Effect of alignment of the medial tibial plateau and x-ray beam on apparent progression of osteoarthritis in the standing anteroposterior knee radiograph

Steven A. Mazzuca, Kenneth D. Brandt, Paul A. Dieppe, Michael Doherty, Barry P. Katz, Kathleen A. Lane

Research output: Contribution to journalArticle

97 Scopus citations

Abstract

Objective. Previous studies of knee osteoarthritis (OA) have yielded variable estimates of the rate of joint space narrowing (JSN) in the standing anteroposterior (AP) radiograph, due largely to longitudinal changes in the alignment of the medial tibial plateau (MTP) and x-ray beam. To characterize this bias, we examined serial radiographs of subjects with knee OA in population-based and clinical OA cohorts from 3 locations in the United States and the United Kingdom. Methods. Radiographic features of knee OA (e.g., osteophytosis, JSN) and MTP alignment in 428 OA knees were evaluated by consensus of 2 readers. Alignment was considered satisfactory if the anterior and posterior margins of the MTP were superimposed within 1 mm. Readers were blinded to subject identity, and films were read in random order. The minimum medial joint space width was also measured manually (standard error of repeated measurements 0.20 mm) in serial knee images. Results. Only 14% of serial radiographs exhibited alignment of the MTP in both images. In OA knees with satisfactory alignment in both images, the mean rate of JSN over 2-3 years (0.26 mm/year) was significantly larger (P = 0.004) than that in OA knees with misalignment in 1 or both radiographs and was 86% more rapid than the mean JSN in all OA knees. Moreover, the within-group standard deviation of JSN was significantly smaller among knees with reproduced alignment of the MTP than in knees in which misalignment occurred in 1 or both images (P = 0.006). Conclusion. Poor standardization of knee positioning in serial standing AP radiographs in previous studies of OA progression has obscured the rate and variability of articular cartilage loss in subjects with knee OA. True JSN (i.e., JSN that is not attributable to longitudinal changes in the alignment of the MTP with the x-ray beam in serial radiographic examinations) may occur more rapidly, and with less between-subject variability, than that previously thought to be characteristic of knee OA.

Original languageEnglish (US)
Pages (from-to)1786-1794
Number of pages9
JournalArthritis and Rheumatism
Volume44
Issue number8
DOIs
StatePublished - Aug 29 2001
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Rheumatology
  • Immunology
  • Pharmacology (medical)

Fingerprint Dive into the research topics of 'Effect of alignment of the medial tibial plateau and x-ray beam on apparent progression of osteoarthritis in the standing anteroposterior knee radiograph'. Together they form a unique fingerprint.

  • Cite this