Palmar approach – modified Henry approach to the distal forearm

In general, there are two palmar surgical approaches to the distal radius– a modified Henry approach to the radius and a more ulnar approach, designed to expose the median nerve as well as the distal radius.

The modified Henry approach is suitable for most fractures of the distal radius.

If it is desired to decompress the carpal tunnel, this may be performed either through one ulnar extensile approach or two separate approaches.

For isolated lunate facet fractures an ulnar approach is more useful.

For high energy fractures an extended ulnar approach may be used.

$Illustration showing two palmar approaches to distal radius: modified Henry approach and ulnar approach, with options for carpal tunnel decompression and fracture management.$

The modified Henry approach uses the plane between flexor carpi radialis tendon and the radial artery.

The classical Henry approach goes between brachioradialis and the radial artery, i.e., radial to the radial artery. The modified approach is ulnar to the radial artery.

The flexor carpi radialis tendon is palpated, before making the skin incision to the radial side.

Illustration showing modified Henry approach between flexor carpi radialis tendon and radial artery, with classical Henry approach radial to radial artery.

The radial artery and the palmar cutaneous branch of the median nerve are at risk during this approach.

Illustration showing the radial artery and palmar cutaneous branch of the median nerve at risk during the modified Henry approach.

Make the skin incision along the radial border of the flexor carpi radialis tendon.

The sheath is opened and the tendon retracted towards the ulna.

Deepen the incision between the flexor pollicis longus and the radial artery.

Care must be taken to avoid damaging the radial artery on the radial side and the palmar cutaneous branch of the median nerve on the ulnar side.

Illustration showing skin incision along radial border of flexor carpi radialis tendon, with care to avoid radial artery and palmar cutaneous branch of median nerve.

A finger is used to sweep the flexor pollicis longus muscle belly towards the ulna.

This increases the space and exposes the pronator quadratus muscle.

Illustration showing a finger sweeping the flexor pollicis longus muscle belly towards the ulna, exposing the pronator quadratus muscle.

Pearl

The pronator quadratus muscle should be elevated using an L-shaped incision.

The horizontal limb is placed at the watershed line. This lies a few mm proximal to the joint line; the position of the joint line can be determined by a hypodermic needle placed in the joint.

Illustration showing L-shaped incision to elevate pronator quadratus muscle, with horizontal limb at watershed line, and joint line determined by hypodermic needle.

The pronator quadratus muscle is incised on its radial border, exposing the distal radius. It is stripped off the distal radius together with the periosteum.