biomechanics of the diabetic foot: forces encountered · watermark exp diabesity res....

Georgetown University Hospital Department of Plastic Surgery

Biomechanics of the Diabetic Foot:

Forces Encountered

Paul J Kim, DPM, MS, FACFAS

Associate ProfessorGeorgetown University School of Medicine

Director of ResearchDivision of Wound Healing & Hyperbaric Medicine

Department of Plastic Surgery

MedStar Georgetown University Hospital

The Diabetic Foot Update

San Antonio, TX

December 4-6

Wate

rmark

Research & Consulting


• Nothing to disclose relevant to the lecture

• I am totally biased

Wate

rmark

Jack of All Trades


Podiatry OrthopedicsPlastics

Dermatology

Infectious

DiseaseVascular

Medicine

Neurology

“We are born with two feet …and one is not a spare”-B. Kalman (Amputee)

Wate

rmark

Soft Tissue of the Diabetic Foot

Georgetown University Hospital Center for Wound Healing

• Is different

• “diabetes” “foot” “soft tissue” “changes”= 63

indexed publications

• “diabetes” “foot” “soft tissue” “differences”= 25

indexed publications

• “diabetes” “foot” “ulcer”= 7467

Wate

rmark

Achilles Tendon of the Diabetic Foot


• Less mobility demonstrated in joints in the hand and the feet

• Achilles tendon undergoes overall thickening with general structural disorganization

Grant WP, Sullivan R, Sonenshine DE, Adam M, Slusser JH, Carson KA, Vinik AI. Electron microscopic investigation of the effect of diabetes mellitus on the achilles tendon. J Foot Ankle Surg. 1997;36(4):272-278.

Mueller MJ, Diamond JE, Delitto A, Sinacore DR. Insensitivity, limited mobility, and plantar ulcers in patients with diabetes mellitus. Phys Ther. 1989;69(6):453-462.

Arkkila PET, Kantola IM, Viikari JSA. Limited joint mobility in type 1 diabetic patients: correlation to other diabetic

complications. J Int Med. 1994;236:215-223.

Frykberg RG, Lavery LA, Pham H, Harvey C, Harkless L, Veves A. Role of neuropathy and high foot pressures in

diabetic foot ulceration. Diab Care. 1998;21(10):1714-1719.

Wate

rmark



• Glycation induced collagen cross-linking is directly associated with the increased matrix stiffness

• The Achilles tendon of Charcot patients demonstrate decrease elasticity and a decrease tensile strength

Grant WP, Foreman EJ, Wilson AS, Jacobus DA, Kukla RM. Evaluation of young’s modulus in achilles tendons with diabetic neuroarthopathy. JAPMA;95(3):242-246.

Reddy GK. Cross-linking in collagen by nonenzymatic glycation increases the matrix stiffness in rabbit achilles tendon.

Exp Diabesity Res. 2004;5(2):143-53.Wate

rmark



• Chbinou et al (2004)

– Examined the wound healing potential of the Achilles tendon in the diabetic rat model vs. control after an acute trauma

Chbinou N, Frenette J. Insulin-dependent diabetes impairs the inflammatory response and delays

angiogenesis following achilles tendon injury. Am J Physiol Regul Integr Comp Physiol.

2004;286(5):R953-7.

Impaired inflammatory response and

angiogenesis in the diabetic rat Achilles tendon

Wate

rmark

FORCES


Wate

rmark

Forces

• The geometry of the diabetic foot wound

tells you what forces are at work

• 2 types of forces

– Sagittal force

– Shear force

• Transverse

• Frontal


Wate

rmark

Forces

• Sagittal plane (Peak Plantar Forces)

– Between the foot and the shoe/ground

– Easier to measure

• Transverse/Frontal plane (Shear Forces)

– Between the underlying structures (bone) and the

plantar soft tissue structures

– Between the plantar soft tissue structures and the

shoe/ground

– Harder to measure


Wate

rmark

Forces


Wate

rmark

Sagittal Forces


Wate

rmark

Sagittal Plane Forces

• Restricted ankle joint

motion(equinus)

contributes to the

development and

chronicity of diabetic foot

ulcers by increasing

plantar pressures


Armstrong DG, Lavery LA. Elevated peak plantar pressures in patients who have charcot arthropathy. JBJS 1998.

Wate

rmark

Sagittal Plane Force


• Wound Shape

– Circular

• Cause– Bony deformity

– Tendon Overpowering

Wate

rmark

Peak Plantar Pressures- DM


Lavery LA, Armstrong DG, Boulton AJM. Ankle equinus deformity and its relationship to high plantar pressure in a large

population with diabetes mellitus. JAPMA. October 2002;92(9):479-482.

Boulton AJM, Hardisty CA, Betts RP, Franks CI, Worth RC, Ward JD, Duckworth T. Dynamic foot pressure and other

studies as diagnostic and management aid in diabetic neuropathy. Diab Care.1983;6(1):26-33.

Orendurff MS, Rohr ES, Sangeorzan BJ, Weaver K, Czerniecki JM. An equinus deformity of the ankle accounts for only a

small amount of the increased forefoot plantar pressure in patients with diabetes. J Bone Joint Surg.

2006;88B(1):65-68.

