What The Evidence Reveals About Midfoot Ulcers In Patients With Diabetes
Given the long-term challenges with conservative care and high recurrence risk associated with diabetic midfoot ulcers, this author examines the literature on surgical procedures including the exostectomy and realignment arthrodesis.
Midfoot ulcerations represent a challenging endeavor for podiatric physicians. Midfoot ulcers are reportedly responsible for approximately 40 percent of lower extremity amputations due to their notorious difficulty in healing and their high rate of recurrence.1-3
The etiology of midfoot ulcerations in patients with diabetes is most commonly active or inactive midfoot Charcot deformity. When destruction centers on the tarsometatarsal joint, this is a Brodsky Type I Charcot deformity. The tarsometatarsal joint is the most common location of occurrence, comprising approximately 60 to 70 percent of Charcot foot deformities.4 Without prompt and accurate detection, and rapid immobilization of acute Charcot, subluxation and dislocation can quickly lead to fracture and destruction. This results in the loss of the osseous architecture of the foot and the classic “rocker bottom” foot deformity associated with Charcot.1
The skin and subcutaneous tissues in areas of the plantar foot that are typically non-weightbearing are not specialized for sustained weightbearing. Osseous prominences in these areas are now subject to increased pressure and shear strain.1 This leads to rapid callus formation and ulceration, which can quickly result in osteomyelitis given the close proximity of bone beneath the ulcer base. Treatments of these ulcerations range from conservative to surgical, depending on the duration of the wound and associated skin/soft tissue and bone infection.
Conservative measures typically consist of total contact casting until resolution of the ulceration. Casting should continue at least seven to 14 days beyond the date the ulceration has healed in order to allow for maturation of the newly epithelialized wound. The patient must then wear custom orthotics and custom shoe gear with or without adjunctive lower extremity bracing to minimize the potential for ulceration recurrence.
Pinzur reported on 147 patients with midfoot Charcot deformity to determine if successful treatment could occur with conservative measures alone.5 The author defined success as the patient having no ulcerations and the ability to remain ambulatory in over-the-counter shoe gear with custom inserts. The reasoning for this was that custom shoe gear takes a minimum of four weeks for production, leaving the patient without these protective devices for that duration. The follow-up time of the study was 12 months. The average patient age was 56.4 years.
Pinzur found that 87 patients (59.2 percent) treated in this manner did not require surgical intervention.5 However, physicians had to follow the patients on a routine basis to provide patient education and monitor for potential recurrent breakdown. Patient education should consist of explaining the need for diligence in maintaining a dedicated daily routine of below the knee hygiene, foot/nail/callus care and the use of orthotics/shoes/braces for each and every step inside and outside of the house. This can be a difficult endeavor for patients to maintain for a lifetime in order to minimize ulceration recurrence.6,7
Given the difficulty of long-term success with conservative treatment measures, podiatric surgeons have utilized surgical intervention targeted at the osseous prominences that can cause calluses and subsequent ulceration. The goal of surgery is to create a stable, plantigrade foot that is free from areas of plantar osseous prominence in order to minimize the potential for ulceration. Surgical treatment ranges from exostectomy and reconstruction to realignment arthrodesis of the foot.