- Medial approach, MIO
Minimally invasive fixation of tibial fractures is preferably done through the medial approach, especially for distal fractures.
However, if the skin is injured, this may not be safe.
A satisfactorily contoured plate can be passed subcutaneously to fit the medial tibial surface relatively easily.
This approach does not affect the tibial blood supply, nor the attached muscles.
This subcutaneous approach leaves the periosteum intact.
Triangular shape of the tibia
The lateral and posterior surfaces of the tibia are covered by muscle. The anteromedial surface has only a thin layer of subcutaneous tissue and skin. This surface provides less blood supply to the underlying bone.
The lower leg has four compartments:
- Deep posterior
- Superficial posterior
The anterior compartment has three muscles and one main artery and nerve: Tibialis anterior, extensor hallucis longus, extensor digitorum longus; the anterior tibial artery and deep peroneal nerve.
The lateral compartment has two muscles and one nerve. The muscles are the peroneus longus and brevis and the superficial peroneal nerve.
The deep posterior compartment has three muscles and two arteries and one nerve: The muscles are the tibialis posterior, the flexor hallucis longus and the flexor digitorum longus. It also has the peroneal artery and the posterior tibial artery as well as the tibial nerve.
The superficial posterior compartment has just two muscles in it: The gastrocnemis and soleus muscles and the sural nerve.
Make separate proximal and distal skin incisions, approximately 5 cm long, on the medial surface of the tibia.
The incisions span a length equal to that of the planned plate.
Distally, two options are possible:
- a straight incision or
- a slightly oblique incision.
The oblique incision may increase the risk of injury to the saphenous nerve and vein, which should be identified and protected.
The straight incision is more direct, but leaves an incision right over the plate.
The oblique incision does not lie directly over the plate, but allows its insertion, while reducing the risk of wound healing complications.
Deepen the dissection to the periosteum, which is left intact.
Remember to identify and protect the great saphenous vein and nerve in the distal incision.
A large distractor helps to reduce and stabilize the fracture. Use a soft-tissue elevator, or an appropriate plate, to prepare a tunnel under the subcutaneous tissues and over the periosteum.