The midaxial approach is indicated for oblique, spiral, comminuted, or transverse fractures, of the diaphysis and metaphysis.
It is also indicated for proximal metaphyseal fractures, when a resection is to be performed.
2. Planning the incision
To plan the line of the incision, fully flex the finger, as shown, and mark the ends of the joint skin creases with dots.
Extend the finger and connect the dots in a line. The resulting line is safe for a skin incision. The digital artery and digital nerve will lie palmar to this line.
3. Skin incision
For proximal fractures, make a skin incision from B to C. For further exposure the incision can be extended to A.
For middle phalangeal fractures, incise from A to B.
4. Nerve identification
Identify and protect the dorsal branches of the radial, ulnar, and median nerves.
5. Retraction of the oblique fibers of the lateral band
Retract the oblique fibers of the lateral band using two retractors.
Try to preserve the periosteum, which should be elevated only immediately adjacent to the fracture line, in order to avoid scar formation, tendon adhesion and fragment devascularization.
6. Alternative: Resection of the oblique fibers of the lateral band (Burton and Eaton)
It is occasionally necessary, for the visualization of very proximal fractures, to resect unilaterally oblique fibers of the lateral band. This resection also avoids impingement with the planned implant and intrinsic tendon adhesions.
7. Palmar access
Generally, avoid penetration of the flexor tendon sheaths. In case of tendon laceration, however, the midaxial approach can be used in order to perform tendon repair.