5 If plain x-ray film results are normal and the index of suspicion is high, wrist MRI is the next study of choice, because it is both sensitive and specific.
#Scaphoid pain full#
Stress radiography (clenched fist view), including a grip view in full supination and an AP (supinated) view in maximum ulnar deviation, helps reveal scapholunate dissociation. Some authors consider a gap of more than 2 mm to be abnormal, especially if the gap is greater than that on the contralateral side. A scapholunate gap is often visible 1 a separation of 3 to 4 mm or greater is significant for injury. 1,4 Obtaining bilateral views is particularly important because many show a cortical ring sign on the asymptomatic side. 2īilateral radiographic studies should be performed, including AP, lateral, radial and ulnar deviation, and clenched fist views, for comparison.
There is no separation of the scapholunate junction.
On the AP x-ray view (below, right), the scaphoid appears foreshortened and results in an end-on view of the bone (the “cortical ring sign”). Often, standard x-ray films reveal a flexed posture of the scaphoid and an extended lunate. Wrist ganglia and carpal tunnel syndrome can be secondary manifestations of an underlying periscaphoid ligament injury. Also, the test may not be accurate in an acute setting or in the presence of other injuries, such as a distal radial fracture. A painful “clunk” with radial deviation and reproduction of the patient’s pain are considered positive test results 3 a clunk is not necessary for the result to be considered positive. In this test, the patient’s forearm is placed in pronation the examiner places pressure on the volar distal pole of the scaphoid and the dorsal lip of the radius and moves the wrist from ulnar to radial deviation. Physical examination reveals tenderness over the scapholunate interval and a positive Watson scaphoid shift test result. Usually, patients recall a specific injury and present with dorsal, radial-sided wrist pain loss of range of motion and weakness of grasp. 1 The diagnosis of scapholunate ligament injury requires a high index of suspicion. Scapholunate dissociation alters articular contact areas and stress patterns with the carpus and leads to progressive degenerative arthritis of the wrist. When the scapholunate interosseous ligament is disrupted, the scaphoid assumes a flexed posture. It has been shown in anatomic studies that for dissociation to have occurred, 2 of the 3 ligaments must be disrupted. The ligaments involved in scapholunate stability are the scapholunate interosseous ligament, the dorsal scapholunate ligament, and the volar radio- scapholunate ligament. Generally, the mechanism of injury is a fall on an outstretched pronated hand (excessive wrist extension and ulnar deviation with intracarpal supination). The most common form of carpal instability involves the scaphoid and the lunate. When enough restraints are lost, static carpal instability results and the bones assume an abnormal alignment on standard wrist radiography.
The carpal bones assume a normal alignment at rest but collapse under stress. 2 If the ligamentous injury is incomplete, dynamic instability results. 1 The scaphoid, along with its support mechanism, is the most vulnerable component of the wrist. When there is disruption of these ligaments, as in the case of this patient, wrist instability results. Wrist stability is maintained by the ligamentous interconnections between carpal bones and between the radius and carpus. Or move on to the next page for more information. What do they show? What is your diagnosis?
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