Ulceration Risk in the Diabetic Foot
Two factors drive ulceration risk more than any others. Peripheral neuropathy. And vascular compromise.
Peripheral neuropathy removes the patient's ability to feel pressure, friction and temperature. A shoe that is too tight, a seam that rubs,
a stone in the footwear - none of these register as pain in a neuropathic foot. The wound develops silently. By the time it is found, it may already be serious.
Vascular status determines how well the foot heals once an ulcer develops. A patient with peripheral arterial disease is not just at higher risk of ulceration.
They are at higher risk of a wound that will not close. Vascular assessment should inform the management plan before any orthotic modification is prescribed.
Diabetic foot risk stratification matters. Not every diabetic patient carries the same risk. Orthotic decisions should match the individual patient's risk level.
Diabetic Foot Australia and Diabetes Australia guidelines provide validated frameworks for risk stratification. Apply them consistently in clinical practice.
Ulcers are graded using systems such as the Wagner classification or the University of Texas ulcer classification. Both grade depth,
infection and ischaemia. Knowing where a patient sits in these systems guides the urgency and nature of orthotic and footwear intervention.
Core Principles of Offloading in Orthotic Design
The central goal of offloading orthotics for diabetic patients is plantar pressure redistribution. Reduce peak pressure at vulnerable sites. Spread load more evenly across the plantar surface.
Total contact is the key principle. A total contact insole maintains contact with the entire plantar surface.
It spreads load across the largest possible area. This stops pressure concentrating at bony prominences, callus sites or areas of deformity.
Fit precision matters more in this population than almost anywhere else. An insole that does not fully
contact the plantar surface creates pressure differences. Those differences defeat the purpose of the modification.
This is where impression accuracy is critical. OG Scan's digital capture process removes the handling and transit variables
that affect plaster casting. For diabetic patients whose tissue cannot tolerate a poorly fitting device, that consistency is vital.
Common Orthotic Modifications for Active Ulceration
Accommodative cut-outs and offloading cavities - For a patient with an active plantar ulcer, the first priority is removing pressure from the ulcer site. A cavity cut into the insole beneath the ulcer offloads the area directly. Size it slightly larger than the wound margins. The surrounding material then takes the load that would otherwise concentrate at that site.
Material selection for cushioning versus shear reduction - These are not the same goal. Cushioning reduces impact force. Shear reduction minimises horizontal friction forces that break down skin at the surface. Viscoelastic materials such as Poron address both to a degree. For high-risk diabetic foot management, a layered construction works best. A firm base layer handles pressure redistribution. A compliant top layer handles shear reduction.
Adjustments for Charcot foot presentations - Charcot neuroarthropathy causes structural deformity. Rocker bottom deformity at the midfoot is common. This creates extreme pressure concentration at the apex of the deformity. Standard accommodative modifications are not enough for these presentations. A custom total contact insole with a deep accommodative shell, combined with rocker-sole footwear, is the standard approach for active Charcot foot management.
Case Scenario 1: Plantar Forefoot Ulcer Under a Metatarsal Head
This is an illustrative composite case based on typical clinical presentations. It does not represent a real patient.
A patient with a fifteen-year history of Type 2 diabetes and peripheral neuropathy presents with a Grade 1 plantar ulcer under the second metatarsal
head. In-shoe pressure mapping confirms peak pressure at the ulcer site during stance phase. The patient has been wearing standard depth diabetic footwear without a custom insole.
Assessment reveals a rigid plantarflexed second ray. This is driving elevated metatarsal head pressure. The modification approach includes a total contact insole with a cut-out cavity beneath the second metatarsal head. A met dome sits proximal to the metatarsal heads to offload the forefoot. A viscoelastic top cover handles shear reduction. The insole goes into medical-grade extra-depth diabetic footwear with a mild rocker sole. Review at two weeks confirms pressure redistribution. The wound begins to reduce in size.
Case Scenario 2: Charcot Foot with Midfoot Deformity
This is an illustrative composite case based on typical clinical presentations. It does not represent a real patient.
A patient with longstanding Type 1 diabetes, bilateral peripheral neuropathy and a resolved acute Charcot episode presents with rocker bottom deformity at the left midfoot.
No active ulcer. But a history of recurrent midfoot ulceration at the deformity apex. Risk stratification places this patient firmly in the high-risk category.
The modification approach uses a custom total contact insole with a deep accommodative shell moulded to the deformity. A firm EVA base layer handles pressure redistribution. A Poron top cover addresses shear reduction. Combined with Solewise custom footwear with a rocker sole
Integrating Orthotics with Footwear and the Care Team
A custom orthotic does not work in isolation. The footwear it goes into is part of the clinical prescription.
For high-risk diabetic feet, the shoe needs to fit the modified insole without creating new pressure points. It needs enough depth and width for both the insole and the foot.
A rocker sole for forefoot offloading is appropriate in many presentations.
Bamboo diabetic socks help with moisture management. They also reduce friction at the sock-skin interface. For patients with fragile plantar tissue, this is a small but useful addition.
Diabetic foot orthotics require coordination with the wider care team. Vascular, endocrinology and wound care input may all be needed. A well-designed orthotic
cannot fix uncontrolled glycaemia, significant ischaemia or an infected wound that needs surgery. Knowing when to refer - and doing it promptly - is as important as the orthotic design decision itself.
OG Scan's digital workflow supports this coordination. Precise scan data and order documentation can be shared with the multidisciplinary care team as part of the patient record.
Monitoring, Review and Escalation
High-risk diabetic patients need more frequent orthotic review than the general population. For patients with active ulceration, review every two to four weeks in the early management phase.
At each review, check the ulcer for signs of healing or deterioration. Check the insole for compression or wear at offloading sites. Ask about any new areas of discomfort.
Signs that a diabetic foot orthotic needs revision include new callus next to the offloading cavity, discomfort at a previously
comfortable site, visible compression of cushioning material at a pressure-sensitive area and any wound deterioration suggesting inadequate offloading.
Escalate when the wound is not responding within an expected timeframe. Escalate when vascular status suggests the wound cannot heal without further
intervention. A removable cast walker or total contact casting may be needed where orthotic offloading alone is not enough. HbA1c level and glycaemic control are relevant at
every review. Poor glycaemic control slows healing regardless of how well the orthotic is performing.