This approach is indicated for ORIF of proximal and distal metaphyseal and epiphyseal fractures of the base of the metatarsals. It can also be used for diaphyseal osteotomies.
The approach can also be used for performing an interposition arthroplasty in cases of degenerative joint disease in the 4th and the 5th tarsometatarsal joints.
2. Preservation of the vitality of the soft tissues and of the bone
Especially wide, deep exposures should be avoided and the specific locations should be approached separately through specific incisions, in order to preserve the vascularity. Specifically in the foot, it is very important to protect and preserve the venous drainage.
The veins are superficial and should be preserved, especially those which run in the long axis of the metatarsus. The long tendons lie superficially, while the short tendons are deep. The best approach is in between the long and the short extensor tendons, staying lateral of the EDL. Branches of the deep peroneal nerve which divides to provide the superficial digital enervation must be identified and protected in this approach.
4. Approach to the second and third metatarsal
Make a longitudinal incision between the second and the third metatarsal extending it from the metatarso-phalangeal to the tarsometatarsal joint.
The approach to the dorsal aspect of the metatarsal is made in such a way as to protect the intermetatarsal nerves and the crossing superficial veins. Basically, the optimal approach goes in-between the long and the short extensor tendon of the corresponding ray.
For this approach no muscle must be incised. Eventually, the interosseous musculature might be detached locally.
5. Approach to the fourth metatarsal
Make a longitudinal incision along the dorsolateral aspect of the 4th metatarsal, from the head to the tarso-metatarsal joint.
At the proximal end of your incision identify the peroneus tertius which is going to its insertion at the base of the fifth metatarsal. Immediately medial to it is the long extensor to the little toe. The base of the fourth metatarsal is best reached by going lateral to the long extensor to the little toe. To go more distally on the fourth metatarsal go between the long extensor to the fourth and fifth toes.
Detach as required the musculature from the lateral aspect of the metatarsal. Protect the cutaneous branches of the sensory nerves going to the toes. They are the cutaneous branches of the sural nerve and of the deep peroneal nerve.
6. Multiple incisions
If all lesser metatarsals (2, 3, 4, and 5) are to be approached, we would advocate three incisions: one between the 2nd and 3rd, the second between the 3rd and 4th and the third between the 4th and 5th.
Pitfall: Multiple close parallel incisions compromise the vitality of the skin. Such an approach should be very carefully considered.