Current Concepts In Ankle Arthroscopy

pt1207cvrankle1.jpg [3]

pt1207cvrankle1and2.jpg [4]

pt1207cvrankle2and3.jpg [5]

   Ankle arthroscopy is an extremely useful skill for a foot and ankle surgeon. Foot and ankle surgeons use ankle arthroscopies to treat a variety of problems, including osteochondral defects, loose osteochondral fragments, ankle impingement, post-traumatic fibrous bands, synovitis and ligamentous/capsular injuries.

   Ankle arthroscopy has several advantages over an open ankle procedure. The surgery is minimally invasive and has a low complication rate. One can perform this on an outpatient basis and it facilitates a relatively easy postoperative recovery period. In contrast to an open ankle technique, arthroscopy allows complete ankle joint visualization and does not result in intraarticular scar tissue formation. Proficiency with ankle arthroscopy develops with good training and experience. [3]

There is a learning curve with ankle arthroscopy that surgeons cannot overcome simply by enrolling in a weekend learning course. It is important to master the instrumentation and develop the skills necessary to visualize three dimensionally. Much of the difficulty lies in being able to move and triangulate the instruments appropriately without actually looking at one’s hands, which is counterintuitive for a surgeon. Utilizing cadaver labs and assisting other surgeons in ankle arthroscopy are the most helpful ways to improve one’s skills.

A Guide To Planning And Preparation

   Preparation for ankle arthroscopy is very important. When scheduling the case, be sure to allow a few minutes of extra time for set-up. The typical operative time for simple arthroscopies ranges from 45 minutes to an hour and a half.

   Request a general anesthetic so the patient and the ankle joint are completely relaxed. One can use a thigh holder so the patient’s knee is bent during surgery and the ankle is hanging downward. This helps to distend the joint. Another technique is to have the patient supine on the bed with the patient as far down on the bed as possible. The surgeon can use his or her own body during the surgery to dorsiflex the ankle by leaning onto the plantar foot. A hip roll can internally rotate the operative leg so the foot and ankle are pointing toward the ceiling. This facilitates the use of the instruments in the portals.

   Typically, an anteromedial portal and anterolateral portal are enough to visualize the joint. Make these incisions from caudal to distal. The incisions should be about 1 cm in length at the level of the ankle joint. Blunt dissection down to the capsular layer is important to minimize neurovascular damage. While standard placement of these incisions is discussed in other publications, one should mark these incisions preoperatively before ankle joint insufflation since anatomical landmarks are more difficult to see when the joint is distended. The patient can also help identify landmarks by contracting the tibialis anterior for the anterior medial portal and extensor digitorum brevis muscle for the anterior lateral portal for marking in the preoperative holding area.

   Position the monitor in a direct visual line to yourself and typically fairly close to the anesthesiologist. One can use a 2.7 mm or 4.0 mm arthroscope with a 30-degree angle for most cases. However, when it comes to smaller patients, a 2.7 mm arthroscope is easier to use and can minimize iatrogenic damage to the cartilage. Surgeons can use a gravity-assisted lactated ringer’s solution or a pump machine, depending upon one’s preference. As a precaution, you may want place a thigh tourniquet on the patient although it is not always necessary in every case. Judicious preoperative use of 1% lidocaine with epinephrine can insufflate the joint and minimize bleeding. The surgeon can also inject epinephrine into the bag of lactated ringers to help control bleeding during the case.

   Visualization is critical to performing ankle arthroscopy. If visualization is compromised by bleeding or cloudiness, attempt to use the tourniquet to control the fluid and suction in the joint. While it is not routine to utilize a non-invasive ankle distractor, it should be available in the operating room in case access to the joint is tight. Surgeons can also use a simple external fixator in the rare cases that require stronger distraction. More complications can occur with invasive ankle distractors and they are not recommended in most cases.

What Are The Indications For Arthroscopy?

   A very common indication for ankle arthroscopy is osteochondral defects. One would commonly perform the procedure by curetting the area and using K-wires to drill the lesion to promote subchondral bleeding. Patients should be non-weightbearing for at least six to 10 weeks depending on the size of the lesion and one should consider using an external bone stimulator. Posterior and medial lesions are more difficult to access and a distractor may be necessary.

   Deeper lesions also tend to have a poorer prognosis. If the size of the osteochondral lesion is very large or if the injury has been long neglected, an ankle arthroscopy with debridement may fail.

