the diabetic foot

The diabetic foot Mollie Donohoe and Zoe Boulton

07 Feb 2014

• Current situation - amputations

• Cases

• Assessment of diabetic foot

• The role of the podiatrist

Evolution and the diabetic foot

Increasing numbers

Fashion victims

Why need to improve diabetic foot care

• Diabetic foot disease accounts for more hospital bed days than all other diabetes complications.

• 100 people a week lose a lower limb because of diabetes in the UK.

• 1 in 20 people with diabetes will develop a foot ulcer in one year.

• 80% of people die within 5 years after amputation.

NHS Atlas of VariationAmputation in Type 2 Diabetes

Percentage of people in the National Diabetes Audit (NDA)

having major lower limb amputations five years prior to the end of the

audit period by PCT1 January 2009 to 31 March 2010

NHS Expenditure – Ulceration and Amputation in Diabetes

• In 2010-11 the NHS spent an estimated £639 million to £662 million a year on diabetic foot care

• Equivalent to £1 in in every £150 of total NHS spending

Primary, Com-munity, Outpa-tient Care and A

& E £307m. - £324m.

Inpatient Care - Ulceration £213m.

Amputation £119m. - £125m.

Why it is so important?

• 80% of people die within five years of having foot ulcers or amputations

• Cost to the NHS

80% 49% 20% 17%

Amputation / Foot Ulcer

ColonCancer

ProstateCancer

Breast Cancer

But …

... up to 80 per cent of amputations are potentially preventable

Targets - NICE

Structured education at time of diagnosis and on ongoing basis (A)

(A) Directly based on evidence from metanalysis of RCTs/at least one RCT

Impact of foot ulcers on quality of life

Health related quality of life (SF-6D) scores for people with diabetic foot ulcers and other long-term conditions, and for healthy people aged 75+ (Source: Jeffcoate et al. (2009), Brazier et al. (2004), Davison et al.(2009)) •Diabetic foot ulcer QOL rated lower than osteoarthritis, COPD, dialysis•SF-6D or EQ-5D are building blocks for QALY estimation

Old PCT boundaries

Devon PCT

Torbay PCT

Plymouth PCT

PCT major amputation rates – YHPHO 2012

1.6

1.01.8

England 1.0

1.3

NEW Devon CCG northern locality NEW Devon CCG

eastern locality

NEW Devon CCG western locality

South Devon and Torbay CCG

New CCG boundaries(also reflect catchment areas)

NEW = North East West

NEW CCG amputation ratesYHPHO 2012

1.6

England 0.9

Calculating rates per catchment area

CCGs are the “externally visible” unit of healthcare• YHPHO has calculated amputation rates by CCG• NEW Devon CCG includes catchment areas of 3 hospitals

Shane Coe obtained the required data• Information analyst for NHS Devon• Used YHPHO methodology• Calculated amputation rates by CCG and locality

New CCG boundaries(also reflect catchment areas)

1.41.3

2.0

1.2

Thanks to Shane Coe – NEW Devon CCG

1.2

England 0.9

Devon is an outlier…

…because it’s the biggest

Ethnicity• White – risk = 1.0• S Asian – risk = 0.25• Black – risk = 0.62

Age• 2% increase per year

Confounding factors?

We are 20 years ahead of the country

(Sidmouth 2075)

Confounding factors?

Holman, Diabetologia 2012; 55: 1919.

Amputation rates in diabetic and non-diabetic patients correlate strongly – r=0.43, p=0.0005

The South Western Region

• High rate of diabetic foot disease in South West

Legacy effect 50% older migrants

Older population25% >65

longer survival

Rural occupation

White 94.1%

Interpret all data with caution

Atlas of Variation is not a scientific document• Some implausible data• Inadequate adjustment for confounders• Health service “units” are not helpful• Successfully achieved headlines

There is lots of room to improve, and we need to• Pan-Devon problem – perhaps pan-SW• Improvements need to cross primary and secondary care

RCA of Major Amputations in Diabetic Patients Jan 2012-13

• 16 patients - 22 amputations• 6 patients had 2 amputations same leg

• 3 patients out of area– 2 Somerset with ESRF – 1 Torbay (patient choice)

• 5 patients under renal physicians: 4 on dialysis

• 2 patients diagnosed with diabetes when admitted

Problems identified so far

• Only 50% of patients known to Diabetic foot clinic

• 5/16 (31%) solely under vascular as inpatient (no involvement from diabetes team)

• 4/16 (25%) of amputees had ESRF

• 5/13 (38%) not referred to podiatry post amputation

• 2/16 (12%) frequent DNA

Problems identified so far

• 5/8 (62%) documented given education in foot clinic.

• 2/16 (13%) had previous care in another area – no record of prior podiatric care.

• 1/16 (6%) critical event was ulcer which developed when patient previous inpatient.

• 16/16 (100%) had no inpatient podiatric care

Inpatient foot care

The Touch Test

The Touch Test• Up to 15% of inpatients have diabetes mellitus at any one time (1)

• 33% had feet examined (14% RD&E).• Robust screening method

–Accurate–Simple–Acceptable–Cost effective•Touch test performs consistently and favourably compared with Monofilament.

