Feet: Facts, Fallacies & FetishesThe role of podiatry Ms Bec Daebeler Manager, Podiatry Services Flinders Medical Centre August 2008
Facts, fallacies and fetishes • The High Risk Foot • Charcot Foot • What podiatrists can do… • Footcare IQ
Podiatry The scope of Podiatry as defined by the Australasian Podiatry Council - • “podiatry deals with the prevention, diagnosis, treatment and rehabilitation of medical and surgical conditions of the feet and lower limbs. The conditions podiatrists treat include those resulting from bone and joint disorders such as arthritis and soft-tissue and muscular pathologies, as well as neurological and circulatory disease.” Need to be registered to practice
What is the High Risk Foot? • Any foot with an increased risk of ulceration, infection and subsequent amputation. • So…who is at risk?
The High Risk Foot • Individuals who are at high risk of developing • Foot problems are those with either: • peripheral vascular disease • peripheral neuropathy • severefoot deformity • history of or a current foot wound. National Association of Diabetes Centres in partnership with the Australian Podiatry Association, 2000
What are the Statistics? • 3 year survival rate for anyone who has undergone a lower limb amputation is 50% • Over half of diabetic related amputations occur as a result of barefoot injuries • The attributable cost of for a 40 – 65 y.o male with a new foot ulcer was $27,987 (US) for 2 years after diagnosis Diabetes Care, Vol.22, no. 3, March 1999
What are the Statistics? • 15% of patients with Diabetes will develop a foot or leg ulcer • 50% of those with a foot or leg ulcer will have an amputation at some stage in their lifetime • People with Diabetes (3-4% of pop.) account for 50% of non-traumatic Lower Extremity Amputation. • Frykberg RG, The Team Approach to Diabetic Foot Management, Advances in Wound Care, 11(2); 71-7: 1998
Vascular status Neurological status Footwear Bio-mechanics Occupation/Activities Systemic disorders Medications Patient needs Patient Assessment
Peripheral Vascular Disease • Slows healing ability • Infections more likely to develop • Increases the chance of gangrene • Increases the risk of foot/amputation
Peripheral Vascular Disease • Increased risk of ulceration • Tissue ischaemia • Atrophic skin changes • Following Ulceration • Retards wound healing • Increases risk of infection • Increases risk of amputation Lavery et al (2000)
Peripheral Vascular Disease • Obtain patient history • Pain or cramping in calves/thighs may indicate intermittent claudication • May experience night pain in more advanced cases • Lipids • Smoking history • BSL’s • BP • exercise levels
Peripheral Vascular Disease Symptoms of: • “Burning” • Claudication • Rest pain
Risk Factors • Family Hx • Diabetes • Obesity • Diet • Exercise • Smoking
Macrovascular Disease Occlusive and often repairable • Atherosclerosis of arteries • Calcification of arteries • Input by Vascular Surgeon important • Always check pulses in the lower leg • Femoral • Popliteal • Posterior Tibial - Dorsalis Pedis
Microvascular Disease Not occlusive, basement membrane thickening, not repairable • Caused by changes in the structure of the arteries and blood cells • Plays a component in the development of peripheral neuropathy • Leads to poor O2 perfusion in tissues and delays healing of wounds • Worsened by smoking
Vascular Assessment • Pulse palpation • Posterior Tibial • Dorsalis Pedis • SVPFT • Colour, Warmth, Hair Growth • Doppler (ABI), Toe pressures, Duplex, Angiogram • Consider Referral to Vascular Surgeon
Clinical signs • Dystrophic nail and skin changes
Management Quit smoking Good BGL control Encourage walking/activity Refer to Vascular Surgeon Education
Smoking and Peripheral Vascular Disease (PVD) • Smoking is the number one risk factor for PVD and symptoms develop earlier in life • Over 80% of people with PVD affecting the lower limbs are smokers or ex-smokers • Smoking causes 40% of PVD in men and 34% of PVD in women in Australia
Smoking and PVD • For people who develop symptoms of PVD, quitting slows down the progress of the disease. Compared to smokers, people who quit have less severe pain when walking and are less likely to develop pain at rest. They live longer, respond better to treatment, and are less likely to require amputation.
