Side Effects of Hyaluronic Acid Injections for Knees

What is osteoarthritis?

The knee is a prime example of a synovial joint. A healthy knee joint is made of bones that are encased with a layer of tough articular cartilage. This protective cartilage constantly secretes lubricating synovial fluid that is rich in hyaluronic acid (HA) to ensure that the bones glide effortlessly against each other without pain or stiffness. The synovial fluid also maintains the joint health by absorbing any sudden impacts. Unfortunately, years of wear-and-tear caused by various factors like excessive weight, genetics, and participating in physically exerting sports (e.g. tennis) can result in disintegration of the articular cartilage. Hence, there will be decreased production of synovial fluid and the bones may grind against each other excruciatingly. When this happens, patients experience tremendous pain, stiffness, and reduced joint mobility; this condition is known as osteoarthritis.

What is hyaluronic acid injection for knees?

Most patients diagnosed with osteoarthritis may resort to numerous management therapies like wearing rehabilitation gears, consuming painkillers, and even losing weight. Due to advancements in the medical industry, hyaluronic acid-based fillers are manufactured to replace the lost synovial fluid. These orthopaedic implants—also known as viscosupplements—are made of HA to closely mimic the properties and actions of natural synovial fluid. Once injected, patients will be able to move the joints without painful friction. Patients who have received hyaluronic acid injections can even delay their joint reconstructive surgery until it is absolutely necessary.

How are the hyaluronic acid fillers injected in the knees?

Hyaluronic acid-based viscosupplements are indicated for injection into the synovial space of the affected knee joint(s). Just like any other procedures involving implantation of HA filler, the patient’s medical history (e.g. underlying health conditions, history of allergies, medications and/or supplements taken, etc.) will be thoroughly reviewed. Those who are hypersensitive to any of the ingredients in the filler material are contraindicated from receiving hyaluronic acid injections. Most importantly, patients with joint effusions must have the accumulated fluid removed completely from the affected joint(s) prior to procedure. Once the proposed injection area is cleaned, sanitised, and possibly, the chosen orthopaedic implant can then be slowly injected intraarticularly.

Side effects of hyaluronic acid injections for the knees

Following the implantation of the viscosupplement, patients experience post-procedure inflammatory reactions such as swelling, pain, and a warm sensation at the injected sites. Some patients may even develop other more adverse aftereffects such as aggravated inflammation and infections if the procedure is not done properly. The origin of the hyaluronic acid—either bacterial or animal-based—can play a huge role in determining the success of the procedure. Hence, is very important to confirm that patients are not allergic to the filler material before commencing the procedure. Patients must be advised to rest their treated joint(s) by avoiding long periods of standing and physically exerting activities until side effects have resolved. Some patients may also be prescribed oral painkillers to help them manage any pain and discomfort after the treatment session.