Semi-automated digital image analysis of joint space width in knee radiographs.

Abstract

To design a semi-automated program to measure the minimum tibiofemoral joint space width (JSW) of knee radiographs. Bilateral knee radiographs were obtained twice within a 2 week period from 34 asymptomatic research participants. Radiographic images were analyzed to report both the variability of the image analysis program and the reproducibility of JSW measurements within a 2 week period. In addition, the results were compared with minimum JSW measurements read manually by an experienced musculoskeletal radiologist. The variability of the image analysis program was shown to be within one pixel. The results showed that reproducibility was better with the automated method. In addition, the manual method measured a greater minimum JSW than the automated method. There was no significant difference in between-day measurements. There was a significant difference reported between the automated and manual minimum JSW measurements. A novel semi-automated method for measurement of JSW has been developed.