The dorsal approach to the distal interphalangeal (DIP) joint is indicated for extensor tendon avulsion fractures of the dorsal base of the distal phalanx, or intraarticular fractures with palmar dislocation.
It is also indicated for DIP arthrodesis.
Note the crisscross alignment of the fibers within the conjoint extensor tendons, and also within the triangular ligament.
Damage to the nail matrix must be avoided, since it may cause permanent deformity of the nail.
There are three common skin incisions: The H-shaped, the Y-shaped, and the lazy S-shaped incision.
The H-shaped incision is usually modified by diverging the sides slightly, to improve vascularity.
Transverse incision
An alternative incision, designed to reduce potential soft tissue trauma, is a simple transverse incision, which will give enough exposure for osteosynthesis or for joint surface preparation for arthrodesis.
Depending on the shape of the skin incision, flaps should be elevated and held with fine sutures to minimize soft-tissue trauma.
Tiny veins will appear, and should be coagulated with the bipolar forceps, as necessary, to gain exposure of the joint.
Divide the terminal extensor tendon with either a transverse tenotomy, a step cut, or a long oblique cut.
The step cut and the oblique cut facilitate repair.
The retinacular ligament of Landsmeer passes obliquely from the palmar aspect at the attachment of the A3 pulley to the terminal conjoint extensor tendon. This ligament must be preserved to avoid a mallet deformity.
If it proves necessary to divide this ligament, it must be repaired carefully.
Retract the terminal extensor tendon proximally, in order to expose the DIP joint.
Repair the extensor tenotomy with multiple fine nonresorbable mattress sutures.