Ankle Arthroscopy

Arthroscopy is an important diagnostic and therapeutic technique for management of disorders of the joints. Ankle arthroscopy can be useful in treating a variety of intra-articular disorders, which may be caused by trauma or by degenerative, inflammatory, or neoplastic conditions. In some cases, the ankle-joint disorder may be related to extra-articular anomalies, which may be regional (eg, mechanical malalignment in the lower extremity) or systemic (eg, inflammatory arthritis).

As the indications for ankle arthroscopy have increased, so has its usage. The availability of modern arthroscopic instrumentation (eg, fiberoptics) and ankle distraction techniques has allowed orthopedic surgeons to manage a growing list of ankle disorders arthroscopically. Surgical procedures of the ankle performed arthroscopically are generally associated with lower morbidity, faster rehabilitation, and better cosmetic results as compared with conventional open surgical methods.[1, 2, 3, 4]

For example, management of osteochondral defects with autologous cartilage replacement has typically required an open procedure to suture a periosteal patch under which harvested and cultured cells are injected. With current techniques, however, the graft can be placed without the need for a periosteal flap and therefore can be implanted arthroscopically.[5]

It must be kept in mind that arthroscopy is not a panacea. For instance, whereas it can assist in reduction and internal fixation of ankle and pilon fractures, its role in the treatment of acute ankle fractures is still unclear. Ankle arthroscopy is also useful for treating syndesmosis disruptions, evaluating and treating posterior malleolar fractures of the tibial plafond, and facilitating removal of debris and reduction of talus fractures. Coincidental or concurrent osteochondral lesions can be managed with replacement of fragments or, if this is not feasible, microfracture surgery.  Indications and applications for arthroscopy are still evolving and require further research.

Arthroscopy is indicated for definitive diagnosis of certain soft-tissue disorders when the exact etiology of ankle symptoms remains unclear, as well as for treatment of a variety of ankle disorders, usually after conservative measures have failed.

Indications for diagnostic ankle arthroscopy include the following:

• Unexplained pain, swelling, stiffness, instability
• Mechanical symptoms such as locking and popping

Indications for therapeutic ankle arthroscopy include the following:

• Articular injury
• Soft-tissue injury
• Posttraumatic soft-tissue impingement
• Bony impingement
• Arthrofibrosis
• Instability
• Arthroscopic-assisted fracture fixation ^[6]
• Synovitis
• Loose bodies
• Intra-articular bands
• Tendinitis
• Osteophytes
• Osteochondral defects (see the image below)
• Arthrodesis
• Septic arthritis

Arthroscopic view of an osteochondral defect being punctured by an awl.

Synovial inflammation and hypertrophy can result from various conditions, including inflammatory arthritis, infection, crystalline arthropathies, degenerative changes, trauma, and overuse. Pigmented villonodular synovitis (PVNS) is a benign synovial neoplasm that can be either generalized or local. Hemophiliacs often have synovial hypertrophy, and synovial impingement can lead to repeated ankle hemarthrosis.

Simple trauma, such as the common inversion injury of the ankle, after a single episode or multiple episodes, can lead to impingement of the superior portion of the anterior talofibular ligament.

Injury to the inferior tibiofibular syndesmosis can lead to tearing, scarring, and synovitis in the region of the anteroinferior tibiofibular ligament and impingement of this structure in the tibiofibular syndesmosis. Increased laxity resulting from torn ankle ligaments allows the talar dome to extrude anteriorly in dorsiflexion and cause soft-tissue impingement.[7]

Osteochondral lesions on the dome of the talus can result from acute trauma (eg, from an ankle sprain), degenerative changes, or repetitive trauma. About 10% of lesions are bilateral and are not associated with trauma. Traumatic lesions are mostly anterolateral in location, and degenerative lesions occur on the posteromedial aspect of the talus.

Loose bodies can be chondral or osteochondral in origin and usually result from trauma. They can also occur with synovial chondromatosis or synovial osteochondromatosis and can be free-floating or embedded in synovium or scar tissue.

Anterior osteophytes form over the anterior lip of the distal tibia and corresponding area of articulation on the dorsum of the neck of the talus. These osteophytes or spurs occur because of repetitive and forceful dorsiflexion. Football players and dancers have a high incidence of spurs.

