Osteoarthritis Progression, Pain, and Function in Early Carpometacarpal Osteoarthritis: A Six-Year Longitudinal Study

Abstract

Purpose: The purpose of this study was to examine the 6-year progression of modified Eaton staging, pain scores, and hand strength in patients with early carpometacarpal osteoarthritis (OA) and healthy controls, illustrating the differences between OA groups and controls. Osteoarthritis patients were stratified into stable and progressing groups using three-dimensional computed tomography imaging to identify clinical and radiographic markers differentiating progressing OA from stable disease and healthy controls.

Methods: Data were collected from 86 early carpometacarpal OA patients, classified as stable or progressing OA based on trapezial osteophyte volume (progression defined as >150 mm³ at any visit or a growth rate >14.6 mm³/y), and from 22 healthy controls. Osteoarthritis patients were assessed at baseline and at 1.5-year intervals up to 6 years, whereas controls were evaluated at baseline and year 6. We analyzed modified Eaton stage, patient-rated wrist/hand evaluation, Australian/Canadian OA hand index pain and function scores, and key pinch and grip strengths across groups over 6 years. Tukey honestly significant difference tests evaluated intergroup differences, and fixed effects models assessed the effects of time and OA progression on outcomes, with statistical significance set at P < .05.

Results: Progressing OA demonstrated an increase in modified Eaton score, with clear progression by year 6. Patient-rated wrist/hand evaluation and Australian/Canadian OA hand index pain scores were elevated in both stable and progressing OA groups at baseline and year 6 compared with controls (P < .05), although minimal differences existed between stable and progressing OA. Functional scores were similarly higher in OA groups, whereas key pinch and grip strength showed little trend over time, with minor differences between stable and progressing OA.

Conclusions: Marked radiographic differences in modified Eaton score distinguish progressing from stable OA, indicating that structural progression is a key marker of disease advancement. Minimal differences in pain, functional scores, and hand strength between OA groups suggest that radiographic changes are more distinct indicators of OA progression than subjective or objective functional measures. These findings emphasize radiographic monitoring as the major parameter for OA progression.

Type of study/level of evidence: Prognostic III.

Keywords: CMC osteoarthritis; Hand strength; Modified Eaton score; Pain assessment; Radiographic progression.

Figure 1

Longitudinal trajectories of the modified Eaton stage over a 6-year follow-up period for three groups: controls (green diamonds), stable OA (blue triangles), and progressing OA (red squares). The continuous lines represent the trend in OA progression for each group over time, with the dotted line for progressing OA, dashed line for stable OA, and solid line for controls. Error bars represent 95% CIs around group means, highlighting the divergence in pain progression between the groups across follow-up periods. C and S denote significant differences between controls and stable OA groups.

Figure 2

Longitudinal trajectories of PRWHE pain scores A and AUSCAN pain scores B over 6 years of follow-up, categorized by controls (green diamonds), stable OA (blue triangles), and progressing OA (red squares). Both panels show that control participants maintain consistently low pain scores, whereas the progressing OA group displays higher pain scores over time. The stable OA group shows intermediate pain levels. Error bars represent 95% CIs around group means, highlighting the divergence in pain progression between the groups across follow-up periods. C and S denote significant differences between controls and stable OA groups.

Figure 3

Longitudinal trajectories of PRWHE functional scores A and AUSCAN functional scores B over 6 years of follow-up, comparing controls (green diamonds), stable OA (blue triangles), and progressing OA (red squares). In both panels, control participants consistently exhibit low functional scores, indicating minimal impairment. The progressing OA group shows higher functional scores over time, reflecting worsening function, while the stable OA group maintains intermediate scores. Error bars represent 95% CIs around the group means at each follow-up time point. C and S denote significant differences between control and stable OA groups.

Figure 4

Longitudinal trajectories of Z-scores for key pinch strength A and grip strength B over 6 years of follow-up in controls, stable OA, and progressing OA groups. Data points represent individual measurements for each group: controls (green diamonds), stable OA (blue triangles), and progressing OA (red squares). Solid lines with error bars (95% CI) represent the group means at each time point. In both panels, controls show relatively stable or slightly increasing strength over time, whereas the progressing OA group tends to show a decreasing trend in strength. The stable OA group remains relatively consistent across time points. C and S denote significant differences between controls and stable OA groups.