Biomechanical factors contribute to the study of RA

The impact of biomechanical factors on rheumatoid arthritis (RA) has gained increased attention from researchers, as evidenced by studies reported in Clinical Biomechanics. For example, reevaluating knee kinematics over time is important in patients with RA who wear a mobile-bearing total knee prosthesis, according to investigators at the Biomechanics and Imaging Group, Department of Orthopaedics, Leiden University Medical Center, Leiden, the Netherlands.

To accurately assess changes in axial rotation in patients with RA, Wolterbeek and associates used fluoroscopy in evaluating study participants for a comparison of rotation of the femoral component and the insert 8 months and 3 years postoperatively. Axial rotation of the femoral component and the insert decreased over time, indicating a kinematic change caused by intrinsic factors. The decline in rotation of the insert could be explained by increased impingement and the formation of fibrous tissue, the researchers concluded.

In an earlier study, biomechanical foot function and factors associated with localized disease burden in patients with RA were evaluated by researchers at Glasgow Caledonian University, Glasgow, UK. Turner and coworkers measured biomechanical foot function using 3-dimensional instrumented gait analysis. Disease activity score, the number of swollen and tender foot joints, and rearfoot and forefoot deformity were recorded. Foot pain, swollen foot joint count, and walking speed were identified as independent predictors of impairment and activity limitation and participation restriction in patients with RA.