Foot and Ankle cases 12

A 22-year-old, police officer presents to your office with bilateral leg pain and foot numbness while partaking in group physical training. He states that as he has been increasing his activities, there is a progressive tight feeling in the front of his lower legs. He also reports that if he runs long enough his feet sound like they are slapping the ground. The only thing abnormal in the appearance of his leg is a bump which appears on the distal/lateral lower leg with exercise. He has been through a course of physical therapy without any improvements.

On physical examination this is a fit male in no distress. He walks with a normal gait and has a neutral alignment of his hindfoot. He is nontender across his anterior tibia. He demonstrates 5/5 strength throughout his bilateral lower extremities. There is a visible and palpable fascial herniation at the distal leg approximately 2 × 2 cm in size (Fig. 5–24). Radiographic evaluation demonstrates no stress fracture of the tibia, no masses, and no arthrosis at either the ankle or the knee.

 

 

 

Figure 5–24 Clinical Photograph of the leg demonstrating a fascial herniation.

 

Your next step in evaluation of this patient is:

1. Triple phase bone scan

2. Noncontrast MRI of bilateral tibia

3. Compartment pressure measurements

4. Vascular ultrasound

 

Discussion

The correct answer is (C). This patient presents with a history consistent with exertional compartment syndrome. A bone scan would be valuable for the evaluation of a stress fracture. An MRI would assist in the evaluation of either a stress fracture or tumor. Vascular ultrasound is valuable for the evaluation of DVT

or popliteal artery entrapment syndrome.

 

The patient obtains pressure measurements of his bilateral legs, which are as follows (mm Hg).

 

	Resting	Post Exercise (5 minutes)
Right anterior compartment	6	43
Right lateral compartment	10	35
Right superficial posterior compartment	11	17
Right deep posterior compartment	11	18
Left anterior compartment	7	47
Left lateral compartment	10	33
Left superficial posterior compartment	11	19
Left deep posterior compartment	12	15

 

The patient reports that during the compartment testing there was a burning, electric-like pain that shot down to the space between his great and second toes, and he has since had numbness in this region which is gradually improving.

What compartment was most likely being tested when the nerve injury occurred?

1. Anterior compartment

2. Lateral compartment

3. Superficial posterior compartment

4. Deep posterior compartment

 

Discussion

The correct answer is (A). The deep peroneal nerve innervates the first web space and is localized in the anterior compartment. The superficial peroneal nerve is located within the lateral compartment. The deep posterior compartment contains the tibial nerve, which provides sensory innervation to the plantar surface of the foot.

The patient’s dysesthesias resolve after approximately a week, and he is continuing to have symptoms and an inability to continue with his physical training program. He is now potentially going to be “booted out of the force” due to his inability to stay within physical fitness standards.

Your recommendation at this point is:

1. Continued observation and continued physical therapy

2. Night splints

3. Bilateral anterior and lateral compartment fasciotomy

4. Bilateral four compartment fasciotomy

 

Discussion

The correct answer is (C). This patient had elevated post exercise compartment pressures in the anterior and lateral compartments only. The diagnostic numbers for chronic exertional compartment syndrome are the same for both the upper and lower extremities. Pre exercise compartment pressures should be below 15 mm Hg, 1 minute post exercise they should be no higher than 30 mm Hg, and at 5 minutes post exercise they should be no higher than 20 mm Hg. There is no indication for deep and superficial posterior compartment releases in this patient. Night splints have been shown to be effective for many problems in the foot and ankle including plantar fasciitis and Achilles tendinosis but not for exertional compartment syndrome.

The patient undergoes an uneventful anterior and lateral compartment release on the left side and is extremely happy with the results. Approximately 6 weeks postoperatively he undergoes surgery on the right side. On the right side, at his first postoperative visit he reports an area of numbness on his foot.

Which nerve was most likely injured during this surgery?

1. Sural

2. Deep peroneal nerve

3. Tibial

4. Superficial peroneal nerve

 

Discussion

The correct answer is (D). During approach to the anterior and lateral compartments, the superficial peroneal nerve is often encountered. It exits the fascia of the lateral compartment approximately 12.5 cm proximal to the tip of the fibula, placing it at risk during distal release. The sural nerve lies posterior and heads laterally placing it at risk during Achilles repairs and lengthening of the tendo-Achilles complex. The deep peroneal nerve is at risk during anterior to posterior screw placement as well as during the anterior approach to the ankle. The tibial nerve lies in the deep posterior compartment.