Viscosupplementation is frequently used for local treatment of osteoarthritis (OA), due to ease of use and good tolerance.
Hyaluronic acid is a key component of the joint fluid produced naturally by the B cells of the synovial membrane. It gives the joint fluid its viscous, slippery quality enabling reduced joint friction and weight-bearing activity. Osteoarthritis affects joints leading to lower concentration of hyaluronic acid in their joint fluid than normal healthy joints, and therefore less protection against joint friction and impact accelerating the joint degeneration process. In this technique, Exogenous hyaluronic acid is injected into diarthrodial joints, restoring the rheological properties of the synovial fluid, thereby producing mechanical, analgesic, anti-inflammatory and chondroprotective effects. In early stage of OA, where all the nonsurgical treatments methods (like Painkillers, Corticosteroid injections, weight loss, physical therapy) are ineffective and the patients opts to postpone the surgery, then Viscosupplementation may be an option.
Indications
- Osteoarthritis on knee
- After Arthroscopic procedure
Procedure
Viscosupplementation is an in-office procedure that usually takes less than 5 minutes.
- The patient lies on his or her back, with the knee either straight or bent at a 20- or 30-degree angle. If the knee bent is preferred, a rolled up towel may be placed under the knee to prop it up at the proper angle.
- Disinfectant like alcohol or Iodine is used to wiped the knee down.
- The patient will be asked to relax the leg muscles; this will facilitate a successful viscosupplementation injections and also make the injection less painful.
- If ultrasound is being used, a gel will be applied to small area of skin near the injection site, and a technician will gently press a hand-held ultrasound transducer against the gel-covered skin. An image of the joint space will be projected on screen for the doctor to see.
- Local anesthetic such as Lidocaine will be used to numb the area.
- If excess fluid is present in the swollen knee,it would be aspirated (draw out) with a needle and syringe.
- Using a new syringe,a small amount (often just 2 mL) of hyaluronan, or hyaluronic acid will be injected on one side of the kneecap.
- The injection area is cleaned and bandaged.
- The patient will be told to straighten and bend the knee several times to help spread the hyaluronate throughout the knee joint.
Results
Viscosupplementation consisting the intra-articular injection of hyaluronic acid derivatives, is one of the main treatment for OA (initial stages) that recovers the rheological properties of the synovial fluid, achieve analgesia, improve function and regenerate the joint cartilage articular. Some patients report pain relieving effects for several months following the injections.If the injections are effective they may be repeated after a period of time, usually 6 months.
