What treatments are available for osteoarthritis of the ankle?
Proper initial treatment of the trauma, which ranges from “just” a sprain to fracture, whether simple or complex, is essential, in order to prevent osteoarthritis. If osteoarthritis sets in even so, there is a range of techniques available.
Non-operative (conservative) treatments
Medical treatment, by general route (analgesics such as paracetamol, and anti-inflammatories such as ibuprofen) can successfully relieve pain in the early stages. These drugs can be taken for several months or longer: treatments for high blood pressure or excess cholesterol often go on for years; in these indications, few patients hesitate. When prescribed correctly, analgesics and anti-inflammatory drugs have no more side-effects than other medications that millions of patients happily take for years on end.
It is when these “conservative” treatments begin gradually to become less effective that it is time to think of alternatives.
In some cases, local medical treatment is possible in the form of injections: cortisone-derivatives generally provide short-to-medium-term relief. The same is true for hyaluronic acid. Unfortunately, however, these drugs tend to be rather limited in effect, notably over time.
Physiotherapy is effective, using anti-inflammatory and analgesic techniques such as ionization or cryotherapy (cold treatment) in crises of pain. In periods of chronic pain, heat treatment (such as mud treatment: “fangotherapy”) is preferable. Alongside physiotherapy, functional rehabilitation provides a means of maintaining range of motion and of proprioceptive reinforcement.
In most cases, correcting overweight relieves pain, as does adjusting activity:
- brief complete rest during painful inflammatory episodes;
- longer term adjustment: adapting the work-station, and changing leisure activities, in favor of sports that do not involve shocks, without completely changing the type of activity (e.g., cycling instead of tennis, roller-skating instead of running, hiking, but without too much climbing up or down…).
Seul l’échec avéré des techniques conservatrices (non chirurgicales) oriente le chirurgien vers des techniques chirurgicales.
Ces techniques sont adaptées au type d’arthrose : globale ou limitée, avec ou sans déformation, avec ou sans lésions ligamentaires associées, adaptées également à la cause initiale de l’arthrose ; elles sont également en fonction du patient : âge, niveau d’activités, facteurs de risques associés, etc
These are techniques that spare the partially damaged joint.
Two small incisions of about 1 cm (half an inch) are made over the joint, and the operation is performed under visual control using a video camera positioned inside the joint.
The technique is suitable in case of:
- loose fragments inside the joint, causing blockage;
- increased synovial tissue volume;
- osteophytes (“parrot beaks”), causing bone impingement and pain.
Exceptionally, the bone impingement is so great that open surgery is preferable, enabling more complete “cleansing”.
Some cases of severe but localized cartilage damage can be treated by grafting. Cartilage is harvested from the knee, in an area where it is not indispensable, and implanted in the diseased ankle.
If the affected area is inaccessible because it is masked by the contours of the joint (the malleoli), osteotomy is required. This consists in cutting the bone so as to gain access to the area needing treatment. The bone is then repaired, and fixed back in place.
In osteotomy, the surgeon cuts in the bone to correct a deformity in a well-identified location: usually, the heel, with “calcaneal osteotomy” to reposition it above the tibia, or sometimes just above the ankle (supramalleolar osteotomy).
Calcaneal valgization osteotomy
Figure showing (left) normal alignment, and (right) pathological alignment: the top of the ankle joint is not horizontal.
Same ankle, after correction by supramalleolar osteotomy: the top of the joint is back to horizontal.
Ligament reconstruction is sometimes associated to osteotomy; these complex techniques aim to correct both anatomic imbalance (malalignment) and ligament imbalance. A useful image would be that of a boat mast leaning to one side: first we straighten it up, then we tighten the stays.
These joint-sparing techniques are rarely definitive: they usually just allow non-conservative treatment to be postponed, gaining some time, but not really stopping the abnormal wear process.
2/Non-conservative surgical techniques
Non-conservative surgery “sacrifices” the joint when it is too badly damaged to be spared. It will be either blocked (“tibiotarsal” or “ankle fusion” (“arthrodesis”)) or replaced (“total ankle replacement” or “arthroplasty”).
a)Total ankle replacement https://youtu.be/mwqiyhUdOuQ
Current designs for total ankle replacement have more than 25 years’ follow-up. While 100,000 hip replacements are performed each year in France, the figure for total ankle replacement is 500.
Why such a difference? First of all, osteoarthritis of the ankle can be tolerated for a long time, thanks to compensations by neighboring joints and the efficacy of conservative treatments such as insoles and orthopedic shoes, and also because good results are obtained with ankle fusion, even if this does sacrifice joint motion.
The advantages of ankle replacement over fusion are numerous: faster recovery, early return to weight-bearing (at around 4 weeks postoperatively), shorter immobilization time (6-8 weeks, compared to an average 12 weeks), and above all greater range of motion for the ankle and the foot.
The indications need to be carefully assessed: ankle replacement involves a resurfacing implant: i.e., it can replace the worn joint surfaces, on condition that they are well-oriented in the three dimensions and well-balance by healthy ligaments. If the joint surfaces are misaligned and/or the ligament system is unbalanced, extra procedures, such as realignment osteotomies or ligament reconstruction, will need to be performed first if ankle replacement is to go forward.
The implant is going to suffer wear as time goes on. In some cases, this will need another operation, either to change the worn components or to resort to fusion.
b)Ankle fusion (arthrodesis) https://youtu.be/S4On7vP6UI8
This is a reliable, well-tested technique, consisting in blocking the joint, usually definitively, although “de-arthrodesis” can exceptionally be performed, to implant a total ankle replacement.
This term “blocking” makes many patients fear that they are going to end up with their foot and ankle blocked. This is not true, as the ankle provides only some of the overall motion of the foot, since there are three other important joints involved, which can provide real compensation. Moreover, osteoarthritis itself tends to “block” the ankle in a very awkward position, and fusion repositions it flat on the ground, in all 3 dimensions.
Illustrations of post-traumatic osteoarthritis of the ankle, with malalignment and stiffening in equinus; the patient can walk only on tip-toes.
The same ankle, after correction: the patient is able to walk with the foot flat on the ground again. Paradoxically, blocking the ankle actually restored the upward motion of the foot, enabling the heel to be placed on the ground.
The advantage of fusion is that it is a definitive operation, and also a very effective one in severe situations such as the one shown here.
It also has disadvantages, however: overworking the neighboring joints (hip, knee, foot joints), which are liable, depending on their original condition, to develop osteoarthritis themselves over the medium-to-long term.
How to choose?
The choice between the various options depends:
- on the surgeon’s assessment,
- which in turn depends on the patient’s weight, age, risk factors, activities etc.,
- and the type of pathology that led to disabling osteoarthritis: malalignment, ligament lesions, previous trauma, history of infection, bone stock, etc.
It also depends on the patient, who needs to be fully informed that, in opting for ankle replacement, he or she is choosing a solution that will not always be definitive, although it does have the advantages mentioned above: easier walking thanks to greater range of motion, conserved neighboring joints, shorter convalescence, etc.
That is to say, the choice is not straightforward, and requires a conversation between the surgeons, who has at heart only the patient’s well-being and long-term comfort, and the patient, to whom the issues are to be explained independently, honestly and in an adapted manner.
The conversation will be a long one, covering all the implications of whichever option, depending on the particular individual case.