Femoro-tibial knee osteoarthritis: One or two X-rays? Results from a population-based study

Area of Science:

• Radiology
• Orthopedics
• Rheumatology

Background:

• Osteoarthritis (OA) diagnosis relies on radiographic assessment.
• Current diagnostic protocols may involve multiple X-ray views, increasing patient burden.
• Optimizing imaging techniques is crucial for efficient OA detection.

Purpose of the Study:

• To compare the diagnostic efficacy of anteroposterior (AP) extended-knee X-ray plus semi-flexed (schuss) X-ray versus semi-flexed X-ray alone for detecting femoro-tibial osteoarthritis (OA).
• To evaluate the impact of different X-ray views on identifying key OA features like osteophytes and joint space narrowing (JSN).

Main Methods:

• Recruitment of 350 individuals aged 40-75 with symptomatic knee OA (Kellgren/Lawrence [KL] score ≥2).
• Performance of both AP and schuss X-rays, with a second blinded reading of the schuss view two years later.
• Comparative analysis of KL stages, osteophyte detection/localization, JSN, and correlation with obesity.

Main Results:

• A higher proportion of patients achieved KL ≥2 when combining AP and schuss views (P<0.0001 for right, P<0.001 for left knee).
• No significant difference was found in detecting JSN or osteophytes when using the schuss view alone versus combined with AP view.
• The schuss view alone was superior for evaluating JSN (P=0.0001) compared to AP view alone, with no difference in osteophyte detection.

Conclusions:

• The semi-flexed (schuss) X-ray view is adequate for identifying knee osteophytes and JSN in OA.
• Utilizing a single X-ray view simplifies the diagnostic process, potentially lowering medical costs and radiation exposure.
• Dual X-ray views may offer advantages for large-scale epidemiological studies of knee OA.