Diabetic Foot

Diabetic Ankle Fracture

• Higher complication rates; significantly higher in-hospital mortality rate, in-hospital postoperative complication rate, length of stay, and rate of nonroutine discharges. Complications include impaired wound healing, infection, malunion, loss of reduction, hardware failure, nonunion, and Charcot arthropathy (Jones KB, JBJS 2005;87Br:489), (Chaudahary SB, JAAIS 2008;16:159).
• Pathology = microangiopathy, hyperglycemia, hypoxia and peripheral neuropathy leading to impaired soft-tissue and fracture healing.
• Transcutaneous oxygen pressure (tcPO2) > 30 mm of mercury (Hg) is generally required for the healing of diabetic surgical wounds.
• Doppler toe pressure measurements associated with adequate limb perfusion is 30 mm Hg.
• Semmes-Weinstein monofilament (SWM). The ability to feel a 4.17 Semmes-Weinstein monofilament implies normal protective sensation The inability to sense the 5.07 SWM (10 g) monofilament correlates with the presence or history of an ulcer and neuropathy.
• The most important factor in maintaining a proper milieu for wound healing in the patient with diabetes is physiologic blood glucose control
• Diabetic patients have a 187% increase in time to union. (Loder RT, CORR 1988;232:210).
• Treatment: prompt reduction and splinting to reduce soft-tissue trauma, followed by delayed surgery after resolution of edema and medical maximization. Consider external fixation to maintain reduction while the soft-tissues stabilize. External fixation may be definitive treatment if severe soft-tissue injury is present. Skin wrinkles at the surgical site indicates definitive fixation is appropriate. Supplementation to standard ankle fixation is commonly required.

Diabetic Foot

• synonyms: Diabetes, DM
• screening  for clinically significant peripheral sensory neuropathy is done with a 5.07 (10-g) Semmes-Weinstein monofilament. Klenerman L, McCabe C, Cogley D, et al: Screening for patients at risk of diabetic foot ulceration in a general diabetic outpatient clinic.  Diabet Med 1996;13:561-563.
• ischemic ulcer, should be worked-up with evaluation of the dorsalis pedis and tibial pulses, as well as transcutaneous oxygen tension on the dorsum of the foot.  Ankle-brachial indices are often unreliable in patients with diabetes due to vessel calcification.It is necessary to include toe pressures in the arterial evaluation.  Karanfilian RG, Lynch TG, Zirul VT, et al: The value of laser Doppler velocimetry and transcutaneous oxygen tension determination in predicting healing of ischemic forefoot ulcerations and amputations in diabetic and nondiabetic patients.  J Vasc Surg 1986;4:511-516.
• Katsamouris A, Brewster DC, Megerman J, et al: Transcutaneous oxygen tension in selection of amputation level.  Am J Surg 1984;147:510-517
• Treatment = total contact casting for Wagner grade 1 and 2 ulcers. 57% recurrence after total contact casting (Frigg A, Foot ankle Int 2007;28:64). Surgical correction of any underlying defromities should be performed after primary ulcer healing to prevent recurrence.

Grading of foot ulcers

• Grade 0- No open lesion
• Grade 1- superficial ulcer without penetration into deeper layers
• Grade 2- deeper ulcer reaches to tendon, bone or joint capsule
• Grade 3- deeper ulcer into tissues with associated abscess, osteomyelitis or tendonitis, usually associated with  extension along the midfoot compartments or tendon sheaths
• Grade 4- deep ulcer associated with gangrene of some portion of the toe(s) and/or forefoot, may be wet/dry, infected/noninfected
• Grade 5- gangrene involves the whole foot where amputation is recommended at below knee level, no local procedures are possible.  Up to Grade 4 local procedures may be possible to salvage foot.
• Treatment options: Orthotics, total contact casts, fractional lengthening of the heel cord (gastrocsoleus recession) as well as a peroneal longus to brevis tendon transfer to decrease forefoot pressures 

Indium-111 white blood cell scan is the study of choice for evaluation of osteomyelitis in the diabetic foot.  Johnson JE, Kennedy EJ, Shereff MJ, et al: Prospective study of bone, indium-111-labeled white blood cell, and gallium-67 scanning for the evaluation of osteomyelitis in the diabetic foot.  Foot Ankle Int 1996;17:10-16

Low-risk patients(sensate to Semmes-Weinstein 5.07mm monofilament, have palpable pulses, and no deformity): treated with safe footwear and foot care instructions. Consider pressure-dissipating insoles and soft leather shoes.

Moderate-risk (insensate to monofilament, deformity, non-palpable pulses): depth-inlay shoes and cosutom accommodative pressure-dissipating orthosis

Calcaneal ulcerations with osteomyelitis

• pts with ABI >.45, Transcutaneous P02 > 28mmHg, Albumin level > 3.0 and WBC > 1500. can be treated with parital calcanectomy. A total contact cast could be used in a pt with adequate blood flow, and no osteomyelitis. A transtibial (BKA) amputation would be the choice for a failed partial calcanectomy or in a patient who had an ABI < .45 and who wasn't a candidate for a revascularization procedure. Ref: Smith DG.: Partial Calcanectomy for the Treatment of Large Ulcerations of the Heel and Calcaneal Osteomyelitis. JBJS 74A: 571�576, 1992

Diabetic Neuropathy

• Most common cause of peripheral neuropathy.
• Clinical Evaluation: symmetric, stocking-glove sensory loss, pain and numbness with distal weakness.

Diabetic Amyotrophy

• Severe pain in hips and thighs, usually associated with pronounced thigh muscle wasting/weakness, decreased patellar reflex, weight loss. Generally older Type 2 diatetics with well controlled diabetes.
• Etiology: microvasculitis.
• Natural history: progressive severe pain, asymmetric thigh muscle wasting/weakness for weeks to months. May take several years to recover.
• DDX: malignancy, radiculopathy, cervical/lumbar stenosis.

Diabetes References

• Papa J, Myerson MS, Girard P: Salvage, with arthrodesis, in intractable diabetic neuropathic arthropathy of the foot and ankle.  J Bone Joint Surg 1993;75A:1056-1066.
• Stuart MJ, Morrey BF: Arthrodesis of the diabetic neuropathic ankle joint.  Clin Orthop 1990;253:209-211.
• Brodsky JW, Kourosh S, Stills M, et al: Objective evaluation of insert material for diabetic and athletic footwear.  Foot Ankle 1988;9:111-116.
• Laborde JM. Midfoot ulcers treated with gastrocnemius-soleus recession. Foot Ankle Int. 2009 Sep;30(9):842-6. 
• Laborde JM. Neuropathic plantar forefoot ulcers treated with tendon lengthenings. Foot Ankle Int. 2008 Apr;29(4):378-84.