Irrigation

Different fluids can be used for arthroscopic irrigation during ankle and foot arthroscopy. Lactated Ringer’s is the most commonly used fluid because it is physiologically compatible with articular cartilage and is rapidly reabsorbed if extravasated from the joint. Glycine and normal saline also can be used. When a 4-mm arthroscope is used, gravity inflow usually is adequate if the fluid is introduced through the arthroscope sheet. When a 2.7-mm arthroscope is used, the gravity inflow should be introduced through a separate (posterolateral) cannula. An alternative is to use an arthroscopic pumping device.

Accessory Instruments

An 18-gauge spinal needle is used to distend the joint and to locate the anterolateral portal. The spinal needle allows precise positioning under direct vision of the portals. The probes used in ankle arthroscopy should be about 1.5 mm in diameter to reach the small recesses of the gutters and to lift up under loose articular cartilage. An angled tip is desirable to touch over the dome-shaped talus and flat tibia. Another important instrument is the grasper. For the removal of small, loose bodies in soft tissue, a flat-tipped grasping forceps with fine teeth can be used. For larger loose bodies and soft-tissue fragments, a cup-shaped, jaw-grasping forceps with serrated edges can be used. Small-joint basket forceps with different tip designs help to remove soft-tissue and chondral fragments. Various small-joint curettes, either straight or curved, are available. These instruments are particularly valuable for removing osteochondral lesions and trimming of articular cartilage edges. Small-joint osteotomes and chisels are available to remove osteophytes and ossicles and can facilitate tissue elevation. Sometimes a small periosteal elevator can be useful. Motorized instruments can excise larger volumes of tissue than conventional hand instruments and suction it quickly out of the joint. They also can be used for debridement of large osteochondral defects. A power burr is useful for abrading or excising hard bone fragments. Holes can be drilled in the subchondral bone to enhance vascularization and to stimulate the repair process.

Anteromedial Portal

The anteromedial portal is placed just medial to the anterior tibial tendon at the joint line (Fig. 16-3). Care must be taken not to injure the saphenous vein and nerve transversing the ankle joint along the anterior edge of the medial malleolus. In the hyperdorsiflexed position, a local depression can be palpated. In the horizontal plane, this depression is located between the anterior tibial rim and the talus. The surgeon’s palpating thumb first detects the interval in the horizontal plane and subsequently locates the vertical position. In the vertical position, the anterior tibial tendon is the landmark. One should palpate the anterior tibial in the dorsiflexed position. In this dorsiflexed position the anterior tibial tendon moves ±1 cm lateral. The location of the anteromedial portal now can be marked onto the skin just medial from the anterior tibial tendon. By moving the ankle joint from the plantarflexed position to the dorsiflexed position, the talus can be felt to move in relation to the distal tibia. The surgeon’s thumb gets locked into this “soft spot” in the hyperdorsiflexed position. A small longitudinal incision is made through the skin only just medial from the anterior tibial tendon. Blunt dissection is performed with a mosquito clamp through the subcutaneous layer and through the capsule into the ankle joint. With the ankle in the forced dorsiflexed position, cartilage damage is avoided. In this forced dorsiflexed position, the arthroscope shaft with the blunt trocar is introduced. When the trocar is felt to contact the underlying bony “joint line,” the shaft with the blunt trocar is gently pushed further into the anterior working area in front of the ankle joint toward the lateral side. The anterior compartment is irrigated and inspected. The next portal to make is the anterolateral portal.

Figure 16-3 Left ankle. The anteromedial portal is placed just medial to the anterior tibial tendon at the joint line. Care must be taken not to injure the saphenous vein and nerve transversing the ankle joint along the anterior edge of the medial malleolus.

Anterolateral Portal

The anterolateral portal is the second standard anterior portal. It is placed just lateral to the tendon of the peroneus tertius at or slightly proximal to the joint line (Fig. 16-4). It is made under direct vision by introducing a spinal needle. In the horizontal plane, it is situated at the level of the joint line. In the vertical plane, the anterolateral portal is located lateral to the common extensor tendons and the peroneus tertius tendon. Care must be taken to avoid the superficial peroneal nerve because it runs subcutaneously. This subcutaneous nerve often can be palpated or visualized by placing the foot in forced hyperplantarflexion and supination. The lateral dorsocutaneous branch of the superficial peroneal nerve thus can be visualized. The intermediate dorsal cutaneous branch of the superficial peroneal nerve crosses the anterior aspect of the ankle joint superficial to the common extensor tendons. Damage to this branch can be avoided by staying lateral to the extensor tendons. Once the lateral branch is identified, its position can be marked with a marking pen on the skin.

