Clinical and radiological factors associated with erosive radiographic progression in hand osteoarthritis

To identify prognostic factors of erosive progression in hand osteoarthritis (OA).

One hundred and fifty-four patients with hand OA were selected from an earlier cohort. X-rays, clinical and demographic data at baseline were present. All patients were seen for a follow-up between January and March 2014. Interphalangeal (IP) finger joints were scored on both radiographs using the anatomical scoring system. Radiographic progression was defined as a joint progressing from at least one anatomical phase, excluding the progression from a 'Normal' to 'Stationary' phase. Odds ratios (OR) and 95% confidence intervals (95% CI) of potential clinical and radiographic prognostic factors were calculated on joint, hand and patient level with a generalized estimating equation (GEE) model.

Radiographic progression, including progression from 'N' to 'S' phase, was present in 1014 of 2750 joints (36.9%) after a mean follow-up of 5.8 years. On joint level, the following clinical factors were associated with radiographic progression (OR [95% CI]): presence of pain (1.48 [1.01-2.15]), tenderness (2.18 [1.56-3.05]), and soft tissue swelling (2.56 [1.54-4.24]). The following radiographic variables were significantly associated with erosive progression: presence of 'J' (16.74 [9.09-30.83]) and 'E' phase (76.34 [42.17-138.23]). On hand and patient level, soft tissue swelling, 'J' and 'E' phase were retained as prognostic factors.

Pain, tenderness, soft tissue swelling, 'J' and 'E' phase were significantly associated with erosive progression in hand OA. These prognostic factors should be confirmed in further studies and considered when selecting patients for therapeutic trials with potential disease-modifying osteoarthritis drugs (DMODs).