Viscosupplementation is a procedure used to treat osteoarthritis, primarily in the knee, by injecting a thick fluid called hyaluronic acid into the joint. Hyaluronic acid is a naturally occurring substance found in the synovial fluid that surrounds your joints, acting as both a lubricant and a shock absorber. This is sometimes referred to as a "gel injection" or "chicken shot".
In a healthy joint, synovial fluid is viscous and slippery, allowing bones to glide smoothly over each other. In a joint with osteoarthritis, the concentration of hyaluronic acid breaks down, leading to increased friction and pain.
Lubrication: The injection restores the slippery quality of the joint fluid, reducing the grinding of bone on bone.
Shock Absorption: The thick consistency of the fluid helps protect the joint during weight bearing activities like walking or climbing stairs.
Anti-inflammatory Effects: Recent research suggests that these injections may also help reduce localized inflammation.
Single Injection: Some modern brands are highly concentrated and only require one shot to be effective.
Multi-Injection Series: Traditional versions may require one injection per week for three to five consecutive weeks.
This treatment is often reserved for patients who have not found relief from traditional painkillers or physical therapy.
Non-Steroidal: Since it is not a drug but a mechanical lubricant, it avoids the side effects of steroids such as tissue weakening or blood sugar spikes.
Delayed Surgery: For many patients, successful viscosupplementation can delay the need for a total knee replacement for several months or even years.
Gradual Relief: Unlike a steroid shot which works in days, the benefits of "gel shots" often peak around four to six weeks after the injection and can last for six months.
While generally very safe, there are some factors to consider before starting a series.
Injection Flare: A small number of patients experience temporary pain, warmth, or swelling immediately after the procedure.
Allergy Concerns: Some older versions of hyaluronic acid were derived from rooster combs, which could cause a reaction in patients with egg or poultry allergies. Most modern versions are now synthetic to avoid this risk.
Effectiveness Variability: Not every patient responds to viscosupplementation. It tends to be most effective for mild to moderate arthritis rather than "bone-on-bone" end-stage cases.