Figure 16-4 Left ankle. The anterolateral portal is placed just lateral to the tendon of the peroneus tertius at or slightly above the joint line.

The location of the anterolateral portal may vary depending on the location of the lesion in the ankle joint. For the treatment of anteromedial ankle pathology, the anterolateral portal can be placed slightly above the level of the ankle joint and as close to the peroneal tertius tendon as possible. For the treatment of lateral pathology, the anterolateral portal is placed at the level of the joint line and more laterally. After a small skin incision has been made, the subcutaneous layer and capsule are divided bluntly with a mosquito clamp.

Accessory Inferior Anteromedial and Anterolateral Portals

The lateral accessory portal is placed just below the anterior talofibular ligament. After introduction of a spinal needle, a skin incision is made in line with the anterior talofibular ligament. The bladeknife can be introduced into the joint under direct vision. On the medial side (after locating the portal with the spinal needle), the incision is made in line with the fibers of the deltoid ligament. The knife can be introduced directly into the joint under direct vision.

Transtibial and Transmalleolar Portals

A transmalleolar portal may be used for debridement and drilling of lesions of the talar dome. It is used most often in combination with ankle distraction. A special guide facilitates the placement of the portal and of the Kirschner wires that are used to drill the defect. Transtibial or transmalleolar drilling with a guiding system is especially useful for tibial plafond lesions. For the treatment of talar dome lesions, the transmalleolar portal has the disadvantage of causing damage to the cartilage of the medial malleolus opposite the osteochondral talar defect and therefore is not recommended to perform on a routine basis.

Posterolateral Portal

The posterolateral portal is made at the level or slightly above the tip of the lateral malleolus, just lateral to the Achilles tendon (Fig. 16-5, A). After making a vertical stab incision, the subcutaneous layer is split by a mosquito clamp. The mosquito clamp is directed anteriorly, pointing in the direction of the interdigital webspace between the first and second toe (Fig. 16-5, B). When the tip of the clamp touches the bone, it is exchanged for a 4.5-mm arthroscope shaft with a blunt trocar pointing in the same direction. By palpating the bone in the sagittal plane, the level of the ankle joint and subtalar joint most often can be distinguished because the prominent posterior talar process can be felt as a posterior prominence between both joints. It is not necessary to enter either joint capsule. The blunt trocar is situated extra-articularly at the level of the ankle joint. The blunt trocar is exchanged for a 30-degree, 4.0-mm arthroscope. The direction of view is lateral to prevent damage to the lens system.

Posteromedial Portal

This portal is made just medial to the Achilles tendon. In the horizontal plane, it is located at the same level as the posterolateral portal (Fig. 16-6). After the skin incision has been made, a mosquito clamp is introduced and directed toward the toward the arthroscope shaft, which already was introduced through the posterolateral portal. When the mosquito clamp touches the shaft of the arthroscope, the shaft is used as a guide to travel anterior in the direction of the ankle joint. All the way, the mosquito clamp must touch the arthroscope shaft until the mosquito clamp touches the bone. The arthroscope is pulled slightly backward and slides over the tip of the mosquito clamp until the tip of the mosquito clamp comes to view. The clamp is used to spread the extra-articular soft tissue in front of the tip of the camera. In situations in which scar tissue or adhesions are present, the mosquito clamp is exchanged for a 5-mm, full-radius shaver.

Figure 16-6 Right ankle. The posteromedial portal is made just medial to the Achilles tendon. In the horizontal plane, it is located at the same level as the posterolateral portal.

The fatty tissue overlying the joint capsule can be partially removed. At the level of the ankle joint, the posterior tibiofibular ligaments and the posterior talofibular ligament can be recognized. After removal of the very thin joint capsule of the subtalar joint, the posterior compartment of the subtalar joint can be visualized. The posterior talar process can be freed of scar tissue, and the FHL tendon can be identified. The FHL is an important landmark to prevent damage to the more medially located neurovascular bundle (Fig. 16-7).

