For most patients, the natural history of osteoarthritis of a lower extremity joint is one of insidious onset and gradual deterioration. The symptoms wax and wane over time, with the frequency of the painful episodes gradually increasing in both intensity and duration. It takes time and personal reflection for patients to decide that a surgical opinion is necessary. The primary role of the treating surgeon is not only to identify the best mode of treatment but also to discuss the limitations of the proposed interventions. With many surgical options, the recovery time can be substantial and the outcomes variable. The entire process can take years by the time the patient decides to proceed with surgery.
During the interval between the onset of symptoms and surgical intervention, many patients seek effective and affordable treatments to manage their worsening condition. Patients often ask if there is a way to rejuvenate or grow the cartilage that has been lost in the joint. The option of injecting a lubricant into the joint makes sense to the patient and is often embraced with enthusiasm. At this point, they are relying on their treating physician to consider all aspects of the proposed intervention, including the risks, benefits, reliability, cost, effectiveness, and duration of the pain relief. It has been our experience that it does not take much time or effort to convince a patient to agree with the option of having his or her arthritic ankle joint injected with a hyaluronic acid-containing solution.
Unfortunately, many physicians themselves have not required much convincing either. Studies supporting the safety and effectiveness of hyaluronic acid-containing injections for the treatment of knee arthritis along with favorable results from many of the initial investigations of its utility for treating ankle osteoarthritis have been met with optimistic enthusiasm by our profession. To our knowledge, nine previous studies have investigated the effects of hyaluronic injections in arthritic ankles. They have looked at single and multiple-dose hyaluronic acid regimens, as well as a variety of hyaluronic acid, or similar, substances, but most of the studies are not considered high-quality by virtue of being underpowered, uncontrolled, nonblinded, noncomparative, and/or industry funded1-9.
The current study is adequately powered, randomized, and prospective, with validated outcomes; thus, it meets the criteria of a Level-I study. This clinical study demonstrates that the use of a single intra-articular injection of low-molecular-weight, non-cross-linked hyaluronic acid for the treatment of symptomatic ankle arthritis does not produce significantly superior outcomes compared with a single intra-articular injection of saline solution. To a scientist, the outcomes are not surprising since injecting a biologic substance regardless of its function is not likely to work unless it can promote development of a normal articular surface, with resorption of the osteophytes and restoration of joint motion—a goal that is not achievable by hyaluronic acid or similar substances. This does not in any way definitively close the door on the subject; we still need equally well-designed studies to investigate multi-injection regimens and other hyaluronic acid-type substances. However, this study does provide us with a firmer base from which we can make important clinical judgments and advise patients of their treatment options.
In the current climate of upward-spiraling medical costs, record national debt, and uncertain economic future, we believe that physicians have a moral obligation to manage the health-care dollar with prudence, regardless of whether its source is government, insurance, or personal. Given the state of the current evidence base for hyaluronic acid-containing injections for the treatment of ankle arthritis, we encourage a healthy skepticism regarding its benefits and will wait for more evidence before recommending it to patients.