Case 51: Neuropathic Ulcers and Osteomyelitis Benefited by Boot, Local Antibiotics and ? Cholinergic Agents

This 48 year old insulin-dependent diabetic stepped on a nail 1/28/90. Subsequently, he was treated unsuccessfully with oral antibiotics, hospitalized for three weeks for intravenous antibiotics and four incision and drainage procedures. He then remained home "off his feet" for the next six months receiving oral antibiotics and making weekly visits to his surgeon. The latter then recommended leg amputation because his feet would not heal. He came to Bryn Mawr for a second opinion.

On examination at Bryn Mawr, he was found to have diabetic retinopathy, atrophy of his thenar muscles, normal pedal pulses, absent vibratory sensation, diminished light touch sensation and two-point discrimination increased to 7 cm on both feet. He had two large plantar ulcers on his right foot with fistula penetrating into the depth of the foot.

Plantar Ulcers on Presentation

Coagulase-negative Staphylococci were grown from his lesions. His treatment program included (1) an initial cleansing Betadine-saline foot soak; (2) local gentamicin injections into his fistulous tracts and adjacent the demineralized areas of bone on his x-rays; (3) Mini-Boot therapy with his foot immersed in Sea Soaks containing gentamicin, Amphotericin and, later, metacholine; and (4) intravenous ceftazidime. His x-ray studies show recalcification of his involved bones.

His foot x-ray on presentation is seen on the left where the 2nd, 4th and 5th metatarsal heads and the proximal phalanges of the same toes are washed out. Recalcification of the bone is seen on the next two films with some ankylosis of the 5th toe on the right film.

The effects of injections with Sea Soaks, atropine and methacholine are shown below in the photoelectricplethysmography (PPG) tracings taken over the injection sites on his good foot.

The six inked lines on his skin mark the outline of the three PPG probe sites. Atropine was injected into the site on the left under the 1st MT head and had minimal effect. Sea Soaks was injected between the center two inked lines and again had little effect. Metacholine was injected into the site under the 4th metatarsal and caused significant vasodilatation.

His feet were close to healed after his limited hospitalization.

The soles of his feet are shown after his three-week hospitalization. He was then pumped intermittently as an outpatient. Unemployed and in need of cash, he was in part living off the major medical funds he was supposed to be forwarding to the office for his treatments. He was lost to follow-up. Phone follow-up three years later revealed that he still had his foot and was ambulatory, but had lost a toe.

Comments: This man is another example of the difficulty clinicians have in healing neuropathic ulcers and their complications. The ulcers are indolent and costly to society in their treatment and the lost time of the patient from his /her job. In this case, the ulcers left the man unemployed and destitute. The injection of metacholine caused a significant increase in local blood flow. This observation suggests that vasodilatation is possible in the neuropathic foot and that the decreased vascular response to injury seen in the dry denervated skin of the neuropathic foot may be due to the loss of the cholinergic postganglionic fibers that allow sweating. We now add a cholinergic agonist to our Mini-Boot baths in such patients in hopes of increasing flow in the nourishing vessels of the skin and increasing delivery of platelets, leukocytes and healing factors. See Dillon in our literature section. This man had come perhaps 500 miles to Bryn Mawr for his treatment. His success and medical costs would have been greatly reduced if he had the treatments close to home.