Percutaneous Fixation for Scaphoid Nonunion With Bone Grafting Through the Distal Insertion Hole of a Fully Threaded Headless Screw

Abstract

Objective: Percutaneous scaphoid screw fixation is a popular treatment for acute scaphoid fractures with no or minimal displacement. For treating scaphoid nonunions, however, open reduction and internal fixation with bone grafting is still the most popular treatment. Percutaneous fixation with bone grafting through the screw insertion hole has received little attention, although it minimizes damage to the surrounding tissues. We report excellent results of 10 scaphoid nonunions treated by retrograde percutaneous fixation with curettage and bone grafting through the distal insertion hole of a fully threaded headless screw. Materials and Methods: Ten scaphoid nonunions with substantial bone loss were treated, including 1 revision case. All nonunions were located at the middle third of the scaphoid. The mean patient age at operation was 24.7 years, and the mean interval between fracture and surgery was 8.8 months. In the revision case, the interval between the primary and revision surgery was 6 months. Surgery was performed under general anesthesia or an axillary brachial plexus block with local anesthesia at the iliac crest donor site. A 1.1-mm guidewire was percutaneously inserted into the scaphoid tuberosity and advanced to the proximal pole of the scaphoid with the wrist in an extended and ulnar-deviated position. A 1.2-mm second derotation wire was also inserted radial or ulnar to the original guidewire. A 2.0-mm cannulated drill was passed over the guidewire, stopping at the distal end of the cystic lesion. The guidewire was then removed. The 1.2-mm second derotation wire maintained the reduction of the scaphoid. Curettage inside the cystic lesion was performed using a small curette inserted through the distal insertion hole. Bone graft was harvested percutaneously from the iliac crest with an 11-gauge bone biopsy needle and inserted into the cystic lesion through the drill hole of the distal scaphoid fragment. The removed guidewire was reinserted into the previously drilled hole followed by insertion of a selected fully threaded headless screw (Acutrak 2 mini; Acumed, Hillsboro, OR, USA). After the operation, the wrist was immobilized in a thumb spica cast for the initial 6 weeks, followed by splinting until bone union was confirmed. In one case, curettage alone was performed before retrograde insertion of the headless screw. In the other cases including the revision, curettage and bone grafting with a bone biopsy needle was required through a distal insertion hole. Results: The mean follow-up was 12.1 months. Radiologically, union was achieved at averaged 12 weeks postoperatively. At the final follow-up, there was significant improvement in the wrist extension range of movement (from 65.8° to 80.8°) and grip strength (from 65.5% to 87.8% of the unaffected side). Nine patients were free of pain, and 1 experienced mild pain only during heavy manual labor. The mean visual analogue scale (VAS), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Cooney wrist scores were 0.1, 1.75, and 98.5, respectively. All patients returned to their work or athletic activities. Conclusions: Retrograde percutaneous fixation with bone grafting through the distal insertion hole of a fully threaded headless screw is a promising option for surgical treatment of scaphoid nonunions.