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Ankle Arthroscopy
Historically, the ankle joint was believed to be unsuitable for arthroscopy because intra-articular access of this joint is narrow. Tagaki and later Watanabe described techniques and pioneered the use of arthroscopy in the examination of the ankle. Compared with open arthrotomy, arthroscopy has recognized benefits of shortened recovery times and limited surgical morbidity. Today, arthroscopy of the foot and ankle has evolved from simply a diagnostic tool to a versatile treatment modality for a variety of pathologies.
It is important to understand the surface and superficial anatomy in the area of the ankle to minimize the risk of damage to the surrounding structures when performing ankle arthroscopy. Important landmarks to identify include the tibialis anterior tendon, the peroneus tertius tendon, the level of the joint line, the superficial peroneal nerve and its branches, and the great saphenous vein. It is also important to understand the location of the deep peroneal nerve and dorsalis pedis artery as they cross the anterior ankle joint. The branches of the superficial peroneal nerve are most commonly injured during this procedure. These branches can be identified and marked prior to the procedure by plantar flexing and inverting the foot.
The anteromedial, anterolateral, and posterolateral portals are most commonly used for ankle arthroscopy. Anterior portal options include the anteromedial, anterolateral, anterocentral, and accessory anteromedial and anterolateral portals. The anteromedial portal is made just medial to the tibialis anterior tendon at the level of the joint line. Confirmation of planned portal placement is recommended with use of an 18-gauge needle to localize and insufflate the joint with approximately 10 mL of saline solution before creating the portal. All portals should be created by making a small incision with a scalpel through the skin only and then using a blunt instrument such as a mosquito clamp to spread the soft tissue down to the capsule. Once the soft tissue is safely cleared, the capsule can be penetrated with a blunt instrument, such as the blunt trocar, with care being taken to prevent injury to the articular cartilage. This technique helps minimize the risk of damage to overlying structures. An accessory anteromedial portal can be created 1 cm anterior and 0.5 to 1 cm inferior to the medial malleolus.
The anterolateral portal is created under direct visualization once the arthroscope has been introduced through the anteromedial portal. A needle is once again used to confirm portal placement at or just above the level of the joint lateral to the peroneus tertius tendon. This helps to avoid injury to the intermediate dorsal cutaneous branch of the superficial peroneal nerve. The needle can be used to confirm that the portal will allow adequate access to the area being treated before making the skin incision. An accessory anterolateral portal can be placed 1 cm anterior to and at the level of the tip of the distal fibula.
The anterocentral portal carries an increased risk of neurovascular damage and thus is not commonly used. It is located between the extensor digitorum tendons, with the deep peroneal nerve and dorsalis pedis artery just medial to this portal, coursing between the extensor hallucis and extensor digitorum communis tendons.
Posterior portal options include posterolateral, trans Achilles, and posteromedial ( Fig. 115.1 ). A posterolateral portal is placed just lateral to the Achilles tendon approximately 1 to 1.5 cm proximal to the tip of the distal fibula. This portal can be established under direct visualization if anterior arthroscopy is being performed. If hindfoot endoscopy is being performed, this portal should be established first, followed by the posteromedial portal. The trans Achilles portal can be established at or just below the joint level through the midportion of the tendon but is less favored because of Achilles tendon morbidity and increased difficulty with instrument manipulation. The posteromedial portal risks damage to the posterior tibial artery and tibial nerve, as well as the calcaneal nerve and branches. If used, it is placed medial to the Achilles tendon at the joint level after establishing the posterolateral portal. After a small skin incision is made, a blunt instrument, such as a mosquito, is directed toward the arthroscope and “walked down,” maintaining contact with the arthroscope until bone is palpated. The lens of the arthroscope is directed laterally to protect it until the mosquito reaches the bone, at which point the lens can be turned medially to visualize the introduction of an instrument, usually a motorized shaver, through the newly established portal.
Arthroscopically assisted ankle fracture open reduction with internal fixation. (A) The view of the medial malleolar fracture before reduction. (B) The view of the medial malleolar fracture after reduction.
Soft Tissue Conditions Amenable to Arthroscopy
It is estimated that 3% of all ankle sprains lead to anterolateral impingement. Wolin et al. were the first to describe the pathology. They described a mass of hypertrophied fibrocartilaginous scar tissue that originated from the anterior talofibular ligament and rested in the lateral gutter. They coined the term meniscoid lesion because of its similar appearance to a knee meniscus. Bassett et al. described another cause of impingement after an inversion sprain. The distal fascicle of the anteroinferior tibiofibular ligament can impinge on the talus when it becomes thickened or scarred from an injury ( Fig. 115.2 ).
