Background
Stress radiographs are useful in determining the amount of ligamentous tears, joint stability and fracture unions. The results may help with a differential diagnosis, indications for surgery and the type and duration of rehabilitation.1 Some techniques for obtaining stress radiographs involve specific positioning of the patient positioning or applying manual force; others require use of a particular testing device. The parameters that define abnormality on stress radiographs should be compared with clinical findings. Many of the more novel techniques for obtaining stress views have helped reduce patient discomfort and minimize exposure to radiation.1
Historical Overview
Stress views are typically used to evaluate patients presenting with thumb injuries or degenerative conditions, because standard views do not capture the oblique orientation of the joint in the coronal and sagittal planes and the saddle shape of the joint overall.2,3 The stress view of the carpometacarpal (CMC) joint of the thumb was first described by Eaton and Littler, who noted that it gave “a valuable index of the degree of capsule laxity.”4
Description
Stress radiographs can be obtained using a number of different positions and applied forces. In Gamekeeper’s thumb, abduction stress x-rays are obtained with the CMC joint in full extension and then in 25 of flexion, with no rotation and under local anesthesia. For comparison, the same stress x-rays are obtained for the contralateral thumb CMC joint.5 The stress x-rays were considered to be positive if the affected joint abducted ≥10° more than the normal, contralateral joint.5 Another type of stress x-ray, the Brewerton view, helps identify metacarpal head fractures that may not be discernible using standard x-ray views. For the Brewerton view, stress x-rays are obtained with the fingers flat on the x-ray plate, the metacarpophalangeal joints flexed 65° and the beam angled from a point 15° to the ulnar side of the hand.6