DEFINITION

Arthroscopy of the ankle has become an invaluable tool for evaluating and treating pathology in the ankle joint.

Arthroscopy allows a minimally invasive approach to the structures of the ankle with a magnified view.

Detailed knowledge of the anatomy surrounding the ankle joint as well as the different structural variations is key to avoiding complications.

 

 

ANATOMY

 

The anteromedial portal is located medial to the tibialis anterior tendon at the level of the ankle joint (FIG 1). Care should be taken to avoid injury to the long saphenous vein and nerve usually located medial to the portal.

 

The anterolateral portal lies on the anterior joint line just lateral to the peroneus tertius tendon or alternatively lateral to the extensor digitorum longus tendons. The intermediate cutaneous branch of the superficial peroneal nerve lies in close proximity to this portal.

 

Posteromedial and posterolateral coaxial portals lie parallel to the bimalleolar axis (FIG 2A).

 

 

 

FIG 1 • Anatomic landmarks for anterior ankle arthroscopy. At the joint line, the anteromedial portal is made immediately medial to the tibialis anterior tendon and the anterolateral portal is created lateral to the extensor digitorum longus tendon.

 

 

The posterolateral coaxial portal (FIG 2B) is located immediately posterior to the peroneus longus tendon, and the posteromedial coaxial portal (FIG 2C) ideally lies between the posterior colliculus (of the medial malleolus) and the posterior tibial tendon. (Placement between the flexor digitorum longus and the posterior tibial tendon is also acceptable.)

 

The sural nerve is located an average of 6.6 mm from this posterolateral portal, whereas the posterior tibial nerve is found an average of 5.7 mm from the posteromedial portal.

 

For advanced arthroscopic ligament reconstruction, an anatomic safe zone exist between the intermediate branch of the superficial peroneal nerve and the sural nerve.

 

DIFFERENTIAL DIAGNOSIS

 

 

Anterior ankle impingement Ankle arthritis or frozen ankle

 

 

 

FIG 2 • Coaxial portal anatomy: cross-sectional (A), posterolateral (B), (continued)

 

 

P.681

 

 

 

FIG 2 • (continued) and posteromedial (C).

 

 

 

Osteochondral tibial or talar defects Lateral ankle instability

 

Ankle fractures

 

Recalcitrant ankle synovitis (often seen in patients with systemic inflammatory disease)

 

NONOPERATIVE MANAGEMENT

 

In general, conservative treatment will include a trial with activity modification, immobilization with a brace, and nonsteroidal anti-inflammatories.

 

Physical therapy using modality treatment, range-of-motion exercises, neuromuscular coordination training (eg, balance board), and strengthening of the secondary or dynamic stabilizing muscles surrounding the ankle is a useful adjunct to most conditions.

 

SURGICAL MANAGEMENT

Preoperative Planning

 

Imaging studies are reviewed to determine ideal portals to be used.

 

Standard anteromedial and anterolateral portals are sufficient to access the anterior and central tibiotalar pathology.

 

Posterior portals are considered when drilling posterior talar lesions or when it is necessary to address pathology (eg, synovitis, loose bodies) within the posterior capsule.

 

 

 

FIG 3 • A,B. Leg holder and bed positions, respectively, for posterior portal access. C. Position of operative leg and padded contralateral limb.

 

 

A preoperative popliteal block may be placed by anesthesia. Over the past 10 years, we have been able to perform 75% of ankle arthroscopies with regional anesthesia and light sedation.

 

An examination under anesthesia including anterior drawer as well as a talar tilt test should be performed before positioning.

 

Positioning

 

The patient is placed on a regular operating table with a well-padded tourniquet on the proximal thigh.

 

The supine position with a towel roll placed underneath the ankle is used when only anterior portals are necessary. In this situation, the tourniquet may be placed on the proximal calf.

 

If access to posterior portals is likely, then we lower the leg extension of the bed and use a standard arthroscopy knee holder (FIG 3A). This restricts thigh motion but allows free leg motion and access to the posterior hindfoot (FIG 3B). The contralateral leg is placed in a well-padded holder or pillow (FIG 3C).

 

Alternatively, a noninvasive ankle distractor is used.

 

Approach

 

The standard working approaches are the anteromedial and anterolateral portals.

 

Auxiliary anterior portals (such as the anterocentral) should be used with caution because of the high incidence of neurovascular injury.

