Viscosupplementation is a relatively new treatment for knee osteoarthritis (OA). When the pain of knee OA doesn’t go away with conservative treatments or even steroid injections, injections using a special ingredient called hylan G-F 20 often help. These treatments involve removing synovial fluid from within the knee joint and replacing it with hylan. The hylan acts like hyaluronan, which is normally found in synovial fluid and helps lubricate and cushion the cartilage. Most knees with OA have low levels of hyaluronan.
Knee lavage, on the other hand, is a treatment for knee OA that has been around for some time. Lavage involves injecting saline into the joint to “wash” it. Doctors think that lavage works by removing debris and other factors that can cause irritation and inflammation. Lavage also seems to help relieve the pain of knee OA.
These doctors tested whether lavage and hylan treatments worked well together, and for which patients. Patients were allowed to pick which treatment they wanted. The first group of patients got knee lavage in the first week, followed by an injection of hylan each of the next three weeks. The second group only got the three injections of hylan over three weeks. The results were followed over an average of one year. The outcome was considered successful when pain was cut in half and patients rated the outcome as good or excellent.
In group one (lavage plus treatment), the outcome was successful in almost 80 percent of patients. In group two, only 54 percent of patients had a successful outcome. However, the authors note that patients with the worst OA saw much less improvement in both groups — 58 percent in group one and 36 percent in group two.
The authors suggest that the treatments of lavage and hylan be combined unless MRI findings show especially bad OA or certain degenerative changes in the knee. They emphasize that proper technique is needed for a good outcome and that this method of treatment is not helpful when total knee replacement is obviously necessary.