After trauma or degeneration, wear and tear of the cartilage can be responsible for intra-articular adhesions, loose bodies, and osteophytes. In the late stages, most of the cartilage is denuded, exposing the subchondral bone and cysts.

Intra-articular injury is increasingly being recognized as associated with ankle fractures, but the role of ankle arthroscopy in the evaluation, treatment, and prevention of long-term sequelae is unclear.[8]

All of these conditions can benefit from arthroscopic intervention.

Absolute contraindications for ankle arthroscopy include the following:

• Active local soft-tissue infection
• Severe degenerative joint disease
• Poor vascularity in the leg

Relative contraindications for ankle arthroscopy include the following:

• Moderate degenerative joint disease
• Severe edema

Anatomy

The ankle joint is a hinged synovial joint with primarily up-and-down movement (plantarflexion and dorsiflexion). However, when the ranges of motion of the ankle and subtalar joints are taken together, the complex functions as a universal joint. A thorough knowledge of the anatomy of the ankle joint, especially the contours of the articular surfaces and the neurovascular and tendinous structures in the surrounding soft tissue, is vital for planning and performing arthroscopy in this joint.[9, 10, 11]

Articular surface contours

The distal tibia is concave in the sagittal plane and convex in the coronal plane. The anterior tibial rim is mildly convex anteriorly and has a notch medially, where it recedes proximally by about 4-5 mm at the junction of the medial malleolus (see the images below).

Cadaver dissection demonstrating the convex anterior aspect of distal tibial lip.

Cadaver specimen with dislocation of the ankle joint showing the contours of the talar dome.

The posterior tibial margin extends further distally than the anterior tibial margin by about 5-6 mm. The lateral malleolus extends further distally and is situated more posteriorly than the medial malleolus. The talofibular articulation slopes medially distally on a coronal plane. The fibular articular surface, in addition, is convex.

Topographic anatomy

About 6.5 cm proximal to the tip of the fibula, the superficial peroneal nerve divides into the intermediate and medial dorsal cutaneous branches.[12] In some individuals, these branches, especially the intermediate branch, can be made prominent under the skin by plantarflexion and supination of the foot (see the image below).

Demonstration of branches of the superficial peroneal nerve.

The intermediate dorsal cutaneous nerve passes superficial to the inferior extensor retinaculum and crosses the ankle joint lateral to the peroneus tertius tendon. The medial dorsal cutaneous branch courses over the lateral part of the extensor digitorum longus (EDL) tendon. These structures are subject to displacement if the joint is distended with fluid.

The deep peroneal nerve and the dorsalis pedis lie centrally in front of the ankle joint between the tibialis anterior and extensor hallucis longus (EHL) tendons.

The great saphenous vein (GSV) and the saphenous nerve run along the anterior border of the medial malleolus. The sural nerve and the small saphenous vein (SSV) are located posterolaterally between the lateral border of the Achilles tendon and the peroneal tendon.

The soft spot between the posterior aspect of the medial malleolus and the anterior margin of the Achilles tendon hosts some important structures. Posteromedial to the ankle and between the posterior margin of the medial malleolus and the Achilles tendon, proceeding from superficial to deep, course the posterior tibial tendon, the flexor digitorum longus (FDL) tendon, the tibial nerve and posterior tibial vessels, and the flexor hallucis longus (FHL) tendon.

The superficial medial calcaneal nerve originates from the posterior tibial nerve 2-3 cm proximal to the tip of the medial malleolus. It runs anteroinferiorly for 2.0-2.5 cm, away from the Achilles tendon, curving posteriorly and medially, dividing in several cutaneous branches at the calcaneal tuberosity.

All these structures are at risk of lesions from surgical intervention at the subcutaneous layer.

Arthroscopic anatomy

The borders of the lateral gutter of the ankle include the talus medially, the fibula laterally, and the tibia superiorly, bordered by the anteroinferior and posteroinferior tibiofibular ligaments. The anteroinferior section of the lateral gutter is bordered by the anterior talofibular, calcaneofibular, and anterior talocalcaneal ligaments. The posteroinferior borders are composed of the posterior talofibular, calcaneofibular, and posterior talocalcaneal ligaments.[13]

The posterolateral gutter structures include the posterior talofibular ligament, the posteroinferior tibiofibular ligament, the transverse tibiofibular ligament, the tibial slip, the FHL tendon, and a synovial nodule in the tibiofibular recess. The structures of the posteromedial gutter of the ankle include the FHL tendon and the deep portion of the deltoid ligament.