Proposed causes for anteromedial impingement include injury to the deltoid ligament and capsule, resulting in scarring and hypertrophy of the synovium, repetitive capsular traction resulting in “traction spurs,” and repetitive dorsiflexion of the ankle.
With a syndesmotic injury, the anteroinferior tibiofibular ligament can become scarred and hypertrophied. Chronic synovitis can occur at the tibiofibular joint, resulting in a soft tissue lesion impinging on the talus.
Plicae have been well described in the knee. The origin of these lesions in the ankle is not well understood, but theories include congenital and traumatic causes. As with the knee, these fibrous cords typically can be found across the anterior ankle joint and have been implicated as a source of ankle pain, clicking, and occasional locking. Plicae syndrome refers to the painful impairment of joint function in which the only finding that helps explain the symptoms is the presence of thickened plicae. When encountered during an arthroscopic procedure, the thickened plicae are routinely excised.
Posterior ankle impingement can be caused by overuse or trauma. The overuse group comprises ballet dancers and athletes in sporting activities that involve forced plantar flexion of the foot. Repetitive plantar flexion results in swelling, partial rupture, and fibrosis of the posterior ankle capsule, synovium, and posterior ligamentous structures. A prominent posterior talar process or os trigonum can produce the syndrome. Dancers or athletes who often go en pointe may have hypertrophy of the flexor hallucis longus (FHL) muscle belly resulting in further impingement of these tissues posteriorly.
The role of arthroscopy in the treatment of a patient with an inflammatory arthritic condition such as rheumatoid arthritis is limited. A patient with painful synovitis that is recalcitrant to conservative therapies may benefit from an arthroscopic complete synovectomy. The synovial lining is typically proliferative and thickened.
Pigmented villonodular synovitis (PVNS) is a benign neoplastic process of the synovium. It is most common in the knee but also can be seen in the ankle and hindfoot. It is seen in two forms: generalized synovitis and a localized form. Localized lesions respond well to arthroscopy, but recurrence is common with the generalized form.
Septic arthritis of the ankle is amenable to treatment with arthroscopic lavage and débridement; however, only two case series have focused on arthroscopic treatment of ankle septic arthritis, and both included various joints in the study. Despite the paucity of literature regarding the use of ankle arthroscopy in the management of septic arthritis, this practice is widely accepted.
Synovial chondromatosis is a benign condition in which the synovial lining of joints, bursae, or tendon sheaths undergoes metaplasia and ultimately forms cartilaginous loose bodies. Milgram described three stages of the process. Stage I is the active synovial phase, without the presence of loose bodies. Stage II is the transitional phase, with both active synovial disease and chondral loose bodies. Stage III describes the burnout phase, with no further synovial activity and residual loose bodies.
Lateral ankle ligament injuries are the most common injuries that occur in sports and recreational activities (refer to Chapter 117 for full details regarding this pathology). Recently, arthroscopic and arthroscopically assisted reconstruction of the lateral ligament complex has been reported either by autograft reconstruction, anchor fixation techniques, and thermal shrinkage.
Pain and disability from ankle arthritis may be treated with arthroscopy. In mild cases without significant loss of cartilage and in active patients for whom a fusion or replacement is not reasonable, arthroscopic débridement provides a low-risk alternative. In cases of end-stage arthritis, ankle arthrodesis may be indicated to relieve pain at the tibiotalar joint when prior conservative treatment has failed. Since the first description of arthroscopic ankle arthrodesis in 1983, this procedure has gained popularity. Contraindications include significant extensive bone loss, active infection, a neuropathic joint, and ankle fusion nonunion.
Arthroscopy of an acute ankle fracture can assist in the anatomic reduction of some fractures, diagnose syndesmotic instability, and assist in the treatment of concomitant osteochondral and chondral injuries. Direct visualization can confirm articular congruency and identify other fracture lines/fragments not seen on preoperative radiographs (see Fig. 115.1A and B ). Arthroscopy in the setting of chronic fractures can assist in the diagnosis and management of postfracture pathology. The indication for arthroscopy in the treatment of chronic ankle fractures (>3 months) is persistent joint pain that is unresponsive to conservative management.
History
Patients with anterolateral impingement typically report pain with weight-bearing activities after an inversion ankle injury that has not resolved. They can describe a feeling of instability, even without true mechanical instability, if the intermittent pain causes a feeling of giving way. Anteromedial impingement presents with anteromedial ankle pain with activities that place the ankle in a dorsiflexed position, such as running, kicking, or climbing stairs. The clinical presentation of syndesmotic impingement is similar to that of anterolateral impingement, with pain upon weight-bearing activities, variable swelling, and the feeling of locking or clicking of the ankle with range of motion (ROM).