Figure 16-7 Left ankle. After removal of the thin joint capsule, the posterior ankle and subtalar joint can be visualized. The posterior talar process can be freed of scar tissue and the flexor hallucis longus tendon can be identified. This is an important landmark to prevent damage to the more medially located neurovascular bundle.

On the medial side, the tip of the medial malleolus and the deep portion of the deltoid ligament can be visualized. By opening the joint capsule from inside out at the level of the medial malleolus, the tendon sheath of the posterior tibial tendon can be opened and the arthroscope can be introduced into the tendon sheath. The posterior tibial (PT) tendon can be inspected. The same procedure can be followed for the flexor digitorum longus (FDL) (Fig. 16-8).

Figure 16-8 Right ankle. By opening the joint capsule from inside out at the level of the medial malleolus, the tendon sheath of the posterior tibial tendon can be opened and the scope can be introduced into the tendon sheath of the posterior tibial tendon. This patient has a tendinitis of the posterior tibial tendon, recognized by the increased vascularity on and around the tendon. Higher up, a vincula is identified. The direction of the view is from distal to proximal.

With application of manual distraction to the os calcis, the posterior compartment of the ankle opens up and the arthroscope and shaver can be introduced into the posterior ankle compartment. A total synovectomy and/or capsulectomy can be performed. The talar dome can be inspected over almost its entire surface, as can the complete tibial plafond. An osteochondral defect or subchondral cystic lesion can be identified, debrided, and drilled. The posterior syndesmotic ligaments are inspected and, if hypertrophic, partially resected.

Removal of a symptomatic os trigonum, a nonunion of a fracture of the posterior talar process, or a symptomatic large posterior talar prominence involves partial detachment of the posterior talofibular ligament and release of the flexor retinaculum, both of which attach to the posterior talar prominence, and removal of the scar tissue on the posterior talar process. Removal of the pathologic bony fragment can be done by reduction from medial to lateral with a burr or by use of a 4-mm osteotome or a small rasp. When using the osteotome it is important not to start too far anterior to prevent damage to the subtalar joint.

Release of the FHL involves detachment of the flexor retinaculum from the posterior talar process. Adhesions surrounding the flexor tendon can be removed. On the lateral side, the peroneal tendons can be inspected (Fig. 16-9).

Figure 16-9 Left ankle. During posterior ankle arthroscopy, the peroneal tendons can be inspected on the lateral side.

When a tight and thickened crural fascia is present, this can hinder the free movement of instruments. It can be helpful to enlarge the hole in the fascia by means of a punch or shaver. Bleeding is controlled by electrocautery at the end of the procedure.

Anterior Ankle Examination

The anterior arthroscopic examination always is performed initially through the anteromedial portal and then through the anterolateral portal. The structures that can be visualized are the following (from medial to lateral): (1)The deep portion of the deltoid ligament as it arises from the tip of the medial malleolus and its fibers run vertically down to the medial trochlear surface of the talus. This is an area where ossicles may be hidden, and it should be evaluated carefully for pathology. (2) Also noted is the articular surface of the tip of the medial malleolus as it corresponds and articulates with the medial talar dome and the posterior recess and posterior ligaments. The medial gutter includes the area from the deltoid ligament to below the medial dome of the talus. Areas of articular damage here should be carefully noted. The tibia articulates with the medial dome of the talus. This is the medial corner of the ankle. In this region, the anterior articular margin of the tibia deviates from its more horizontal configuration centrally and laterally to a more convex configuration in the coronal plane. At this medial articular notch, the arthroscope may be maneuvered most easily into the central and posterior aspects of the joint without damaging the articular surfaces.