 

The standard posteromedial and posterolateral portals should also be used with extreme caution due to the close proximity of neurovascular structures (FIG 4).

 

We prefer to use posterior coaxial portals parallel to the bimalleolar axis when addressing the posterior ankle joint.

 

Although the standard 4-mm arthroscope may be used, we prefer to use 2.7-mm arthroscopic instruments, which facilitate access and simplify the approach.

 

Instruments usually include 2.5-mm shaver, 3.5-mm shaver, thermal ablation device (this is especially helpful for synovectomy and débridement of the joint; however, care must be taken to avoid articular cartilage damage), and small arthroscopic biter and grabber devices.

 

 

P.682

 

 

 

FIG 4 • Conventional posterior portal crosssectional anatomy.

 

TECHNIQUES

• Anterior Portal Placement

The operative leg is identified and marked preoperatively. The patient is placed supine on the operating table.

Surgical timeout is performed.

Inject the ankle with 10 mL of sterile saline via the anteromedial ankle. This step also allows identification of the correct orientation and location for the anteromedial arthroscopy portal.

Make a 5-mm longitudinal skin incision and spread the subcutaneous tissue down to and then through the capsule with a small hemostat. A small gush of fluid confirms the intra-articular location.

Use the blunt-tip trocar with the arthroscopic cannula to enter the joint. Insert the arthroscope and start the water flow. Place the water pressure about 5 mm Hg above the systolic pressure if possible (no

 

higher than a pressure of 120 mm Hg). This significantly reduces bleeding, which often obscures the view.

 

Unless there is severe arthrofibrotic tissue in the anterior ankle, the anterolateral ankle is easily visualized upon introducing the arthroscope (TECH FIG 1).

 

Introduce an 18-gauge needle from the anterolateral portal location. This serves two purposes: (1) it allows for water flow through the needle, allowing for better visualization, and (2) it identifies the correct location of the portal incision in order to access the joint properly.

 

 

 

TECH FIG 1 • View of anterolateral (A) and posterolateral (B) gutter using simple distraction with towel roll underneath ankle.

 

 

 

Inspect the joint. Distraction allows for much greater joint inspection than otherwise would be possible. Make the anterolateral portal in a similar fashion to the anteromedial portal.

 

Using both portals, various arthroscopic instruments are used to address the individual patient's pathology.

 

The addition of an anteromedial inferior portal is helpful when dealing with synovitis near the deltoid insertion.

 

This is performed by visualizing the medial gutter with the arthroscope through the anteromedial portal.

 

An 18-gauge needle is introduced under arthroscopic visualization into the inferior medial gutter (usually about 10 mm inferior to the normal anteromedial portal location).

 

Once the needle is confirmed to be in the proper position, a new portal is then made as described earlier.

 

 

This portal in combination with the conventional anteromedial portal can be used to first inspect and then débride the far inferomedial ankle joint and deltoid insertion.

 

• Posterior Coaxial Portals

  P.683

   

  With the arthroscope and inflow in the anterolateral portal, make the posterolateral portal with a small, vertical skin incision immediately posterior to the peroneal tendon sheath and 1.5 cm proximal to the tip of the fibula (TECH FIG 2A).

   

  While holding the ankle in neutral dorsiflexion, insert the arthroscopic sheath and blunt trocar anterior

  and slightly inferior on a plane parallel to the bimalleolar axis.

   

  Confirm intracapsular placement by briefly inserting the arthroscope.

   

  Insert a long switching rod through the cannula and direct it toward the medial malleolus.

   

  Use the rod to palpate the posterior colliculus and penetrate just anterior to the posterior tibial tendon (TECH FIG 2B).

   

   

   

  TECH FIG 2 • A. Lateral coaxial portal. B-D. Medial coaxial portal. E,F. Arthroscopic views through medial portal. (C-F: Courtesy of M. T. Busch, MD.)

   

   

  Tent and incise the skin over the posteromedial ankle. Subsequently, pass a second cannula over the switching stick into the posterior ankle recess.

   

  Alternatively, the medial portal can be made directly using a small, vertical skin incision posterior to the medial malleolus (posterior colliculus).

   

  The arthroscopic sheath and blunt trocar are inserted anterior and slightly inferior on a plane parallel to the bimalleolar axis. Intracapsular placement is confirmed by briefly inserting the arthroscope (TECH FIG 2C-F).

