High-Res Peripheral Quantitative CT Identifies More Erosions than Radiographs in Early Arthritis

High-resolution peripheral quantitative computed tomography (HR-pQCT) identified more joint erosions than conventional radiographs (CR) in patients with early inflammatory arthritis (EIA), according to a study in Joint Bone Spine.

This study included a total of 46 patients who had experienced arthritic symptoms for <1 year and who had a clinical diagnosis of inflammatory arthritis. Patients were prospectively imaged at baseline and 12-month follow up. The investigators took HR-pQCT scans of the second and third metacarpophalangeal (MCP) joints and CR of the hands and feet.

Assessment of joint space width (JSW), total bone mineral density (tBMD), erosion presence, and volume with HR-pQCT. Additionally, the investigators conducted regression analyses to identify prognostic factors for progression of bone damage.

There were no significant changes between groups in terms of JSW, tBMD, or erosion volume. The use of HR-pQCT was able to detect more erosions than CR in the second and third MCP. Increased duration of symptoms at time of diagnosis was weakly associated with lower minimum JSW and higher JSW standard deviation (p < 0.10). These findings suggested that for every 100 days of symptoms, there was a 0.05 to 0.1 mm decrease in the minimum JSW. No association was found between diagnosis at baseline or 12 months with the number of erosions.

Limitations of the study were the exclusion of several observations due to motion artifacts and the lack of mean HR-pQCT variables in patients with early inflammatory arthritis. Additionally, the sample size was based on feasibility rather than a statistical analysis approach.

The investigators of the study added that the “incorporation of image registration and less operator-dependent erosion analyses will improve the ability to monitor change at the individual level.”

Reference

Brunet SC, Finzel S, Engelke K, Boyd SK, Barnabe C, Manske SL. Bone changes in early inflammatory arthritis assessed with High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT): A 12-month cohort study. Joint Bone Spine. Published online September 4, 2020. doi:10.1016/j.jbspin.2020.07.014