The dorsal approach is indicated for oblique, spiral, comminuted, or transverse fractures of the diaphysis and metaphysis of metacarpals. It can also be used for corrective osteotomies of malunited fractures.
2. Surgical anatomy
The extensor tendons of the 3rd and 4th fingers run dorsally directly over the metacarpals. The extensor tendons of the index and little fingers converge slightly from their metacarpal axes towards the center of the wrist joint. Be aware of the intertendinous connections, which are located over the distal thirds of the metacarpals. The sensory nerve branches and longitudinal veins must be protected.
3. Skin incision
Make a straight longitudinal skin incision in the interval between adjacent metacarpal bones, not directly over the extensor tendons. The incisions can be extended proximally and distally in an oblique direction.
Adjacent metacarpals can be approached with a single skin incision.
4. Retract extensor tendons
The extensor tendons are retracted together with the surrounding loose connective tissue. If necessary, the intertendinous connection can be divided
5. Detach interosseous muscles
Partially detach the dorsal interosseous muscles from the bone subperiosteally.
6. Pitfall: Avoid complete muscle detachment
Avoid complete muscle detachment and injury to the volar structures. Use short, blunt retractors (Langenbeck) rather than Hohmann levers.
7. Wound closure
Cover the implant with the periosteum, as far as possible; this helps to minimize contact between the extensor tendons and the implant. If an intertendinous connection has been cut, it should be repaired.