Background Radiographic features are important in diagnosing hip osteoarthritis (OA)^1,2. In daily practice, only the anterior-posterior view is visualized but not the false profile view. Since we assessed radiographic features in both types of radiographic hip images in the AMS-OA cohort, we were able to examine the differences in radiographic features in two regions of the hip (superior-lateral and central-axial region).

Objectives (i) To describe the presence of radiographic features in patients with hip OA; and (ii) to determine whether radiographic features differ between the superior-lateral and central-axial region of the hip.

Methods Data from 97 patients with bilateral hip pain and a Kellgren and Lawrence score of ≥1 of the Amsterdam Osteoarthritis (AMS-OA) cohort of patients with knee and/or hip OA were used. Standard radiographic images were examined of patients in an erect position, both with an anterior posterior view and with a false profile view, which is an oblique lateral view of the hip. Radiographic images were scored by an experienced radiologist (DR) and an independent researcher (ME). Consensus between two raters was achieved for each score. Four radiographic features were scored: presence of joint space narrowing, osteophytes, sclerosis and cysts. All joint features were scored separately for the superior-lateral and the central-axial region of the hip. A Fisher's exact test was performed for testing the significance of the differences between the two regions of the hip.

Results Table 1 shows the frequencies of radiographic features (joint space narrowing, osteophytes, sclerosis and cysts) in the superior-lateral and the central-axial region of the left and right hip joint of patients with hip OA. Significant differences between the two regions were found for osteophytes, sclerosis and cysts with the highest frequency of these features in the superior-lateral region of the hip.

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Conclusions In our cohort we found as expected, that joint space narrowing of the hips was the most frequent feature (>80% in both the superior- lateral and central-axial region). Moreover, osteophytes, sclerosis and cysts were more frequently present in the superior-lateral region. Our findings indicate that hip OA may exist of two subgroups with differences in radiographic features (i.e., superior-lateral and central-axial). Future research should confirm these results and focus on possible associations with biomechanical and physical function variables.

References

1. Altman RD, Gold GE. Atlas of individual radiographic features in osteoarthritis, revised. Osteoarthritis and Cartilage (2007); 15, A1-A56.

2. Krishanu B, Gupta MD, Duryea J, Weissman BN. Radiographic evaluation of osteoarthritis. Radiol Clin N Am 42 (2004) 11–41.

References

Disclosure of Interest None declared