- See:
-
Carpal Instability:
-
scapholunate advanced collapse:
-
scapholunate instability
- Discussion:
- scapholunate and lunate injuries cause tenderness just distal to
Lister's tubercle;
- marked prominence of the entire carpus dorsally may indicate of a
perilunate dislocation;
- SLD is characterized by limited range of motion and increased weakness;
-
Watson test:
- this test provokes dorsal subluxation of the proximal scaphoid over the dorsal rim of the radius, as the wrist is radially deviated;
- is performed by grasping the patient's hand from its ulnar aspect of the small metacarpal with the
examiner's thumb on the palmar surface of the distal pole of the scaphoid;
- alternatively, the patient's hand is grasped by the examiner's hand from the radial aspect of the index metacarpal with the thumb and the palmar surface;
- it is critical for the examiner's thumb to apply pressure to the distal pole of the scaphoid, inorder to prevent it from flexing;
- move wrist from ulnar to radial deviation w/ distal tuberosity compressed;
- as scaphoid flexes to more vertical orientation w/ radial deviation, tuberosity comopression forces proximal pole subluxation dorsal to lip of radius;
- as the examiner's thumb pressure is removed, the subluxed scaphoid reduces, and may produce a palpable clunk and dorsal wrist pain (indicating
instability of the scapholunate ligament);
- this test has been criticized for low specificity;
- in the study by Wolfe et al 1997, 36% of normal individuals had a positive shift test;
- when examined flouroscopically, many of these individuals had a
capitolunate instability;
The scaphoid shift test.
Kinematics of the scaphoid shift test.
Examination of the scaphoid. HK Watson et al. J. Hand Surg. Vol 13-A. 1988. p 657-660.
The scaphoid shift test. Lane, LB. J. Hand Surg. Vol 18-A. 1993. p 366-268.
Radiographic observation of the scaphoid shift test.
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