Diabetic Foot Ulcers Recur Less With Custom-Made Orthoses

Custom-made in-shoe orthoses manufactured to incorporate both foot shape and barefoot plantar pressures may prevent foot-ulcer recurrence more effectively than do standard Medicare-reimbursed orthoses that are simply molded to a patient’s foot, a new study finds.

The research was published online April 23, 2014 in Diabetes Care by Jan Ulbrecht, MD, director of endocrinology and diabetes services, Mount Nittany Health System, State College, Pennsylvania, and colleagues.

In their 15-month randomized study of 150 patients with recently healed submetatarsal-head plantar ulcers, Dr. Ulbrecht and colleagues found a 3-fold reduction in ulcer recurrence among those who wore the specially made orthoses compared with those who received standard ones.

Dr. Ulbrecht told Medscape Medical News that results of previous trials of standard diabetic footwear have yielded variable results in terms of ulcer prevention; “often they failed to document that the shoes effectively offloaded pressure or to document adequate use or both.” But this new research illustrates that “if shoes adequately offload pressure and are used consistently, they reduce risk of ulceration,” he said.

He added that incorporating plantar pressure into current orthoses design is “very easy” and not expensive, although the cost would exceed existing Medicare reimbursement levels.

Currently, Medicare requires for reimbursement only that in-shoe orthoses be custom-molded to the shape of the patient’s foot and that materials of specific hardness/thickness be used.

“The incremental cost is not huge and, when contrasted with the cost of treating diabetic foot ulcers and amputations, we believe the economic modeling will demonstrate overall economic as well as, of course, patient benefits,” he said.

The researchers explain in their paper that a foot ulcer is a critical step in the causal pathway for most amputations in diabetes and such ulcers result in significant morbidity and cost even when they do not lead to an amputation. After an initial foot ulcer, the risk for reulceration is extraordinarily high, in some studies >80% after 3 years.

As approximately 40% of diabetic foot ulcers are located on the plantar surface related to metatarsal heads, where plantar pressure tends to be greatest, he and his colleagues hypothesized that therapeutic footwear designed to prevent plantar ulceration should maximally offload areas of high plantar pressure.

Their Care For Ulcer Prevention (CareFULPrevent) trial took place at 11 US outpatient diabetic-foot clinics. In the study, 150 patients with recently (within 4 months) healed plantar metatarsal-head–related foot ulcers were randomized to either standard in-shoe orthoses made by 1 of 3 recognized manufacturers or experimental orthoses. The latter were similar to the standard ones but with additional modification using computer-aided design according to defined algorithms based on the patient’s peak barefoot plantar-pressure distribution contours.

At the end of the study, 66 of the experimental orthoses patients and 64 controls were available for analysis. Part of the drop-off related to patients not receiving the shoes or receiving them too late, “reflecting the clinical reality where several weeks often elapse between footwear and orthoses being ordered and dispensed because of manufacturing and shipping times,” the authors write.

The primary end point was either an ulcer or nonulcerative lesion (hemorrhage into callus or persistent redness at a site of bony prominence) involving the plantar surface and associated with a metatarsal head. Overall, primary end points occurred in 37.9% of patients in the experimental arm and 45.3% of those in the control arm.

There was a trend toward a difference in the composite end point across the 15-month follow-up period (P = .13).

But when the 2 end points were analyzed separately, ulcer recurrence was highly significantly reduced in the experimental orthoses group compared with controls (P = .007), while no difference was seen in the rate of nonulcerative lesions (P = .76).

For the occurrence of ulcers, the hazard ratio was 3.4 for the control vs the experimental group.

Most of the benefit of the experimental orthoses was seen in the first few months. At 180 days, both the difference in ulcer rate and the composite end point were significant in favor of the experimental orthoses (P = .003 and P = .042, respectively).

It’s not entirely clear why there was no difference between the 2 groups in nonulcerative lesions, which are established risk factors for ulceration if left untreated. The authors suggest that “some anatomical locations that would develop nonulcerative lesions in control footwear may escape damage altogether in the experimental footwear. Furthermore, some locations that would ulcerate in the control condition may result in nonulcerative lesions in experimental footwear.”

Dr. Ulbrecht told Medscape Medical News that the exact cost for making orthoses of this type commercially available has not been established, but it is probably “in the low hundreds of dollars.” By contrast, Medicare reimbursement for orthoses for diabetic patients is less than $100. “At that price, providing this product is not viable.”

He said that he and his colleagues plan to make Medicare aware of their data.

In the meantime, he offered some advice for clinicians: “Only accept ‘diabetic shoes’ for your patients from providers who demonstrably care about outcomes and have the capacity to individualize footwear. ‘Diabetic shoes’ out of the box or worse — by mail — are really not useful.”

Diabetes Care. Published online April 23, 2014. Abstract