| 1 | The relative utility of imaging techniques (plain x rays, MRI, ultrasonography, scintigraphy) in early diagnosis and evaluation of progression of the HOA subsets needs to be determined. |
| 2 | Risk factors for development and long-term clinical outcome of the different subsets of HOA need to be determined. |
| 3 | Potential biomarkers of bone, cartilage, synovium and inflammation should be examined in HOA subsets for utility in terms of early diagnosis, assessment of disease activity and prediction of outcome. |
| 4 | Diagnostic and classification criteria to better define HOA and its subsets need to be developed and validated. |
| 5 | Further studies are required to confirm the associations between HOA and systemic risk factors such as menopausal state, bone density, obesity and metabolic syndrome, and to explain the mechanisms that underlie such associations. |
| 6 | The genetic factors that predispose to the different phenotypes of HOA need to be identified. |
| 7 | The population incidence and prevalence of HOA and its subtypes (symptomatic and asymptomatic), standardised by age and gender, need to be confirmed. |
| 8 | Studies should be undertaken to determine whether erosive HOA is a discrete subset with specific risk factors and pathogenesis, or a subgroup of HOA with a worse outcome. |
| 9 | The association between the different HOA phenotypes and large joint OA (ie generalised OA) needs further examination. |