Outcome and prognosis vary, depending on the condition being managed. Good-to-excellent results have been reported at 2-year follow-up in as many as 84% of patients after arthroscopic management of anterolateral impingement.[14]

Persistent pain after an ankle sprain is often caused by the development of intra-articular fibrous scars or even tibiotalar spurs as a consequence of repetitive trauma. This may result in a posttraumatic impingement syndrome of the ankle. Pain is typically provoked by dorsiflexion of the ankle and palpation of the tibiotalar anterior joint space.

In a retrospective study evaluating 32 patients who underwent arthroscopy because of a grade I-III impingement syndrome of the ankle due to trauma without therapeutic response to conservative therapy over 3 months, ankle arthroscopy with resection of hypertrophic synovium and fibrous bands (type I) or tibial spurs (type II and III injuries) after an ankle sprain proved to be a reliable therapy for a posttraumatic impingement syndrome of the ankle that had not responded to conservative treatment.[15]

This approach was characterized by low morbidity and good-to-excellent results in most cases.[15] The outcome of arthroscopic treatment was related to the extent of chondral lesions. Diagnostic criteria included anterior ankle joint pain on palpation and pain provoked by dorsiflexion, in cases of grades II and III lesion spurs on the radiograph as well. The mean follow-up time was 49 months.

On the West Point Ankle Score, 26 patients had more than 80 points, corresponding to a good or excellent result (mean, 86 points; range, 80-98); their preoperative mean score was 64 (range, 57-70).[15] Of the remaining six, five had a fair postoperative result and one had a bad result (mean, 73 points; range, 62-78); their preoperative mean score was 56 point (range, 48-62). The fair and poor results were associated with severe ankle sprain leading to ligament ruptures or fractures where severe chondral lesions were to be found with arthroscopy.

In another study, arthroscopic resection of a torn portion of the interosseous ligament causing syndesmotic impingement successfully relieved symptoms in all 19 patients.[16]

In other studies, arthroscopic drilling of osteochondral defects in the talus yielded good-to-excellent results in 28-93% of patients.[17, 18, 19, 20]

A study that correlated the size of the lesion with results after arthroscopic microfracture treatment for osteochondral lesions of the ankle in 105 consecutive patients achieved excellent results for lesions smaller than 15 mm, regardless of location, at a mean follow-up of 31.6 ± 12.1 months.[21] Increased age, a higher body mass index (BMI), a history of trauma, and the presence of osteophytes negatively affected outcome. The presence of instability and anterolateral soft tissue scars was correlated with a successful outcome.

A prospective cohort study designed to evaluate whether residual degenerative cartilage at the lesions may obstruct the healing of the articular cartilage showed that in the treatment of osteochondral lesions of the talar dome, removal of the remaining degenerative cartilage may be of some therapeutic benefit.[22] A total of 39 patients underwent arthroscopic drilling that kept the remaining cartilage at the lesion, and 30 underwent arthroscopic drilling that removed the remaining cartilage at the lesion.

In a prospective, controlled trial, patients with symptomatic, recalcitrant Ferkel class 2b, 3, and 4 osteochondral lesions of the talus were randomly assigned to chondroplasty, microfracture, or osteochondral autologous transplantation (OAT) treatment groups; no differences were found between chondroplasty, microfracture, and OAT.[23] In all, 11 patients underwent chondroplasty, nine patients (10 ankles) underwent microfracture surgery, and 12 underwent OAT. Mean time to follow-up was 53 months (range, 24-119 months).

Arthroscopic ankle arthrodesis has shown good-to-excellent results in approximately 85-97% of patients, with a rapid fusion time, a low rate of nonunion, and few complications.[24, 25]

Leontaritis et al studied 84 ankle fractures (categorized according to the Lauge-Hansen criteria) that were treated with open reduction and internal fixation (ORIF) and for which ankle arthroscopy had been routinely performed in order to determine whether the severity of an acute ankle fracture was correlated with the number of arthroscopically detected intra-articular chondral lesions.[26]  Chondral lesions were found in 61 patients (73%). The lesions were associated with individual fracture types as follows:

• Fractures graded as pronation-external rotation or supination-external rotation type I (n = 17) - Fifteen were associated with one or no chondral lesion; two were associated with two or more chondral lesions
• Fractures graded as pronation-external rotation or supination-external rotation type II (n = 10) - Nine were associated with one or no chondral lesion; one was associated with two or more chondral lesions
• Fractures graded as pronation-external rotation or supination-external rotation type IV (n = 56) - Twenty-seven were associated with one or no chondral lesion; 29 were associated with two or more chondral lesions

The more severe ankle fracture patterns were found to be significantly more likely to be associated with two or more chondral lesions.[26]

Kunzler et al reported a case of synovial chondromatosis in a 54-year-old man leading to pain and limited range of motion in the ankle.[27] This unique case of extensive nodule formation was treated via a three-port arthroscopic approach. Removal of loose bodies and synovectomy were successfully performed arthroscopically. A total of 76 loose bodies were removed, and synovectomy was performed with a 3.5-mm diameter full-radius shaver. This case demonstrated that a three-port arthroscopic approach could provide adequate treatment while maintaining the superior risk profile inherent to arthroscopic intervention.

Bojanic et al reported on 17 patients who underwent combined posterior and anterior ankle arthroscopy within the same operative session and had histologically confirmed primary synovial chondromatosis (PSC) of the ankle.[28]  In 14 patients, loose bodies were found in both compartments of the ankle; in two, only in the anterior compartment; and in one, only in the posterior compartment. In all 17, signs of synovial inflammation were evident in both compartments.

At final follow-up,[28] the median American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score had increased from 65 (range, 29-90) preoperatively to 95 (range, 65-100). Fourteen patients were extremely satisfied with the outcome, one was moderately satisfied, and two were dissatisfied. No recurrences of synovitis, loose-body formation, or signs of malignant transformation were noted. These findings led the authors to believe that ankle PSC should be regarded as a whole-joint disorder and felt that a combined posterior-anterior arthroscopic procedure within the same operative session should always be considered in patients with ankle PSC.

A retrospective study (N = 31; 18 male, 13 female; mean age 41.7 y; range 17-69 y) by Colasanti et al evaluated the clinical outcomes of in-office needle arthroscopy (IONA) for the treatment of anterior ankle impingement in the office setting and also assessed patient experience of IONA.[29]  Patients were followed for a minimum of 12 months (mean, 15.5 mo). For outcome assessment, Foot and Ankle Outcome Scores (FAOS) and Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference and pain intensity domains were obtained preoperatively and at final follow-up.

At final follow-up, the mean postoperative FAOS values were 79.4 for symptoms, 82.9 for pain, 83.5 for daily activities, 71.9 for sports activities, and 64.3 for quality of life.[29] Minimal clinically important differences were achieved for FAOS pain by 84% of patients, for FAOS symptoms by 77%, for FAOS quality of life by 75%, for FAOS sports by 74%, for PROMIS pain interference by 65%, for FAOS activities of daily living by 61%, and for PROMIS pain intensity by 42%. Of the 31 patients, 29 (94%) stated that they would be willing to undergo the same procedure again.

A review of the clinical evaluation and workup is important in planning for the surgical procedure. Determining the nature and location of the pathology in the ankle joint will help in selecting the equipment and arthroscopic portals. Consultation with a hematologist and supplementation of coagulation factors are necessary if arthroscopic synovectomy is planned in chronic forms of hemarthrosis resulting from hematologic disorders.

Clinical findings

Clinical findings in patients with ankle joint pathology vary according to the condition present. Chronic pain after an ankle sprain occurs in 20-40% of cases. Pain, swelling, and tenderness in the anterolateral region of the ankle are indicative of soft-tissue impingement, especially if the tenderness is increased with ankle dorsiflexion.

Ankle swelling, pain, catching, locking, popping, and feelings of instability or of the ankle giving way are associated with osteochondral lesions of the talus, loose bodies, and degenerative disorders of the ankle.

Tenderness along the anterior border of the distal tibia, along with reduced range of motion (ROM) in the ankle joint, is associated with bony impingement.

Laboratory studies

Routine preoperative blood work is performed if indicated. A complete blood count (CBC), assessment of the erythrocyte sedimentation rate (ESR), and measurement of C-reactive protein (CRP) levels are necessary if infection is suspected. Additional blood work to check the autoimmune profile, such as rheumatoid factor and antinuclear antibodies, may be necessary if inflammatory arthritis is suspected.