Peripheral Neuropathy • Numerous causes (eg diabetes, alcoholism, Syphilis, Leprosy, renal failure, HIV, CMT, spina bifida, spinal cord injury, stroke and RA) • Diabetes is most common • Exclude • Malignancies • Toxic (alcohol) • Infections (HIV) Referral to Neurologist Jude & Boulton (1999)
Peripheral Neuropathy • Sensory Neuropathy • Autonomic Neuropathy • Motor Neuropathy
Diabetic Peripheral Neuropathy Paradox: • Patients with insensate feet who are asymptomatic may first present with foot ulcers • Patients with severe neuropathic pain who on examination may have only a minimal deficit
Diabetic Peripheral Neuropathy Two main types: 1. Acute sensory neuropathy 2. Chronic sensorimotor neuropathy
Acute sensory neuropathy • Characterised by severe sensory symptoms • Few if any clinical signs • Usually precipitated by episode glycaemic instability (ketoacidosis or institution of insulin) • Gradual improvement symptoms with establishment of stable glycaemic control (appropriate symptomatic treatment)
Chronic Sensorimotor neuropathy • Insidious onset • Up to 50% may be asymptomatic • 10-20% may experience painful symptoms • Often accompanied by autonomic dysfunction • Late sequelae: foot ulceration, Charcot neuroarthropathy • Prevalence increases age and duration of diabetes
Typical Neuropathic Symptoms PainfulNon painful Burning pain Asleep Knife like “Dead” Electrical sensations Numbness Squeezing sensations Tingling Constricting Prickling Hurting Freezing Throbbing Allodynia
Sensory Neuropathy • Loss of temperature, pain and pressure sensation • Increases chance of unnoticed foot injury • Burns (physical, chemical) • Cuts (accidental, self inflicted) • Pressure lesions (corn, callus, blisters) • Wounds may develop and progress to a lower extremity amputation
Loss of protective sensation (LOPS) • LOPS greatest risk factor for development of plantar ulcers • Peripheral sensory neuropathy primary factor in 60-90% of all diabetic foot ulcers • Daily foot inspections/examinations
Sensory neuropathy • ‘healthy’ but hazardous
Autonomic Neuropathy Loss of function of skin structures • Sweat glands • Skin tears • Atrophic skin changes Arterio-venous shunting • May lead to neuropathic osteoarthropathy (Charcot’s Foot) Loss of flare response Infection may not present clinically reduces visible erythema
Motor Neuropathy • Loss of intrinsic muscle function • Decreases foot stability • Muscle atrophy • Altered foot structure • Development bony prominences • Increased focal pressure areas • Increased risk of pressure wounds Lavery et al, (2000) • Loss of anterior muscle group function • Promotes development of foot deformity • Muscle atrophy
Motor Neuropathy • Toes curled up (claw like changes) • Metatarsal heads on the plantar surface prominent • Fat pads pushed upwards proximally (fullness noted at base of toes) • Absence of ankle and knee reflexes
Neurological Assessment • 10g Monofilament • Fine Touch • Vibration • Proprioception • Reflex • AJ • KJ • Hot/Cold • Subjective Hx.
Structural Changes - the forgotten factor! • Alter foot structure increased load sites foot type • flat/pronated feet callus • bunions, hammer toes diabetes related • motor neuropathy • Glycosylation (reduced or lost joint mobility) • increased loads + neuropathy = ulcers • simple, low tech measures can prevent
Severe foot deformity • Increases the chance of pressure lesions • Blisters • Callus • Corns • Usually associated with poor fitting footwear • May result in ulcers / amputation
Footwear Assessment • Length • Width • Stable heel counter • Sole flexes at ball of foot only • Appropriate for activity • Socks/hosiery • Wear them!
History of or a Current Foot Ulcer/Amputation • Increased chance of reoccurrence • Foot wound may progress to lower extremity amputation
Common problems following amputation • Callus • Contracted digits • Limited joint mobility • Foot deformity • Foot ulcers
Biomechanical impact • Peak plantar pressures are higher in patients with diabetes following partial foot amputation • Areas of high pressures implicated as one of the most important cofactors in ulceration of patients with diabetes
Biomechanical Impact • Causes of peak plantar pressures includes: • Foot deformity • Clawing of toes • Callus formation • Limited joint mobility • Lack of soft tissue cushioning • Charcot foot
Types of Amputation • Digital amputation • Ray Resections • Transmetatarsal amputation • Midfoot amputation • Lisfranc’s amputation – tarsometatarsal jt. line • Chopart’s amputation – midtarsal jt. line • Syme’s amputation – disarticulation of the ankle • Rearfoot amputation
Amputation Management • Foot care programs / education • Appropriate wound care • Padding • Orthoses • AFO • Shoes • Restoration of joint and muscle function • Liasing with orthopaedic / vascular specialties/Orthotists/Prosthetists
Charcot Foot • Neuropathic Osteoarthropathy (NOA) otherwise known as Charcot Foot • Characterized by: Pathologic fractures Joint dislocation • Deformity occurring in individuals with a neuropathic foot.
Risk factors • Neuropathy • Osteoporosis reduced bone density leads to reduced bone strength increasing chance of traumatic fracture • Elevated plantar pressures • Retinopathy reduced visual acuity may increase trauma to foot • Nephropathy • Recent history of trauma
Risk factors • Duration of diabetes for >10 years • Poorly controlled diabetes Progressive sensory, motor and autonomic neuropathy • Obesity elevated plantar pressures • Renal transplantation: immunosuppressive agents • Limited joint mobility: promotes increased plantar pressures and altered biomechanics • Rupture of the plantar fascia: loss of windlass mechanism to support longitudinal arch may reduce foot stability • Multiple amputations of the foot
Aetiology • Contemporary thought about the aetiology lies somewhere between the neuro-traumatic and neuro-vascular theories • Autonomic neuropathy may cause osteopenia by an increase in blood flow to the extremity • Sensory neuropathy makes the patients unaware of the abnormal stress on the joint caused by motor neuropathy • Abnormal stress can cause bone damage through osteoclastic activity and which can lead to fractures.
Pathomechanics - Charcot 1.A/V shunting => increase blood flow in arterioles 2.Increase in blood flow => de-mineralisation of bones 3.Demineralised bones more fragile 4.Un-noticed trauma with neuropathy leads to micro-fractures