(1) National Diabetes Inpatient Survey 2009

Testing for neuropathy• The Ipswich Touch Test (IpTT)

A simple and novel method to identify inpatients with diabetes at risk of foot ulceration Diabetes Care, 34, July 2011

n = 2653 hospitals18 examiners 4 physicians, 9 podiatrists, 5 medical students>2 of 6 insensate areas signifying at risk feet

IpTT MFSensitivity 76% 81%Specificity 90% 91%

Concordance IpTT v MF Very good (k=0.85, p<0.0001)Inter observer reproducibility Good (k=0.68, p<0.001)

Results

• Prevalence of neuropathy = GP:11.4% ,DM:16.6%

• Compared to MF as “gold standard”• IpTT : 88.9% sensitivity (PPV 94%)

: 99.28% specificity (NPV 98%)• Overall accuracy 98.1%• Concordance: excellent agreement between

IpTT + monofilament (k=0.9, p<0.001)• Inter operator reproducibility N= 27 IpTT Good (K=0.51, p=0.006) MF Less good (K=0.44, p=0.01)

MANAGEMENT OF PAINFUL NEUROPATHY

• Is the pain neuropathic?• What is the dominant unpleasant

symptom?• When are the symptoms worse?• Does the patient have important fears or

beliefs about the pain?• What are patient’s expectations?

Painful diabetic peripheral neuropathy

Amitriptyline (unlicensed)

Start at 10mg, titrate to max. tolerated over 8/52

GabapentinDay 1 300mg odDay 2 300mg bdDay 3 300mg tdsMax 1800mg daily

8/52 trial

Pregabalin75mg bd

Increase to150mg bd

over 3-7 days8/52 trial

Duloxetine60mg od

Max 60mg bd8/52 trial

Discuss/refer – options capsaicin, GTN, lignocaine patches

Start tramadol meantime

Sausage toe - Osteomyelitis

HISTORY

Mrs C: Age 22Type 1 DM of 20

years° Smoker° AlcoholPT shop assistant.C/O severe pain left foot 2/12

History stubbing toe left toe 3/12 ago

HbA1c 78, Chol 5.1, Creatinine 100, CRP 10, Urate 317

Mrs C

Left foot warmer than right

Monofilament 3/6

All peripheral pulses felt

Left foot medial protrusion of inner long arch

Differential diagnosis

?

Charcot /SprainInfection: osteomyelitis: CellulitisGoutDVT

One month later

Bones in foot

Mr A

• Type 1 diabetes (HBA1c 51 , creat 85 chol 4 ,proliferative retinopathy )

• Developed neuropathic fracture of talus and navicular + cuboid when playing squash 2010

• Treated with off loading but continued to exercise fluctuating temp difference

• 2012 : S/B orthopaedics – stop squash • 2013 : L mid foot fusion with bone grafting . 5*C difference

between feet • 2014 Recommenced cycling competitively

Mr D

• Type 1 DM

• CKD4

• Proliferative retinopathy

• Biphasic pulses

• Foot ulcer healed R 2nd met head.

• Hot foot

CHARCOT’S JOINT/NEUROARTHROPATHY

• Relatively painless progressive arthropathy of single or multiple joints, caused by an underlying neurological deficit.

• Simultaneous presence of bone and joint destruction, fragmentation and remodelling.

DEMOGRAPHICS

• 0.1 - 5% in patients with diabetic peripheral neuropathy.

• Age 20 - 70 + years (50 - 60 > common)• History of long-standing diabetes.• Bi-lateral in about 15%.

• Joints: tarso-metatarsal 60% (mid foot) metatarsophalangeal 20%

ankle 10%

Patterns of bone and joint destruction Sanders LJ, Frykberg RG: Diabetic Neuropathic osteoarthropathy; The Charcot foot: the high risk foot in diabetes mellitus, New York 1991, Churchill Livingstone

Radiographic Staging (Eichenholtz, 1966)

• I Developmental (acute) stage

• II Coalescence (quiescent) stage

• III Consolidation (resolution) stage

Eichenholtz Classification

• Stage I - Developmental (acute)

–Hyperemia due to autonomic neuropathy weakens bone and ligaments

–Diffuse swelling, joint laxity, subluxation, frank dislocation, fine periarticular fragmentation, debris formation

Radiographs

• Stage I


• Stage II - Coalescence (quiescent)–Absorption of osseous debris, fusion of

larger fragments–Dramatic sclerosis– Joints become less mobile and more stable–Aka the “hypertrophic”, or “subacute”

phase of Charcot

Radiographs

• Stage II


• Stage III - Consolidation (resolution)

–Osseous remodelling – for clinical purposes, stage I is regarded as

the acute phase, while stages II and III are regarded as the chronic or quiescent phase

Radiographs

• Stage III

PATHOPHYSIOLOGY• Initiating event: trivial injury/unnoticed

repetitive minor trauma minor or periarticular or major fracture.

• Susceptible feet: peripheral neuropathy loss of protective sensation.

: >Inflammatory cytokines (TNF-α): Autonomic neuropathy >blood flow with

osteopenia.: Increased osteoclastic activity bone

resorbtion.

An algorithm depicting a basic approach to the Charcot foot

Cycle of pathophysiology of Charcot osteoarthropathy

RANKL pathway in the pathophysiology of Charcot arthropathy

The Role of RANKL in Charcot neuroarthropathy

TREATMENT

• Non-weight bearing: rest

aircast

shoes• Bisphosphonates - PAMIDRONATE• Watch other foot

• Surgery - trimming of bony exostos - arthrodesis

Maggot Therapy

FEET FIRST

the diabetic foot

Health & Medicine