   Clinical symptoms in addition to a follow-up MRI can determine the success of the surgery. In the past, one would not have considered a repeat ankle arthroscopy due to a perceived higher failure rate. However, certain studies indicate that a repeat arthroscopy may be beneficial.¹

   If the arthroscopy fails, an osteochondral allograft transplant procedure would be the next operation. It is generally accepted that osteochondral autografting can produce significant clinical improvement.² Other studies indicate that the outcomes of chondroplasty versus microfracture versus osteochondral autologous transplantation show no differences at the final outcome.³ Clearly, the surgeon must make these decisions on a patient by patient basis, taking into consideration the size of the osteochondral lesion, the length of recovery and the patient’s desire.

   Loose osteochondral fragments are often associated with osteochondral defects. While one may not always see these on advanced imaging studies, surgeons can easily remove them from the ankle joint when they encounter them. Flushing the ankle joint out with lactated ringers or saline during the procedure can “loosen” unattached fragments.

   These fragments can cause impingement pain. Ankle impingement can result from solid fragments in the joint or even soft tissue that decreases range of motion. Most of these impingement issues are anterior in the ankle joint and one can access them more easily by dorsiflexing the ankle and creating an anterior pouch in the capsule. Fluoroscopic guidance can also be helpful in these cases to ensure adequate resection of the impingement. Take care to avoid the anterior neurovascular structures. There also may be more postoperative bleeding from the bone resection than what one might see with a standard ankle arthroscopy.

Can Ankle Arthroscopy Have An Impact For RA Patients With Ankle Pain?

   Ankle arthroscopy is also a good treatment modality when it comes to rheumatoid arthritis patients with ankle pain. Preoperatively, cortisone injections help relieve the pain temporarily but do not improve range of motion or mobility. Attempt braces, orthotics and other conservative therapies first. Rheumatoid cases are often more difficult in ankle arthroscopy since visualization in the joint can be poor when the surgeon first enters the joint. The ankle joint is often full of acute synovitis, which appears inflamed and hemorrhagic.

   Conversely, if the rheumatologist has recently treated the patient with prednisone or other rheumatologic agents, the surgeon will see a less inflamed yet still pathologic ankle joint. The less acute rheumatoid ankle typically has copious amounts of fibrous white bands and tissue. Extensive debridement of the synovitis is necessary to “clean” the joint. The synovitis causes these patients to have ankle stiffness and an antalgic gait. Patients respond well postoperatively with significant pain relief and increased ankle range of motion. Increased motion in the ankle joint will decrease the stress load on other joints in the foot, which often become inflamed and painful in the rheumatoid patient. Rheumatoid patients typically respond very favorably to an ankle arthroscopy.

    [4]In one case from my practice, a 23-year-old female presented with significant pain in her right ankle for two years. She was recently diagnosed with rheumatoid arthritis. She limped with every step and began suffering from depression. Her medications included prednisone, methotrexate, Lexapro, Motrin, ferrous iron and calcium. She had extensive anterior edema in her right ankle and limited range of motion. Her dorsiflexion was about 10 degrees and plantarflexion was about 15 degrees with pain. [5]

I gave her a cortisone injection, which improved her pain temporarily. I also cast her for custom orthotics, which also helped slightly. Radiographs of her right foot showed significant talonavicular joint destruction. Magnetic resonance imaging of her ankle showed extensive joint effusion and inflammation.

   The patient underwent a right ankle arthroscopy, which I performed after a month of conservative treatment. She had extensive fibrous tissue in her ankle joint that I shaved during the arthroscopy. The patient did extremely well postoperatively despite initial non-compliance about physical therapy. Physical therapy did not start until one month postoperatively. At a one-month postoperative visit, the patient had 20 degrees of ankle joint dorsiflexion and 40 degrees of ankle joint plantarflexion.

   This motion improved after physical therapy. She has since seen a rheumatologist and has had no foot and ankle complaints in two years postoperatively.

What You Should Know About The Potential Of Ankle Arthroscopy

   Ankle arthroscopy can also help diagnose ligament disorders and ankle instability. Soft tissue disorders may explain chronic ankle pain after a severe ankle sprain. One can view torn or detached ligaments through the arthroscope.⁴ Ankle arthroscopy can also facilitate easy visualization and removal of other soft tissue impingements. Surgeons can easily coblate and remove synovitis, which can significantly reduce ankle range of motion.

   Post-traumatic fibrous bands are rare and are difficult to see even with MRI.⁵ One can easily identify and remove these with ankle arthroscopy. With simple arthroscopies, early weightbearing will improve range of motion and hasten recovery. Postoperative physical therapy also improves patient outcomes.

   More recently, doctors have been developing arthroscopic techniques to assist in open reduction internal fixation (ORIF) of ankle fractures. The arthroscope enables the surgeon to see articular congruity and can minimize the invasiveness of the surgery.^6,7 One can use percutaneous screws instead of an open procedure due to improved visualization of the fragments in comparison to fluoroscopy or intraoperative radiographs alone. Surgeons have mostly used this technique in younger patients as it allows a faster return to activities and better long-term clinical results. Similar concepts apply when it comes to the use of subtalar joint arthroscopy for visualization of calcaneal fractures.

   Arthroscopically assisted ankle arthrodesis is only indicated for in-situ fusions in which no significant angular correction is needed. This is also a technique that surgeons can consider for patients with soft tissue compromise in cases in which larger incisions may not heal. Examples include cases that involve venous stasis ulcers or burn scars. Percutaneous screw fixation guided by fluoroscopy or C-arm reduces the need for large incisions.

   Arthroscopic arthrodesis is not a recommended technique for a revision of a failed ankle fusion. When successful, arthroscopic arthrodesis appears to have a faster union rate and thus facilitates patient recovery.⁸ Appropriate patient selection is a key factor in facilitating successful unions with this procedure.

   Clinicians often use ankle arthroscopy as a diagnostic tool to visualize the ankle joint directly. Direct visualization is often the most reliable way to see chondromalacia or the extent of another diagnosis that one may or may not appreciate on MRI. When a patient has persistent ankle pain that is relieved by a diagnostic injection yet demonstrates negative findings on X-ray, CT or MRI, he or she is a good candidate for a diagnostic ankle arthroscopy.

   In these cases, one must ensure the patient has a proper understanding (and has given his or her consent) that the purpose of the surgery is to attempt to diagnose a problem, not necessarily fix the idiopathic pain. In this scenario, ankle arthroscopy can be a last option. Surgeons should first attempt conservative treatments including physical therapy, custom orthotics or ankle foot orthosis, and perhaps an occasional soluble cortisone injection

In Summary

   One can use ankle arthroscopy to treat a variety of disorders successfully. Although this surgery can be very rewarding for both the patient and the surgeon, there is a learning curve to performing ankle arthroscopy efficiently, responsibly and successfully. Careful planning and preparation before the surgery will allow the case to proceed as easily as possible, thereby minimizing complications and maximizing results.

   Editor’s note: For a related article, see “A Pertinent Guide To Basic Ankle Arthroscopy” [6]in the November 2003 issue.

References:

=

1. Savva N, et al. Osteochondral lesions of the talus: Results of repeat arthroscopic debridement. Foot Ankle Intl 28(6):669-673, 2007.
2. Kreuz PC, et al. Mosaicplasty with autogenous talar autograft for osteochondral lesions of the talus after failed primary arthroscopic management: a prospective study with a 4-year follow-up. Am J Sports Med 34(1):55-63, 2006.
3. Gobbi A, et al. Osteochondral lesions of the talus: randomized controlled trial comparing chondroplasty, microfracture and osteochondral autograft transplantation. Arthroscopy J Arthroscopic Rel Surg. 22(10):1085-1092, 2006.
4. Liu TH. Arthroscopic-assisted lateral ligamentous reconstruction in combined ankle and subtalar instability. Arthroscopy J Arthroscopic Rel Surg. 23(5):554.e1-554.e5, 2007.
5. Slavotinek, et al. Intra-articular fibrous band of the ankle: an uncommon cause of post traumatic ankle pain. Australasian Radiology. 50(6):591-593, 2006.
6. Laffosse JM, et al. Osteosynthesis of a Triplane Fracture under arthroscopic control in a bilateral case. Foot Ankle Surg 13(2):83-90, 2007.
7. Panagopoulos A, et al. Knee Surgery, Sports Traumatology. Arthroscopy. 15(4):415-417, 2007.
8. Collman, et al. Arthroscopic ankle arthrodesis: factors influencing union in 39 consecutive patients. Foot Ankle Intl 27(12):1079-1085, 2006.