Am Fam Physician. 2009;80(12):1351-1356
Original Article: Diabetic Foot Infection
Issue Date: July 1, 2008
to the editor: This article is an excellent review of antibiotic treatment of foot infections. Dr. Bader correctly states that most diabetic foot infections develop because of a foot ulcer, and that decreasing pressure in the ulcer area is crucial to healing the ulcer and the infection. However, there are newer and more successful surgical treatments that were not mentioned in the article.
Tendon lengthening has been shown to decrease pressure in the forefoot, where most ulcers are located.1 One study examined ulcers that did not heal with use of a total contact cast and were treated with Achilles tendon lengthening (ATL); 93 percent healed and did not recur.2 Results of a randomized controlled study demonstrated that the healing rate after ATL combined with treatment in a total contact cast was higher than that associated with treatment with a total contact cast alone.3 The recurrence rate at two years after ulcer healing was 81 percent in patients treated with a total contact cast alone compared with 38 percent in those treated with a total contact cast and ATL. These two studies demonstrated the superiority of tendon lengthening over management with a total contact cast in terms of the rate of healing and especially the rate of recurrence of ulcers.2,3
Additional studies with longer follow-up demonstrated that treating forefoot ulcers with tendon lengthening without the use of a total contact cast results in a higher rate of healing, a lower complication rate, and a much lower recurrence rate compared with the results of treatment with a total contact cast alone.4,5
This literature indicates the superiority of tendon lengthening over other methods of decreasing pressure for the treatment of diabetic foot ulcers, and that tendon lengthening should be considered the best available treatment for diabetic forefoot ulcers.
in reply: I thank Dr. Laborde for his commentary on my article. Although detailed treatment and prevention options for patients with diabetic foot ulcers were not discussed in the article, several surgical and nonsurgical treatment strategies are available. Non-surgical treatment options include wound dressings, edema management, off-loading pressure, adequate nutrition, optimizing glycemic control, and smoking cessation. If nonsurgical options are ineffective, surgical treatment options include wound debridement, Achilles tendon lengthening (ATL) for forefoot plantar ulcers, and revascularization in patients with ischemia.1,2
True randomized clinical trials comparing surgical techniques for the treatment of diabetic foot ulcers are few and are difficult to perform. Despite variable degrees of success, the trials lack large sample size and long-term follow up and have uncontrolled confounding variables. Confounders in the only randomized trial of ATL were weight-bearing and the use of a walking boot.3 Although ATL has been shown to be successful in healing forefoot plantar ulcers, it is associated with initial reduction of active and passive plantar-flexor muscle performance, which could impair gait performance and physical functioning with increased perceived disability in diabetic patients with neuropathic plantar ulcer.4–6 The compromise in plantar-flexor muscle performance can be improved with exercise programs.
Other possible risks of ATL include over-lengthening of the Achilles tendon, a calcaneus gait with decreased push-off power, heel ulcer caused by increased heel pressure, deep surgical infections, and possible perioperative mortality.3 Consideration of the benefits and risks of ATL and response to other treatment options should be taken into consideration before performing this procedure. I disagree that ATL should be considered the standard treatment for diabetic forefoot ulcers; rather, ATL is one of several available treatment options when dressings and off-loading are not successful in healing diabetic ulcers.