Foot and ankle arthroscopy has become a valuable adjuvant to the diagnosis and treatment of an increasing amount of disorders. Diagnostic indications (Box 30-1) for ankle arthroscopy include unexplained pain, swelling, stiffness, instability, hemarthrosis, locking, and abnormal snapping or popping.

Operative indications for ankle arthroscopy include loose body removal, excision of anterior tibiotalar osteophytes, débridement of soft tissue impingement and arthrofibrosis, and treatment of osteochondral lesions and ankle instability. Other indications include arthrodesis for posttraumatic degenerative arthritis and treatment for ankle fractures and postfracture defects.

Absolute contraindications for ankle arthroscopy include localized soft tissue or systemic infection, and severe degenerative joint disease (DJD). With end-stage DJD, occasionally successful distraction may not be possible, precluding visualization of the ankle joint. Relative contraindications include complex regional pain syndrome (CRPS), moderate DJD with restricted range of motion (ROM), severe edema, and tenuous vascular supply.

Ankle arthroscopy is usually performed in one of four ways: (1) in the supine position, (2) with the knee bent 90° over the end of the table, (3) in the decubitus position, or (4) in the prone position for posterior ankle arthroscopy. The method of choice is a surgeon’s preference, while taking into account specific surgical circumstances. Different types and sizes of arthroscopic equipment can be used depending on surgeon’s preference and availability of equipment. The procedure described is that used most commonly by the senior author of this chapter; a more detailed description of ankle arthroscopy can be found in his textbook.2

Positioning

The patient is taken to the operating room and placed in the supine position. The hip is flexed to 45°, and the thigh is placed onto a well-padded support placed proximal to the popliteal fossa and distal to the tourniquet. The lower extremity (LE) is then prepared and draped so that good access is available posteriorly. A tourniquet is applied as needed. A noninvasive distraction strap is placed over the foot and ankle. Distraction is used to separate the distal tibia from the talus so that at least 4 mm of joint space opening is obtained (Fig. 30-1). Without distraction, the surgeon has difficulty positioning the arthroscopic instruments in the ankle without scuffing the articular cartilage; visualizing the central and posterior portions of the ankle also is difficult without adequate joint separation. The distraction device is carefully positioned so as not to injure the neurovascular structures, and approximately 30 to 40 lb of force is placed across the ankle for no more than 60 to 90 minutes. Before applying the distraction strap, the surgeon should identify and outline the dorsalis pedis artery, the deep peroneal nerve, saphenous vein, tibialis anterior tendon, peroneus tertius tendon, and superficial peroneal nerve and its branches on the skin with a marker. Identification of the superficial peroneal nerve and its branches is facilitated by inverting and plantar flexing the foot and flexing the toes.

Arthroscopic Portal Placement

The surgeon uses three primary portals or access areas to insert the arthroscope and instrumentation (Fig. 30-2). These include the anteromedial, anterolateral, and posterolateral portals. Accessory portals can be used as needed but are rarely required. Portals are made by nicking the skin only, then with the use of a clamp spreading through the subcutaneous tissue and into the ankle joint. The surgeon must take great care to avoid injuring the neurovascular and tendinous structures.

The anteromedial portal is established first and a 2.7-mm, 30° oblique small joint videoscope is inserted. The surgeon establishes the anterolateral portal under direct vision, using extreme care to avoid injuring the superficial peroneal nerve branches. The arthroscope is then positioned in the posterior portion of the ankle so the posterolateral portal can be made just lateral to the Achilles tendon, entering the ankle beneath the posterior ankle ligaments.

In recent years, techniques have been developed for arthroscopy in the prone position, using the posterolateral and posteromedial portals. This allows access for treatment of a variety of problems, including osteochondral lesions of the talus (OLT), os trigonum, and flexor hallucis longus tendinitis or tears.^7–10 The senior author of this chapter occasionally uses this position.

Arthroscopic Examination

A 21-point arthroscopic examination of the ankle is performed to ensure a systematic evaluation.2 After completing the arthroscopic evaluation, the surgeon identifies the pathology and treats it accordingly, using small joint instrumentation ranging in size from 2.0 to 3.5 mm. These instruments include baskets, knives, intraarticular shavers, and burrs. Scar tissue is removed using baskets and an intraarticular shaver. Synovectomy is performed with an intraarticular shaver (Fig. 30-3). OLT are carefully evaluated and, if they are found to be loose, excised with a ring curette and banana knife. The surgeon can use transmalleolar or transtalar drilling, and/or microfracture techniques, to promote fibrocartilage formation and new circulation in the avascular area (Fig. 30-4). Acute ankle fractures can be evaluated arthroscopically; the surgeon can perform percutaneous screw insertion while monitoring fracture reduction arthroscopically (see Chapter 29).

