Introduction
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Ankle joint was initially thought to be anatomically too restrictive for arthroscopy (Burman, 1931).
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Advances in the field of arthroscopy from Japanese surgeons (Takagi and Watanabe) led to more widespread use and application to ankle joint in the 1970s.
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Watanabe published his series of 28 ankle arthroscopies in 1972.
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Numerous published studies and advances over last 40 years
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Developed into key modality for treatment of post-traumatic injuries and other acute and chronic disorders
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Limited role in diagnosis only (only 26% to 43% success of ankle arthroscopy in absence of preoperative diagnosis)
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Can be utilized for treatment of both anterior and posterior pathology
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Expansion to periarticular problems, particularly tendoscopy of the peroneal, posterior tibial, and FHL tendon sheaths
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Performed much less frequently than arthroscopy of the knee or shoulder
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Complication rate is higher than knee or shoulder arthroscopy
Preoperative Considerations
History and Physical Examination
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Know all relevant history including injury patterns, prior treatments and the success or failure of each, progression and characterization of symptoms. Perform a thorough examination and review all relevant imaging.
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Location of pain may provide clue to diagnosis or differential diagnosis
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Assess range of motion of the tibiotalar and subtalar joints, location of tenderness, swelling deformity, strength testing in all planes, gait (heel to toe, toe to toe, heel to heel), alignment of the hindfoot and forefoot, laxity of the tibiotalar and subtalar joint. Complete motor and sensory evaluation.
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Imaging
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Plain radiographs of the ankle
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AP, lateral, mortise views
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May reveal osteochondral lesions, arthritis, distal tibial and talar osteophytes, calcifications, loose bodies, syndesmosis injuries and fractures
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Stress radiographs
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Anterior drawer and talar tilt tests
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May reveal tibiotalar or subtalar instability, and rotational stress testing may demonstrate injury to the syndesmosis.
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MRI
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May demonstrate soft tissue sources of pain and effusion including ligament injuries, tendon injuries, impinging scar tissue, loose bodies and integrity of the overlying articular cartilage in osteochondral injuries.
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A diagnostic intra-articular injection may be useful preoperatively to help determine if the source of the pain is intra-articular to verify the utility of arthroscopy.
Indications
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Diagnostic indications include unexplained pain, swelling, locking, catching, stiffness, hemarthrosis, evaluation of syndesmosis stability and ligament injuries.
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Therapeutic indications include
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Treatment of injuries to articular cartilage (i.e., chondral and osteochondral lesions)
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Anterior ankle impingement
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Synovectomy
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Loose body removal
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Reduction and fixation of some ankle fractures
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Irrigation for septic joints
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Arthrofibrosis
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Biopsy
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Assistance in fracture fixation, arthrodesis and ankle ligament reconstruction procedures.
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Contraindications include moderate-to-severe arthritis and limited motion, significantly reduced joint space, vascular compromise, complex regional pain syndrome, significant edema and local soft tissue or intra-articular infection.
Positioning
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Classically the patient is positioned supine, although many techniques have been described including the lateral position and a prone position for arthroscopy of the posterior hindfoot.
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In the supine position, the operative leg is allowed to flex at the knee and hang over the break in the table with the foot of the table lowered to allow for relaxation of the gastrocnemius complex
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Various distraction techniques can be used and are recommended.
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Commercially available sterile distraction straps are available for noninvasive distraction ( Fig. 4-1A,B ).
Figure 4-1
A . Example of commercially available ankle distraction device for arthroscopy. Shown here with knee flexed over break in table with weights applied for distraction. B . Ankle distraction device with knee flexed over padded leg holder with traction apparatus attached to table for distraction. Lowering the foot of the bed can result in additional distraction.
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Invasive distraction techniques have been described with variations of the external fixator; however, this is less common.
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A loop of sterile gauze roll may also be used with manual distraction with the surgeon’s foot pulling a loop to the floor.