Patient presentation can vary widely with synovial chondromatosis, with ankle pain, swelling, limited ROM, and palpable nodules at the joint line.
Patients with posterior ankle impingement report pain toward the posterior aspect of the talus, mainly with plantar-flexion maneuvers.
Physical Examination
The diagnosis of anterolateral impingement is clinical, based on the physical examination. Molloy et al. reported a sensitivity of 94.8% and specificity of 88% on special physical examination testing for impingement. Patients exhibit palpable tenderness along the anterolateral corner of the ankle, along with anterior syndesmosis. Occasionally, asymmetric fullness along the anterolateral corner can represent scar tissue. Pain often can be elicited with passive dorsiflexion of the ankle, either while it is unloaded or with weight bearing. Tenderness at the sinus tarsi may be present but should be mild compared with the anterolateral ankle. An injection of a local anesthetic can confirm the diagnosis of soft tissue impingement when excellent pain relief is achieved.
Examination reveals anteromedial ankle joint tenderness and pain with dorsiflexion either while the ankle is loaded or with no weight bearing in patients with anteromedial impingement.
Patients with syndesmotic impingement have a more variable examination than do those with anterolateral or anteromedial impingement; findings can range from significant tenderness at the distal syndesmosis to no pain elicited on palpation. In chronic cases, examination of syndesmotic disruption (the squeeze test and external rotation test) may not be painful.
Patients with PVNS present with nonspecific findings such as a swollen, warm, diffusely tender ankle that is painful with activity. During the workup, aspiration of the joint can produce dark, serosanguineous fluid.
Palpation of the posterior talar process performed posterolaterally between the peroneal tendons and the Achilles tendon will reproduce the pain in patients with posterior impingement. The passive forced plantar-flexion test is executed with repetitive quick passive hyper-plantar-flexion movements with the patient sitting and his or her knee flexed at 90 degrees. van Dijk described application of a rotational movement at the point of maximal plantar flexion and stated that a negative test rules out posterior impingement. The diagnosis is supported by relief of the pain with plantar flexion upon infiltration of an anesthetic.
Imaging
In the setting of anterolateral impingement, radiographs are often normal but can demonstrate anterior tibial and talar neck spurring. Standard anteroposterior and lateral radiographs may not detect the presence of all osteophytes, specifically off the medial aspect of the tibia and talus. van Dijk et al. described an oblique anteromedial impingement view (a 45-degree craniocaudal radiograph with 30-degree external rotation of the leg and the foot in plantar flexion). The anteromedial impingement view improves diagnosis of both talar and tibial anteromedial osteophytes. Radiographs may reveal ossification along the syndesmosis in the setting of syndesmotic impingement, and in cases in which instability is a concern, fluoroscopic external stress imaging is necessary to determine the presence of laxity. Radiographs can appear normal in stage I and early stage II cases in patients with synovial chondromatosis, whereas multiple calcific nodules within the anterior and posterior aspects of the ankle clearly indicates the diagnosis.
Plain radiographs may reveal an os trigonum or Stieda process in the setting of posterior impingement.
Magnetic resonance imaging (MRI) is the most valuable modality for evaluating soft tissue pathology. The reported sensitivity for an MRI scan in the diagnosis of anterolateral impingement varies from 39% to 100%, and its specificity varies from 50% to 100%. MR arthrography with diluted gadolinium solution increases the sensitivity in diagnosing ankle impingement. Although not required for the diagnosis of impingement, it is helpful in excluding other ankle pathologies, such as osteochondral defects. MRI can also identify soft tissue edema, bone edema involving an os trigonum/Stieda process, tenosynovitis of the FHL, and loose bodies when evaluating patients with posterior impingement. In the setting of PVNS, MRI scans typically reveal swollen synovial tissue and hemosiderin deposits. Computed tomography (CT) and MRI have been useful tools in the diagnosis of synovial chondromatosis. Depending on the extent of calcification and synovial proliferation, the appearance may vary.
Decision-Making Principles
A wide variety of pathologic conditions can be treated by means of routine anterior ankle arthroscopy. Diagnostic ankle arthroscopy without a preoperative diagnosis has limited value. Relative contraindications for ankle arthroscopy include moderate degenerative joint disease and joint disease with severely reduced joint space, vascular disease, and severe edema. Absolute contraindications include severe degenerative joint disease not amendable to arthroscopic arthrodesis and a localized soft tissue infection.
