# A Meta-Analytical Way of Systematizing the Use of Hyaluronan Gels for the Relief of Osteoarthritis, Compared with New Treatment Alternatives

## TL;DR

This paper uses meta-analysis to argue that hyaluronan gels remain a useful treatment for osteoarthritis when tailored to patient needs, despite newer alternatives.

## Contribution

The study introduces a meta-regression model to guide clinicians in choosing viscosupplementation over newer treatments based on patient-specific factors.

## Key findings

- Hyaluronan gels are still clinically useful and should not be completely replaced by newer treatments.
- Meta-regression models can help predict the effectiveness of viscosupplementation versus platelet-rich plasma.
- Reproducible research practices were followed, with all data and R scripts made publicly available.

## Abstract

Hyaluronic acid, in the form of a gel or viscoelastic colloidal solution, is currently used for the viscosupplementation of joints affected by osteoarthritis, but its effectiveness is under debate in relation to newer alternatives. Based on meta-analytical arguments, the present article reinforces the opinion that there are still no decisive arguments for its complete replacement but for its use adapted to the peculiarities of the disease manifestation and of the patients. A “broad” comparison is first made with almost all alternatives studied in the last decade, and then a meta-regression study is performed to compare and predict the effect size induced by viscosupplementation therapy and its main challenger of clinical interest, the platelet-rich plasma treatment. If they are computerized, the developed models can represent tools for clinicians in determining the appropriateness of the option or not for viscosupplementation in a manner adapted to the pain felt by the patients, to their age, or to other clinical circumstances. The models were generated using algorithms implemented in the R language and assembled in different R packages. All primary data and necessary R scripts are provided in accordance with the philosophy of reproducible research. Finally, we adhere in a documented way to the opinion that HA-based products, currently under circumspection, are still clinically useful.