Radiography

Weightbearing anteroposterior, mortise, and lateral views of the ankle joint are helpful in detecting bony abnormalities (eg, malalignment, incongruity, bony spurs, loose bodies, and cysts in the talar dome). They may reveal calcifications or heterotopic bone in the interosseous space, which indicates preexisting injury to the distal tibiofibular syndesmosis and ossicles along the tip of the fibula and the lateral talar dome, consistent with anterior talofibular ligament injuries. Stress view radiographs are helpful in determining ankle ligament laxity.

Computed tomography

Computed tomography (CT) can be helpful in obtaining better bony detail, if necessary. For example, in planning treatment of an osteochondral defect, the dimensions of a bony cyst are better determined with CT than with radiography or magnetic resonance imaging (MRI).[30]

Magnetic resonance imaging

MRI provides excellent detail of the soft tissues and is very useful for detecting tears and abnormalities of the ligaments and tendons, as well as evaluating osteochondral integrity. An abnormal signal in sagittal T1 and STIR (short tau inversion recovery) images helps identify a collection of fluid (edema) or soft tissue that has caused displacement of the subcutaneous fat normally found immediately adjacent to the fibula anteriorly. A dynamic MRI can demonstrate soft-tissue impingement.[31]

Joint aspiration

Joint aspiration can be performed if infection is suspected. A dark serosanguineous fluid is a feature associated with pigmented villonodular synovitis.

Ankle arthroscopes include the following:

• Smaller-diameter scopes, 1.9 and 2.7 mm (30° and 70°) - These provide an excellent picture and a wide-angle field of vision; they take up less room, so that there is less crowding with instrumentation; they are associated with a lower risk of chondral damage; they are delicate and, therefore, associated with an increased risk of bending and breaking; they are more useful in tight ankle joints; they have a shorter lever arm that generates less torque
• Larger-diameter scopes, 4.0 mm (30° and 70°) - These provide a larger and clearer picture and are more resistant to bending or breakage
• 70° scopes - These provide better vision over the dome of the talus and in the medial and lateral gutters

Arthroscopic instruments include the following:

• Shavers and burrs, 2.0, 2.9, and 3.5 mm
• Ring and cup curettes, 3.5 and 4.5 mm
• Probes, 1.5 mm
• Graspers and baskets, 2.9 and 3.5 mm
• Osteotomes, 2.9 mm
• Pituitary rongeurs
• Microfracture picks, 90° and 70°
• Banana blades
• Microvector guide

Ankle distraction devices are also employed. Their main advantage is that they provide better visualization of the joint and of structures otherwise poorly seen, such as the posterior talofibular ligament, flexor hallucis longus tendon, and calcaneofibular ligament. The main risk is the potential for nerve injury. There are two main approaches to ankle distraction, as follows:

• Invasive - Unicortical pins are inserted proximally in the tibia and distally in the calcaneus; the points where the pins are inserted can be stress risers; this approach is contraindicated in patients with complex regional pain syndrome, open epiphysis, pyarthrosis, or soft tissue infection
• Noninvasive - An ankle strap is connected to a distraction device attached to the table frame or to a belt worn by the surgeon (see the images below); this approach has replaced the invasive method, which is now rarely used

Ankle stirrup attached to a distraction device fixed to the operating table.

Ankle distraction stirrup attached to a belt worn by the surgeon.

Three positions are commonly used for ankle arthroscopy: supine, lateral, and prone. Use of a thigh holder in the supine position helps provide countertraction and elevates the ankle above the table to allow room for maneuvering the instruments through the posterior portals.

The operating table foot pad can be removed to allow even better access. However, the thigh holder should be well padded to prevent injury to the sciatic nerve and should be positioned away from the popliteal fossa. It is set to flex the hip at 45°.

The patient is secured with side supports or belts. A bolster placed under the hip or tilting the table brings the ankle into a neutral orientation. All bony prominences are padded, and the patient is prepared and draped to isolate the operative area below the knee in a sterile field.

After the procedure, further management and follow-up vary, depending on the condition, on the arthroscopic procedure performed, and on any concomitant surgery. Wounds are reviewed at 1 week, when the splint is discarded and a compression stocking and a supportive brace are provided. Weightbearing is allowed when tolerated, which is usually about 3 weeks after a soft-tissue procedure and about 6-8 weeks after a bony procedure. Physical therapy is started at 2-3 weeks after surgery, and sports activities can be resumed after 6 weeks.