Although septic arthritis can be treated effectively with arthroscopy, infection involving the soft tissue envelope around the ankle is best treated with an open débridement. In the early phases of synovial chondromatosis, with active synovial disease, a synovectomy with loose body removal is indicated. For patients with stage III disease, only removal of loose bodies is indicated.
When considering whether to perform an arthroscopy ankle arthrodesis, the surgeon should understand that this technique is an in situ fusion and that significant deformity in any plane is considered a contraindication. Coronal plane deformities greater than 15 degrees are not appropriate for an arthroscopic approach. Additionally, in the setting of osteoporosis or loss of bone stock of the talar body, an open approach with plate fixation should be considered to ensure adequate fixation.
With regard to posterior ankle arthroscopy, a systematic review was published assessing the current level of evidence supporting its use for certain pathologies. The article concluded that posterior ankle impingement syndrome, subtalar arthritis, and retrocalcaneal bursitis have the strongest recommendation in favor of treatment.
Nonoperative Management
Initial management involves rest, activity modification, use of oral antiinflammatory medications, ice, corticosteroid injections, orthoses, heel lifts, and physical therapy. Patients with chronic symptoms who fail to respond to conservative treatment after 3 to 6 months are appropriate surgical candidates. Surgery may be considered more urgently if the patient notes mechanical symptoms, such as catching or locking, which may suggest a loose body or cartilaginous flap tear.
General Surgical Technique: Ankle Arthroscopy
Arthroscopic Equipment
A range of arthroscope sizes are available, with the 2.7-mm size being the most versatile for the ankle and allowing visualization in the reduced space available in the medial and lateral gutters. The smaller sized arthroscopes are designed for smaller joints and include a shorter lever arm, which affords increased control over the instrument in a small joint and is preferred to prevent articular cartilage injury during the procedure. A 30-degree arthroscope is recommended for most ankle arthroscopic procedures because it increases the field of view (compared with a 0-degree scope) without the disadvantage of a central blind spot (as with the 70-degree scope). Occasionally a 70-degree arthroscope can be helpful, particularly when it is necessary to see around a corner, such as into the posterior ankle, but its use is accompanied by a learning curve. When performing hindfoot endoscopy, a 4.0-mm arthroscope is commonly used because the size and anatomic constraints are not as limiting as in anterior ankle arthroscopy.
As is the case with the arthroscope itself, a line of small joint instruments has also been developed; these instruments are smaller in diameter and have shorter lever arms. Availability of a probe, graspers, punches, curettes, and baskets is important. Other instruments now available include osteotomes designed for arthroscopic ankle arthrodesis, awls for microfracture, small joint drill guides and targeting devices, and small radiofrequency probes. A range of options are available for disposable arthroscopic shavers and burrs as well, ranging in aggressiveness and sizes from 2.0, 2.9, to 3.5 mm. Generally a 3.5-mm shaver is recommended; the smaller options can be quite useful in certain circumstances, such as in tighter joints or in the gutters, although they do tend to reduce efficiency.
Inflow/Outflow
A two-portal or three-portal system (usually with use of the posterolateral portal for inflow) with gravity or a pump system can be used. A two-portal system is most commonly used for both anterior ankle arthroscopy and hindfoot endoscopy, along with a pump to improve flow and visualization. Frequently, if a soft tissue procedure, such as a lateral ligament reconstruction is planned, a pump system is not used to minimize the amount of soft tissue fluid extravasation.
Positioning
For anterior ankle arthroscopy, the patient is positioned supine on the operating table. A beanbag can be used underneath the patient and positioned so that the ipsilateral hip is slightly elevated, and the remaining part of the beanbag is gathered under the thigh to hold the patient in position if distraction is applied. This area needs to be well padded. Alternatively, a padded leg holder or thigh support can be used and serves to position the limb and provide support to keep the patient in position when distraction is used. A nonsterile tourniquet can be placed on the thigh and inflated if necessary or according to the surgeon's preference. The patient should be positioned toward the end of the table to ease access and surgeon comfort while allowing enough room for the distraction setup to effectively apply a force.
For hindfoot endoscopic procedures, the patient is positioned prone. A small bolster or support under the operative leg will allow for adequate ankle motion. Again, a thigh tourniquet should be applied; it may be used more often in these procedures than during anterior ankle arthroscopy.
