Dorsal approach to the fifth carpo-metacarpal joint
This approach is used for intraarticular fractures of the fifth metacarpal base, fracture dislocations of the fifth carpo-metacarpal joint, and for tendon avulsion fractures of the extensor carpi ulnaris. This approach can also be used for the rare displaced extraarticular fractures of the fifth metacarpal base.
2. Surgical anatomy
The extensor tendons of the little finger converge slightly towards the center of the wrist joint. The dorsal sensory branch of the ulnar nerve and longitudinal veins must be protected. The insertion of the extensor carpi ulnaris tendon is onto the ulnar side of the fifth metacarpal base.
3. Skin incision
A curved skin incision is used, running parallel to the fifth metacarpal on the dorso-ulnar margin and curving radially over the hamate bone.
4. Retract extensor tendons
The extensor tendons are retracted radially together with the surrounding loose connective tissue. The dorsal sensory branch of the ulnar nerve is retracted to the ulnar side, possibly together with the extensor carpi ulnaris tendon.
A capsulotomy is made in cases of intraarticular fractures. In many cases there is already a tear in the capsule which can be extended.
6. Pearl: Mark the joint with a hypodermic needle
If a capsulotomy is not needed, mark the position of the joint with a hypodermic needle or a small K-wire in order to prevent inadvertent damage to the joint with screws.