Intra-articular injections
Corticosteroid and hyalurons
The research evidence from intra-articular corticosteroid injections is that it provides short term pain relief (from 1 to 4 weeks) with a small increase in physical function. This short pain relief may be useful for settling a flare up or as a means of introducing other interventions such as muscle strengthening exercises. NICE (2008) has recommended its use as an adjunct to core treatment. Hyalurons (previously known as hyaluronic acid) is produced by the lining layer cells of the joint. Its main function is to confer viscoelasticity, lubrication and help maintain tissue hydration. The mechanism by which commercial preparations of Hyalurons works is uncertain and the effect size for reduction in pain up to 3 months is small. Given the cost of the injections and the number of injections (3 to 5), the cost effectiveness is outside the standard of threshold to the NHS (NICE 2008).
Joint Lavage
Joint lavage means to wash out any loose tissue or debris from inside the joint space. Tidal irrigation joint lavage uses one entry point to alternatively inject fluid and then draw it out. Non-arthroscopic joint lavage uses two entry points, one to inject the fluid and a separate one for the withdrawal of the fluid but no visual inspection. Arthroscopic joint lavage is a washout plus a visual inspection. A Cochrane review (Reichenbach et al 2009) included 7 trials and found little benefit at 3 months both in terms of pain relief (0.3cm. on a 10cm. Visual analogue scale), and functional scores between joint lavage and control (0.2cm. on a WOMAC disability sub-scale from 0 to 10cm.). Therefore, this procedure is not recommended.