Review Question - QID 214078

An uncontrolled diabetic (Hb A1C > 8) with a persistent non-healing forefoot ulcer is most likely to fail a primary transmetatarsal amputation and require revision amputation to a higher level.

Diabetic foot ulcers are responsible for approximately 85% of lower extremity amputations. The pathophysiology is related to the lack of protective sensation and to a lesser degree the decreased blood flow. Healing of diabetic ulcers is improved with serum albumin > 3.0, total lymphocyte count 1,500/mm3, transcutaneous oxygen pressure > 30mmHg, and ABIs > 0.45. Initial treatment consists of shoe modifications, local wound care, and total contact casting. Operative treatment can include surgical debridement, ostectomy, gastrocnemius/Achilles lengthening, and finally amputation. Determining the amputation level is multifactorial and takes into consideration the patient's overall health, wound status, personal feelings, and surgeon's recommendations/experience.

Wukich et al. prospectively compared surgical site infections among 4 groups: non-diabetics with and without neuropathy and diabetics with and without complications. The authors found that diabetics with complications had a 7.25-fold increased risk of infection as compared to non-diabetic patients without neuropathy and a 3.72-fold increased risk of infection as compared to diabetics without complications. Non-diabetics with neuropathy additionally had a 4.72 increased risk of infection, but this was not different than uncomplicated diabetic patients. They concluded that complicated diabetes and the presence of neuropathy both significantly increase the risk of surgical site infection.

Younger et al. compared 21 patients who had a failed transmetatarsal amputation within the first year to 21 patients who had undergone successful transmetatarsal amputations. The authors found that HbA1c followed by the need for a debridement were the most significant variables in predicting success. They concluded that the quality of blood glucose control is the primary factor in the success of a transmetatarsal amputation.

Incorrect Answer:
Answer 1: A long transtibial amputation has not been associated with an increased risk of failure or revision based on this patient presentation.
Answer 2: A short transtibial amputation has not been associated with an increased risk of failure or revision based on this patient presentation.
Answer 4: A transfemoral amputation has not been associated with an increased risk of failure or revision based on this patient presentation.
Answer 5: A Syme amputation has not been associated with an increased risk of failure or revision based on this patient presentation. The requirements of a Syme amputation are a patent posterior tibial artery and a stable heel bad.