This article is more than 5 years old. Information may no longer be current.

Adequacy of deformity correction must be considered in arthroscopic vs open ankle arthrodesis, part 2

Issue: August 2018

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

The appropriate indications for arthroscopic ankle fusion are debated. Studies have demonstrated low rates of nonunion and complications with the arthroscopic technique that are comparable to traditional open ankle fusion. Despite this, open approaches are widely used.

In the second part of this Round Table, participants discuss the learning curve with arthroscopic ankle arthrodesis and the risks associated with ankle fusion of any kind. Click here to read the first part of the discussion.

Nelson SooHoo, MD
Moderator

Nelson SooHoo, MD: How do you suggest surgeons interested in this procedure should deal with the learning curve? Do you have any technical tips that may increase the safety of arthroscopic ankle arthrodesis?

Richard D. Ferkel, MD: The best way for surgeons to learn this technique is attend either a course at the Orthopaedic Learning Education and Conference Center in Chicago or a cadaver course that teaches arthroscopic ankle arthrodesis techniques. Through these courses, surgeons can gain some practice and confidence in appropriate cartilage removal and correct preparation of the underlying tibia or talar bone and insertion of screws. There is a learning curve with this technique like with other procedure and, initially, the procedures will take longer. But, as the surgeon’s experience improves, the procedure should go more smoothly and quickly. Tips that may be helpful include using dedicated inflow and small joint arthroscopes that can be easily maneuvered, as well as using a large shaver and burr to remove the debris that accumulates rapidly during the procedure. In addition, we use soft tissue distraction. However, usually at 1 hour into surgery, we will click it back one click to relax some of the distraction and take stress off the neurovascular structures.

The surgeon must be careful to avoid injuring the saphenous nerve and vein medially, and all wounds should be closed with 3-0 black nylon suture that is left in for 3 weeks. As is done in all ankle arthroscopy cases, the neurovascular structures must be carefully marked out, as well as the portals. The key to ankle arthroscopy safety is to never point your shaver dorsally into the neurovascular structures anteriorly or posteriorly. We feel it is important to remove about 1 mm of bone each from the tibia, talus and fibula and perform spot welds on all the bony surfaces as well as the drill holes, to promote bleeding and healing.

Bruce J. Sangeorzan, MD: Since I place a high priority on maintaining the anatomy of the joint, including the curve of the talar dome, I prefer removing cartilage and subchondral bone through a lateral approach. A small incision along the fibula can be significantly enhanced by osteotomy of the fibula that removes a 1-cm to 2-cm block of the fibula at the joint line. That way the osteotome or arthroscope can get to about 85% of the joint without having to trough out spaces.

Thomas S. Roukis, DPM, PhD, FACFAS: A learning curve is just a nice way of saying you are hurting people while you learn a new task. As such, I have attended multiple foot-and-ankle-specific arthroscopic cadaveric-based surgical skills courses nationally and internationally. I would recommend the same to those interested in routinely performing ankle arthroscopy. Some tips I have stumbled upon or were taught include the following:

• Wedge a blunt trocar between the tibia and talus through an accessory portal to distract a particularly tight joint in order to have a better working space;
• Use a 4-mm, 30° arthroscope for a larger field of view and have a 4-mm, 70° arthroscope available to peer down the medial, lateral and posterior gutters.
• Start the cartilage resection sequentially with a 3.5-mm shaver, then a 4.5-mm shaver and, once the subchondral bone plate is encountered, use an acromionizer burr to expose the cancellous bone substrate; and
• Use chondral picks to fenestrate any particularly sclerotic areas similar to performing a microfracture technique.

Positioning and delivery of internal fixation can be difficult. I have found that provisional fixation with two large-diameter Steinmann pins to be helpful. I first place a wire axially from the calcaneus into the tibia as would be performed for a straight retrograde intramedullary, hindfoot-ankle arthrodesis nail. This makes certain I do not have the foot too far forward and not plantarflexed in the sagittal plane as these situations would cause increased stress across the mid-tarsal joint complex. It also assures the talus is centered under the tibia in the transverse and frontal planes while allowing for rotational adjustment and axial compression.

