Currently there is no agreed "gold standard" definition of radiographic hand osteoarthritis (RHOA) for use in epidemiological studies. We therefore undertook a systematic search and narrative review of community-based epidemiological studies of hand osteoarthritis (OA) to identify (1) grading systems used, (2) definitions of radiographic OA for individual joints and (3) definitions of overall RHOA.
The following electronic databases were searched: Medline, Embase, Science Citation Index and Ageline (inception to Dec 2006). The search strategy combined terms for "hand" and specific joint sites, OA and radiography. Inclusion and exclusion criteria were applied. Data were extracted from each paper covering: hand joints studied, grading system used, definitions applied for OA at individual joints and overall RHOA.
Titles and abstracts of 829 publications were reviewed and the full texts of 399 papers were obtained. One hundred fifty-two met the inclusion criteria and 24 additional papers identified from screening references. Kellgren and Lawrence (K&L) was the most frequently applied grading system used in 80% (n=141) of studies. In 71 studies defining OA at the individual joint level 69 (97%) used a definition of K&L grade > or = 2. Only 53 publications defined overall RHOA, using 21 different definitions based on five grading systems.
The K&L scheme remains the most frequently used grading system. There is a consistency in defining OA in a single hand joint as K&L grade > or = 2. However, there are substantial variations in the definitions of overall RHOA in epidemiological studies.