DEFINITION

Arthritis of the ankle can evolve from multiple causes, including, but not limited to, osteoarthritis, rheumatoid arthritis, and posttraumatic conditions. As the condition progresses, it generally leads to increased pain, gait abnormalities, and diminished function.

Surgical remedies are employed when conservative measures fail; they consist of the time-honored tibiotalar arthrodesis as well as total ankle replacement.2,3,4,9,19,21,28 We will be discussing and illustrating the technique of arthroscopic ankle arthrodesis (AAA).7,12,17,23

 

 

ANATOMY

 

The ankle joint is composed of the tibiotalar and fibulotalar articulations, with the fibula bearing about one-fifth of the weight-bearing stress across the ankle joint (FIG 1).

 

PATHOGENESIS

 

As with any condition, when articular cartilage is destroyed, either by systemic or local disease, the progression of arthritis may be unpredictably slow or rapid. If malalignment is an accompanying factor, the progression and pain are usually more pronounced.

 

NATURAL HISTORY

 

Once the breakdown of the articular surface has begun, it will progress at a rate that is not always predictable. Radiographic changes will not always reflect the degree of pain that the patient presents with. Some patients will come to surgery early, whereas others may languish for decades without needing surgical intervention.

 

 

 

FIG 1 • Mortise view of right ankle.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Generally, the patient will complain of pain with weight bearing, usually lateral more than medial. Generally, it localizes anteriorly in a band from the lateral to the medial side of the ankle. There may be associated swelling and occasional night pain. The symptoms may in part be relieved by nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, crutches, bracing, and activity modification. When other joints are involved, such as the knee and the hip, the discomfort in these areas may overshadow the ankle symptomatology.

 

The patient will generally walk with an antalgic gait, and if there is any leg length discrepancy, there may be a short-leg component to it. Gait will generally improve with the assistance of crutches or a cane.

 

Stability is assessed with talar tilt and anterior drawer tests.

 

Standing evaluation is critical in determining the feasibility of arthroscopic technique versus open as well as necessary osteotomies.

 

 

Range of motion will be restricted in all planes, and pain will be elicited at the extremes of range of motion. Loss of dorsiflexion with plantarflexion contracture needs to be addressed at surgery.

 

Careful isolation of ankle joint motion during the examination is critical so as not to confuse it with pathologic changes in the subtalar or midtarsal joints.

 

There will usually be associated swelling about the ankle joint. Synovial hypertrophy, osteophytes, and generalized enlargement of the ankle will present rather than a frank effusion, which could indicate a systemic component.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Standing anteroposterior (AP), lateral, and mortise radiographs are necessary to determine the extent of arthritis, alignment, presence of osteophytes, and the presence or absence of avascular necrosis of the talus (FIG 2). Minor degrees of malalignment may be corrected up to 7 degrees, varus being the most important element to reverse to neutral.

 

 

Magnetic resonance imaging (MRI) scans may be helpful if avascular necrosis is suspected. Computed tomography (CT) may be indicated if bone loss needs to be addressed.

 

Should there be questions on the circulatory status, a vascular workup may be necessary.

 

DIFFERENTIAL DIAGNOSIS

 

 

Infection Charcot joint

 

Pseudogout and gout

 

 

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FIG 2 • Standing AP radiograph showing degenerative arthritis of the ankle.

 

 

 

Osteochondral lesions of the talus Impingement

 

Inflammatory synovitis

 

NONOPERATIVE MANAGEMENT

 

As with most arthritic conditions, a wide variety of nonoperative measures can be employed. Medication in the

form of NSAIDs, acetaminophen, and glucosamine sulfate can be used with careful monitoring for side effects. Bracing with simple soft tissue supports or a custom-made ankle-foot orthosis (AFO) can be effective.

Cortisone injections, if used sparingly, can offer short-term pain relief. Off-label hyaluronic acid injections have been used with some reported success.

 

SURGICAL MANAGEMENT

 

When patients fail to respond to conservative care, a number of procedures can be undertaken for isolated end-stage ankle arthritis. The time-honored procedure is an open ankle arthrodesis, but over the past 15 years, some surgeons have come to prefer AAA.

 

Total ankle arthroplasty has been popularized recently and has the obvious advantage of motion preservation at the cost of a more challenging technical procedure and a higher complication rate.16

 

AAA will be discussed in detail in the following section.

 

Preoperative Planning

 

We cannot overstress the need for a thorough evaluation of alignment before AAA is undertaken (FIG 3). The films must be done in a standing position and compared to the opposite side. Often, patients will present with outside films showing a pseudovarus deformity, but when a weight-bearing film is taken, the alignment is satisfactory.

