Osteoarthritis (OA) is the most common of all joint diseases, affecting more than 30 million Americans. In the next few decades, the number of people suffering with osteoarthritis is expected to skyrocket, as people are living longer and the percentage of the population that is obese continues to increase. A common treatment intervention for osteoarthritis is to inject corticosteroids directly into the arthritic joint. In theory, these injections reduce the inflammation associated with arthritis and allow people suffering with osteoarthritis to resume a more pain-free lifestyle. To evaluate the efficacy and safety of intra-articular corticosteroid injections, doctors from Boston University injected 459 patients presenting with hip and knee arthritis with intra-articular corticosteroids. Over the next 2 to 15 months, 8% of these patients developed serious complications, the most common being accelerated joint destruction. While an 8% percent complication rate is high, the authors only followed up on 241 of the 459 individuals injected, so the complication rates were most likely significantly higher. The authors of this study were surprised by the high prevalence of adverse events, but a recent study of 70 patients by Simeone et al. (1) showed the 44% of patients receiving intra-articular corticosteroid injection had accelerated progression of osteoarthritis and a shocking 17% developed articular surface collapse (Fig. 1). This was a controlled study in that the authors compared outcomes between 2 groups with similar degrees of arthritis: one group received the intra-articular corticosteroid, and the other group did not. In the group that did not receive the injection, 24% had radiographic progression of arthritis but only 1% suffered joint collapse. Although the exact mechanism for adverse events remains unclear, there is some evidence that corticosteroid injections, especially when combined with an anesthetic, can be toxic to cartilage (2).
When I initially saw this paper, I thought of a prior study evaluating the effectiveness of either diet, diet plus exercise, or exercise alone in the management of osteoarthritis in overweight and obese elderly individuals (3). Nearly 90% of the 454 people who began this 18 month study completed it, with the majority of them achieving more than 10% loss in body mass. Not surprisingly, the combination of diet and exercise achieved the best outcomes, as these individuals had less pain, better function, faster walking speeds, and a better self-reported quality of life than the diet alone group. The diet and exercise group also had greater reductions in interleukin-6, which is a marker of systemic inflammation that correlates strongly with the development of osteoarthritis. The bottom line with all of these studies is that rather than bombarding an arthritic joint with potentially harmful pharmacological agents with limited proven efficacy, a safer and more effective protocol is to encourage controlled exercise in conjunction with a reduced calorie diet. Although many people would argue that diet and exercise interventions are too difficult to follow and compliance is low, it still has to be presented as an option, as the risks associated with pharmacological management are too great.
References:
1. Simeone F, et al. Are patients more likely to have hip osteoarthritis progression and femoral head collapse after hip steroid/anesthetic injections? A retrospective observational study. Skeletal Radiol 2019;48:1417–1426.
2. Breu et al. The cytotoxicity of bupivacaine, ropivacaine, and mepivacaine on human chondrocytes and cartilage. Anesth Analg 2013; 117:514.
3. Messier S, et al. Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: The IDEA randomized clinical trial. JAMA 2013;310:1263-1273.