Arthritis of the ankle can be a challenging and often debilitating problem for patients. Although there have been dramatic improvements and more options in the treatment of ankle arthritis, the common treatment options are best suited to older patients and more sedentary patients. Other than ankle fusion, the options for younger patients have been limited.
Accordingly, I would like to share our experience and outcomes with several new approaches to ankle arthritis in younger patients, and what my colleagues and I see in the future as upcoming options.
Ankle arthritis is most commonly post-traumatic. Unlike the knee and the hip, which often wear down over time, the ankle joint has not been subject as much to degeneration from aging. However, arthritic changes from traumatic damage have been the mainstay of ankle arthritis. With the advent of more active lifestyles and extreme sports, there has been a rash of younger patients who have mild to moderate post-traumatic ankle arthritis due to injury. These patients are very difficult to treat as the common options of ankle replacement and ankle fusion are not well suited to them.
Ankle replacement has advanced dramatically in the past 25 years but is best suited to patients over the age of 55. However, more and more patients in the 45 to 55 years of age range are also getting replacements. Replacement is not a great option for the 20- to 30-year-old crowd as there is a high likelihood these patients will need to undergo the implant procedure several times in a lifetime. Ankle fusion is a good option for a younger patient from a structural and stability standpoint, but a fusion will often result in stress on the surrounding joints with associated wearing down and arthritis of these joints over time.
So what options are best suited to a young, active patient with arthritis of the ankle? Our options for ankle arthritis run a spectrum from injection therapy to joint distraction and cartilage replacement.
Our examination and testing are fairly detailed and extensive in arthritis cases. During the physical exam, we determine range of motion, the level of crepitus and pain. We also determine the location of greatest pain, which is often medial or lateral, and rarely on both sides.
Following examination, take standard radiographs to see the level of arthritis. I consider a radiograph a 30,000-foot view with few details. In order to thoroughly plan the surgical options, my suggestion is a combination of weightbearing computed tomography (CT) scans and magnetic resonance images (MRI).
The reason for the two exams is that the weightbearing CT allows for alignment analysis and bone assessment of degeneration, spur formation and wear. Use MRI for marrow and cartilage assessment as well as examination of the tendons and ligaments about the ankle. Often, there is a combination of bone and soft tissue damage. Therefore, I suggest a full check of the bone and soft tissue.
After an examination and diagnostic studies, one can establish a treatment plan. In dealing with the soft tissue, address the laxity of the ligaments and possible tendon tear. This will allow proper function of the ankle and fewer issues with weakness and instability. On MRI, check the subchondral bone. If there is significant subchondral edema of the bone, it may be a source of pain. One can often address this with bone marrow aspirate concentrate injection and decompression of the subchondral bone. Subchondroplasty has gained popularity in the past few years but we have found better outcomes with bone marrow aspirate than the calcium phosphate surgeons use in subchondroplasty cases.
From an articular damage standpoint, the MRI enables us to consider the level of articular damage and correlate this with CT findings. Be careful not to use only MRI for articular assessment as edema will make the articular damage look worse than it actually is and CT will show the true articular damage. The problem with only using CT is that you cannot tell if articular damage is superficial or marrow edema-related. Accordingly, I highly recommend using both CT and MRI for articular assessment.
Use CT scans to check for alignment and assess for spurring and loose bodies. Weightbearing CT enables you to check for leg alignment and it also breaks down the alignment into a 3D model that allows for rotation and proper surgical planning. In many cases, there is a malalignment of the ankle, which results in increased pressure on the medial or lateral ankle related to post-traumatic deformity. Supramalleolar osteotomies can align the ankle in a better position in order to decrease the abnormal stress about the joint. At times, there is a malalignment of the talus or calcaneus, and surgeons often address this through a calcaneal osteotomy or possible subtalar fusion. Finally, in certain soft tissue cases, such as a deltoid instability, an osteotomy of the calcaneus can help adjust pressure distribution about the ankle.
The final consideration and most difficult issue to deal with is the actual damage to the articular cartilage. We currently do not have a great approach to the attachment of articular cartilage to bone. However, we are making advancements in this arena and several procedures we have used could be helpful.
Prior to cartilage consideration, we usually perform an arthroscopy of the ankle to check the joint, perform a comprehensive debridement of intra-articular scar formation and remove regions of minor spurring. If there is significant spurring, we prefer to address this through a mini-arthrotomy and joint cleanup with an osteotome to truly remove the larger spur regions.
After cleaning up the joint, one should address the articular surface. We have found three current options to be helpful. The first is BioCartilage (Arthrex), which is non-viable cartilage mixed with bone marrow aspirate. One can create a soft mixture of this and place it in regions of cartilage damage after debridement and subchondral drilling.
A better option, albeit a more expensive one, is DeNovo NT Natural Tissue Graft (Zimmer Biomet). The DeNovo material is live cartilage cells morselized that one can place into the area of cartilage damage. One can debride the damaged cartilage but the surgeon performs no subchondral drilling. Place the DeNovo in the region and use fibrin glue to hold the material in place.
The final and most promising option is cartilage paste grafting. In this case, the surgeon needs to coordinate the procedure with a knee specialist. Take the cartilage from the non-weightbearing chondral notch of the knee. Morselize the cartilage into a paste, place the paste into the ankle joint and spread it over the arthritic regions. Often, one can cover the paste with a thin cover of fibrin glue to adhere the material in place. Do this in a dry field using a small open incision approach. It is important to allow the cartilage paste to adhere. Do not allow weightbearing for approximately six weeks. Patients start range of motion exercises at two weeks post-surgery but patients should be non-weightbearing and perform dorsiflexion/plantarflexion only.
What You Should Know About Joint Distraction
A final additional concept is joint distraction. The idea of joint distraction is to allow the cartilage a chance to heal itself without the chronic pressure of bone-on-bone rubbing.
Distract the ankle joint with an external fixation system, often Ilizarov style. The patient remains this way for six to 10 weeks. This procedure has been in extensive use for over 30 years and has served many patients well. We believe the addition of cartilage paste, joint debridement and a possible bone aspirate stem cell injection to the mix improves an already common option.
Furthermore, the Ilizarov fixation system allows for weightbearing throughout any of the aforementioned treatment options as long as one performs joint distraction. Accordingly, this may be a great option for the patient who cannot be non-weightbearing.
In the future, advances in cartilage repair are sure to make the current treatments seem simple and archaic. That being said, currently there are very few options to treat cartilage damage in the ankle in a young patient without offering ankle replacement or ankle fusion options. The aforementioned procedures allow hope for the younger patient with ankle arthritis and allow us to have additional options in our tool chest for the time being.
Dr. Baravarian is an Assistant Clinical Professor at the UCLA School of Medicine, and the Director and Fellowship Director at the University Foot and Ankle Institute in Los Angeles (https://www.footankleinstitute.com/podiatrist/dr-bob-baravarian ).
For further reading, see “Keys To Considering Ankle Replacement In The Treatment Of Ankle Arthritis” in the September 2011 issue of Podiatry Today or “Essential Insights On Treating End-Stage Ankle Arthritis” in the April 2013 issue.