   

  For synovectomies or posteromedial osteochondral lesions, the arthroscope is placed in the

   

  posterolateral cannula while the posteromedial cannula is used as the working portal.

   

• Ankle Distractor Placement

 

P.684

 

Inspect all instruments and confirm that all parts of the noninvasive external distractor are sterile and on the operative field (TECH FIG 3A).

 

The patient is placed supine on the operating table so the foot rests within 10 cm of the end of the bed.

 

A bump (made from a rolled blanket) is placed under the hip to rotate the leg so the toes point straight up.

 

A tourniquet is placed on the calf below the level of the fibular head to prevent peroneal nerve impingement (TECH FIG 3B).

 

The hip is flexed 60 degrees and the posterior thigh is placed in a padded thigh holder and secured with straps.

 

It is important that the thigh holder be placed so that the leg rests in the holder and does not rest in the popliteal fossa. If the thigh holder rests in the popliteal fossa, the pressure on the popliteal vein will increase bleeding throughout the case and make arthroscopic visualization much more difficult.

 

With limited pressure on the popliteal space, the tourniquet is rarely needed during the arthroscopic portion of the case (TECH FIG 3C).

 

The operative leg and ankle region are prepared and then draped using a standard arthroscopy drape.

 

 

 

TECH FIG 3 • Distractor setup: instruments (A), tourniquet placement (B), thigh holder placement (C), optimal clamp position placed as far distal as possible (D), final ankle setup with manual tensioning (E).

 

 

The distal portion of the arthroscopy drape is pulled off the end of the foot to allow for the distractor placement.

 

The bed clamp is placed as far distal on the bed as possible. For the clamp to fit properly, the circulating nurse should make sure all of the underlying drapes except the top layer are moved away from the clamp attachment site (TECH FIG 3D).

 

The external distractor strap is placed with the foam portions over the posterior inferior heel and on the dorsal foot. After creating equal lengths on the medial and lateral sides of the foot, the hook-loop is pulled distally with manual distraction.

 

The L-shaped metal post is placed and secured.

 

The foot is then pulled manually via the strap and connected to the threaded attachment rod.

 

We recommend the initial placement requires moderate effort to get the hook-loop secured so that initial manual distraction provides most of the distraction.

 

Once this is connected, use the threaded rod to provide further distraction to the ankle (TECH FIG 3E).

The joint can be flexed or extended while in the distraction device to allow for complete evaluation of the joint.

Some cases of purely anterior pathology can be performed with either minimal or no ankle distraction. However, one must be careful when introducing the trocar to dorsiflex the ankle to avoid damaging the articular cartilage of the talus.

 

 

 

P.685

 

PEARLS AND PITFALLS
	Indications ▪ Careful analysis of preoperative films will allow proper planning of necessary portals (anterior only vs. both anterior and posterior).   Coaxial portal ▪ Spread soft tissues laterally directly behind the peroneals to avoid sural nerve placement injury. Palpate the posterior colliculus medially with a switching stick before penetrating between the posterior tibial tendon and medial malleolus. Occasionally, the medial coaxial portal will occur between the posterior tibial tendon and the flexor digitorum longus. Avoid forceful medial penetration, which can result in tendon splitting. When exposing the medial portal directly, posteromedial skin incision lies along the course of the posterior tibial tendon behind the posterior colliculus. The posterior tibial tendon can be retracted anteriorly or posteriorly to visualize bulging capsule.   Additional ▪ One additional scope cannula with inflow port (total of two scope cannulas) equipment ▪ Small (about 2.5 mm) blunt-tip switching stick needed for posterior portals   Intra-articular ▪ After joint injection, several factors indicate intra-articular placement: (1) inflow confirmation of saline without resistance, (2) ballooning of the anterolateral joint capsule, and (3) passive dorsiflexion of the ankle with insufflation of the joint.   Limiting time ▪ Care should be taken to avoid thigh holder placement such that direct pressure needed for occurs into the popliteal space when distraction is applied. Direct pressure in the tourniquet popliteal space decreases outflow through the popliteal vein and will increase using ankle venous pressure and intra-articular bleeding. distraction   Arthroscopic ▪ Use conventional anteromedial and anterolateral portals. ankle fracture ▪ Assess for osteochondral lesions. management ▪ Direct evaluation of syndesmotic instability Allows direct assessment of deltoid ligament injury and medial gutter Allows direct visualization of fracture reduction

