Background
Osteoarthritis (OA) is a chronic, degenerative condition that affects a significant proportion of the general population. The way the condition progresses can be variable; however, there is no doubt that it has a negative impact on the quality of life of individuals due to associated pain and loss of function in the affected joint. Typically, patients present with OA in major joints such as the hip and knee, with cartilage degradation usually attributed to an underlying inflammatory process (Stott & Wells, 2016). In contrast, in patients with OA of the ankle, the cause of the disease is different. These patients tend to be younger and typically present with pain and loss of function following fracture of the ankle or lower leg. It is well recognized that in the younger population, ankle trauma due to sporting injury is a common occurrence. As a result, these patients can expect to experience pain and loss of function for a much longer period of time, which has a significant impact on their quality of life
From a clinical management perspective, there are a number of treatment options available. For example, for those patients with end-stage OA, surgical treatment is available. This includes arthrodesis, ankle replacement, or osteotomy. However, this treatment is viewed as a "last resort" due to high complication rates such as delayed wound-healing, infection, delayed union, and OA of associated joints. For patients who present with symptomatic ankle OA in its early stages, interventions tend to be conservative and focus on preventing further deterioration of the joint and managing symptoms such as pain and stiffness. Currently, conservative management interventions include the use of nonpharmacological and pharmacological treatments. Nonpharmacological interventions include providing education on the value of weight reduction, physiotherapy, and occupational therapy such as shoe adjustment, which use inlays to offload the joint, thus resulting in reduced pain. Generally, these interventions are supplemented with the use of analgesics such as acetaminophen, opioids, and nonsteroidal anti-inflammatory drugs. In the clinical environment, when simple analgesics are unsuccessful, the use of hyaluronic acid (HA) can be used as a means of reducing pain in those patients with ankle OA. Hyaluronic acid is a natural component of synovial fluid, and injections help lubricate the joint and act as a shock absorber for joint loads.
There is no doubt that OA has a significant biopsychosocial impact on those patients with ankle OA, and nurses are well placed to deliver evidence-based treatment strategies aimed at improving their quality of life. The problem is, however, that despite having a number of interventions available, unlike OA of the hip and knee, which have clear evidence-based treatment guidelines, there is no evidence-based treatment guidelines for ankle OA (Witteveen, Hofstad, & Kerkhoffs, 2015).
Objective
The purpose of this systematic review was to assess the benefits and harms of any conservative treatment of ankle OA in adults in order to provide a synthesis of the evidence as a base for future treatment guidelines.
Intervention/Methods
The researchers undertook a comprehensive search of the literature up to September 2014 to identify randomized controlled trials (RCTs) and controlled clinical trials that investigated the efficacy of nonsurgical treatment for adults (older than 18 years) with a diagnosis of symptomatic ankle OA. Specifically, the researchers were seeking to assess the effect of the intervention on outcome measures such as pain, safety, physical function, and quality of life. Despite a comprehensive search of relevant databases, the only evidence eligible for inclusion in this review were six RCTs that investigated the efficacy of the use of HA. No other studies using nonsurgical treatment interventions were found. The six studies investigating the use of HA ranged in year of publication from 2006 to 2014, and a total of 240 participants took part in the trials. All participants were diagnosed with radiographically confirmed ankle OA. Of the six studies, three compared HA with a placebo, one compared HA with exercise therapy, one compared HA combined with exercise therapy with an intra-articular (IA) injection of botulinum toxin, and one compared four different dosages of HA. Follow-up of outcome measures in all studies ranged from 3 to 12 months using a number of data collection tools. Primary outcomes measured included the Ankle Osteoarthritis Scale (AOS) score, the American Orthopaedic Foot and Ankle Society score, and the visual analogue scale (VAS) score. Different types of HA dosage and dosing schedules were used in each trial (Witteveen et al., 2015).
Results
The findings indicate that for the primary investigation that assessed the pooled analysis of three studies comparing the use of HA with a placebo, at the 6-month follow-up, the total AOS score, which measured pain and physical function, was reduced by 12%. Despite this initially encouraging result, the researchers advocate caution when interpreting these results. This is due to the low-grade quality of the evidence resulting from study design limitations such as small sample sizes, selection and attrition bias, and imprecision with the results. For this reason, participants' quality of life at 6 months could not be reported because of missing data. A small number of adverse events (AEs) were reported in both the HA and placebo groups, with the number in the HA group being slightly higher. However, this evidence is reported as inconclusive. For the studies that compared the use of HA with exercise alone and HA combined with exercise therapy with an IA injection of botulinum toxin, all results were inconclusive and no AEs were noted.
The only other finding of note in the review was for the RCT that compared four different dosages of HA. In this trial, 1 ml, 2 ml, 3 ml, and 3 weekly injections of 1 ml were compared for efficacy at the end of 15 weeks. The 3 x 1-ml dose group performed best with a reduction in pain during walking as measured by the VAS score. Despite the positive trend, the results were not statistically significant and again, due to design limitations such as the small sample and imprecision with the results, the quality of this evidence was rated as moderate by the researchers. A total of seven of the 26 participants in this study did report an AE that consisted of pain and swelling of the ankle joint; however, these AEs ranged from mild to moderate and generally resolved quickly (Witteveen et al., 2015).
Implications for Practice
This systematic review has revealed that currently there is a lack of robust research evidence available to support the development of a tailored, nonsurgical treatment guideline for those patients presenting with ankle OA. For those nurses working in acute as well as primary healthcare contexts, this is of concern. As mentioned earlier, the cause of ankle OA differs from OA of other major joints and it is reasonable to assume that current treatment guidelines that are tailored primarily for OA of the hip and knee may be less useful when more broadly applied. What is clear is that for nurses who are involved in the care of patients with ankle OA, pain control using simple analgesics is a valid initial treatment approach. Less clear, however, is the efficacy of HA as a treatment modality for ankle OA. Despite some weak positive trends in the results, the authors of this review were unable to establish conclusively if there is a clinically significant benefit to the use of HA when compared with placebo and other treatments. This was primarily due to lack of available data and studies that had major design flaws. If the goal of achieving an evidence-based treatment guideline for ankle OA is to be realized, further research is required that implements well-designed RCTs using large sample sizes and investigates the range of conservative treatments that are currently in use.
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