Foot and Ankle cases 30

A 32-year-old, professional ballet dancer presents with right ankle pain. She reports that she has had several severe ankle sprains in the past but denies ankle instability. She localizes the pain to the anterior aspect of the ankle and reports that it is worse with deep knee bends and activities requiring ankle dorsiflexion. She complains of intermittent locking of her ankle as well. On physical examination there is tenderness to palpation over the anterior aspect of the ankle with ankle dorsiflexion of only 5 degrees compared to 15 degrees on the contralateral ankle. There is anterior ankle pain with passive ankle dorsiflexion. Radiographs and a CT scan were obtained (Figs. 5–59 and 5–60).

 

 

 

Figure 5–59 Lateral ankle radiograph depicting mild degenerative changes in the ankle with anterior tibial and talar osteophyte formation and a loose body posteriorly.

 

 

Figure 5–60 A, B: Sagittal and coronal CT scan images of ankle showing anterior tibial and talar osteophyte formation and multiple loose bodies.

 

After failure of nonoperative management, what is the best surgical treatment option for this patient?

1. Distraction arthroplasty

2. Ankle arthrodesis

3. Ankle arthroscopy with anterior decompression

4. Total ankle arthroplasty

 

Discussion

The correct answer is (C). Ankle arthroscopy with anterior decompression is a good treatment option for patients with symptoms of impingement and without global tibiotalar arthritis. The severity of osteoarthritic change is a better prognostic indicator for outcome after arthroscopic surgical treatment for anterior impingement than the size and location of spurs. Distraction arthroplasty is more appropriate for advanced ankle arthritis. Ankle arthrodesis is not a good option for this young ballet dancer with only mild degenerative changes. Total ankle arthroplasty is an alternative to arthrodesis in some patients with end-stage arthritis, but would not be a good choice in this individual.

What is the most common complication associated with ankle arthroscopy?

1. Deep peroneal nerve injury

2. Superficial peroneal nerve injury

3. Saphenous nerve injury

4. Tibialis anterior tendon injury

 

Discussion

The correct answer is (B). An injury to the dorsal intermediate cutaneous branch of

the superficial peroneal nerve is the most common complication following ankle arthroscopy. Injury to this nerve occurs at the anterolateral portal. The superficial peroneal nerve and the course of its branches can typically be visualized by flexing the fourth toe. Visualizing the course of the nerve prior to portal placement may help to protect the nerve from injury. The deep peroneal nerve is at risk from an anterocentral portal. The saphenous nerve and vein are at risk from an anteromedial portal. The tibialis anterior tendon is not commonly injured during ankle arthroscopy. Ferkel reports an overall complication rate during ankle arthroscopy of 9.0%, with neurologic complications in 4.4%. Most nerve complications are transient and resolve within 6 months.

Which one of the following is a contraindication to total ankle arthroplasty (TAA)?

1. Patient weight of 200 lb

2. Preoperative hindfoot valgus of 10 degrees

3. Massive talar avascular necrosis

4. Posttraumatic arthritis

 

Discussion

The correct answer is (C). Massive or unresectable osteonecrosis is a contraindication to TAA because there is not a stable platform on which to seat the talar component. In addition, peripheral vascular disease, severe osteoporosis, neuropathy, neuropathic joint disease, and history of infection are considered contraindications to TAA. The ideal candidate for TAA would have end-stage ankle arthritis, weigh less than 250 lb, be greater than 50 years old, have a moderate activity level, have no significant comorbidities, and have less than 20 degrees of varus or valgus hindfoot deformity with excellent bone stock. Posttraumatic arthritis is not a contraindication to TAA.

 

Objectives: Did you learn...?

 

Identify the risk of nerve injury with ankle arthroscopy?

 

Describe some of the indications and contraindications for total ankle arthroplasty?