Over the past 30 years, the medical community has been working hard to invent a method that would reduce osteoarthritis of the knee caused by a loss of joint lubrication. Efforts seem to have finally been successful in producing artificial synovial fluid for this purpose. A problem encountered in the initial stages was that this artificial fluid was still unable to actually be used as a true replacement, due to a lack of important features. Today, however, artificial synovial fluid has been developed and improved in its effectiveness to the extent that it is able to be used in the treatment of knee osteoarthritis patients. Results have shown that it can reduce knee pain, allow more activity and range of movement of the knee and may be effective for up to six months.
The body naturally produces a substance known as synovial fluid, a sticky, jelly-like fluid found in the joints which helps the joints to move more easily and lubricates cartilage surfaces in order to reduce friction when bending or stretching the knee. Synovial fluid also helps to reduce pressure and absorb shock to the bone surface while walking or running.
In some conditions, such as when you get older or when joints are overworked or overused, the synovial fluid will decrease or there may be synovial fluid abnormalities, resulting in the deterioration of certain joints or even injury. Artificial synovial fluid or HA is a synthetic compound that mimics the properties of true synovial fluid. Its characteristics include the creation of lubrication in the joints and a reduction of inflammation, as well as properties as a potential substrate for the creation of increased fluid in the articular cartilage and the synovial membrane. HA injections can, therefore, help reduce joint injury.
Hyaluronic acid can be divided according to molecular size or weight – high molecular weight which has larger molecular sizes, medium molecular weight with medium molecular sizes and low molecular weight and size.
Larger molecular sizes are known for their outstanding lubrication properties, while medium and low molecular sizes are known for being potential substrates for fluid in the articular cartilage and synovial membrane. Doctors will normally consider the various types of hyaluronic acid appropriate for use according to its properties along with the needs of the patient.
A clear indication for the necessity of HA injections is the presence of osteoarthritis in patient groups who are unresponsive to treatment with medication but who have not yet reached the stage of needing surgery. In other words, those who are in the middle between medication and surgical treatment.
When injected, artificial synovial fluid injections is effective for about six months. Additionally, it is also used in cases of articular cartilage damage or injuries, such as kneecap injuries, and can also be used in conjunction with surgery in the form of injections following articular cartilage repair surgery to help the patient recover and enjoy a faster return to the use of their injured joints.
When considering the best treatment for osteoarthritis patients, the decision of whether to use platelet-rich plasma (PRP) injections or hyaluronic acid injections must be at the discretion of the patient’s doctor, as there are some principal differences between the two treatment methods.
HA injections focus on the treatment of osteoarthritis patients by increasing lubricating fluid and stimulating artificial cartilage substrate. PRP injections, on the other hand, are a treatment that stimulates the repair of tissues or joints. Both types of injections can be carried out post-surgery, with HA injections used to help adjust fluid balance in the joints, and PRP injections to reduce inflammation.
Both treatments may be used at the same time, but are not usually injected simultaneously as this would cause an overload on the knees. In cases where a combination of both treatments is necessary, doctors may first give artificial synovial fluid injections, after which an appointment would be made with the patient to come back for PRP injections at a later date.
Currently, however, symptoms can be greatly reduced due to modern HA extraction methods, making it almost as pure as the patient’s own synovial fluid.
The amount of HA injected is based upon the patient’s condition, disease duration and the area of the joint affected. Normally, the doctor will give a course of 3-5 injections, with 1-2 injections given at a time, separated by about a week, depending on the symptoms and severity of the disease as well as the type of HA being used. Today, HA has been developed as an effective single-dose treatment. The advantage of this is that it is a single injection. However, the price is still currently quite high compared to a course of a number of injections carried out over a period of time.
With regard to treatment results, the most obvious, actual results of the injections are usually seen after approximately 4-6 weeks, although it could take as long as six months, depending on the severity of the disease.
There is a variety of treatments available for osteoarthritis today, and still, the medical community will always be taking strides forward, developing and creating new and up-to-date innovations and treatments. The first and most important choice, however, is always prevention. Choose to eat healthy foods beneficial to your body, exercise in a way that is appropriate to your age and the condition of your joints, and avoid any high-impact activities, especially for elderly patients who have a higher risk level of joint injuries and promote their healthy potential.
M.D., Faculty of Medicine, Srinakharinwirot University, 1998