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Posterior ankle arthroscopy is performed prone and often without distraction.
Equipment
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A standard 4.0-mm, 30-degree arthroscope may be used (and preferred by the senior author), although a smaller 2.7-mm arthroscope may be helpful and is available in a shorter version to reduce the lever arm
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A traction device (noninvasive or invasive/external distractor) is used.
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A tourniquet may be used, and is based on surgeon preference.
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Gravity inflow is often adequate; however, an arthroscopic pump can be used with caution.
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Small joint arthroscopic equipment should be available
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Standard size and small joint (2.0 mm and 2.7 mm) shavers and high speed burrs, pituitary rongeurs, small joint arthroscopic graspers, rasps, and probes, miniset probes and biters, microfracture picks, cup and ring curettes
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A 70-degree arthroscope may also be helpful to visualize the medial and lateral gutters and the posterior ankle joint.
Relevant Anatomy
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An understanding of the superficial and intra-articular anatomy is key to avoiding complications from ankle arthroscopy ( Fig. 4-2A,B ).
Figure 4-2
A . Anterior anatomy of ankle with diagram of standard portal placement. B . Posterior anatomy of ankle with diagram of standard portal placement.
(From Ferkel RD, Heath DD, Guhl JF. Neurological complications of ankle arthroscopy. Arthroscopy 1996; 12(2):200-208.)
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The neurovascular structures and tendons are at greatest risk with portal placement.
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The medial and lateral malleoli are key palpable landmarks and are useful for identifying the joint line because this typically is felt with dorsiflexion and plantar flexion of the ankle and is located approximately 2 cm proximal to the tip of the fibula and 1 cm proximal to the tip of the medial malleolus.
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Key structures to identify before portal placement that can be traced with a marking pen include the palpable dorsalis pedis artery, tibialis anterior and peroneus tertius tendons, the intermediate dorsal cutaneus branch of the superficial peroneal nerve, the tibiotalar joint line and the often visible greater saphenous vein.
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The intermediate dorsal cutaneous branch of the superficial peroneal nerve can usually be identified prior to placement of the anterolateral portal, reducing risk of nerve injury.
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The superficial peroneal nerve divides into the intermediate and medial dorsal cutaneous branches approximately 6.5 cm proximal to the tip of the fibula with the intermediate branch overlying the superficial extensor retinaculum, traversing the extensor tendons between the third and fourth metatarsals. The medial dorsal cutaneous branch crosses the anterior aspect of the ankle joint superficial to the extensor tendons, lateral and parallel to the extensor hallucis longus (EHL) tendon.
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The dorsalis pedis artery is palpable throughout its course anteriorly and at the level of the ankle joint; it resides between the tibialis anterior tendon and the extensor hallucis longus tendon. It courses deep to the EHL tendon as it migrates toward the great toe medially.
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The peroneus tertius tendon is palpable at the level of the ankle joint as the lateral border of the common extensors, lateral to the EHL tendon
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When entering the joint, recall that the dome of the talus is convex and the plafond of the tibia is slightly concave.
Portals
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Careful placement of vertical incisions through skin only can be performed with a 15-blade scalpel to minimize the risk of injury to superficial nerves.
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Deeper layers should be penetrated bluntly with the use of a straight mosquito clamp to enter the joint, followed by a blunt obturator.
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The safest portals are the anterolateral, anteromedial and posterolateral portals and these are the most commonly used.
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The anteromedial portal
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Often created first because it is typically the easiest and safest (risks are the greater saphenous vein and nerve, which are on average 9 mm and 7.4 mm medial to the portal site)
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It is recommended to distend the joint initially with 10 to 15 mL of saline or lactated Ringer (LR) solution before making portals to minimize the risk of damaging intra-articular structures and to move the periarticular nerves away from the joint.
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Insert an 18- to 20-gauge needle just medial to the tibialis anterior tendon at the level of the joint line or slightly proximal and inject 10 to 15 mL sterile saline or LR solution to distend the ankle joint.