If bone graft is needed, this is the ideal time to add it since the ankle joint can be distracted and the graft injected across the tibiotalar space. Once the first Steinmann pin’s position and alignment are verified under image intensification, I place a second large-diameter Steinmann pin in the fibula perpendicular to its long axis and into the center of the talar body. Image intensification is used to verify the alignment prior to delivery of guidewires for large-diameter cannulated compression screws. I prefer using three headless compression screws over standard-headed screws as the latter frequently require use of washers that are bulky, difficult to remove and can damage adjacent structures during insertion. I have not found one particular screw configuration to be superior to another. I remove the provisional Steinmann pin fixation and place the screws in the same order as the guidewires are placed.

SooHoo: What are the risks to consider in arthroscopic fusion? For example, what is your approach to the use of a tourniquet, thigh holder and arthroscopic pump? Do you think use of these devices for any prolonged surgical time increases the risk of compartment syndrome?

Ferkel: The risks of arthroscopic arthrodesis include prolonged tourniquet time with subsequent neurovascular injury, prolonged distraction with subsequent neurovascular injury and possible compartment problems with the use of an arthroscopic pump. In addition, malunion, nonunion, screw breakage, infection and other potential complications should always be avoided at all cost. I perform the procedure in the supine position with a thigh holder positioned proximal to the popliteal fossa. I then paralyze the patient with general anesthesia and use soft tissue distraction. We do not use an arthroscopic pump in the ankle, but we do use a dedicated posterolateral inflow cannula, which gives more than adequate flow. All patients receive antibiotics. I anticoagulate patients at 2 weeks postoperatively. In addition, we check every patient’s vitamin D level and adjust it accordingly. If tourniquet use exceeds 2 hours, we release it to avoid prolonged tourniquet time and possible complications.

Sangeorzan: The biggest risks in arthroscopic fusion are failure to properly position the talus and failure to maintain the shape of the joint. Because there is no direct observation of the overall tibiotalar position through an arthroscope, ample reliance on fluoroscopy is needed. Because a scope and debrider are straight and the dome is curved, one needs multiple portals and good distraction to prepare the surfaces without excess or uneven removal of bone. Both risks can be minimized by experience and proper position of the instruments. There is ample evidence in the literature that placing traction on a limb that is braced proximally against a thigh holder can lead to compartmental syndrome. Surgeons must be aware of that during patient positioning, as well as of how long the procedure takes. An alternative to traction is the application of a distractor from the tibia to the talus or calcaneus. A pin in the talus is more effective at distracting, but it also gives little opportunity to change the position of the talus while it is being distracted. Attaching the distractor to the calcaneus is less effective at creating open space, but this allows a separate action on the talus to improve its position. Whether done open or closed, most ankle fusions should be accomplished in less than 1 hour. Although using a tourniquet certainly makes this a simpler procedure, it is not entirely necessary. In circumstances where one might be concerned about perfusion pressure, surgery can be done without a tourniquet.

David I. Pedowitz, MS, MD: Fortunately, I have not had any problems with massive irrigation fluid extravasation into the soft tissues. You bring up a good point though; with any technique, it is important to consider some of the additional risks that may exist that would otherwise not be plainly obvious. For surgeons with little arthroscopic fusion experience, the arthroscopic ankle fusion can be quite time consuming. Visibility, like in traditional acromioplasty in the shoulder, can be challenging. In my experience, it is important to have a posterior portal — something many surgeons have little experience with. These challenges are not insurmountable, but, in an effort to minimize error and risk, must be anticipated when approaching this technique. I do arthroscopic fusions under general anesthesia with a calf tourniquet and with an indwelling popliteal catheter for postoperative pain relief. Like most of my colleagues, I use a noninvasive distractor. I do use an arthroscopic pump for fluid inflow. Unlike when doing a standard arthroscopy for impingement/synovitis or an osteochondral lesion, where my portal size is just slightly larger than the 2.7-mm scope, for fusions, I make my portals larger to allow for greater egress of fluid and debris during the procedure. This allows for better visualization and minimizes fluid pressure in the joint and surrounding tissues. Anecdotally, as this technique rarely takes more than 90 minutes and there is ample fluid outflow, I think the risk of compartment syndrome is very low.

