From the Guidelines
Hyaluronic acid works by attracting and retaining moisture in the skin and joints, serving as a lubricant and shock absorber in synovial fluid, but its effectiveness in treating osteoarthritis is limited and not consistently supported by high-quality studies. The mechanism of action of hyaluronic acid involves its unique molecular structure, which allows it to bind water molecules while maintaining flexibility, making it an excellent hydrator 1. When applied topically to skin, hyaluronic acid forms a protective barrier that prevents moisture loss while drawing water from the environment and deeper skin layers to the surface, resulting in plumper, more hydrated skin. In joint health, hyaluronic acid reduces friction between cartilage and bones, but its use in intra-articular injections for osteoarthritis is not recommended due to limited evidence of benefit 1. The American Academy of Orthopaedic Surgeons recommends against the routine use of hyaluronic acid in patients with knee osteoarthritis, citing inconsistent evidence and a lack of identification of the subset of patients who may benefit from it 1. However, some studies suggest that hyaluronic acid may be effective in improving mobility and decreasing pain in certain patients with osteoarthritis, particularly when used in conjunction with other treatments 1. Key points to consider when evaluating the effectiveness of hyaluronic acid include:
- Its unique molecular structure and ability to bind water molecules
- Its use as a lubricant and shock absorber in synovial fluid
- The limited and inconsistent evidence supporting its use in treating osteoarthritis
- The potential for contextual factors, such as patient expectations and effective communication, to influence treatment outcomes 1. Overall, while hyaluronic acid has potential benefits, its use in treating osteoarthritis should be approached with caution and considered on a case-by-case basis, taking into account the latest evidence and individual patient needs 1.
From the Research
Mechanism of Action
- Hyaluronic acid is a naturally occurring polysaccharide with distinct physicochemical properties that underlie its application as a viscoelastic tool in various medical fields 2.
- It has lubricating and cushioning properties, which make it useful in ophthalmological surgery and as a treatment for osteoarthritis 2, 3.
- Hyaluronic acid also has anti-inflammatory properties, which contribute to its therapeutic potential in joint disease and wound healing 2, 4.
Applications
- In ophthalmology, hyaluronic acid is used as a surgical aid in cataract surgery, penetrating keratoplasty, trabeculectomy, retinal reattachment, and trauma surgery 2, 3.
- In rheumatology, hyaluronic acid is used to treat osteoarthritis, with weekly intra-articular injections improving knee pain and joint motion 2.
- In dermatology, hyaluronic acid is used as a dermal filler to improve wrinkles and volume loss, and to hydrate the skin 5, 6.
Properties
- Hyaluronic acid has a high molecular weight, which enables it to retain water and provide lubrication and cushioning properties 3.
- It is biocompatible, biodegradable, non-toxic, and non-immunogenic, making it a suitable component of biomedical products 4.
- Hyaluronic acid can stimulate collagen synthesis and fibroblast stimulation, which contributes to its duration of effect in dermal fillers 5.