Chapter 18 Arthroscopically Assisted Scaphoid Fracture Fixation

10.1055/b-0035-121128

Chapter 18 Arthroscopically Assisted Scaphoid Fracture Fixation

Introduction

Scaphoid fractures represent 2% of all fractures, 11% of hand fractures, and 60% of wrist fractures. Luckily, these fractures are becoming easier to diagnose due to a better understanding of the clinical signs, physician training, and modern imaging methods such as X-rays, but especially magnetic resonance imaging and computed tomographic scans.

These fractures have typically been treated by cast immobilization, but internal fixation is increasingly used. In the mid-1980s, Herbert and Fisher1 transformed the indications for fracture fixation by developing a scaphoid-specific screw. More recently, the use of cannulated screws has led to the development of percutaneous techniques, which simplify postoperative recovery and, more importantly, preserve vascularization. Nevertheless, it is not unheard of to have minor rotational problems that can lead to delayed union or nonunion. Wrist arthroscopy allows for evaluation and reduction of scaphoid fractures, while limiting incisions and therefore preserving the scaphoid’s vascularity.

Operative Technique

Patient Preparation and Positioning

Surgery is generally performed on an outpatient basis under regional anesthesia. The patient is placed supine, with the arm resting on an arm board with an attached tourniquet. A standard traction tower is used during the arthroscopic procedures.

First Phase: K-wire Insertion into the Scaphoid

A small (2 mm) anterior volar incision is made through which a 1 mm K-wire is inserted into the scaphoid under fluoroscopic control ( Fig. 18.1a–c ). This can be the most difficult step of the entire procedure. It is important to know how the scaphoid is shaped and oriented. If a rolled drape is placed under the wrist to extend it to 60°, the K-wire will be about 45° to horizontal. The K-wire is angled from the distal tubercle toward the middle of the carpus.

**Fig. 18.1a–c** Drawing (a), intraoperative view (b), and X-ray (c) of the retrograde percutaneous insertion of a K-wire into the scaphoid.

The scaphoid’s position can be determined by placing a thumb on the distal tubercle and the index finger on the proximal pole of the scaphoid on the dorsal side of the wrist ( Fig. 18.2 ). It then becomes obvious that the distal tubercle is in line with the flexor carpi radialis (FCR), closer to the midline than to the lateral side of the wrist, and that the proximal pole is located in the middle of the wrist. If the wrist is extended without moving the thumb and index from their positions, the scaphoid will feel nearly horizontal. These maneuvers can provide the surgeon with a spatial reference when inserting the K-wire.