 

	Arthroscopic ▪ Arthrobrostrom technique: Use standard anterior portals. lateral ligament ▪ Other techniques require accessory anterolateral portal. reconstruction ▪ May decrease operative time Biomechanically equivalent to open techniques   Follow anatomic safe zones (FIG 5).   FIG 5 • Arthrobrostrom safe zones (mean distances): internervous safe zone = 51 mm, intertendinous safe zone = 43 mm; medial suture to superficial peroneal nerve (SPN) = 20 mm; inferior suture to sural nerve = 23 mm; inferior suture to peroneal tendons = 19 mm.

 

 

 

POSTOPERATIVE CARE

 

For most conditions addressed with ankle arthroscopy, patients are placed in a well-padded short-leg splint.

 

 

Five to 7 days postoperatively, the splint is removed and patients are allowed weight bearing as tolerated in a brace.

 

In cases in which drilling, microfracture, or retrograde bone grafting of an osteochondral lesion is performed, a period of non-weight bearing is emphasized.

 

Early range of motion is always encouraged unless a fusion is performed.

OUTCOMES

Ankle arthroscopy allows the surgeon to address a myriad pathology with a minimally invasive technique.

Success of outcomes varies according to underlying pathology but is generally in the range of 85% good to excellent.

P.686

The complication rate ranges from 0.7% to 17%, with neurologic injuries accounting for most of these problems.

The superficial peroneal nerve is the most commonly injured nerve, followed by the sural nerve and then the saphenous nerve.

In one study using the posterior coaxial portals in 29 ankles, no complications were observed at an

 

average 45 months of follow-up.

 

 

 

COMPLICATIONS

Neurovascular injury Cartilage damage

Reflex sympathetic dystrophy Sinus tract formation Infection

Skin necrosis

 

 

SUGGESTED READINGS

1. Acevedo JI, Busch MT, Ganey TM, et al. Coaxial portals for posterior ankle arthroscopy: an anatomic study with clinical correlation on 29 patients. Arthroscopy 2000;16:836-842.

    

    

2. Acevedo JI, Mangone PG. Arthroscopic lateral ankle ligament reconstruction. Tech Foot Ankle Surg 2011;10(3):111-116.

    

    

3. Acevedo JI, Ortiz C, Golano P. Arthrobrostrom lateral ankle stabilization technique: an anatomical study. Presented at the 33rd Annual Meeting of the Arthroscopy Association of North America, May 1-3, 2014, Hollywood, FL.

    

    

4. Corte-Real NM, Moreira RM. Arthroscopic repair of chronic lateral ankle instability. Foot Ankle Int 2009;30(3):213-217.

    

    

5. Drakos M, Behrens SB, Mulcahey MK, et al. Proximity of arthroscopic ankle stabilization procedures to surrounding structures: an anatomic study. Arthroscopy 2013;29:1089-1094.

    

    

6. Ferkel RD, Guhl JF, Heath DD. Neurological complications of ankle arthroscopy. Arthroscopy 1996;12:200-208.

    

    

7. Ferkel RD, Hewitt M. Long-term results of arthroscopic ankle arthrodesis. Foot Ankle Int 2005;26:275-280.

    

    

8. Giza E, Shin EC, Wong S, et al. Arthroscopic suture anchor repair of the lateral ligament ankle complex: a cadaveric study. Am J Sports Med 2013;41:2567-2572.

    

    

9. Golano P, Vega J, Perez-Carro L, et al. Ankle anatomy for the arthroscopist, part I: the portals. Foot Ankle Clin 2006;11:253-273.

    

    

10. Lui TH, Chan WK, Chan KB. The arthroscopic management of frozen ankle. Arthroscopy 2006;22:283-286.

     

     

11. Maiotti M, Massoni C, Tarantino U. The use of arthroscopic thermal shrinkage to treat chronic lateral ankle instability in young athletes. Arthroscopy 2005;21:751-757.

     

     

12. Nihal A, Rose DJ, Trepman E. Arthroscopic treatment of anterior ankle impingement syndrome in dancers. Foot Ankle Int 2005;26:908-912.

     

     

13. Sim J, Lee B, Kwak J. New posteromedial portal for ankle arthroscopy. Arthroscopy 2006;22:799.