Dorsal approach to the phalangeal metaphysis (after Pratt)
1. Indications for this approach
Use the dorsal approach to access intraarticular, metaphyseal, or diaphyseal fractures of the proximal phalanx, or any basal intraarticular fracture extending into the metaphysis, or diaphysis.
2. Straight skin incision
Make a straight skin incision, starting at the metacarpophalangeal (MCP) joint, ending at the proximal interphalangeal (PIP) joint. Depending on the fracture geometry, the incision may be shorter. With this incision, vascularity and venous drainage are well preserved. Early postoperative motion will prevent scarring between skin, tendon and bone. The disadvantage of this incision is that any skin and tendon scarring will be in the same line.
3. Alternative: curved skin incision
Alternatively, make a gently curved skin incision, extending from the proximal phalangeal base to the PIP joint. The convexity of the incision is planned so that the scar does not involve the radial border of the index, or the ulnar border of the little finger. The fracture configuration and implant placement must be taken into account when planning the incision.
Advantage and disadvantage of the curved incision
The advantage of the curved incision is that the skin and tendon scarring are not in the same line. The disadvantage is reduced vascularity at the apex of the curve, with a risk of necrosis and delayed skin healing.
4. Nerve identification
Blunt dissection extends the approach through the thin subcutaneous tissue, taking care to identify and protect the dorsal sensory branches of the radial, ulnar, and median nerves.
5. Vein identification
The dorsal venous system of the fingers has longitudinal and transverse branches. Be careful to preserve the longitudinal branches. The transverse branches may be ligated, or cauterized with a bipolar cautery, for better exposure, but preserve as many dorsal veins as possible to avoid venous congestion and swelling.
6. Tendon splitting
Split the extensor tendon apparatus along the midline longitudinal fibers of the tendon. Be careful not to incise the periosteum. Avoid incising too distally, which could result in injury to the central slip and a secondary boutonnière deformity.
Alternatively, the incision may be placed between the lateral band and the central slip of the extensor tendon.
7. Fracture exposure
Retract the tendon to expose the fracture site. Try to preserve the periosteum, which should be elevated only adjacent to the fracture line.
8. Suturing the tendon
After finishing the osteosynthesis, complete the procedure by closing the tendon incision using multiple fine mattress stitches, as shown in the drawing.