 

All medical conditions must be addressed. Vascular status needs to be examined as well as the skin condition. Patients need to stop smoking 3 months before the operative procedure and must stay off NSAIDs 5 days before and 3 months after the surgery.

 

 

 

 

FIG 3 • Posterior view of varus malalignment, right ankle.

 

 

Perioperative antibiotics are used as well as postoperative deep venous thrombosis prophylaxis in high-risk

patients.

 

Positioning

 

The patient is placed in a supine position.

 

The use of a leg holder and tourniquet allows the extremity to be placed in a neutral position so that both the anteromedial and anterolateral aspects of the ankle can be easily accessed.

 

The foot of the table is dropped about 30 degrees.

 

The ankle is placed in a sterile traction device using a tensiometer, controlling traction to about 25 pounds (FIG 4).

 

Approach

 

The approach that will be described is that of an AAA.

 

Generally, a two-portal technique can be used with anteromedial and anterolateral portals, and on occasion, accessory portals located anterolateral, anteromedial, or posterolateral for additional flow or drainage (FIG 5).

 

 

 

 

FIG 4 • Sterile traction device with tensiometer applied to right ankle.

 

 

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FIG 5 • A,B. Standard and accessory anterior portals for ankle arthroscopy.

 

TECHNIQUES

• Traction and Exposure

Delineate anatomic landmarks with a marking pencil (TECH FIG 1A). Apply a traction device after thoroughly preparing and draping the ankle. Apply traction to about 25 pounds (TECH FIG 1B).

Countertraction is effective with the use of a tourniquet and leg holder. Dorsiflexion and plantarflexion are facilitated by the design of the traction strap. Instill 8 mL of normal saline into the ankle joint.

Using a “nick and spread” technique, create the anteromedial portal with a no. 11 blade. Use a hemostat to bluntly dissect down to the capsule.

Introduce a 2.7-mm wide-angled and small joint arthroscope through the anteromedial portal (TECH FIG

 

1C).

 

 

Establish drainage through the anterolateral portal. Use a pump to control pressure at about 30 mm Hg.

 

 

Take care, as with any infusion technique, to avoid excessive pressure and fluid extravasation. Anterior osteophytes may impede entry and visualization in the joint (TECH FIG 1D).

 

Osteophytes can be removed anteriorly to create a space for visualization and performance of the arthrodesis.

 

 

38

 

 

 

TECH FIG 1 • A. Anatomic landmarks consisting of the superficial peroneal nerve and anterior tibial tendon, right ankle. B. Soft tissue traction device for the ankle with 25 pounds of traction applied. C. A camera and small arthroscope are introduced through the anteromedial portal, the shaver is introduced through the anterolateral portal, and drainage is introduced through an accessory inferior anterolateral portal, right ankle. D. Lateral radiograph of an ankle with prominent tibial and talar osteophytes that need to be resected for access to the ankle joint during arthroscopy.

• Arthrodesis

   

  Perform a synovectomy with a 3.5-mm resection blade (TECH FIG 2A).

   

  Use a soft tissue motorized blade and a burr to remove the articular cartilage.

   

  One to 2 mm of subchondral bone is generally removed with the burr (TECH FIG 2B).

   

  Spinal curettes can be used to débride the medial and lateral gutters as well as the posterior tibial plafond and posterior talus (TECH FIG 2C).

   

  A radiofrequency device can be used for débridement in some areas where access is limited.

   

   

   

  TECH FIG 2 • A. A soft tissue resection blade is being used to perform a synovectomy in the ankle joint.

  B. One to 2 mm of subchondral bone is removed with a burr and spot welds are created. (continued)

   

   

  During débridement, maintaining the normal architecture of the tibiotalar joint is imperative.

   

  Medial and lateral gutters need to be débrided thoroughly, removing 1 to 2 mm of subchondral bone as well (TECH FIG 2D).

   

  Débriding the gutters allows for coaptation of the tibiotalar surfaces (TECH FIG 2E).

   

   

  Multiple spot welds placed on the tibiotalar surfaces will allow increased vascularity (TECH FIG 2F). Release the tourniquet and visualize the vascularity of both surfaces (TECH FIG 2G).

   

  Further débridement may be necessary if diminished vascularity is encountered in any one particular area.

