Percutaneous Treatment of Proximal Pole Scaphoid Fractures

Joseph F. Slade III and John D. Mahoney

History and Clinical Presentation

A 20-year-old male college football player sustained a hyperextension injury to his wrist after a fall during practice. He initially had radiographs taken, and his injury was diagnosed as a sprain and was splinted for 2 weeks. He was referred to the hand clinic for evaluation and treatment.

Physical Examination

The patient complains of pain at the base of his thumb, and locates pain to the region of the snuffbox. There is minimal swelling noted, and range of motion is decreased when compared with the opposite wrist. There is point tenderness over the proximal pole of the scaphoid. There is no carpal or wrist instability (Shuck test evaluating lunate-triquetrum, scaphoid shift test for scapholunate instability, and ballottement test for distal radioulnar joint are all negative).

Diagnostic Studies

Fracture of the Proximal Pole of the Scaphoid (Herbert B3)

Scaphoid fractures are the most common fracture of the carpus (80% of total), and of the wrist, the second most common after fractures of the distal radius. The typical patient is a young man injured after a fall on an extended wrist. Diagnosis of fracture is suggested by the patient’s age, mechanism of injury, and symptoms. Radiographs are required to confirm diagnosis.

The scaphoid bone is anatomically unique. First, its blood supply from the superficial palmar branch of the radial artery and the dorsal carpal branch of the radial artery runs from distal to proximal, with the proximal pole receiving the most tenuous blood supply. Thus, the proximal pole is particularly susceptible to avascular necrosis as a complication of fracture. Second, its irregular three-dimensional shape presents special problems in diagnosis of acute fractures and their treatment. It is an intraarticular bone, with 80% of its surface covered with articular cartilage. Displaced fractures result in early degenerative arthritis, and malunions can lead to carpal collapse.

The scaphoid is most commonly fractured across its middle third, with 70% of fractures across the “waist.” Ten percent are distal third fractures, and 20% are proximal third fractures. All proximal pole fractures should be considered unstable regardless of radiographic appearance. Russe classified scaphoid fractures into three categories based on the fracture axis: horizontal oblique, transverse, and vertical oblique. Horizontal oblique and transverse fractures together comprise ∼95% of fractures, and respond equally well to therapy. Vertical oblique fractures comprise the remaining 5%, and they tend to have a slower progress to union and a higher rate of nonunion.