Hand Surgery Source

Watson Scaphoid Shift Test

Test, Exam and Signs

Historical Overview

  • The Watson Scaphoid Shift test is used to diagnose failure of the scapholunate interosseous ligament (SLIL).1
  • Watson first described the test to the American Research in General Orthopedics conference in New Orleans in March 1978.2

Description

  • Failure of the SLIL can allow abnormal wrist kinematics, pain, and subluxation. The Watson Scaphoid Shift test provokes pain and subluxation by applying a force to the distal pole of the scaphoid while moving the wrist from ulnar to radial deviation.

Pathophysiology

  • The scapholunate joint is the most frequently injured joint in the carpus. Injury typically occurs after a fall on an outstretched hand, after impact to the hypothenar region, and with forced extension in ulnar deviation and supination..1
  • The SLIL is an intra-articular structure (ie, synovial) composed of three regions:1,3
    • Dorsal ligament: transversely oriented collagen fibers providing primary restraint for distraction and torsional/translational movements
    • Palmar ligament: provides rotational stability
    • Proximal fibrocartilage: negligible contribution to restraint of abnormal motion
  • The dorsal ligament is twice as strong as the palmar ligament and about nine times stronger than the proximal structure.3
  • The elements of the SLIL can be injured in isolation or in combination.

Instructions

  1. Take a patient history
  2. Per Watson: “The patient is approached by the examiner as if to engage in arm wrestling.”2
  3. Grasp wrist and use thumb to apply pressure to the scaphoid tubercle as the patient’s wrist is moved (using examiner’s other hand) from ulnar deviation and slight extension to radial deviation and slight flexion. That is to say apply dorsally directed pressure over the distal pole of the scaphoid with the wrist in mild extension and ulnar deviation
  4. Relax thumb pressure on the tubercle at full radial deviation and be aware of palpable and/or audible reduction of the dorsally displaced scaphoid moves back into its radial fossae.  Palpate and note  for sense of hypermobility, clicking, or “clunking” on raial deviation and release of the scahpoid.2
  5. Alawys compare findings with the opposite wrist.

Related Signs and Tests

  • Scapholunate tenderness
  • SLIL injury can also cause scaphoid tenderness

Diagnostic Performance Characteristics

  • SLIL injury allows the examiner’s thumb to shift the scaphoid from its radial fossa onto the dorsal articular lip of the radius. Relief of thumb pressure allows the subluxed scaphoid to spontaneously reduce.1,2
  • Watson estimated that 20% of normal wrists exhibit a false positive;2 others have reported false positives in up to 33% of normal wrists.1
Presentation Photos and Related Diagrams
  • Left wrist with scapholunate advanced collapse (SLAC) osteoarthritis. Note slight swelling in the area of the scaphoid.
    Left wrist with scapholunate advanced collapse (SLAC) osteoarthritis. Note slight swelling in the area of the scaphoid.
  • Left wrist with early SLAC changes. Note large gap between arrows and minimal OA changes. Scaphoid (S) and Lunate (L).
    Left wrist with early SLAC changes. Note large gap between arrows and minimal OA changes. Scaphoid (S) and Lunate (L).
  • Right wrist with severe SLAC changes. Note large gap between arrows and marked OA changes. Scaphoid (S), Radius (R) and Lunate (L).
    Right wrist with severe SLAC changes. Note large gap between arrows and marked OA changes. Scaphoid (S), Radius (R) and Lunate (L).
Definition of Positive Result
  • A positive result occurs when there is a palpable and/or audible reduction of the subluxed scaphoid1,2 and elicitation of symptomatic pain, usually on the dorsal side.2
Definition of Negative Result
  • A negative result occurs when the scaphoid moves normally, pushing back on the examiner's thumb with ulnar deviation of the wrist, and there is no symptomatic pain.
Comments and Pearls
  • Watson noted that this was “not so much a test as a provocative maneuver. It does not offer a simple positive or negative result, but rather a variety of findings. With experience, an examiner will learn to recognize and interpret these findings in their patients.”2
  • Stress x-rays, computed tomography, or magnetic resonance imaging studies may be helpful in determining the severity of injury and deciding on surgical treatment.1
  • Because many acute injuries are not diagnosed, it is not known whether progression always occurs, but it does appear to happen frequently. Symptoms can worsen as secondary structures fail.3
Diagnoses Associated with Tests, Exams and Signs
Video
Watson Scaphoid Shift Test Right Wrist
References
  1. Kitay A, Wolfe SW. Scapholunate instability: current concepts in diagnosis and management. J Hand Surg Am 2012;37(10):2175-96. PMID: 23021178 
  2. Watson HK, Ashmead D,4th, Makhlouf MV. Examination of the scaphoid. J Hand Surg Am 1988;13(5):657-60. PMID: 3241033
  3. Pappou IP, Basel J, Deal DN. Scapholunate ligament injuries: a review of current concepts. Hand (N Y) 2013;8(2):146-56. PMID: 24426911