The need to perform ankle arthroscopy varies according to the specific condition present. Usually, ankle arthroscopy is indicated after the failure of conservative measures, such as physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), ankle braces, heel lifts, or wedges. It is also indicated in cases where symptoms persist and study results are inconclusive.

Although ankle arthroscopy is useful in addressing intra-articular pathology, the underlying cause of this pathology could be extra-articular, and this possibility should also be addressed. Thus, ankle arthroscopy is sometimes performed concomitantly with other procedures to address the underlying pathology. For example, ankle arthroscopy may address soft-tissue impingement or an osteochondral lesion,[32, 31] but if there is underlying lateral ligament laxity or a hindfoot varus deformity, additional procedures are appropriate.

In a retrospective study of patients treated for acute ankle fracture in the United States from 2007 to 2011, Ackermann et al found that despite the availability of good evidence in favor of performing arthroscopy at the time of ankle fracture treatment, only a small percentage of US surgeons performed these procedures concurrently during this time period.[33]

A sterile tourniquet can be used and is usually applied on the leg just above the ankle. However, the ankle joint distention (see below) with the irrigation fluid may be enough to provide a bloodless field and is sufficient in some cases.

A high inflow and outflow system is helpful in obtaining hemostasis; it permits improved visualization and irrigation of debrided material; and it can be adjusted throughout the operative procedure.

In establishing the arthroscopy portals, it is important to be aware of the surface anatomy. A skin marker is used to outline the important neurovascular structures in the vicinity of the portals and the joint line. An 18-gauge needle is introduced medial to the tibialis anterior tendon, and 15-20 mL of saline or 0.25% bupivacaine solution with epinephrine is injected to distend the ankle joint (see the image below).

Joint distention before establishment of the anteromedial portal.

At the portal site, a No. 11 blade is used to incise the skin layer only, and a fine mosquito hemostat forceps is then used to perform blunt dissection into deeper layers and to enter the capsule.

The two most commonly used anterior portals are the anteromedial and anterolateral portals (see the image below). An anteromedial portal is placed just medial to the anterior tibial tendon at the joint line. An anterolateral portal is placed just lateral to the peroneus tertius tendon; this is at the level of, or slightly proximal to, the joint line.

Intraoperative photo showing establishment of an anterolateral portal. The arthroscope is inserted into the anteromedial portal.

Posterior portals are also useful during arthroscopy of the ankle. These portals are placed immediately medial or lateral to the Achilles tendon or through its substance just distal to or at the joint line. A posterolateral portal is established in the soft spot just lateral to the Achilles tendon, 1.2 cm (0.5 in.) above the tip of the fibula. Because of the potential for serious complications and the difficulty of maneuvering the arthroscope, trans-Achilles and posteromedial portals are contraindicated in most instances.

Hirtler et al, in a cadaver study using 20 matched pairs (n = 40) of anatomic ankle specimens, evaluated accessibility of the talar dome in neutral position, dorsiflexion, or noninvasive distraction in posterior ankle arthroscopy.[34]  In neutral position, 13.7 ± 1.2 mm of the talar dome was reached laterally and 14.0 ± 1.0 mm medially; in maximal dorsiflexion, 19.0 ± 1.1 mm was reached laterally and 19.8 ± 1.4 mm medially; and in noninvasive distraction, 16.1 ± 1.5 mm was reached laterally and 15.7 ± 1.0 mm medially. There was significantly better reach in dorsiflexion laterally and medially. Accessibility of the talar dome in maximal dorsiflexion was superior to that in neutral or in noninvasive distraction.

Transmalleolar portals through either the tibia or the fibula are used in cases where a more direct approach is required—for example, when Kirschner wires are drilled into the talar dome under fluoroscopic and endoscopic control for the purpose of establishing new vascularity in an osteochondral lesion. Transtalar portals can also be used for retrograde drilling and possibly for bone-grafting osteochondral lesions of the talus.

A 30° 2.7-mm arthroscope is used initially, and the ankle is visualized through all portals to perform a systematic examination of the entire ankle joint. Interchangeable cannulas should be used to minimize the trauma associated with the passage of instruments.

Debridement includes removal of the inflamed synovium, thickened adhesive bands, inflamed capsular bands and ligamentous tissue, osteophytes, and loose bodies (see the images below). Debridement is performed to expose the underlying cartilage.

Arthroscopic view of an intra-articular band.