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After the joint is distended, the needle is removed and a superficial vertical incision is made, centered on the needle entry site.
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Through this portal the arthroscope cannula with blunt trocar can be introduced and then the arthroscope exchanged for the trocar and the joint can be infused with saline through the side port on the cannula.
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The anterolateral portal
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At risk are the branches of the superficial peroneal nerve with an average distance of 6.2 mm from the nearest branch to the portal site
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Identify this nerve by plantarflexing fourth toe to put the nerve on stretch. The nerve may also be visualized with transillumination of the skin and subcutaneous tissue with the scope camera light (see later).
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Can be made under arthroscopic visualization for improved accuracy and be modified slightly depending on identified pathology
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This portal is made just lateral to the peroneus tertius tendon at the tibiotalar joint line.
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A 1.5-inch 25-gauge needle is used to identify the portal site, and confirmation of its location at an optimal entry location can be visualized with the arthroscope.
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The skin can be transilluminated with the arthroscope to help avoid the neurovascular structures by bringing the arthroscope to the capsule at the anterolateral joint, reducing the room lights, and looking for the tendons and nerves through the illuminated skin.
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The posterolateral portal
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This portal site is on average 6 mm posterior to the sural nerve and 9.5 mm posterior to the lesser saphenous vein.
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Needle localization and arthroscopic visualization is recommended to assist in placement, using the arthroscope in either the anterolateral or anteromedial portal.
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This portal is made just lateral to the Achilles tendon approximately 1.5 cm proximal to the distal tip of the fibula, placing the needle at a 45-degree angle aiming toward the medial malleolus.
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Other described portals and at-risk structures
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Anterocentral
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Between the tendons of the extensor digitorum communis
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Dorsalis pedis artery and deep peroneal nerve at risk
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Use of this portal discouraged due to neurovascular risk
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Posteromedial
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Used during posterior ankle arthroscopy. See later for details
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Posterocentral (trans-Achilles)
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Through Achilles tendon and inferior to joint line
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Not recommended due to morbidity to the Achilles tendon
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Diagnostic Arthroscopy Technique
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A thorough diagnostic evaluation should be undertaken in a systematic format to allow for reproducible documentation and accuracy of diagnosis.
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The specific order of evaluation is surgeon-dependent but should be completed in a systematic fashion.
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A 21-step examination has been described by Ferkel and colleagues as a guideline to evaluate all aspects of the ankle joint.
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Anterior
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Deltoid ligament
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Medial gutter
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Medial talus
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Central talus
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Lateral talus
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Trifurcation of talus, tibia, and fibula
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Lateral gutter
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Anterior gutter
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Central
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Medial tibia and talus
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Central tibia and talus
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Lateral tibiofibular or talofibular articulation
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Posterior inferior tibiofibular ligament
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Transverse ligament
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Reflection of flexor hallucis longus
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Posterior
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Posteromedial gutter
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Posteromedial talus
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Posterocentral talus
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Posterolateral talus
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Posterior talofibular articulation
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Posterolateral gutter
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Posterior gutter
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Begin with gentle distraction of the ankle joint.
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Enter the joint through the intended location for the anteromedial portal with an 18- to 20-gauge needle and inject 10 to 15 mL of saline or LR solution.
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Make a small vertical incision through skin only, centering over injection site.
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Use a straight mosquito clamp to bluntly penetrate the capsule and enter the joint. This can also be used to gently widen the portal.
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Then place the arthroscopic cannula with blunt obturator.
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Remove the obturator and place the 30-degree arthroscope into the cannula and begin the diagnostic arthroscopy.
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The anterolateral portal can be made by aiming the arthroscope toward the intended entry site and transilluminating the skin to help avoid nerves and veins with the localizing needle and the incision.
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An 18- to 20-gauge needle can be used to penetrate in the intended location and, with the use of the arthroscope, the ideal location can be verified before making the incision ( Fig. 4-3 ).
