Arthroscopy of the Foot and Ankle

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Chapter 50 Arthroscopy of the Foot and Ankle

Ankle Arthroscopy

The most common current indications for ankle arthroscopy include soft tissue or bony impingement and treatment of osteochondral lesions of the talus. These patients often have continuing ankle pain after injuries such as a sprain that have not responded to the usual conservative therapy, and tenderness is noted specifically at the ankle joint line on physical examination. A definite diagnosis should be made before arthroscopy is performed; purely diagnostic arthroscopy has a low success rate. If an MRI is not helpful with the diagnosis, a diagnostic intraarticular injection can be used. Significant relief from an intraarticular anesthetic suggests the presence of an intraarticular pathological process, for which ankle arthroscopy and débridement may be beneficial. Arthroscopy also has been used to treat ankle instability, septic arthritis, arthrofibrosis, and loose bodies.

Arthroscopic Examination and Débridement of the Ankle Joint

Technique 50-1

image For routine ankle arthroscopy, place the patient supine, with the operative extremity in a leg holder such that the hip and knee are flexed, with the foot hanging free, resulting in gravity-assisted distraction. This also allows free ankle range of motion, which can assist in access to different parts of the ankle (Fig. 50-1).

image Mark portal placement after establishing the path of the superficial peroneal nerve, which can be seen subcutaneously after plantar flexion and inversion of the foot (Fig. 50-2).

image Mark anterolateral and anteromedial portals at the joint line, which can be palpated, staying away from the peroneal nerve (Fig. 50-3).

image After Esmarch exsanguination of the extremity and inflation of the thigh tourniquet, establish the anteromedial portal by inserting an 18-gauge spinal needle at the marked site and insufflating the joint with saline to ensure intraarticular placement and to provide more space for introduction of the blunt trocar (Fig. 50-4). Successful insufflation occurs when there is minimal resistance to the introduction of saline, when the foot dorsiflexes as the joint capsule becomes tight, and when there is backflow of the saline into the syringe after the joint is maximally distended. The anteromedial portal is established first, because there are fewer structures at risk than with the anterolateral portal.

image After localization of the anteromedial portal with the spinal needle, make a skin incision just large enough to insert the cannula. A large incision allows more extravasation of fluid into the surrounding soft tissues and can make the procedure more difficult.

image Further penetrate the joint with a blunt straight hemostat to avoid damage to the saphenous nerve, which is at risk in this area.

image Place a 2.7-mm 30-degree arthroscope into the anteromedial portal, and establish the anterolateral portal by direct visualization of a spinal needle introduced at the site of the anticipated portal placement.

image When appropriate needle placement is seen, make the skin incision for the anterolateral portal and penetrate the joint with a blunt instrument (Fig. 50-5); then introduce the arthroscopic shaver in this portal.

image Inspect the lateral aspect of the joint with use of instruments in the anterolateral portal as needed for débridement (Fig. 50-6), and then switch portals (arthroscope in the anterolateral portal and instruments in the anteromedial portal) for treatment of the medial side of the joint (Fig. 50-7).

image Noninvasive distraction can be used if needed to access the deeper aspects of the joint (Fig. 50-8). Occasionally, a posterolateral portal is needed to treat pathological processes in the posterior aspect of the ankle that cannot be reached even after distraction is applied.

image After the procedure is completed, close the portals with suture to avoid the development of a fistula, which is a reported complication of ankle arthroscopy.

Ankle Impingement Syndromes

Anterior Ankle Impingement

Anterior ankle impingement can be caused by anterior tibial and talar osteophytes and by anterior soft tissue that becomes compressed with dorsiflexion of the ankle. Patients present with pain localized to the anterior aspect of the ankle and have tenderness at the joint line anteriorly. Lateral radiographs may not show the osteophytes; an anteromedial view of the ankle is often helpful. MRI can show osteophytes but is not very sensitive for soft tissue impingement; MR arthrography or contrast-enhanced, fat-suppressed, three-dimensional (3D), fast-gradient recalled acquisition in the steady state with radiofrequency spoiling (CE 3D-FSPGR) MRI is more sensitive and specific but is less practical. Careful physical examination and diagnostic injection can help to pinpoint the diagnosis. The use of intraarticular injections has been questioned because of the potential cytotoxicity to chondrocytes; however, these are all in vitro studies and there are no studies substantiating the effects in the clinical setting.

If symptoms persist despite activity modification and immobilization, arthroscopic débridement can be helpful in alleviating symptoms. Reported success rates for this procedure range from 73% to 96% in level II studies. Patients with a poorer prognosis include those without a clear diagnosis and those with higher grades of arthritic changes of the ankle. Osteophytes may recur but usually are not symptomatic. There currently is a grade B recommendation (fair evidence) to support use of ankle arthroscopy for ankle impingement according to a systematic review from 2009.

Posterior Ankle Impingement

Patients with posterior ankle impingement point to the back of the ankle as the area of pain and have tenderness in the deep posterior aspect of the ankle and pain with a forced plantar flexion test (Fig. 50-9). Studies may show an os trigonum or hypertrophic posterior process of the talus, and patients obtain relief with a fluoroscopic-guided injection in the area.

Posterior Débridement for Ankle Impingement

Technique 50-2

Good and excellent outcomes have been reported in from 91% to 100% of patients with this procedure. Posterior débridement enabled all 27 elite professional soccer players to return to training at an average of 5 weeks and can result in significant reduction in pain. Outcomes after arthroscopic and open posterior débridement are similar, but earlier return to sports is possible with arthroscopic treatment. Complication rates range from 4% to 20%; complications include neurological symptoms of the tibial and sural nerves, infection, chronic regional pain syndrome, Achilles tightness, and wound problems.

A systematic review suggested a grade C recommendation (poor quality evidence) for arthroscopic treatment of posterior ankle impingement, given the level of studies available in the literature.