Foot and Ankle cases 37

While on call, you receive a consult to see a 75-year-old male who had been admitted to the medical service with fevers, swelling, redness, and drainage from a forefoot ulcer. He has a history of diabetes for which he takes insulin, coronary artery disease status-post bypass grafting, and atrial fibrillation for which he takes coumadin. Upon examination, you observe the following (Fig. 5–77). You attempt to palpate pulses and are unable to palpate a dorsalis pedis or posterior tibial pulse. Ankle range of motion is tested and is noted to be from zero degrees dorsiflexion to 40 degrees of plantar flexion, with dorsiflexion increasing to 10 degrees when you flex his knee.

 

 

 

Figure 5–77 Photograph of plantar aspect of the foot.

 

You obtain an x-ray of the foot, which shows multiple insulin syringe needles in the

soft tissues (Fig. 5–78).

 

 

 

Figure 5–78 Plain radiograph showing multiple insulin syringe needles in the soft tissues.

 

In addition to the physical examination, the most appropriate additional studies include which of the following?

1. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, vascular studies

2. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, MRI

3. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, vascular studies, MRI

4. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count

 

Discussion

The correct answer is (A). Given the patient’s presentation, you should be concerned about a foot infection. Because of this, basic laboratory work that includes inflammatory markers and a WBC count is appropriate. While an MRI is a reasonable study to obtain in most situations, you may be concerned about an MRI in the setting of multiple metallic foreign bodies (insulin syringes) in his foot. For

this reason, an MRI should probably be deferred. Vascular studies should be obtained because of the lack of palpable pulses.

Noninvasive vascular studies are obtained and reveal infrapopliteal stenosis in the extremity with the ulceration.

Based upon the vascular studies, you recommend the following?

1. Below knee amputation

2. Consultation with a vascular surgeon

3. Transmetatarsal amputation

4. No further vascular intervention as his blood flow seems to be adequate

 

Discussion

The correct answer is (B). With absent pulses and abnormal vascular studies, it is appropriate to involve a vascular surgeon to determine the need for a revascularization procedure to accompany further treatment of the foot ulcer. While this patient may at some point come to require an amputation, obtaining further vascular input is appropriate before an amputation.

Based upon your clinical evaluation, you have a high concern that this patient has osteomyelitis of the forefoot associated with the plantar ulcer. You take him to the operating room for irrigation and debridement as well as a gastrocnemius recession.

The Silfverskiold test, performed during your initial evaluation of the patient, tests for which of the following?

1. Isolated soleus contracture

2. Foot drop

3. Achilles contracture

4. Isolated gastrocnemius contracture

 

Discussion

The correct answer is (D). The Silfverskiold test is done by measuring ankle dorsiflexion with the knee extended and then again with the knee flexed. The gastrocnemius muscle spans both the ankle and knee joints, and therefore examining ankle dorsiflexion while altering the flexion of the knee specifically measures the effect of the gastrocnemius muscle. If dorsiflexion improves with knee flexion, then a gastrocnemius contracture is present. Alternatively, if ankle dorsiflexion does not

improve, then a contracture of the tendo-Achilles is present.

 

Objectives: Did you learn...?

 

Discuss basic laboratories to be sent upon initial evaluation of a patient with a foot ulcer?

 

Describe the importance of evaluating and treating the vascular status, pressure overload, and infection in the setting of a foot ulcer?