Volar Approach to the Scaphoid

Volar Approach to the Scaphoid

The volar approach provides good exposure of the scaphoid bone.39 It also avoids damaging the dorsal blood supply to the bone’s proximal half, as well as the superficial branch of the radial nerve. It does pose a threat to the radial artery, however, which is close to the operative field. It leaves a more cosmetic scar than the dorsal approach, and its uses include the following:

1. Bone grafting for nonunion of the scaphoid

2. Excision of the proximal third of the scaphoid

3. Excision of the radial styloid, either alone or combined with one of the above procedures

4. Open reduction and internal fixation of fractures of the scaphoid. In such cases this approach frequently is combined with the dorsolateral approach to the scaphoid.

 

Position of the Patient

 

Place the patient supine on the operating table, with the arm lying on an arm board. Supinate the forearm to expose the volar aspect of the wrist, and apply an exsanguinating bandage and tourniquet (see Fig. 5-15).

Landmarks and Incision

Landmarks

Palpate the tubercle of the scaphoid on the volar aspect of the wrist, just distal to the skin crease of the wrist joint.

The flexor carpi radialis muscle lies radial to the palmaris longus muscle at the level of the wrist. It crosses the scaphoid before inserting into the base of the second and third metacarpal just on the ulnar side of the radial pulse.

Incision

Make a vertical or curvilinear incision on the volar aspect of the wrist, about 2 to 3 cm long. Base it on the tubercle of the scaphoid and extend it proximally between the tendon of the flexor carpi radialis muscle and the radial artery (Fig. 5-63).

 

Internervous Plane

 

There is no true internervous plane; the only muscle mobilized is the flexor carpi radialis (which is supplied by the median nerve).

 

 

 

Figure 5-63 Incision for the volar approach to the scaphoid. Base the incision on

the tubercle of the scaphoid and extend it proximally and distally. The proximal extension is between the tendon of the flexor carpi radialis and the radial artery.

 

Superficial Surgical Dissection

 

Incise the deep fascia in line with the skin incision and identify the radial artery on the lateral (radial) side of the wound (Fig. 5-64). Retract the radial artery and lateral skin flap to the lateral side. The superficial palmar branch of the artery which runs close to the scaphoid tubercle may cross the operative field and need ligation. Identify the tendon of the flexor carpi radialis muscle and trace it distally, incising that portion of the flexor retinaculum that lies superficial to it. After the tendon has been freed from its tunnel in the flexor retinaculum, retract it medially to expose the volar aspect of the radial side of the wrist joint (Fig. 5-65).

 

 

 

Figure 5-64 Incise the deep fascia between the radial artery and the flexor carpi radialis.

 

 

Figure 5-65 Retract the radial artery and skin flap laterally and the flexor carpi radialis medially to expose the volar aspect of the radial side of the wrist joint capsule.

 

Deep Surgical Dissection

 

Incise the capsule of the wrist joint obliquely over the scaphoid to expose the distal two-thirds of the scaphoid. Begin at the tubercle of the scaphoid distally and extend the incision proximally until palmar rim of the distal radius is reached. Try to preserve as much of the palmar ligament complex as possible to stabilize the proximal pole of the scaphoid. This anterior area of bone is nonarticular. To gain the best view of the proximal third of the bone, place the wrist in marked dorsiflexion (Fig. 5-66).

 

 

Figure 5-66 Incise the joint capsule. Dorsiflex the wrist to gain exposure of the proximal articular third of the bone.

 

 

Dang

 

 

Vessels

The radial artery lies close to the lateral border of the wound and can be incised accidentally at any time during the dissection. Therefore, it must be identified early in the procedure. The superficial palmar branch of the artery usually crosses the operative field and needs to be ligated to prevent a postoperative hematoma.

 

How to Enlarge the Approach

 

The incision can be extended usefully to a limited extent. Proximally, extend the skin incision along the line of the flexor carpi radialis muscle. Identify the distal border of the pronator quadratus muscle and elevate it gently from the underlying bone. This will create adequate exposure of the distal end of the radius, allowing a bone graft to be taken from this site. Adequate exposure also will be obtained to allow excision of the radial styloid, if this is indicated.

The key to exposing the scaphoid lies in forceful dorsiflexion of the

wrist. This will expose the proximal pole of the scaphoid, which is the site of most cases of nonunion. If the location of the fracture is not completely clear, place a small, radiopaque mark at the operative site and carry out a radiographic examination on the operating table. Bone grafting can be carried out adequately with this exposure, but the insertion of a screw may require a combined dorsal and volar approach to the scaphoid.40