Radiographic predictors of knee osteoarthritis

Osteoarthritis is considered as a progressive disease that can result in disability. Radiological examination provides an effective non-invasive tool to visualize subtle changes. Therefore, more radiographic assessment methods are required to diagnose knee osteoarthritis at early stages. This study combined and evaluated six different radiographic measurements such as femorotibial angle between osteoarthritic group and non-osteoarthritic group, and assessed their inter-observer measurement reliability.

A cross-sectional retrospective imaging study was conducted and included subjects who underwent knee X-ray from January 2022 to December 2023. Their images were retrieved and reviewed by two independent radiologists who were blinded about the results of each other. The Kellgren-Lawrence classification system of osteoarthritis was used for classifying subjects as osteoarthritic or non-osteoarthritic. Six radiographic measurement methods such as femorotibial angle were evaluated on the X-ray images.

This study included 353 subjects. The number of the males (59 %) was higher than the females. For the Kellgren-Lawrence classification system, most of the subjects were classified as normal (67 %) with grade zero, while 33 % demonstrated knee osteoarthritis radiographic signs. The majority of the osteoarthritic group were female subjects (61 %). The medial joint space width measurement showed the lowest values for the osteoarthritic group (P value < 0.001). An increased value of the distance between medial tibial eminence and medial femoral condyle is significantly associated with an increased likelihood of the knee osteoarthritis (odd ratio: 1.2).

The current evaluated radiographic measurement methods can be potential diagnostic tools for knee osteoarthritis and are useful for detecting different severity stages.

Applying the radiographic measurement methods can support the conventional Kellgren-Lawrence classification system of osteoarthritis and enhance the diagnostic performance of knee osteoarthritis.