Review Question - QID 147

"Dog ears" at the edge of a long posterior flap BKA incision are typically left intact because removal risks posterior flap blood supply.

Gray et al conducted an anatomic study to examine the BKA vascular anatomy and specifically the blood supply contribution of the soleus muscle. In their article, they describe the saphenous and sural arteries as being the main blood supply to the proximal posterior aspect of the calf. These arteries lie on the medial and lateral border of a long posterior flap, and can be at risk for transection when excising "dog ears". These arteries are particularly important in patients with severe vascular disease, as the popliteal artery and its immediate branches may be occluded, while the collateral smaller vessels (ie. saphenous and sural arteries) remain patent. Of note, the authors did conclude that the soleus muscle does not contribute blood supply to a long posterior flap, and it should be entirely excised.

Faltie-Jensen et al compared the rate of complications with long posterior flaps vs. equal sagittal flaps in diabetic and non-diabetic patients. They found that in diabetic patients, there was a higher incidence of infection and failure of wound healing in patients with the long posterior flap.

Manoli argues against the use of equal coronal flap, "fish mouth" incisions for below the knee amputations in patients with diabetes and peripheral vascular disease because of the increased risk of anterior flap necrosis.