstable, this pressure induces a 'shift' or movement, indicating potential SL ligament injury.

This test is an invaluable asset for healthcare practitioners, especially those in physiotherapy and orthopedic surgery. It assists in accurately diagnosing wrist conditions, thereby enabling the development of effective treatment strategies. distal pole dorsal intercalated segmental instability distal radius

Is the Scaphoid Shift Test a different test?

No, the Scaphoid Shift Test is not a different test; it is simply another name for the Watson Test. Other synonyms include the scaphoid stress test and the Watson scaphoid test. This test should not be confused with the "Watson-Scott Test," which is an assessment for entertainment purposes, described by its developers as a personality assessment.

How does it work?

The Watson Test, while crucial, is not complex. It involves a series of simple steps allowing healthcare practitioners to diagnose potential wrist pathologies effectively. Here's how it works:

Step 1: Access the template

Download a copy of the printable template from the Carepatron app, the website's resource library, or via the download button below. Users can also customize the template directly within the app.

Step 2: Position the patient

Have your patient in a sitting position facing you. Their elbow must be flexed and supported by a table while their forearm and hand are pointing up. The position is similar to an arm wrestling position. Wrap your hand around the patient’s wrist. Your thumb must be on the patient's scaphoid (palm-side) and place some pressure on their scaphoid tubercle.

Step 3: Move the wrist

Using your other hand, grasp the patient’s metacarpals, palm side. You will use this hand to move the wrist. Bend the hand towards you, then extend it (ulnar deviation) while maintaining constant thumb pressure. Afterward, move the wrist to a radial deviation, where the hand is bent towards the thumb. Finally, release the pressure your thumb is placing on the patient’s scaphoid. 

Step 4: Observe and assess

If the Watson Test is positive, the patient will experience pain during the movement. Additionally, the clinician will notice a distinct 'clunk' as the scaphoid bone subluxates or partially dislocates over the dorsal rim of the radius bone. This sign is indicative of ligament instability.

The presence or absence of the 'scaphoid shift' is a key factor noted in the documentation. This shift, discernible when pressure is applied to the scaphoid bone, indicates potential ligament instability. Any pain experienced by the patient during the test is also recorded, as it can provide further insight into the severity of the condition.

Whichever the result may be, it’s best to have them undergo further testing before formulating a diagnosis. Some tests that can produce clear results are X-ray, MRI, radioscopy, and fluoroscopy. 

When would you use this form?

The Watson Test is a key diagnostic tool for healthcare practitioners across various disciplines. But when exactly would you use this form? The primary application of Watson Tests comes into play when a patient presents with wrist pain or following a wrist injury. 

The Watson Test becomes particularly relevant if a patient complains of persistent wrist pain, especially after a fall on an outstretched hand, or experiencing difficulty performing wrist movements. This test is also crucial when there's suspicion of damage to the scapholunate ligament, a critical structure that ensures the stability and smooth movement of the wrist.

Conduct the test on your patient if they are experiencing the symptoms of a tear, such as:

• Wrist weakness
• Popping or grinding feeling
• Bruising
• Limited range of motion
• Pain when the wrist is bent backward
• Pain and swelling at the wrist’s back side, which has been worsening over several days

The Watson Test is commonly employed in several medical fields. 

• In sports medicine, athletes often present with wrist injuries due to falls, sudden impacts, or overuse.

• Orthopedic surgeons also frequently utilize Watson Tests, as these professionals often deal with bone and ligament injuries.

• Physiotherapists rely on the Watson Test to assess the wrist's condition before designing a rehabilitation program.

• General practitioners may use the Watson Test as part of their initial examination when a patient presents with wrist pain. It offers a quick, non-invasive method to detect potential ligament damage, helping direct appropriate referrals to specialists if necessary.

Research & evidence

Since its inception by David Watson, the Watson Test has been extensively researched and validated as a robust tool for detecting scapholunate instability. According to several research papers, the Scaphoid Shift Test can be a preliminary test to identify, confirm, and diagnose scapholunate ligament tears that can worsen and become scapholunate interosseous ligament instability (SLIL). However, it cannot be used as the sole basis.

On a brighter note, however, the test is still useful because, according to Wolfe (1994), the test can give practitioners an idea of the severity of the displacement based on the stiffness of the patient’s wrist while it’s being radially deviated. Valdes (2013) reports that it has enough clinical value to rule out scapholunate ligament tears despite having a low value to confirm it. Park (2003) reports that the test may still confirm suspicions of scaphoid instability, especially if the patient gets a positive test result due to pain.

Research on thermal shrinkage for scapholunate instability also emphasized the Watson Test's importance, particularly in cases where apprehension with pain during the examination was an evident source (Danoff et al., 2011). Moreover, studies on injuries to the scapholunate ligament in children recognized the Watson Test's role in revealing the scapholunate instability among younger populations (Alt et al., 2004).

References

Alt, V., Gasnier, J., & Sicre, G. (2004). Injuries of the scapholunate ligament in children. Journal of Pediatric Orthopaedics B, 13(5), 326–329. https://doi.org/10.1097/01202412-200409000-00008

Danoff, J. R., Karl, J. W., Birman, M. V., & Rosenwasser, M. P. (2011). The use of thermal shrinkage for scapholunate instability. Hand Clinics, 27(3), 309–317. https://doi.org/10.1016/j.hcl.2011.06.005

Park, M. J. (2003). Radiographic observation of the scaphoid shift test. The Journal of Bone and Joint Surgery. British Volume, 85-B(3), 358–362. https://doi.org/10.1302/0301-620x.85b3.13699

Valdes, K., & LaStayo, P. (2013). The value of provocative tests for the wrist and elbow: A literature review. Journal of Hand Therapy, 26(1), 32–43. https://doi.org/10.1016/j.jht.2012.08.005

Wolfe, S. W., Gupta, A., & Crisco, J. J. (1997). Kinematics of the scaphoid shift test. The Journal of Hand Surgery, 22(5), 801–806. https://doi.org/10.1016/S0363-5023(97)80072-X