Published 3/1/2011
Kristy L. Weber, MD; Michael J. Goldberg, MD

New TOs examine treatment of ankle arthritis

Ankle arthritis is a degenerative condition that can cause significant pain and functional limitation. In its early stages, a variety of nonsurgical options can be applied, but for end-stage ankle arthritis, fusion has been the traditional treatment. Recently, however, new implant designs for total ankle arthroplasty (TAA) have shown promising results.

Because evidence supporting the efficacy of both nonsurgical and surgical treatments is poor, the AAOS Guidelines Oversight chairs and members of the physician work group on ankle arthritis chose not to complete a clinical practice guideline (CPG) on this topic. Instead, they developed technology overviews (TOs) examining the literature and investigating key questions about the results of these treatments. In keeping with the definition of a TO, the documents do not make recommendations for or against the use of any specific treatment. TOs are considered evidence-based educational tools that encourage readers to consider the information presented and reach their own conclusions. They do not define the standard of care and are not meant to advise insurance company coverage decisions. Insurance companies perform their own systematic reviews of the literature.

During its December 2010 meeting, the AAOS Board of Directors approved the TOs on surgical and nonsurgical treatment of ankle arthritis.

Nonsurgical treatments
Traditional nonsurgical treatment options for symptomatic ankle arthritis include activity modification, anti-inflammatory medications, bracing, and assistive devices. A wide range of additional treatments—including physical therapy modalities, chiropractic care, and acupuncture—are also used. Injections of corticosteroids or hyaluronic acid, as well as the less common use of prolotherapy or platelet-rich plasma (PRP) may be employed as well. Despite their use in clinical practice, the efficacy of these treatment alternatives for ankle arthritis is poorly documented.

The work group sought to address the following key questions:

  • What is the efficacy of nonsurgical treatments in patients with ankle arthritis?
  • Do the clinical results differ for nonsurgical treatments in patients with ankle arthritis?

A systematic review of the literature found no peer-reviewed data specific to ankle arthritis that addressed most nonsurgical interventions.

A few studies addressed the use of hyaluronic acid injections. Very low quality evidence suggests that treatment of ankle arthritis with hyaluronic acid result in an improvement in patient-oriented outcomes (pain relief, patient satisfaction, and walking ability) with limited adverse events.

Evidence comparing hyaluronic acid to other treatments also was limited. In addition, the disparate presurgical ankle function scores and demographic characteristics between the groups enrolled in the relevant comparative studies prohibited the work group from making meaningful comparisons.

Surgical treatments
Treating end-stage ankle arthritis with fusion is effective at relieving pain but may result in functional limitation from loss of range of motion and an increased long-term risk for arthritis in adjacent hindfoot joints. Although early implant designs for TAA resulted in high failure rates, newer designs have demonstrated promising short- and medium-term results.

The TO on surgical treatment of ankle arthritis sought to answer the following key questions:

  • What are the clinical results of TAA?
  • What are the clinical results of ankle arthrodesis?
  • What are the factors that predict outcomes of TAA?
  • Do patients treated with TAA have different clinical outcomes than patients treated with ankle arthodesis?

Although multiple studies were found, data were limited and the quality of the evidence was not high. The TO notes that, in response to the first key question, treatment of ankle arthritis with either a generation 2 or generation 3 TAA results in an improvement in pain and function. This conclusion, however, is based on low quality evidence.

Multiple studies compared preoperative and postoperative assessments of patients treated with ankle arthrodesis. Based on these data, which the work group noted are of low quality, ankle arthro-desis results in an improvement in patient-oriented outcomes (device failure, reoperation, pain relief, patient satisfaction, walking ability).

The literature does not conclusively demonstrate predictors of better or worse patient-oriented outcomes for TAA, and data directly comparing the efficacy of TAA to arthrodesis in patients with arthritis are limited. The disparate preoperative ankle function scores and demographic characteristics between the groups enrolled in the relevant comparative studies prohibit meaningful comparisons.

The work group also noted that analysis of adverse events that corrected for preoperative differences in patients characteristics provided conflicting results.

Work group members
The work group members include Johnny Lau, MD, chair; Nelson Fong SooHoo, MD, vice-chair; John G. Anderson, MD; Sameh Labib, MD; Stephen J. Pinney, MD; Steven M. Raikin, MD; Simon Carette, MD; William C. Watters III, MD, chair of the Guidelines & Technology Oversight Committee; Charles Turkelson, PhD; Jan Wies, MPH; and Sara Anderson, MPH.

These TOs are not intended to convey any official position by the AAOS. Instead, the information is provided as a service to help members identify and evaluate the available published literature on these topics so that they can provide the best possible care to their patients.

AAOS is involved in the development of TOs because technology plays a central role in the practice of orthopaedic surgery. In addition, AAOS seeks to be a resource for those seeking unbiased information on newly developed surgical procedures, drugs, biologics, and orthopaedic devices. The TO was funded solely by the AAOS.