Lateral versus skyline views in assessessment of patellofemoral joint disease

Abstract EN

Objective: The aim of this study was to assess the reproducibility of different methods of radiological assessment of patellofemoral osteoarthritis (OA) to determine the optimal method for assessing patellofemoral OA.

Methods: The study population included 250 normal subjects (500 knees).

Lateral and skyline radiographs for each individual were graded for joint space narrowing and osteophytes using a standard atlas.

Reproducibility was assessed by two observers on 50 knees.

Radiographic features were assessed on their ability to predict knee pain.

Results: The skyline views were better than the lateral views in the assessment of patellofemoral joint OA.

The reproducibility for osteophytes was high (?>0.8) and that for joint space narrowing was moderate (? > 0.6) for both lateral and skyline views.

Although, the specificity for detecting knee pain was similar in both views (79.5% for lateral versus 86.1% for skyline views), the sensitivity of skyline views in the assessment of knee pain was greater (54.7% versus 31%).

The odds ratio for skyline osteophytes as a predictor of knee pain was 7.54 (95% confidence interval (CI) 3.5 to 15.43); that for osteophytes seen on lateral view was 1.83 (95% CI 0.96 to 3.49).

Narrowing on both views was a poor predictor of pain.

There was frequent disagreement between the lateral and skyline views for detecting osteophytes.

Conclusion: The skyline view should be the preferred method of assessing the patellofemoral joint in radiological survey of osteoarthritis of the knee, since they were better than lateral views in terms of reproducibility and for identifying symptomatic patellofemoral joint OA.