Distraction
Initially, distraction was described using the placement of pins in the calcaneus and distal tibia to allow the application of a distractive force. Although this technique provides excellent distraction, disadvantages include risk of fracture, pin site infection, and neurovascular injury. Therefore noninvasive distraction has become the more favored option. Noninvasive distraction is performed using a disposable strap that passes over the dorsal foot and around the posterior aspect of the heel. This strap is attached to a sterile distractor that connects to the table rail ( Fig. 115.3 ). To minimize the risk of neurovascular injury for either method of distraction, it is recommended that the distractive force be applied for a maximum of 90 minutes.
Anesthesia
Inducement of regional anesthesia with use of a popliteal nerve block can be very effective in managing postoperative pain and minimizing the need for general anesthetics. Administration of a popliteal nerve block can be performed with use of a nerve stimulator or ultrasound guidance. We recommend the use of a popliteal nerve block in conjunction with general anesthesia to facilitate distraction and the use of a tourniquet if needed.
Tourniquet
A well-padded thigh tourniquet should be applied prior to patient positioning at the start of the case. Depending on the surgeon's preference and anticipated bleeding, the use of the tourniquet may or may not be necessary. Commonly the case can be performed without a tourniquet, but if bleeding becomes problematic, it can be inflated. A randomized, controlled trial assessing the use of a tourniquet versus no tourniquet for anterior ankle arthroscopy demonstrated that there was no difference in surgical time, visualization, and functional scores between the two groups. However, it was noted that there was statistically less pain in the early postoperative period for the nontourniquet group.
Arthroscopic Examination
The ankle can be divided into the anterior, central, and posterior compartments. Ferkel has described the 21-point examination, including 8 points in the anterior compartment, 6 in the central compartment, and 7 in the posterior compartment. The anterior compartment examination includes the deltoid ligament, medial gutter, medial talus, central talus, lateral talus, talofibular articulation, lateral gutter, and anterior recess (see Fig. 115.3 ). The central compartment focuses on the tibiotalar articulation, examining the medial, central, and lateral aspects of this articulation, as well as slightly posteriorly looking at the posteroinferior and transverse tibiofibular ligaments and the reflection of the FHL tendon. The posterior compartment examination is performed while viewing from the posterolateral portal and includes the deltoid ligament, medial gutter, posteromedial talus and tibial plafond, central and lateral talus, posterior talofibular articulation, lateral gutter, and posterior recess.
Authors’ Preferred Technique
Anterior Arthroscopic Débridement
Patients are placed in the supine position with a thigh tourniquet (inflation is optional). The patient's leg is secured on a nonsterile thigh holder. Before preparing the area, the course of the superficial peroneal nerve is identified by plantar flexing and inverting the foot. The path of the nerve is marked with a surgical marking pen. For use of noninvasive distraction, the foot strap harness is placed and distraction is applied to the foot. It is important to avoid excessive use of distraction. With longer procedures (more than 90 minutes) consideration should be given to relaxing some of the tension on the distraction device. Palpation of the joint line, anterior tibialis tendon, and peroneus tertius is performed. As previously described, the anteromedial and anterolateral portals are marked. At the marked anteromedial portal, sterile normal saline solution is infused through a 22-gauge needle. A knife with a no. 11 blade is then used to make a small vertical incision through the skin only. Blunt dissection through the subcutaneous tissue is made with use of a mosquito clamp. The blunt trocar with the attached arthroscope cannula (a 4.0- or 2.7-mm scope) is carefully introduced through the ankle capsule into the joint. The arthroscope (typically 30 degrees) is exchanged for the blunt trocar, and the inflow side post is opened to infuse normal saline solution. For most procedures, the inflow is set up to gravity pressure only, or a pressure pump set to small joints. A 22-gauge needle is inserted at the anterolateral portal into the ankle joint and visualized with the scope. The position of this portal can be adjusted on the basis of the location of the ankle lesion. Using the same technique as with the anteromedial portal, the anterolateral portal is established. Sequential examination of the ankle is performed as previously described. A posterolateral portal can be established for inflow or visualization if necessary. For many anterior impingement lesions, visualization of the anterior compartment is maximized with minimal distraction and dorsiflexion of the ankle.
After the diagnostic examination, débridement with use of various arthroscopic tools and shavers is performed. Débridement includes removal of inflamed synovium, thickened adhesive bands and ligamentous tissue, osteophytes, and loose bodies. Typically the postfracture ankle and the arthritic ankle are contracted and challenging to navigate. Iatrogenic injury to the already traumatized articular surface should be avoided. Osteophytes are first débrided of soft tissue, capsule, or adhesions. An arthroscopic burr, pituitary rongeur, and small osteotome can be introduced through both anterior portals to completely remove the spurs. The goal for adequate resection is to establish an angle of 60 degrees with lines tangential to the talar neck and anterior tibia. Chondral lesions are débrided of loose fragments with a motorized shaver. Full-thickness lesions are débrided, and the subchondral base is drilled, similar to the technique described for microfracture/abrasion arthroplasty for talar osteochondral defect.
