Whereas the original Henry approach goes between brachioradialis laterally and the radial artery medially, the modified approach uses the plane between the Flexor Carpi Radialis (FCR) tendon medially and the radial artery laterally.
The radial artery and the palmar cutaneous branch of the median nerve are vulnerable during this approach.
4. Skin incision and exposure
The FCR tendon is palpated, before making the skin incision to its radial side.
The sheath is opened and the tendon retracted medially.
The incision is deepened between the flexor pollicis longus (FPL) and the radial artery.
Care must be taken to avoid damaging the radial artery on the lateral side and the superficial palmar cutaneous branch of the median nerve on the medial side.
A finger is used to develop the interval between the FPL muscle and the radial artery, exposing the pronator quadratus muscle.
The pronator quadratus muscle should be elevated using an L-shaped incision.
The horizontal limb is placed at the distal edge of the muscle extending medially. The position of the radiocarpal joint can be determined by the insertion of a hypodermic needle.
Retraction of the incised edges of the pronator quadratus muscle exposes the distal radius. The muscle is elevated from the distal radius extraperiosteally.
6. Wound Closure
The pronator quadratus should be replaced over any anterior implant(s), and every attempt should be made to reattach its distal edge to the capsule.
If possible, the vertical limb should be reattached to its lateral insertion.
The FCR tendon sheath may be closed, but care must be taken to avoid incorporating the cutaneous branch of the median nerve.