The "Standing Peanut" Scaphoid View: A Semi-supinated Radiographic View for Intraoperative Evaluation of Screw Placement in Scaphoid Waist Fractures.

Abstract

Scaphoid waist fractures are the most common fracture of the scaphoid. Operative management is indicated with unstable fractures and often for nondisplaced waist fractures to decrease time to union and return to work/sport. Screw placement within the central axis of the scaphoid is paramount and correlates with outcomes. Assessment of intrascaphoid screw placement is classically done via intraoperative fluoroscopy. An additional fluoroscopic view is presented to assist in confirming implant positioning. Along with the standard anterioposterior, lateral, pronated oblique, and "scaphoid" view we obtain a "standing peanut" view for assessment of central screw placement. This view also allows for further evaluation of center/center positioning and better assessment of fixation crossing the fracture into the proximal pole. The "standing peanut" view is best obtained in a sequential manner beginning with the forearm in neutral rotation. First, the forearm is then supinated 30 degrees; next, the wrist is placed at 45 degrees of ulnar deviation. Then finally, 10 degrees of wrist extension. We utilize this additional intraoperative view in conjunction with the standard fluoroscopic views for assessing and ensuring center-center implant positioning, particularly within the proximal pole. When ensuring center-center positioning, we prefer this view as an adjunct view to the standard fluoroscopic views intraoperatively. It provides a beneficial view of the proximal pole delineating the number of screw threads that have obtained proximal pole purchase. We have found it particularly useful in the setting of scaphoid waist fracture nonunion with the classic 'humpback' deformity after correction with volar interposition grafting. Standard radiographic views may be misinterpreted regarding implant positioning if there remains any residual flexion. The view requires little in the way of training to obtain once appreciated and exposes the patient to minimal additional radiation.