**13. Arthroscopic treatment of scaphoid fractures**

The incidence of acute scaphoid fractures is about 70% of all carpal fractures and 11% of all wrist fractures. Young men in the 2nd and 3rd decade of life are the main target population of this injury. Two-thirds of all scaphoid fractures occur in the waist area and 60 – 85% are non-dislocated fractures. Distal third is affected in 25% of cases, but proximal third in 5-10% of fractures [90]. Two morphological bone types are identified: type I or full scaphoids and type II or slender scaphoids. Type I possess more robust internal vascular network than type II scaphoids which may prove to be related to development of nonunion, avascular necrosis or Preiser disease [91]. Indications for surgical treatment are: displacement greater than 1 mm, commination, open fracture, scaphoid fracture with perilunate dislocation, associated carpal instability – scapholunate angle greater than 60°, radiolunate angle greater than 15°, as well as angulation of the scaphoid – intrascaphoid angle greater than 35° and height to length ratio greater than 0.65 [92].

In cases when volar approach with retrograde screw insertion is chosen, arthroscopic treatment of scaphoid fracture has to be started with a small, anterior volar incision through which a 1-mm K-wire is inserted into the scaphoid under fluoroscopy control. This step can be the most difficult one of the entire procedure. If a rolled-up 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. The second stage includes an arthroscopic evaluation when the wrist is placed in vertical traction. Usually midcarpal portals (MCU) are used to visualize the fracture site. If the additional reposition is required, the K-wire can be removed from the proximal pole and manual maneuvers as well as hook probe can be used to achieve the correct position. Then cannulated headless compression screw can be inserted when wrist is released from traction. After the compression of the fracture fragments it's recommended to make a final arthroscopic evaluation of the midcarpal and radiocarpal joints, to verify the compression and length of the screw [93, 94]. The alternative is a dorsal approach. It provides direct unobstructed access to the proximal scaphoid pole permitting the placement of a central axis guide-wire for antegrade screw implantation [95, 96].

Active wrist motion exercises are initiated immediately or within 10 days after surgery. Strengthening exercises were delayed until healing was well established on X-rays of the scaphoid, usually 3 to 4 months after surgery [93, 97].