After the procedure is performed, the wounds are closed with a nonabsorbable suture, and a compression dressing and posterior splint are applied.

The primary cause of chronic ankle pain after an ankle sprain is soft tissue impingement. This can occur along the syndesmosis, the syndesmotic interval between the tibia and fibula, or the medial, lateral, and/or posterior gutters. Most commonly it is located anterolaterally given the common occurrence of a common inversion ankle sprain.11 Diagnosis is done by careful history, physical examination, and selective injections. MRI can also be very helpful in assessing the problem (Fig. 30-5).¹²

The sequence of lateral ankle pain after a sprain can be explained as shown in Fig. 30-6.

A distraction device may be necessary to identify some of the synovial pathology involving the posterolateral corner of the ankle, because such identification can be sometimes difficult. The inflamed synovium, thickened adhesive bands, osteophytes, and loose bodies are débrided arthroscopically using motorized shavers and burrs, graspers, and baskets (Fig. 30-7).

Postoperatively, patients are splinted for 1 week, and then put into a CAM (controlled angle motion) walker for 2 to 3 weeks. Subsequently, they wear a soft ankle brace and begin formal physiotherapy. Return to activity or sport is allowed only after all rehabilitation goals are achieved.

Arthroscopic treatment of anterolateral soft tissue impingement of the ankle has been proven successful at alleviating chronic ankle pain after an inversion sprain. Numerous authors have reported a good to excellent outcome in approximately 80% to 85% of patients.^11,13,14

OLT that do not respond to conservative treatment are treated arthroscopically. Most chronic OLT in adults are loose and have to be excised. The osteochondral lesion bed is then microfractured and/or drilled. Occasional they can be pinned back (Fig. 30-8).

Postoperatively, patients are splinted for 1 week in neutral position. Once the portal incisions have healed (approximately 1 to 2 weeks), ROM exercises are begun, since early motion appears to facilitate cartilage healing. Patients remain non–weight bearing for 6 to 8 weeks, depending on the size of the lesion. Usually by 4 to 6 weeks, patients start physical therapy in the pool and then progress to land exercises. Cutting, shear stress, or impact activities are avoided for 6 months.

Arthroscopic treatment of OLT has proven to be comparable with open surgery, with less morbidity and less recovery time. Ankle arthroscopy has proven to be one of the most reliable methods in classifying OLT. Recently, clinical management of articular cartilage defects has generated significant research interest in the orthopedic world. Attempts to stimulate a hyaline cartilage response have included transplantation of various cells, including periosteal and perichondral tissues, woven carbon-fiber pads, and osteochondral autografts/ allografts.

In addition, chondrocyte transplantation has been studied extensively now in the United States. With further research, it is hoped that osteochondral defects can be successfully covered by articular cartilage instead of fibrocartilage replacement.⁹

Numerous papers have been published regarding the outcome of arthroscopic surgery of the ankle. Results vary depending on the type of procedure and the study that was undertaken.15–23 In general, a large percentage of patients should achieve a successful outcome depending on the nature of the pathology. Expectations after surgery include a full ROM, strength, and full function. The preoperative ROM, strength, and severity of the pathologic condition heavily influence the results.

All arthroscopic procedures have potential complications.24 The most common complications in foot and ankle arthroscopy are injuries to the neurovascular structures, especially the superficial peroneal nerve.⁸ The overall complication rate has varied with the transition from invasive to noninvasive distraction. Current complication rates are between 6.8% and 9%.^25,26 The physical therapist should report to the physician any problems they note after surgery. Sometimes, excessive massage over the portals can even irritate the nerves and cause tingling and numbness. In general, we wait 2 to 3 weeks to initiate physical therapy after ankle and foot arthroscopy to avoid wound problems and increased pain while the soft tissues are healing.

The physical therapist should consider the following 6 basic principles when planning an ankle rehabilitation protocol:

The following rehabilitation program was designed for a patient who has chronic pain because of a recurring inversion sprain suffered during the basketball season. The patient underwent an arthroscopic procedure to débride the anterolateral soft tissue because of impingement.