For anterolateral lesions, the diseased tissue may extend superiorly to the syndesmotic ligaments. For medial lesions, the arthroscope is placed in the anterolateral portal with instruments passed through the anteromedial portal. Care is taken to preserve the deep deltoid ligament. For cases of syndesmotic impingement, before preparing the limb, the stability of the syndesmosis is evaluated with stress radiographs obtained with the use of an anesthetic.
Gravity inflow should be used in the setting of an acute ankle fracture to avoid excessive fluid extravasation into the soft tissues. Hemarthrosis, fibrinous debris, and chondral/osteochondral fragments are removed or repaired. Fracture reduction is performed with a Freer elevator, arthroscopic probe, or reduction tenaculum. Fracture fixation is performed based on the pattern of injury, and the arthroscope is used to confirm an anatomic reduction.
The portals are closed with use of nylon suture in a vertical mattress pattern.
Authors’ Preferred Technique
Posterior Impingement
Patients are placed in a prone position, with placement of a thigh tourniquet. With the ankle in a neutral position, the posterolateral portal is made at the level of the tip of the lateral malleolus, just lateral to the Achilles tendon ( Fig. 115.4 ). A vertical incision is made using a no. 11 blade through skin only. A mosquito clamp spreads the subcutaneous layer and is directed anteriorly in the direction of the interdigital web space between the first and second toe. Once the clamp touches bone, it is exchanged for a 2.7- or 4.0-mm 30-degree arthroscope. The camera is directed laterally. The posteromedial portal is made at the same level. Once the skin incision is made, a mosquito clamp is directed to the arthroscope shaft. When the mosquito clamp touches the arthroscope shaft, the clamp moves anteriorly toward the ankle joint, touching the arthroscope the entire way. The arthroscope is slightly pulled back, visualizing the tip of the clamp. An arthroscopic shaver is exchanged for the clamp, and the fatty tissue and synovium overlying the posterior ankle and subtalar joint are débrided. The posterior tibiofibular and talofibular ligament are identified. The posterior talar process, os trigonum, and FHL are identified. Care is taken to stay lateral to the FHL to prevent injury to the medial neurovascular bundle. Excision of an os trigonum or hypertrophic posterior talar process requires partial detachment of the posterior talofibular ligament, flexor retinaculum, and posterior talocalcaneal ligament ( Fig. 115.5 ). After débridement, the skin portals are closed with nylon suture in a vertical mattress pattern.
Authors’ Preferred Technique
Lateral Ankle Ligament Reconstruction
Position, equipment, distraction, and portal placement were outlined previously for a standard anterior ankle arthroscopy approach. After a complete diagnostic arthroscopy of the ankle and treatment of accompanying lesions, lateral ankle instability can be visually confirmed with talar tilt and anterior drawer maneuvers. The lateral gutter is débrided of all scar tissue, and the periosteum is removed off the anterior aspect of the fibula (immediately distal from the anterior-inferior tibiofibular ligament). With the suture-anchor technique, a suture anchor is delivered through the anterolateral portal and placed into the prepared surface of the fibula. An accessory anterolateral portal is made 1 to 2 cm in front of the tip of the distal fibula. The sutures are pulled through the accessory anterolateral portal, and deep stitches with the sutures are made in the lateral ligament complex. The knot is tightened with the foot held in eversion and with a slight posterior drawer force. With the thermal energy technique, the thermal electrode is passed through the anterolateral portal and serially swept across the area of the anterior talofibular ligament (and calcaneofibular ligament posteriorly) with the foot placed in an everted position.
