[Analysis of reinjection periodicity in knee osteoarthritis with different types of hyaluronic acids].

OBJECTIVE

To evaluate the periodicity of hyaluronic acid (HA) reinjection in patients with knee osteoarthritis. Secondary aim: To relate the degree of arthrosis with the time between infiltrations and the possible study by subgroups between the different commercial preparations.

DESIGN

Retrospective observational study.

MATERIALS AND METHOD: Review of medical records and X-rays of patients with knee osteoarthritis that had been treated with intra-articular HA at the Rehabilitation Service in the period between January 2017 and June 2019.

VARIABLES: Socio-demographic, Laterality, Intervention Date, Degree of Arthrosis according to Kellgren and Lawrence, HA used, Time between filtrations. Statistical analysis carried out by Kaplan-Meier curves, taking into account the reinfiltration as final event, and Kruskal-Wallis test for non-parametric quantitative data.

RESULTS

We analysed 110 infiltration acts in 67 patients: average age at the time of infiltration 72.12 years, 85.1% women, 59.1% right knee. 4 types of HA: 33 cases at 1%. MW: 0.9MDa (HA1), 12 at 1.5%. MW: 1.5-2MDa (HA2), 42 at 2%. MW: 1.2MDa (HA3) and 6 Hylan G-F20. MW: 6MDa (HA4). We reinfiltrated in 31 occasions (28.2%). Average of months (IC 95%) between infiltrations: HA1 6.9 (5.7-8.16), HA2 12.5 (0-35), HA3 9.3 (5.5-13.1), HA4 5 (3-6.9). In 2 cases where it was not possible to establish the type of infiltrated formulations, the mean value between reinfiltrations was 8.5 (5.6-11.4) There were no statistically significant results by relating the HA type or the degree of arthrosis with the reinfiltration time.

CONCLUSIONS

In our study, we observe that the HA3 presented a longer time between infiltrations in comparison with other types, with no possibility to detect significant differences.