On 2013 Oct 29, Hilda Bastian commented:

This systematic review identifies serious publication bias, along with small poor quality trials, as contributing to the over-estimation of benefit of viscosupplementation for osteoarthritis of the knee by some other groups (including Bellamy N, 2006). Rutjes and colleagues found that none of the multiple previous systematic reviews on the subject had included all the trial evidence available at the time.

Relying primarily on larger, better quality studies, the authors conclude that these intra-articular injections have a non-clinically relevant effect on pain, no significant effect on function over time, but are associated with serious unexplained adverse events. It is not clear what effect long-term use of the intervention has on the risk of serious adverse events. Rutjes and colleagues discourage use of the intervention.

An analysis of this systematic review in DARE goes into detail about the methods and data in this review. That assessment suggests that the pooling of baseline and end of treatment effects introduces minor uncertainty around the review's results.

Some other systematic reviews had also failed to identify major clinical benefit from viscosupplementation of the knee (including Lo GH, 2003 and Samson DJ, 2007). Rutjes and colleagues conclude that an individual patient data meta-analysis would be required to clarify questions about serious adverse events.

UPDATE: Bannuru RR, 2015 subsequently published an extensive network meta-analysis, which created a network for comparison that included intra-articular (IA) injection, IA placebo, and oral placebo. While their outcome for IA hyaluronic acid is similar to that in this analysis by Rutjes and colleagues, they identified a clinically relevant difference attributable to IA injection.

(I discussed the implications of the 2015 review in a February 2015 blog post.)

On 2013 Oct 29, Hilda Bastian commented:

This systematic review identifies serious publication bias, along with small poor quality trials, as contributing to the over-estimation of benefit of viscosupplementation for osteoarthritis of the knee by some other groups (including Bellamy N, 2006). Rutjes and colleagues found that none of the multiple previous systematic reviews on the subject had included all the trial evidence available at the time.

Relying primarily on larger, better quality studies, the authors conclude that these intra-articular injections have a non-clinically relevant effect on pain, no significant effect on function over time, but are associated with serious unexplained adverse events. It is not clear what effect long-term use of the intervention has on the risk of serious adverse events. Rutjes and colleagues discourage use of the intervention.

An analysis of this systematic review in DARE goes into detail about the methods and data in this review. That assessment suggests that the pooling of baseline and end of treatment effects introduces minor uncertainty around the review's results.

Some other systematic reviews had also failed to identify major clinical benefit from viscosupplementation of the knee (including Lo GH, 2003 and Samson DJ, 2007). Rutjes and colleagues conclude that an individual patient data meta-analysis would be required to clarify questions about serious adverse events.

UPDATE: Bannuru RR, 2015 subsequently published an extensive network meta-analysis, which created a network for comparison that included intra-articular (IA) injection, IA placebo, and oral placebo. While their outcome for IA hyaluronic acid is similar to that in this analysis by Rutjes and colleagues, they identified a clinically relevant difference attributable to IA injection.

(I discussed the implications of the 2015 review in a February 2015 blog post.)