   

  39

   

   

   

  TECH FIG 2 • (continued) C. A spinal curette is used to débride the medial gutter of the ankle. D. A burr is used to remove subchondral bone. E. Tibial-talar surfaces are prepared, as well as the gutters, for coaptation of the surfaces. F. A spot weld vascular access channel is created in the talus. G. After release of the tourniquet, vascularity of the tibial-talar surface is assessed.

• Stabilization, Fixation, and Closure

 

 

Hold the ankle in the acceptable corrected neutral position and insert guidewires. Use two 7.3-mm AO cannulated cancellous screws to stabilize the tibiotalar joint.

 

Place screws parallel and obliquely from the medial tibia into the lateral talus (TECH FIG 3).

 

 

 

TECH FIG 3 • A. AP radiographs showing two parallel oblique screws used for fixation of the arthroscopic fusion. B. Lateral radiographs showing two parallel oblique screws fixing the ankle fusion.

 

 

 

Perform fixation under fluoroscopic control to avoid any potential encroachment on the subtalar joint. Apply compression alternately to each screw.

 

Check the final position both clinically and under fluoroscopy.

 

Close the arthroscopic portals with Steri-Strips and close the operative site for screw insertion with 3-0 nylon sutures.

 

Apply a local anesthetic and incorporate the leg into a bulky dressing and a bivalve cast.

 

 

 

40

PEARLS AND PITFALLS

Indications

• If possible, avoid operating on smokers and patients with Charcot joints and

  avascular necrosis of the talus.

• Carefully explain to the patient what the associated stiffness and lack of motion of the ankle will involve.

• Avoid noncompliant patients.

Arthroscopic

procedure

• Use careful fluid management to avoid extravasation and compartment

  syndrome.

• Do not exceed 25-30 pounds of traction.

• Have the appropriate small joint arthroscopy system available.

Surgical

technique

• Early removal of the anterior osteophytes will aid in visualization.

• Do not remove excessive amounts of subchondral bone.

• Spot weld technique will increase the vascular access.

• Medial and lateral gutters need to be débrided for better coaptation.

• Guide pins need to be checked carefully under fluoroscopy.

• Avoid violating the subtalar joint with screws.

 

 

POSTOPERATIVE CARE

 

Patients are placed in a bulky dressing with a bivalve cast in the operating room. Circulatory checks are done in the recovery room and 24 hours postoperatively. The cast is removed and the wounds are inspected at 7 days postoperatively. The patient is then fitted for an AFO brace (FIG 6).

 

The patient is allowed touch weight bearing the first few days after surgery, with progressive weight bearing, and may attain a full weight-bearing status as soon as tolerated. Generally, the patient will use crutches for 2 to 3 weeks. Full weight bearing is encouraged.

 

The patient is allowed to remove the AFO for bathing and range-of-motion exercises. Range of motion and weight bearing reduce stress deprivation. The patient is allowed to remove the AFO and walk with normal shoe wear when radiographic union has taken place, there is no motion at the screw sites, and the patient is essentially pain-free.

 

OUTCOMES

Fusion rates for AAA are generally in the range of 90% to 95%.10,15,22,27,29,30

 

 

FIG 6 • An AFO brace is used for immobilization, postoperative week 1.

 

There is definitely less pain after the arthroscopic procedure than with the open procedure.

The operation is generally done as an outpatient procedure. Alignment is thought to be easier to obtain because of the maintenance of the normal architecture and geometry of the tibiotalar joint.

 

 

 

COMPLICATIONS

The complication rate from ankle arthroscopy has been reported to be about 9%.1,5,6,8,11,13,14,18,20,24,25,26

Infection

Synovial fistula (FIG 7A) Delayed union (FIG 7B) Nonunion

Charcot joint

Secondary degenerative changes, subtalar and midfoot Equinus or dorsiflexion malposition

Residual varus malalignment

Fibular-talar and fibular-calcaneal impingement (FIG 7C) Neurapraxia and nerve injuries

Vascular injuries

Skeletal traction complications (FIG 7D) Screw encroachment in subtalar joint (FIG 7E)

 

 

 

 

FIG 7 • A. Synovial fistula after ankle arthroscopy. (continued)

 

 

41

 

 

 

FIG 7 • (continued) B. AP radiographs showing delayed union-nonunion of open ankle arthrodesis. C. AP radiograph in 40 degrees of internal rotation, showing fibular-talar and fibular-calcaneal impingement. D. Skeletal traction device previously used for ankle arthroscopy. E. Screw encroachment on the subtalar joint as seen with a 40-degree internal rotation and plantarflexion view.

 

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