Prophylactic Foot Surgery In Patients With Diabetes: Is It Worth The Risk?
Lower extremity complications associated with diabetes present a special challenge to any physician contemplating surgical management. Prophylactic foot surgery can be described as a procedure to prevent ulceration or re-ulceration in patients with diabetes without significant vascular compromise. This concept is part of a larger classification system, which stratifies the risks associated with various types of foot surgery.1
Why and when would you consider prophylactic surgery? A history of previous ulceration and/or amputation is an important consideration when assessing a patient for prophylactic surgery.2 Patients with diabetes are clearly at a higher risk for non-traumatic lower extremity amputation if they exhibit peripheral neuropathy, structural deformity, vascular disease, ulceration and infection.3 Patients with peripheral neuropathy and structural deformity without critical limb ischemia may be candidates for prophylactic intervention.
The annual incidence of diabetic ulceration is between 5 and 7.5 percent when neuropathy is present.4 Peripheral neuropathy and mechanical stress play central roles in diabetic foot ulcerations. Components of distal symmetric polyneuropathy include sensory and motor neuropathy. Motor neuropathy may lead to bony deformities such as hammertoes with areas of high pressure. When combined with limited joint mobility, these areas can eventually become pre-ulcerative sites with the potential for skin breakdown. Patients are unable to detect any discomfort in these areas due to the loss of protective sensation. As a result, repetitive pressure leads to local ischemic necrosis.4,5
Although researchers have shown that therapeutic shoes can be effective in reducing the recurrence rates of ulcers in patients with diabetes, these rates can range from 28 percent at 12 months to 100 percent at 40 months.6,7 When attempts at conservative therapy fail, one should consider surgical intervention.
Pertinent Advice From Classification Systems On Diabetic Foot Surgery
Class I: Elective. This procedure alleviates pain or limitation of motion in people without a loss of protective sensation. There is a very low risk of a high-level amputation.
Class II: Prophylactic. This reduces the risk of ulceration or re-ulceration in a patient with a loss of protective sensation but without an open wound. There is a low risk of high-level amputation.
Class III: Curative. This procedure assists in healing an open wound and carries a moderate risk of a high-level amputation.
Class IV: Emergent. This procedure limits the progression of an acute infection and carries a high risk of high-level amputation.
Armstrong, et al., also published a treatment-based classification system for the diabetic foot.2 (See “A Guide To Treatment Options For The Diabetic Foot” below) Within this classification system, physicians may consider prophylactic surgery for patients who have an insensate foot with deformity (category 2 patients) or those who have demonstrated pathology (category 3 patients). Both categories share the presence of sensory neuropathy, foot deformity and adequate vascular supply (ankle brachial index >0.80 and toe systolic pressure > 45 mmHg). However, category 3 patients have a previous history of ulceration and/or Charcot joint.
What The Literature Reveals About Prophylactic Surgery
Researchers have investigated various types of prophylactic surgery including digital arthroplasty, flexor tenotomy, tendo-Achilles lengthening (TAL), exostectomy and first metatarsophalangeal joint (MPJ) arthroplasty.8-13