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TRANSCRIPT
Diabetic Foot and Ankle Disorders
William P. Grant, DPMInstructor Department of
Surgery EVMS
April 1, 2011
Podiatry fhe Primary Physician
DIABETES PREVALENCE
• In the United States total 15.7 million or 5.9% of the population
• Diabetes is the 6th leading cause of death in the US
• 15% of diabetics will experience a foot ulcer.
• 14 to 24% diabetics with foot ulcer will require an amputation
• More than 50% of all non-traumatic below knee amputation occur in diabetics
• 86,000 BKA amputations are performed a year
COMPLICATIONS OF DIABETES
• Heart disease, CVA, PVD,CAD: diabetics are at a risk 2-4 times higher than non-diabetics.
• Kidney Disease: diabetes is the leading cause of new cases of end-stage renal disease (40% of new cases)
• Blindness: 12,000-24,000 people lose their sight due to diabetes each year
• Peripheral Neuropathy: 60-70% of diabetics have mild to severe forms of nerve damage
Contralateral amputation in 3-5 years (51%)Institutionalization (25%)Early death – within 3 years
Complications Following First Amputations
Leading cause of hospitalization for diabetic admissions59.6 hospitalizations per 10,000 patients per yearUp to 25% of all diabetic admissions in U.S. and Britain
Foot Complications and Hospitalizations
Poor glycemic control
- HgA1C > 7
Duration of diabetes > 10 years
Male gender
Impaired visual acuity
Loss of protective sensation (neuropathy)
History of ulceration/amputation
Increased plantar pressure
Peripheral Vascular Disease
Risk Factors for Foot Ulceration
Dyshydrosisanhydrosis
Abnormal Wound Healing
- TCPO2
- Bacterial Load
- Malnutrition
- Immune Function
Other Contributing Factors
Shear Stress
Static Deformity
Claw Toes
Soft tissue
contracture
Gait abnormality
Abnormal Mechanical Environment
Overuse
Brand, Jhass; 1991 :
“repetitive stress applied to sensate rat fore paw led to blistering in one week and ulceration in 10 days”
Abnormal Mechanical Environment
Vascular Exam
•Pedal Pulses
•Venous Filling time
•Elevation / Dependency
•Temperature / digital Hair
•CFT / ABI
•Doppler Ultrasound
Pedal Pulses
Pedal Systolic Pressure
Arm Systolic Pressure
= ABI
Ankle / Brachial Index
≥ .9* No Arterial Occlusion.6 – .8 Intermittent Claudication
.4 – .6 Associated With Rest Pain
< .4 Severe Ischemia AssociatedWith Ulcers and Gangrene
* ABI > 1 may indicate calcified vessel disease which is non-compressible and may falsely elevate the ABI
The Biomedix internet PVL
Neurological Exam
•Sharp vs. Dull
•Filament Test
•Vibratory Sensation
•Muscle Strength / Reflexes
Wagner Classification
Grade 0: Pre-ulcerative
Grade 1: Superficial Ulcer
Grade 2: Full-thickness Ulcer
Grade 3: Abscess/Osteomyelitis
Grade 4: Gangrene Toes/Forefoot
Grade 5: Gangrene Whole Foot
1 → 2 1 → 0
Grade 3 Deep Abscess or Osteomyelitis
Grade 3Deep Abscess in Osteomyelitis
•Appearance
•Exudate
•General Health
•Radiographs
•Laboratory Test
•CBC•Sed Rate•CRP•Deep
Cultures•Bone Biopsy
Grade 4Gangrene of the Toes or Forefoot
Grade 5
• Physics of abnormal foot structure during gait with diabetic neuropathy results in 60% of diabetic foot ulcerations
Biomechanics and Diabetes
Normal anatomy provides stable digits and metatarsal heads against Reactive ground forces during gait
• Loss of Stability by Interossei and LumbricaleIntrinsic Muscles of the Foot Results in:A. Overpowering by the flexor tendons during push off with clawing of the toesB. Resultant contracture at the metatarsophalangealjoints displacing the metatarsal heads downward
The Intrinsic Minus Foot
• Digital ulcerations• Ulceration beneath the ball of the foot• Cavus deformity (high in-step)• The etiology is the intersection of neuropathy and
abnormal structure
Intrinsic Minus Foot
Abnormal Structure Results In Abnormal Pressure on the Foot
Trans Metatarsal Stump Ulcer frequently an indication for BKA
Stump ulceration Ulceration resolved with TAL
• Inability to dorsiflex the foot above 0o
•Compensation usually occurs by pronation at midtarsal joint
•Leads to pes planus foot type
•Abduction of forefoot
•Eversion of STJ
•Unlocking of MTJ
Equinus
•In neuropathic diabetics, AGEs may produce an equinus deformity of the foot and ankle whose compensation is markedly more severe than pronation
•1. Diabetic forefoot ulcerations
•2. Distal stump ulcers
•3. Neuropathic joint disease
Equinus con’t
Achilles tendon lengthening rebalances the imbalance
Achilles tendon isolated for Z-plasty lengthening
Before & After Tendo Achilles Lengthening
Forefoot ulceration Forefoot ulceration resolved with TAL
Charcot Neuroarthropathy
Seen with increasing frequency in diabetic neuropathsFrequently recommended for BKA
•Etiology still obscure (vascular and microtrauma explanations)
Alternative Explanations of Charcot Foot
• Advanced Glycation End-Products: with sustained high glucose concentration a chemical reaction occurs between free amino groups of structural proteins and glucose (AGEs)
• Biomechanical: AGEs may affect the structural integrity of ligaments and the function of tendons resulting in failure of foot integrity
Midfoot stability relies on ligaments which stabilize the joints from reactive gravity and achilles tendon pull
In Charcot, Tendons are contracted, ligaments are weakened, eventually, the foot collapses
In Charcot, Tendons are contracted, ligaments are weakened, eventually, the foot collapses
Achilles Tendon Pathology
•Changes in ultra-structure of Achilles Tendon in control vs. Charcot patients
•Only seen in electron microscopy
•“Electron Microscopic Investigation of the Effects of Diabetes Mellitus on the Achilles Tendon”
» WP Grant, et al, J. Foot &Ankle Surg., Vol. 36 No.4
• Aligned parallel collagen fibrils
• No extensive foci of fibrillar disruption
Normal Tendon vs Charcot Achilles Tendon
• Disruption of Collagen Fibrils
• Irregular appearance compared to normal tendon
• Evidence of Glycation of tendon
Approach to Charcot Disease
• 1. Indications for surgery– Infection including osteomyelitis– Non-healing ulcers– Pain– Walking intolerance– Instability– Progression of disease– Persistent and unremitting edema– Alternative to below knee amputation
Our Systematic Surgical Approach Based on 4 Principals to Charcot Reconstruction
• Foot reconstruction including:1. Tendon Achilles lengthening2. Internal Fixation (beaming) for stability3. Midfoot/hindoot realignment fusion using
autologous Growth FactorsFusion site selected by unstable level of anatomic deformity Goal is normal anatomic alignment
Meary’s angleCalcaneal inclination angle
4. Application of External Fixation for compression
Achilles Z-Plasty
Structural realignment of complex deformity
K-wire osteotomy guides
Lateral Column Beaming
Beaming the Medial Column
External Fixation
6 months post op
Planter grade foot
Fits standard footgear
Report Of 50 Consecutive Charcot Diabetic Salvage ProceduresJanuary 2000-may 2003
DISTRIBUTION OF PROCEDURESSOLID FUSIONS
14 Ankle/Tibiocalcaneal Fusion 43%
13 Triple Arthrodesis 85%
18 Midfoot (Midtarsal) 72%
5 Lisfranc’s 83%
TOTAL OF 50 CASES: utilizing this systematic approach
RESULTS: COMPLICATIONS:
36 Solid Fusion 72% 13 Pin Tract Infection 26%
Psedoarthrosis 9 Dehiscence 18%
8 Stable 12% 8 Osteo/MRSA 16%
1 Unstable 2% 1 DVT 4%
1 Not Know 4%
2 Amputation 4%
2 Frame in Place 4%
BONE STIMULATOR: TOTAL OF 37 CHARCOT CASES HAD BONE STIMULATOR
Results with Internal & External Fixation
Discussion
This retrospective study of our standardized protocol for reconstruction showed:
• Low rate of limb amputation
• Improved quality of life for those patients treated with surgical realignment
• In our study all patients surveyed expressed satisfaction and long term stable functional lower extremity.
• All but one maintained or regained ability to walk
• All patients able to use diabetic or standard shoe gear
• No complication of ulceration
Conclusion
Sometimes your only foot is a Charcot Reconstructed Foot
Thank you for your
attention!