Right Foot: No UlcerLeft Foot: Ulcer

Wate

rmark

Lack of Consensus for Sagittal Plane

Measurement• Jonson SR, Gross MT: Intrexaminer reliability, interexaminer reliability, and mean values for nine lower

extremity skeletal measures in healthy naval midshipmen. J of Ortho Sports Phys Ther 25: 253, 1997.

• Clapper MP, Wolf SL: Comparison of the reliability of the orthoranger and the standard goniometer for assessing active lower extremity range of motion. Phys Ther 68: 214, 1988.

• Diamond JE, Mueller MJ, Delitto A: Reliability of a diabetic foot evaluation. Phys Ther 69: 797, 1989.

• Gheluwe BV, Kirby KA, Roosen P: Reliability and accuracy of biomechanical measurements of the lower extremities. JAPMA 92:317, 2002.

• Fosang AL, Galea MP, McCoy AT: Measures of muscle and joint performance in the lower limb of children with cerebral palsy. Dev Med Child Neuro 45: 664, 2003.

• Kilgour G, McNair P, Scott NS: Intrarater reliability of lower limb sagittal range-of-motion measures in children with spastic diplegia. Dev Med Child Neuro. 45: 391, 2003.

• Digiovanni CW, Holt S, Czerniecki J: Can the presence of equinus contracture be established by physical exam alone? J Rehab Res Dev 38: 355, 2001.

• Weaver K, Price R, Czerniecki J: Design and validation of an instrument package designed to increase the reliability of ankle range of motion measurements. J Rehab Res Dev 38: 471, 2001.

• Martin RL, McPoil TG: Reliability of ankle goniometric measurements: a literature review. JAPMA 95: 564, 2005.

• Elveru RA, Rothstein JM, Lamb RL: Goniometric reliability in a clinical setting. Phys Ther 68: 672, 1988.

• Pandya S, Florence JM, King WM, ET AL: Reliability of goniometric measurements in patients with Duchenne Muscular Dystrophy. Phys Ther 65: 1339, 1985.

• Youdas JW, Bogard CL, Suman VJ: Reliability of goniometric measurements and visual estimates of ankle joint active range of motion obtained in a clinical setting. Arch Phys Med Rehab 74: 1113, 1993.

• Wilson RW, Gieck JH, Gansneder BM: Reliability and responsiveness of disablement measures following acute ankle sprains among athletes. J Ortho Sports Phys Ther 27: 348, 1998.


Wate

rmark

Sagittal Plane Force


Wate

rmark


Circular

Wound Geometry

Wate

rmark

Peak Sagittal Pressures


Wate

rmark

Shear Forces


Wate

rmark

Shear Force


• Wound Shape

–Oval, Elliptical

• Cause

–Rubbing (classic blister)• Poorly fitting shoes

• Loose dressingsWate

rmark

Transverse Plane (Shear) Force


Wate

rmark

Frontal Plane (Shear) Force


Wate

rmark


Oval, Elliptical

Wound Geometry

Wate

rmark

Practical Assessment for Shear Forces


Wate

rmark

Shear Forces- DM PN


Lord M, Hosein R. A study of in-shoe plantar shear in patients with diabetic neuropathy. Clin Biomech. 2000;15(4):278-

83.

• 6 DM PN

patients

• Shear

measured

during

ambulation

• From 3.9-7.2

N/cm2 (highest

1st met head,

lowest 4th met

head)

Wate

rmark

Lack of Consensus for Shear

Measurement


• Perry JE, Hall JO, Davis BL. Simultaneous measurement of plantar and shear forces in diabetic individuals.

Gait and Posture. 2002;15(1):101-107.

• Lord M, Hosein R. A study of in-shoe plantar shear in patients with diabetic neuropathy. Clin Biomech.

2000;15(4):278-83.

• Akhlaghi F, Pepper MG. In-shoe biaxial shear force measurement the Kent shear system. Med Biol Eng

Comput. 1996;34(4):315-17.

• Wang WC, LeDoux WR, Sangeorzan BJ, Reinhall PG. A shear and plantar pressure based on fiber-optic

bend loss. J Rehab Res Dev. 2005;42(3):315-26.

• Tappan JW, Pollard J, Beckett EA. Method for measuring “shearing” forces on the sole of the foot. Clin Phys

Phsyiol Meas. 1980;1(1):83-85.

• Wang WC, LeDoux WR, Sangeorzan BJ, Reinhall PG. A shear and plantar pressure based on fiber-optic

bend loss. J Rehab Res Dev. 2005;42(3):315-26.

Wate

rmark

Sagittal & Shear Forces


Perry JE, Hall JO, Davis BL. Simultaneous measurment of plantar and shear forces in diabetic individuals. Gait and

Posture. 2002;15(1):101-107.

• 12 patients with DM and PN

• Sagittal and Shear measured during the initiation of gait

• Custom built transducer array

Wate

rmark

Conclusions

• The foot cannot tolerate excessive,

chronic stress

• Sagittal and shear forces play a

detrimental role

• Regardless of the treatment rendered,

unless you address the forces (sagittal,

shear) the wound will not heal or will recur

or relocate


Wate

rmark

biomechanics of the diabetic foot: forces encountered · watermark exp diabesity res....

Documents