Authors’ Preferred Technique
Arthroscopic Ankle Arthrodesis
As previously described, two- or three-portal arthroscopy is performed. Noninvasive or invasive distraction facilitates exposure. Good visualization may require the removal of anterior scar tissue and osteophytes. The joint often has a large distal tibial and talar neck osteophyte that must be débrided not only for exposure but also to achieve adequate apposition of the joint surfaces. All remaining articular cartilage is removed with use of an arthroscopic shaver, straight and angle curettes, and osteotomes. The posterior talus and posterior malleolus are best approached from the posterolateral portal. After removal of all residual cartilage, the subchondral surface is prepared with a motorized abrader, removing a 1- to 2-mm layer of bone to the level of viable bleeding bone ( Fig. 115.6 ). After débridement, the distractor is removed and the foot is positioned. The ideal position for fusion is 0 to 5 degrees of valgus, neutral dorsiflexion, and external rotation matching the contralateral ankle (typically 0 to 5 degrees). Internal fixation is performed with 6.5- or 7.0-mm cannulated, partially threaded screws. Two-screw fixation includes one placed from the medial malleolus toward the lateral process of the talus and a second screw placed lateral traversing the fibula into the talus. Three-screw fixation includes a final screw placed laterally, either anterior or posterior to the fibula. Final fluoroscopic views of the ankle are taken to confirm screw length and placement, as well as reduction and compression of the joint.
Postoperative Management
We prefer the use of a well-padded below-knee splint as the initial surgical dressing. This splint protects the limb, diminishes pain, and helps control swelling. The splint is removed around 10 to 14 days after surgery, and sutures are removed. For most conditions, a removable fracture boot is used to permit early motion exercises. The patient also increases weight bearing as allowed by pain and swelling of the limb. Formal physical therapy may also assist in facilitating the patient's rehabilitation and recovery. Patients typically perform therapeutic exercises without restrictions except if a lateral ligament reconstruction is performed; in that instance, limitation of inversion for the first 4 to 6 weeks can assist in early ligament healing. Discontinuation of the boot brace occurs around 4 to 6 weeks, followed by use of a lace-up ankle brace for patients with ligament reconstruction.
An exception to this general protocol is in cases of arthroscopic ankle arthrodesis; patients who have undergone this procedure are typically immobilized in a below-knee cast and restricted from weight bearing for approximately 6 to 8 weeks followed by progression of partial weight bearing to full weight bearing in a boot over another 4 to 6 weeks. Final discontinuation of the boot immobilization occurs once clinical and radiographic healing is confirmed.
Return to play in cases of loose body removal, synovectomy, and débridement of anterior or posterior impingement lesions is variable, but in most cases it is permissible 10 to 12 weeks after surgery. This time frame allows resolution of pain and edema along with advancement of the patient's rehabilitation and conditioning. Later phases of recovery focus on return to running, cutting and lateral movements, jumping, agility training, and sport-specific drills. Return to aggressive sports is, of course, very limited in cases of ankle arthrodesis, with many patients able to participate in light sporting activities but not in sports that entail heavy running or cutting.
Results
Most studies on ankle impingement are level IV case series, and rates of good to excellent patient outcomes are reported in more than 80% of cases. Scranton and McDermott compared open resection and arthroscopic resection of osteophytes in a retrospective study (level III). Length of stay and time to recovery were shorter in the arthroscopic group. In several prospective studies (level II), the success of arthroscopic débridement was reported as being between 73% and 96%. One prospective, randomized (level I) study compared arthroscopic treatment of patients with a chronic syndesmotic injury both with or without medial instability. The authors found no significant outcome difference between the two groups and reported an overall satisfaction rate of 90%. Long-term studies assessing the outcomes of ankle arthroscopy for anterior impingement are lacking, however Parma et al. published a study with a mean follow-up of 104.6 months. The authors concluded that while the postoperative American Orthopaedic Foot and Ankle scores (AOFAS) were still significantly improved at final follow-up compared to the preoperative assessment, chondral lesions, advanced age, and previous trauma were negative prognostic factors.
Most studies involving the benefits of posterior ankle endoscopy involve level IV research. Morag et al. and Ogut et al. reported on the results of endoscopic treatment of several pathologies in their patients, including Haglund deformity, peroneal tendonitis, and Achilles pathologies. Another series reviewed the outcomes of 55 patients treated for posterior ankle impingement with hindfoot endoscopy. Symptoms were caused by trauma in 65% of patients and by overuse in 35% of patients. Postoperative AOFAS improved, with patients in the overuse group more satisfied than those in the posttraumatic group. Willits et al. reported their results for 23 patients treated for posterior ankle impingement. All patients showed satisfactory scores on all outcome measures and a high rate of return to sports. Smyth et al. published a systematic review assessing the outcomes of arthroscopic management of posterior ankle impingement. The authors noted that the overall complication rate of the procedure was 6.2%, with the most common being sural nerve dysthesia.
A further indication for ankle arthroscopy for treating impingement is in patients who develop the symptoms following total ankle arthroplasty (TAR). In a study assessing the outcomes following TAR, the authors noted that 12 patients suffered from anterior, anteromedial, medial, lateral gutter, or posterior impingement. Following ankle arthroscopy, eight patients reported good pain relief, while the remaining patients reported minimal benefit. As the number of TAR being performed increases each year, the role of ankle arthroscopy for treating postoperative complications will likely grow.
With regard to arthroscopic management of ankle instability, only level IV studies for both plication and anchor fixation techniques are available at the time of the writing of this chapter. Despite the debate over the effects of thermal energy on ligamentous tissue, the existing studies have demonstrated good results. Nery et al. reviewed 38 patients treated with arthroscopic Broström-Gould repairs who were followed up an average of 9.8 years. Postoperative AOFAS scores were graded as excellent and good in 94.7% of patients. The Ankle Instability Group published a systematic review assessing the evidence of arthroscopic surgical management of ankle instability. They noted that the highest recommendation that good be given is grade C (poor-quality evidence) for the use of arthroscopic repair and arthroscopic reconstruction. Prospective, randomized, controlled trials are needed to compare this approach with the standard open procedure.
Outcomes of degenerative ankles with arthroscopy have paralleled the experience of arthroscopic débridement of other joints. The treatment of specific degenerative pathology, such as impinging osteophytes, loose bodies, and limited chondral lesions, improves the chance of a good result. Ogilvie-Harris and Sekyi-Out reported on the arthroscopic débridement of 27 arthritic ankles and found that two-thirds of patients had symptomatic relief (level IV). Amendola et al., in a level IV study, found uniformly poor results with arthroscopic débridement in 11 arthritic ankles. Patients with anterior tibiotalar osteophytes and loose bodies have demonstrated better outcomes after arthroscopic débridements. The consensus in the literature is that arthroscopic ankle débridement for degenerative joint disease is only appropriate in select cases and should be reserved for persons with early-stage disease.
Arthroscopic ankle arthrodesis has demonstrated faster rates of union, decreased complications, reduced postoperative pain, and shorter hospital stays. Myerson and Quill compared patients who underwent open and arthroscopic arthrodesis in comparative studies (level III). Both groups demonstrated similar fusion rates, with a shorter time to union in the arthroscopic group. O'Brien et al., in another retrospective study (level III), noted that both the open and arthroscopic groups had a similar fusion rate; however, the arthrodesis group demonstrated shorter operating room times, tourniquet time, and hospital stays. In the study with the longest term of follow-up, Glick et al. followed up 34 patients for an average of 7.7 years after arthroscopic ankle fusions. A 97% rate of fusion success was reported, with clinical results reported as excellent and good in 86%. The results of open versus arthroscopic ankle arthrodesis has been compared in a large database study, noting that there was no difference in consequent revision arthrodesis between the two techniques. In addition, arthroscopic arthrodeses will likely become more popular, with a significant increase over a 12-year period being reported in the literature.
Two level I studies were conducted to compare ankle fracture treatment with open reduction and internal fixation (ORIF) with and without arthroscopy. In the smaller study with 19 patients, Thordarson et al. showed similar outcomes at 21-month follow-up. Takao et al. compared 72 patients and found that the arthroscopic group had statistically higher AOFAS scores.
van Dijk et al. compared the results of arthroscopic débridement in postfracture patients who had impingement symptoms with the results of those who had more diffuse ankle complaints (level II). At 2-year follow-up, the impingement group reported better pain relief with 86% satisfaction compared with the patients with grade II osteoarthritis, who had a satisfaction rate of 70%. Utsugi et al., in a prospective case series (level IV), performed an arthroscopic débridement in 33 ankles at the time of removal of their ankle fracture hardware. These investigators recognized a negative correlation between the presence of arthrofibrosis and joint function. They stated that arthroscopic débridement resulted in functional improvement in 89% of the patients.
Complications
The average complication rate of ankle arthroscopy in the literature ranges from 3.5% to 10.3%. Neurologic injury is the most common complication reported, comprising almost half of all complications. Neurovascular injury can be contributed to incorrect portal placement, prolonged or inappropriate use of distraction, or use of a tourniquet. Anterolateral portal nerve injury can result in hypersensitivity or paresthesia over the intermediate branch of the superficial peroneal nerve. During noninvasive distraction, the foot strap has been implicated in the development of midfoot dysesthesias. Overly aggressive anterior débridement can potentially result in hemarthrosis or deep peroneal nerve injury, although these complications are rare. Nonneurologic complications included wound complications, deep venous thrombosis, tourniquet complications, articular cartilage damage, compartment syndrome, and complex regional pain syndrome.
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