Dorsal approach to the middle phalanx

The dorsal approach offers access to the extensor tendon, and the metaphysis and diaphysis of the middle phalanx.

This approach is indicated for oblique, spiral, comminuted, or transverse fractures of the diaphysis, or metaphysis of the middle phalanx.

It can also be used for corrective osteotomies of malunited fractures.

$Illustration showing dorsal approach to the middle phalanx, indicated for various fractures and corrective osteotomies.$

AO teaching video

Finger, middle phalanx, dorsal approach

Nerve identification

Identify and protect the dorsal sensory branches of the radial and ulnar nerves in the thin subcutaneous tissue.

Illustration of dorsal approaches to the PIP joint, showing identification and protection of dorsal sensory branches of radial and ulnar nerves in thin subcutaneous tissue.

Vein identification

The dorsal venous system of the fingers has longitudinal and transverse branches. Be careful to preserve the longitudinal branches. For better exposure, the transverse branches may be ligated or cauterized but preserve as many dorsal veins as possible to avoid congestion and swelling, with consequent fibrosis and stiffness.

Illustration of dorsal approaches to the PIP joint, showing preservation of longitudinal branches and careful handling of transverse branches to avoid congestion and swelling.

Several skin incision options are available. Each comes with benefits and disadvantages.

Straight dorsal incision

Perform a straight, midline, dorsal skin incision, starting at the proximal interphalangeal (PIP) joint and ending at the distal interphalangeal (DIP) joint. Depending on the fracture geometry, the incision may be shorter.

Pitfall: Take care distally to avoid injury of the nail matrix.

Advantages:

Perfusion and venous drainage are well preserved.
Early postoperative motion will prevent scarring between skin, tendon, and bone.

Disadvantage:

Skin and tendon scarring will be in the same line and tethering may occur.
Limited approach to lateral structures.

Illustration showing dorsal approach to the middle phalanx with a straight midline incision from PIP to DIP joint. Advantages: preserved perfusion and venous drainage, early motion. Disadvantages: potential scarring and limited lateral access.

Curved skin incision

Perform a curved skin incision extending from the PIP joint to the DIP 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 considered when planning the incision.

Illustration showing dorsal approach to the middle phalanx with a curved skin incision from PIP to DIP joint, avoiding radial and ulnar borders.

Advantage:

Skin and tendon scarring are not in the same line and tethering due to scarring may be avoided.

Disadvantage:

Relatively poor perfusion at the apex of the curve may risk skin necrosis and delayed healing.

Illustration showing dorsal approach to the middle phalanx, avoiding scarring in the same line but risking poor perfusion at the curve's apex.

Dorsal fasciocutaneous flap

Start a transverse incision at the level of the DIP joint crease. Continue the incision midaxially parallel to the bone axis avoiding damage to the neurovascular bundle. Curve it gently over the PIP joint crease.

Pearl: This flap derives the blood supply from the contralateral digital artery. Therefore, dissection should be limited at the base of the flap.

This skin incision allows for an extensile paratendon or tendon split approach.

Depending on the fracture pattern, the flap may be created on the ulnar or radial side.

The skin on the ulnar side of the 5th finger and the radial side of the 2nd finger should be preserved to protect sensitivity.

It has the advantage of low risk of scar adhesion, apical flap necrosis, and a better esthetic result of skin scars.

Illustration showing dorsal approach to the middle phalanx with a transverse incision at DIP joint crease, curving over PIP joint crease, avoiding neurovascular bundle, and preserving sensitivity. Advantages: low risk of scar adhesion, apical flap necrosis, and better esthetic result.

Elevate the fasciocutaneous flap by sharp dissection in the subfascial plane outside the epitenon. Retract it using fine sutures.

Identify and preserve nerves and longitudinal veins.

Illustration showing dorsal approach to the middle phalanx, elevating fasciocutaneous flap, retracting with sutures, preserving nerves and veins.

Keep in mind, when developing the flaps, that the layers must be elevated together to avoid devascularization.

There are two alternative deep approaches:

Midline extensor tendon splitting
Paratendon

Midline extensor tendon splitting

Expose the terminal extensor tendon with its triangular ligament.

Make a longitudinal incision through both the terminal extensor tendon and its triangular ligament, taking care to preserve the periosteum.

Pitfall: Take care distally to avoid injury of the nail matrix.

Pitfall: Take care to avoid detaching the terminal extensor tendon to prevent mallet finger deformity.

Illustration showing dorsal approach to the middle phalanx, exposing and incising terminal extensor tendon and triangular ligament, preserving periosteum, avoiding nail matrix injury and mallet finger deformity.

After incising the terminal extensor tendon and its triangular ligament, two small retractors are used to expose the bone.

Illustration showing dorsal approach to the middle phalanx, using two small retractors to expose the bone after incising the terminal extensor tendon and triangular ligament.

Paratendon approach

Perform an incision between the lateral band and the central slip of the extensor tendon. The incision may be on the radial or ulnar side according to the fracture pattern.

Pitfall: Take care distally to avoid injury of the nail matrix.

Illustration showing dorsal approach to the middle phalanx, incising between lateral band and central slip, avoiding nail matrix injury.

Retract the extensor tendon towards the midline, according to the fracture pattern and requirements of fixation

$Illustration showing dorsal approach to the middle phalanx, retracting extensor tendon towards midline based on fracture pattern and fixation needs.$

Regardless of the chosen approach, all tendon incisions must be repaired with nonabsorbable monofilament sutures with an atraumatic needle prior to wound closure.

Repair the terminal extensor tendon and its triangular ligament with fine interrupted mattress sutures.

The following suture dimension should be used: