Essential Insights On Treating End-Stage Ankle Arthritis
Sharing insights from the literature and surgical experience, these authors suggest a re-evaluation and possible elevation of ankle arthroplasty over ankle arthrodesis as a preferred option for appropriate patients with end-stage ankle arthritis.
End-stage arthritis is the point where progressive wearing down of the articular cartilage results in bone-on-bone grinding down of the joint surface. The patient with end-stage arthritis has pain combined with a loss of function and mobility, which severely limits normal activity. When a patient reaches this stage and has failed conservative care (NSAID therapy, other oral therapy, corticosteroid injections, bracing) as well as alternative methods of pain control and management, there are three possible methods of surgical treatment: ankle arthrodesis, ankle replacement and distraction arthroplasty.
A lack of good supportive data for distraction arthroplasty has made it a temporary solution at best that surgeons seldom employ. Until more favorable literature suggests this as a corrective method of treating end-stage ankle arthritis, for the purposes of this article, we will focus on the two remaining treatment options.
End-stage arthritic changes secondary to progressive wearing of the articular cartilage cause pain, disability, decreased quality of life, limitation of activity, loss of function and loss of mobility. The prevalence of ankle arthritis is approximately nine times lower than that of the knee and hip.1 However, despite advancing medical treatment as well as technological advances in internal and external fixation, there are approximately 50,000 new cases of lower extremity arthritis each year.2
Primary osteoarthritis is the most common indication for total hip and knee arthroplasty whereas post-traumatic arthritis is the most common diagnosis for ankle replacement or arthrodesis.3 Secondary causes of degenerative joint disease are inflammatory conditions, infection, dysplasia and vascular or neurological insults.4 With an increasing aging population, the numbers of patients with severe osteoarthritis who want to remain active longer continues to grow. Conservative options for ankle arthritis traditionally include medications, injections and bracing.
When patients have severe arthritic changes that are unresponsive to non-operative care, one may perform ankle arthrodesis or total ankle replacement.
Various researchers have noted that cemented, first-generation total ankle implants (constrained and unconstrained) “often failed” due to poor implant design, loosening and instability.5-7 The first-generation Agility implant had several design flaws that caused higher re-operation rates and failure. Gougoulias and colleagues noted that the Agility implant was “designed to absorb rotational forces by allowing a space between the medial and lateral sides of the talar component resting against the bearing.”8 Delays in syndesmotic fusion, frequent malleolar fractures in the perioperative period and subsidence secondary to a nominal talar component plagued the initial generation of total ankle implants. The loosening rates of the initial generation implants were as high as 60 percent and 90 percent after five and 10 years respectively.8,9
Although failure rates of total ankle arthroplasty initially led to the favoring of ankle arthrodesis, advancements in total ankle implants have recently improved implant longevity, function and overall outcomes.