The distal portion of the tibial lip directs slightly anteriorly in the sagittal plane. This portion of the tibia articulates within a depression in the talar surface and is called the sagittal groove. This groove lies between the medial and lateral shoulders of the talus and projects from anterior to posterior. At the area between the anterior tibial lip and the capsule is a periosteum-covered subchondral bone, the synovial recess. This extends from medial all the way to the lateral portion of the ankle. This is where tibial osteophytes develop and synovium and capsule become adherent at the margins of the osteophyte. More laterally, the trifurcation includes the distal lateral tibial plafond, the lateral dome, and the fibula and is bounded by the anterior inferior tibiofibular ligament superiorly. This relation is important in the ankle, because this is often the site of soft-tissue pathology. The syndesmotic or anterior inferior tibiofibular ligament runs at approximately a 45-degree angle from the lateral portion of the distal tibia to the fibula, just below the level of the lateral talus. The anterolateral talar dome also is the site of osteochondral lesions of the talus, and access into ankle joint usually is easy in this region. The lateral gutter is the space between the medial border of the fibular articulation and the lateral border of the talar articulation. It extends from below the anterior inferior tibiofibular ligament to the anterior talofibular ligament. This often is the site of chondromalacia and ossicles at the tip of the fibula within the ligament substance. The anterior talofibular ligament lies intracapsular and runs from the tip of the fibula to the inferior lateral portion of the talus. It can be easily reached for a shrinkage procedure in case of laxity in patients with chronic anterolateral ankle instability. The anterior gutter represents the capsular reflection anteriorly of the ankle as it inserts along the talar neck. There is a normal bare area proximal to the capsular insertion, similar to the area on the central portion of the distal tibia. A synovial recess also can be found at the anterior inferior aspect of the talar dome. In this area, anterior talar osteophytes may articulate or butt against osteophytes of the anterior tibial lip.¹⁰

Posterior Ankle Examination

Using a posterolateral and posteromedial portal with the patient in the prone position, one first approaches the fatty tissue overlying the joint capsule (Fig. 16-10). This tissue can partially be removed. At the level of the ankle joint, the posterior tibiofibular ligaments and the posterior talofibular ligament can be recognized. After removal of the very thin joint capsule of the subtalar joint, the posterior compartment of the subtalar joint can be visualized. The posterior talar process can be freed of scar tissue and the FHL tendon identified. The FHL tendon is an important landmark to prevent damage to the more medially located neurovascular bundle. When manual distraction is applied to the os calcis, the posterior compartment of the ankle joint opens up and can be visualized. The arthroscope and instruments can be introduced into the posterior ankle compartment. Procedures such as a synovectomy and/or capsulectomy of both ankle and subtalar joint can be performed. On the medial side, the tip of the medial malleolus, as well as the deep portion of the deltoid ligament, can be visualized. Opening the joint capsule from inside out at the level of the medial malleolus permits the tendon sheath of the posterior tibial tendon to be opened and the arthroscope to be introduced into the tendon sheath. The posterior tibial tendon can be inspected. The talar dome and nearly the entire surface of the complete tibial plafond can be inspected, as well. An osteochondral defect or subchondral cystic lesion can be identified, debrided, and drilled. The posterior syndesmotic ligaments are inspected and, if hypertrophic, partially resected. The intrinsic syndesmotic area and the posterior talofibular ligament can be inspected (Figs. 16-11 and 16-12). Removal of a symptomatic os trigonum or a nonunion of fracture of the posterior talar process involves partial detachment of the posterior talofibular ligament and release of the flexor retinaculum, both of which attach to the posterior talar prominence. Release of the FHL tendon involves detachment of the flexor retinaculum from the posterior talar process (Fig. 16-13). Adhesions surrounding the flexor tendon can be removed. On the lateral side, the peroneal tendons can be inspected. A tight and thickened crural fascia can hinder the free movement of instruments; it can be helpful to enlarge the defect in the fascia by means of a punch or shaver.

Figure 16-10 Right ankle. Using a posterolateral and posteromedial portal with the patient in the prone position, one first approaches the fatty tissue overlying the joint capsule. This tissue can be partially removed.

Figure 16-11 Left ankle. Removal of a symptomatic os trigonum (OT) or a nonunion of fracture of the posterior talar process involves partial detachment of the posterior talofibular ligament and release of the flexor retinaculum, both of which attach to the posterior talar prominence.

Figure 16-12 Left ankle. Removal of a symptomatic os trigonum (OT) involves partial detachment of the posterior talofibular ligament (PTFL) and release of the flexor retinaculum, both of which attach to the posterior talar prominence (see also Fig. 16-13).