Roukis: The main risk for all anterior-approach arthroscopic ankle procedures is still iatrogenic injury to the lateral branches of the superficial peroneal and the saphenous nerves. I have not found a predictable way of avoiding nerve injury despite adherence to good surgical technique. I counsel patients that they will likely have hypoesthesia in the area of one of more of these nerve distributions that this will be annoying but not debilitating. I tell them it routinely resolves with time, which can be up to 1-year postoperatively. I routinely avoid the use of non-invasive stirrup-type distraction devices because they place direct compression across the nerves as they course across the dorsum of the foot. Instead, I place the leg in a thigh holder such that the entire lower leg is hanging free and gravity alone helps distract the ankle joint sufficiently. I routinely apply, but rarely use, a thigh tourniquet during arthroscopic ankle arthrodesis.

The exceptions to this practice are with excessively bleeding synovial tissues that create a “red-out” in the joint or if I must raise the pressure setting or fluid rate of the arthroscopic pump continuously to maintain good visualization in the joint. Under these circumstances, the risks associated with a well-padded, appropriately placed thigh tourniquet outweigh the risks associated with blindly attempting preparation of the ankle joint or using excessively high pump settings. I use an arthroscopic pump and prefer the default knee settings as these seem to work better with the 4-mm arthroscope I use. I have not witnessed a clinically apparent compartment syndrome following arthroscopic ankle arthrodesis. By keeping the incisions small so fluid does not flow readily out of the incision portals, the pressure in the joint is easier to maintain and a minimal volume of fluid is required.

• References:
• Ferkel RD. Arthroscopy. 2018;doi:10.1016/j.arthro.2018.01.006.
• Ferkel RD, et al. Foot Ankle Int. 2005;doi:10.1177/107110070502600402.
• Ferkel RD. Foot and Ankle Arthroscopy. 2nd ed. Philadelphia: Wolters Kluwer; 2017.
• Jones CR, et al. Arthroscopy. 2018;doi:10.1016/j.arthro.2017.11.031.
• Park JH, et al. Arthroscopy. 2018; doi: 10.1016/j.arthro.2017.08.284.

• For more information:
• Richard D. Ferkel, MD, can be reached at Southern California Orthopedic Institute, 6815 Noble Ave., Van Nuys, CA 91405; email: eobrien@scoi.com.
• David I. Pedowitz, MD, MS, can be reached at Rothman Institute, 825 Old Lancaster Rd., Suite 100, 140 and 200, Bryn Mawr, PA 19010; email: drpediowitz@yahoo.com.
• Thomas S. Roukis, DPM, PhD, FACFAS, can be reached at Gundersen Health System, Orthopaedic Center, Mail Stop: CO2-006, 1900 South Ave., La Crosse, WI 54601; email: tsroukis@gundersenhealth.org.
• Bruce J. Sangeorzan, MD, can be reached at Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA 98104; email: bsangeor@uw.edu.
• Nelson SooHoo, MD, can be reached at UCLA Department of Orthopedic Surgery, 1250 16th St., Suite 3142, Santa Monica, CA 90404; nsoohoo@mednet.ucla.edu.

Disclosures: Ferkel reports he is a consultant for Smith & Nephew. Pedowitz reports he is a paid consultant and paid presenter or speaker for Arthrex; receives IP royalties from, is a paid consultant and paid presenter or speaker for, and receives research support from Integra; is a paid consultant for MiRus; and receives IP royalties from and is a paid consultant and paid presenter or speaker for Zimmer Biomet. Roukis, Sangeorzan and SooHoo report no relevant financial disclosures.