- Discussion:
- soleus is a bipiniform (double feather) shaped muscle;
- its width encompasses the posterior two thirds of the calf;
- it originates from the upper one third of the dorsum & medial surface of the fibula and mid-posterior tibia;
- it inserts into the achilles tendon over a 5 cm area just anterior and distal to the insertion of the Gastrocnemius muscle;
- soleus muscle, when freed from its insertion on achilles tendon and based proximally, covers defects into the mid tibia;
- because its most distal portion is narrow the coverage is smaller than one would like;
- it has become flap of choice for middle, & some distal, tibial defects;
- little function deficit occurs when hemi-soleous flap is raised;
- blood supply can be unreliable, especially w/ tibial fractures;
- soleus may be split into two independent segments, a maneuver that allows one hemisoleus muscle to be used as a flap and the other to be retained in situ for donor motor preservation;
- this muscle may also be reversed on a distal blood supply to cover ankle defects, however, this may not be reliable;
- Contra-indications:
- crushing tibial injury which disrupts blood supply to soleus;
- Flap Harvest:
- skin incision proceeds from the medial aspect of tibial plateau to a point above the medial malleolus;
- excise any small skin bridges that might be created;
- dissection should begin at the midpoint of the flap, where the soleus is is easily separated from the more superficial gastrocnemius;
- subsequent separation of the deep surface of the soleus from FDL is easily performed;
- w/ a medial hemi-soleus flap, split the soleus longitudinally just lateral to the midline, to ensure that the intermuscular artery is not transected;
- the posterior neurovascular bundle is identified;
- the superficial and deep surfaces are cleared of soft tissue attachments;
- ligation of distal perforators:
- for a proximally based soleus flap, distal perforators from posterior tibial artery are ligated and divided until the muscle can be transposed to cover the defect;
- following ligation of the distal perforators, it is important to look for distal flap necrosis;
- the distal muscle is relased from the Achilles, but a small portion of tendon should be left attached to the muscle