title: Osteophytes, juxta-articular radiolucencies and cancellous bone changes in the proximal tibia of patients with knee osteoarthritis.
abstract: OBJECTIVE
  To determine differences in tibial cancellous bone organisation in knee osteoarthritis (OA) between the central weight-bearing region and juxta-articular radiolucencies adjacent to small, medium or large marginal osteophytes.
  
  
  METHODS
  Patients with medial compartment OA (n = 60; F = 39), mean (SD) age 60.0 (9.7) years, and non-OA reference subjects (n = 21; F = 5), mean (SD) age 36.8 (11.5) years, had x4 macroradiographs digitised by laser scanner. Using a modified Osteoarthritis Research Society (OARS) Atlas, right and/or left knees were graded according to marginal osteophyte size into those with small (n = 30), medium (n = 30) or large (n = 27) marginal osteophytes, identified as OPH1, OPH2 and OPH3, respectively. Non-OA knees (n = 30) were anatomically normal. Computerised method of Fractal Signature Analysis (FSA) quantified differences in cancellous bone structure between non-OA and osteophyte subgroups at two regions of interest (ROIs); central weight-bearing and tibial margin.
  
  
  RESULTS
  Compared to non-OA, vertical trabecular number increased significantly (P < 0.05) in all osteophyte subgroups (width range 0.12-1.14 mm) within both ROIs. In OPH3, this increase was significantly (P < 0.05) greater compared to OPH2 in the central ROI, and to OPH2 and OPH1 in the marginal ROI at most trabecular widths (0.12-1.14 mm). In the marginal ROI, compared to non-OA, horizontal trabeculae number decreased in all osteophyte subgroups. This decrease was significantly greater in OPH3 compared to OPH2 and OPH1 at small to medium trabecular widths (0.12-0.54 mm).
  
  
  CONCLUSIONS
  Compared to disease associated bone loss at the central ROI of the tibia, the extent of juxta-articular bone loss appears to be associated with the size of the marginal osteophytes.
authors.affiliation: Department of Applied Clinical Anatomy, King's College London, School of Biomedical Sciences, Guy's Hospital Campus, London, UK.
authors.forename: E A
authors.initials: EA
authors.lastname: Messent
authors.forename: R J
authors.initials: RJ
authors.lastname: Ward
authors.forename: C J
authors.initials: CJ
authors.lastname: Tonkin
authors.forename: C
authors.initials: C
authors.lastname: Buckland-Wright
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology*; D011856:Radiographic Image Enhancement / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging