Radiographic hand OA affects one in five adults. Symptomatic hand OA can result in functional impairment, pain and reduced quality of life. A prevalent form of hand OA is IP joint OA, however prognostic factors for IP joint OA remain poorly understood. This systematic review aimed to identify prognostic factors for IP joint OA, and to summarize the diagnostic criteria for IP joint OA in prognostic studies.
EMBASE, MEDLINE, Scopus and The Cochrane Library were searched from inception until 19 February 2020 (PROSPERO CRD42019116782). Eligible studies described diagnostic criteria defining IP joint OA, and assessed potential prognostic factors for IP joint OA. Risk of bias was assessed using a modified Quality in Prognosis Studies (QUIPS) tool and a best evidence synthesis was used.
Eighteen studies were included (risk of bias: eight high, three moderate, seven low). All defined OA radiographically, and three studies incorporated clinical symptoms into their definition of OA. Forty-nine potential prognostic factors were assessed. Eight were prognostic: older age in women, female gender (both moderate evidence); family history of Heberden's nodes, Kashin-Beck disease, older age in men, dental occupation in men, finger fracture, parity (all limited evidence). Higher BMI in women (limited evidence) was prognostic for symptomatic radiographic OA. No prognostic factors for symptomatic OA were identified.
IP joint OA is most commonly defined radiographically, yet criteria were heterogeneous. Eight prognostic factors for radiographic IP joint OA and one for symptomatic radiographic IP joint OA were identified, all with limited or moderate evidence. Further studies on causality and on prognostic pathways are needed.