Arthroscopic view following debridement with an arthroscopic shaver of the intra-articular band seen in the figure above.

Arthroscopic view of a loose body.

Bony spurs causing impingement are shaved with arthroscopic burrs and shavers. Employ extreme caution when using these instruments; never direct them dorsally into the soft tissues, because doing so may injure the neurovascular structures.

Osteochondral lesions of the talus that are located anterolaterally can be approached through the anterior portals for curettage and for microfracture or drilling. Lesions that are located posteromedially can be visualized with plantarflexion of the ankle. If a direct approach is required for antegrade or retrograde drilling, a microvector drill guide is used to establish a transosseous portal.

Preparation of surfaces for arthroscopic ankle arthrodesis requires thorough denudation of all hyaline cartilage exposure of vascular subchondral bone. In addition, multiple puncture holes in the prepared surfaces allow easy vascular ingress across the surfaces to be fused.

After the arthroscopic procedure has been completed, the joint is thoroughly irrigated, with the remaining fluid expressed out of the joint. The portals are closed with absorbable sutures and covered with sterile gauze and soft, bulky dressing. A posterior splint is applied to provide comfort and allow the portals to heal. Patients are instructed to keep the limb elevated and to exercise the toes, knees, and hips. Cryotherapy can help minimize and reduce the postoperative swelling.

In a review of 53 consecutive ankle arthroscopies, Barber et al reported nine complications (complication rate, 17%), which included permanent dorsal sensory nerve injury (three cases), synovial fistula (two), wound infection (three), and  reflex sympathetic dystrophy (one).[35] Other complications identified in a literature review were instrument breakage, synovitis, painful scars and nodules, and fibula fracture.

In a study involving 612 patients undergoing ankle arthroscopy, the overall complication rate was 9.8%. Among these patients, the most common complications were neurologic (49%), primarily involving the superficial peroneal nerve (56%), the saphenous nerve (24%), or the sural nerve (20%). Other complications included superficial infection, deep infection, adhesions, fractures, instrument failure, ligament injury, and incisional pain.[14]

Zengerink et al reported on complications in ankle arthroscopy after a review of a consecutive series of patients undergoing ankle arthroscopy in their hospital between 1987 and 2006.[36] Anterior ankle arthroscopy was performed by means of a two-portal hindfoot approach with a dorsiflexion method and intermittent soft-tissue distraction. Complications were registered in a prospective national registration system. Apart from this complication registry, patient records, outpatient charts, and operative reports were reviewed. Patients with a complication were asked to visit the hospital for clinical examination and assessment of permanent damage and persisting complaints.

The overall complication rate was 3.5% in 1305 procedures.[36] Neurologic complications (1.9%) were related to portal placement. Age was a significant risk factor for complications. Most were transient and resolved within 6 months. Complications did not lead to functional limitations. Residual complaints did not influence daily activities. The authors concluded that the complication rate was less than half of that reported in the literature (3.5% vs 10.3%), that the dorsiflexion method for anterior ankle arthroscopy can prevent a significant number of complications, and that posterior ankle arthroscopy via a two-portal hindfoot approach is safe with a complication rate comparing favorably to anterior ankle arthroscopy.

Zekry et al reviewed the literature on complications following anterior and posterior ankle arthroscopy and identified a total of 107 papers, of which 55 were deemed appropriate for analysis.[37] The overall complication rate of ankle arthroscopy was found to be in the range of 3.4-9%. No life-threatening complications were identified with either anterior or posterior ankle arthroscopy. The most common complications after anterior and posterior ankle arthroscopy were superficial peroneal nerve injury and temporary Achilles tendon tightness, respectively.

The goals of pharmacotherapy are to reduce morbidity and prevent complications.

Class Summary

Local anesthetics block the initiation and conduction of nerve impulses.

Bupivacaine and epinephrine (Marcaine with Epinephrine, Vivacaine, Sensorcaine with Epinephrine)

These decrease permeability to sodium ions in neuronal membranes. This results in the inhibition of depolarization, blocking the transmission of nerve impulses. Epinephrine prolongs the duration of the anesthetic effects from bupivacaine by causing vasoconstriction of the blood vessels surrounding the nerve axons.

An 18-gauge needle is introduced medial to the tibialis anterior tendon, and 15-20 mL of saline or 0.25% bupivacaine solution with epinephrine is injected to distend the ankle joint.