Interventions for wounds on a high-risk foot

A foot wound in a patient with a high-risk foot can result in amputation so requires prompt management. Interventions for high-risk foot wounds include:

pressure redistribution (see Pressure redistribution strategies)
treating infection (see Ulcer and wound infection)
wound cleansing and debridement
management of ischaemia
use of appropriate wound dressings.

Ideally, patients with a high-risk foot wound are managed by a specialised multidisciplinary team (usually comprising of medical, surgical, podiatry, wound care, orthotic and footwear specialists). For patients in rural areas who may not have access to a specialist foot clinic, liaise with the closest clinic (telehealth review may be an option).

Interventions for high-risk foot wounds depend on the aetiology of the wound. Patients with a combination of peripheral neuropathy, peripheral arterial disease and foot deformity are at highest risk of amputation and require earlier and more comprehensive interventions.

Note: Consider pressure redistribution strategies when developing a management plan for foot wounds.

For foot wounds in patients with peripheral neuropathy, redistribution of pressure (pressure offloading) is essential for wound healing. Pressure redistribution must be considered when developing a management plan for any foot wound.

Basic pressure redistribution involves:

encouraging patients to rest
avoiding weight-bearing activities in the affected area
using offloading devices; see Pressure redistribution strategies.

Pressure offloading devices are specialised and need appropriately trained therapists (usually a podiatrist or orthotist) to fit them and advise on their use. Patients may incur a cost.

Peripheral neuropathy is frequently irreversible and progressive. Ensure regular review and educate about foot care and footwear (see Advice for patients about foot care and Advice for patients about footwear). Referral to a neurologist may be useful if the peripheral neuropathy is treatable. If the cause of neuropathy is diabetes, blood glucose control can limit progression.

If foot deformity is contributing to the development or chronicity of a wound, invasive interventions may also be required; see Invasive interventions for high-risk foot wounds.

When foot wounds have an ischaemic component (ie patients with peripheral arterial disease), refer to a vascular specialist for revascularisation—manage as for Arterial leg ulcers. Risk factor modification and ongoing monitoring is required; see Intermittent claudication.

Table 1. Pressure redistribution strategies
Nonremovable: total contact cast instant total contact cast (iTCC) Removable: Charcot restraint orthotic walker (CROW) removable cast walker soft boots or pressure relief shoes felt padding orthoses pressure-relieving ankle foot orthotic (PRAFO or MPO) medical grade footwear
total contact cast
Efficacy and features	very effective (gold standard)
Other considerations	time consuming to apply application requires expertise falls risk (especially in older, visually impaired or disabled patients) contraindicated in patients with peripheral arterial disease or infection requires replacement every 1 to 2 weeks expensive
instant total contact cast (iTCC) (a removable cast walker is made nonremovable using plaster or similar material)
Efficacy and features	outcomes likely similar to a total contact cast can have pop-out insole for pressure relief, orthoses or padding
Other considerations	minimal expertise required for application enables weight bearing falls risk (especially in older, visually impaired or disabled patients) caution with infected wounds due to limited ability to monitor progression of infection
Charcot restraint orthotic walker (CROW)
Efficacy and features	good pressure redistribution custom moulded for optimal redistribution allows for walking longer-term device (good for unstable Charcot or recalcitrant wounds)
Other considerations	patient can remove high one-off cost availability is limited by the requirement for expertise to fit and modify falls risk (especially in older, visually impaired or disabled patients)
removable cast walker

Efficacy and features	good pressure redistribution can have pop-out insole for pressure relief, orthoses or felt offloading
Other considerations	patient can remove initial cost and ongoing cost of liners requires some expertise to fit and modify for each patient limited sizes—caution in obesity or patients with wide feet (foot may not fit and device can break with excess weight) the height of the boot can cause uneven limb length (this can be overcome with an ‘even-up’ device on the opposite shoe)
soft boots or pressure relief shoes

Efficacy and features	not as effective at offloading as devices that immobilise the ankle lightweight easy for patients to walk in easy to apply and remove can have pop-out insole for pressure relief, orthoses or felt offloading
Other considerations	limited sizes need some training to fit correctly low cost wear out quickly poor compliance due to ease of removal
felt padding

Efficacy and features	inexpensive readily available can be applied to shoes and boots, or directly to the foot
Other considerations	requires clinician expertise risk of skin trauma with incorrect placement only for short-term use (after 3 days it loses efficacy) low cost
orthoses

Efficacy and features	good for preventing wound recurrence after healing
Other considerations	need expert fitting and regular monitoring because foot shape may change in patients with diabetes, gout or rheumatoid arthritis high cost (usually annual replacement needed) usually used in combination with extra depth and width footwear, or custom footwear—adds to cost needs expertise to manufacture appropriately wound needs to be completely healed before prescription and fitting of orthoses
pressure-relieving ankle foot orthotic (PRAFO or MPO)
Efficacy and features	removes pressure from the entire heel can be used in ambulant patients as well as bed-bound patients
Other considerations	limited sizes—may not fit large feet or feet with significant deformities increased risk of falls not always well tolerated by patients, especially if used bilaterally not effective for Achilles wounds (adds pressure to Achilles)
medical grade footwear
Efficacy and features	protective; aims to prevent trauma caused by footwear can accommodate offloading devices such as orthoses or felt padding accommodates most foot deformities
Other considerations	expensive poor aesthetic in cases of severe foot deformity, a custom-made shoe may be required

Table 2. Invasive interventions for high-risk foot wounds
Intervention (specialist)	Description	Rationale and considerations
surgical correction (orthopaedic specialist)	Achilles lengthening surgery tenotomy (tendon release)	shortening of the Achilles tendon occurs frequently due to motor neuropathy; lengthening can reduce forefoot pressures and reduce incidence of wounds tenotomy is used to correct musculoskeletal deformities that can lead to abnormal pressures in the foot patient needs adequate blood supply and to be suitable for surgery normally a lengthy period of non–weight bearing in a cast after surgery
surgical debridement (orthopaedic specialist or vascular surgeon)	aggressive debridement of devitalised tissue under anaesthesia incision and drainage of pus	patient needs to be suitable for surgery; generally performed under general anaesthesia in wounds with osteomyelitis, can produce bone fragments that delay wound healing
conservative sharp debridement (podiatrist or wound specialist)	effective for removal of nonviable tissue from wound callus removal using a scalpel low-frequency ultrasound debridement	reduces plantar pressure reduces bacterial burden caution in patients with peripheral arterial disease clinician should be experienced or competent in debridement cost effective reduces time to healing