Most ankle arthroscopy can be done as outpatient ambulatory surgery. The modern setup for ankle arthroscopy includes a small-joint 2.7 mm arthroscope; a 4.0 mm arthroscope also can be used if care is taken to avoid iatrogenic injury. Gravity or an arthroscopic pump at a low pressure (40 mm Hg) and flow can be used to control the fluid inflow.

A general anesthetic is routinely used for ankle arthroscopy. A recent prospective randomized study evaluated the influence of a preoperative intra-articular injection of local anesthetic on postoperative pain following ankle arthroscopy. In addition to a general or spinal anesthetic, patients receiving a preoperative intra-articular anesthetic injection reported significantly lower pain levels during the first 24 hours following surgery. Lower amounts of supplemental analgesics also were required when a preemptive anesthetic injection was administered. No significant differences in pain were seen on postoperative days 2 or 3.⁵

Traditionally, a thigh tourniquet has been used during arthroscopy to minimize bleeding, improve surgeon visibility, and decrease operative time. A recent
prospective randomized controlled trial evaluated anterior ankle arthroscopy with and without the use of a tourniquet. Although the quality of visualization was statistically different between the two groups, there was no difference in operative time or blood loss. As the tourniquet did not need to be inflated for procedure completion in any of the nontourniquet patients, the authors concluded that ankle arthroscopy could be performed adequately without the use of a tourniquet.⁶

Noninvasive ankle distraction can be used to improve visualization of the joint space, and a padded thigh holder is useful for providing countertraction. Distraction improves visualization of the central and posterior compartments, as well as the medial gutter and deltoid ligament. As most complications are neurologic in origin, prolonged use of traction should be avoided to prevent neurapraxia. Dorsiflexion of the ankle without traction also can be done. By increasing the volume of the anterior joint pouch, this technique is advantageous for evaluating the anterior compartment and lateral gutter, including inspection of the lateral ankle and syndesmotic ligaments.^2,7

An anteromedial portal is made at the joint level medial to the tibialis anterior tendon. An 11-blade scalpel is used to nick the skin, and a small hemostat is used to vertically spread the underlying soft tissue for entering the joint capsule. The saphenous nerve and vein can be at risk with establishment of the anteromedial portal. The superficial peroneal nerve, which frequently can be seen through the skin, is at risk during establishment of the anterolateral portal. The superficial peroneal nerve moves 4 mm laterally when the ankle is brought from plantar flexion to neutral, and the anterolateral incision should be made medial to the visualized nerve to avoid iatrogenic damage.⁸ Although the skin closure can be done according to surgeon preference, an improperly placed suture can irritate the intermediate branch of the superficial peroneal nerve.¹

Anterolateral soft-tissue impingement by the anterior-inferior tibiofibular (Bassett) ligament has been well described.⁹ These lesions are believed to be caused by the formation and resorption of hematoma after an ankle sprain. The patient commonly reports a history of ankle sprains and swelling. MRI can be useful for ruling out other entities, but often the MRI findings do not contribute to making a correct diagnosis of anterolateral soft-tissue impingement.¹⁰ The use of a diagnostic intra-articular injection may be useful in this regard.

Anteromedial impingement lesions can occur after repeated capsular traction injuries. The typical patient is a soccer player or a martial artist. Anteromedial osseous abnormality, if present, often can be seen on oblique radiographs of the foot. Arthroscopic resection of anteromedial impingement lesions was found to have a satisfactory outcome in 93% of patients.¹¹

Arthroscopic ankle arthrodesis is routinely performed as an outpatient procedure, and fusion rates of more than 90% can be consistently expected.¹² Purported advantages of the arthroscopic approach include less disruption of the soft-tissue envelope, shorter time to bone union, preservation of bony anatomy allowing potential conversion to future ankle arthroplasty, and the ability to operate on high-risk patients as well as those with compromised soft tissues (Figure 2).

Historically, arthroscopic arthrodesis was reserved for patients without significant ankle deformity; however, results of arthroscopic ankle fusion in patients with minor (<15°, range 0 to 14) and major (>15°, range 15 to 45) preoperative coronal plane deformities showed no difference in fusion rate, time to fusion, complication rate, or clinical outcomes. Importantly, there was no difference in postoperative alignment between the two techniques in the coronal and sagittal planes. These results suggest that even marked ankle deformity can be arthroscopically corrected, depending on the surgeon’s familiarity with the procedure.¹²

A recent multicenter study evaluated open and arthroscopic arthrodesis using a validated AOS (Ankle Osteoarthritis Scale) score measuring disability and pain. Although both groups had significant improvements after surgery, the arthroscopic group had significantly better scores than the open arthrodesis group at both 1- and 2-year follow-up, as well as a more rapid rate of postoperative improvement. No difference in tourniquet times between open and arthroscopic techniques was reported, and equivalent deformity correction and nonunion rates were achieved.¹³

Because of the high rate of associated intra-articular pathology, arthroscopy frequently is done in the same surgical setting as treatment of chronic lateral ankle instability, and arthroscopically assisted ankle stabilization procedures are being reported with increasing frequency. These techniques primarily focus on the repair and reconstruction of the anterior talofibular ligament and less commonly include the calcaneofibular ligament.

The open modified Broström technique incorporates the extensor retinaculum into the ankle ligament repair. A recent randomized controlled trial found no significant clinical differences between arthroscopic all-inside repair and open modified Broström technique procedures at 1-year follow-up. Furthermore, there were no radiographic differences in talar tilt and anterior drawer between the two techniques 1-year postoperatively.¹⁴

A long-term study reported a 95% rate of good to excellent outcomes with a three-portal technique for reconstruction of the anterior talofibular ligament with extensor retinaculum reinforcement at 9.8 years average follow-up; the calcaneofibular ligament was not surgically treated. Eighty-seven percent of active patients were able to return to sporting activities at their preoperative level, whereas 13% changed to a lower level or gave up sport.¹⁵

As a developing technique, the reported complication rate of arthroscopic ankle stabilization in some studies has approached 30%.^14,16 To avoid soft-tissue and nerve entrapment during arthroscopic ligament repair, a safe zone has been described. This quadrant includes the 51 mm intertendinous safe zone from peroneus tertius to brevis, 43 mm internervous zone between the sural and superficial peroneal nerves, and 15 mm from the tip of the fibula to the inferior extensor retinaculum.¹⁷

Intra-articular injuries are common with acute ankle fractures, and these injuries may be under- or misdiagnosed with traditional radiographic evaluation alone. Arthroscopic-assisted open reduction and internal fixation (AA-ORIF) provides additional diagnostic information by allowing a thorough evaluation of the articular space, cartilage surfaces, ligaments, fracture fragments, and surrounding soft tissues for associated pathology. Joint lavage and débridement, loose body removal, deltoid ligament and syndesmosis evaluation, treatment of cartilage lesions, and assistance with fracture reduction can be done concurrently, but the risks of nerve injury, fluid extravasation with potential for limb swelling and compartment syndrome, and other complications must be recognized.

There are relatively few studies directly comparing ankle fracture ORIF with and without arthroscopy. A recent study compared functional outcomes following ankle fracture ORIF with and without simultaneous arthroscopy at an average follow-up of 67 months. Using a validated PROMIS (Patient Reported Outcomes Measurement Information System) score, the authors found no significant differences between the two groups despite 21% of the AA-ORIF group having removal of loose bodies and 62% having associated cartilage lesions of the tibia or talus. Notably, the operative time was significantly longer during AA-ORIF. The results of this study did not support the routine use of arthroscopy to improve functional outcomes of ankle ORIF.¹⁸

A systematic review in 2016 concluded that the current literature has not shown that AA-ORIF provides any outcome improvements over traditional ankle ORIF. Despite a limited number of comparative studies, the authors did assign a fair quality (grade B) to evidence that AA-ORIF can be successfully used for diagnosis and treatment of joint pathology when treating acute ankle fractures.¹⁹

The relevant posterior anatomy of the talus includes the posterior bony tubercles, flexor hallucis longus (FHL)
tendon, multiple ligamentous attachments, and the ankle and subtalar joints. The posterior process of the talus includes the medial tubercle, or Cedell process, which is the attachment for the posterior tibiotalar/deltoid ligament. The lateral tubercle, or Stieda process, is the attachment for the posterior talofibular ligament. An os trigonum results from the unossified posterior lateral tubercle forming a synchondrosis, as opposed to complete bone fusion with the talus, at its secondary ossification center.

The FHL tendon courses between the medial and lateral tubercles of the posterior process of the talus at the ankle joint level and serves as a major landmark during ankle arthroscopic procedures. The neurovascular structures should be safe from harm if arthroscopic surgery is lateral to the FHL (Figure 3, A). However, the occasional presence of an accessory muscle called the peroneocalcaneus internus muscle, or false FHL, can disorient an inexperienced arthroscopic surgeon and jeopardize the neurovascular structures.²¹