Biomedical subjects

C J Tonkin

Publications and source records attributed to C J Tonkin.

3 recordsLinked to original sources

PubMed2006

Differences in trabecular structure between knees with and without osteoarthritis quantified by macro and standard radiography, respectively.

OBJECTIVE: To compare the sensitivity of standard and macro-radiography for quantifying cancellous bone differences between subjects with and without medial compartment knee osteoarthritis (OA). METHODS: Patients with medial compartment knee OA (n=24) and non-OA reference subjects (n=10) had a standard and a macro-radiograph (x4 magnification) of one knee. Fractal Signature Analysis (FSA), a computerised image analysis technique, measured differences in cancellous bone structure between OA and non-OA tibiae in all radiographs. RESULTS: Compared to non-OA, FSA of vertical trabeculae in macro-radiographs increased significantly (P<0.05) in the OA group at several trabecular widths (0.30-0.60mm, 0.7 mm, 0.98-1.14 mm) and in standard radiographs at a single trabecular width (0.48 mm). CONCLUSION: Compared to standard radiography, increased spatial resolution of macro-radiography allowed greater detection of trabecular bone differences between OA and non-OA knees. Nonetheless, difference was also detected in standard radiographs.

Adult↗

PubMed2006

Osteophytes, juxta-articular radiolucencies and cancellous bone changes in the proximal tibia of patients with knee osteoarthritis.

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). CONCLUSION: 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.

Adult↗

PubMed2005

Cancellous bone changes in hip osteoarthritis: a short-term longitudinal study using fractal signature analysis.

OBJECTIVE: To quantify changes to the trabecular structure in the femoral heads of patients with hip osteoarthritis (OA). METHODS: Patients with OA (n=14; F=7), mean (standard deviation age) 50.6 (10.1) years, had macroradiographs at approximately x4 magnification at baseline and 18 months later using a standardized protocol. Following digitization, computerized measurement was obtained of minimum hip joint space width and fractal signature analysis (FSA) measured longitudinal changes separately in the principal compressive (vertical) and horizontal trabeculae at the region of interest within the centre of the head. RESULTS: The patient group had mean annual rate of joint space narrowing of 0.14+/-0.36 mm/yr. FSA detected no significant changes in horizontal trabeculae, whereas the larger principal compressive (vertical) trabeculae (0.96 mm to 1.02 mm) increased significantly in thickness and the fine to medium trabeculae (0.18 mm to 0.54 mm) decreased significantly in number. CONCLUSION: The increased thickness of the larger trabeculae within the compressive structural element of the femoral head is a response to the increase in stress associated with an overall loss of trabeculae in this region, suggesting the presence of an osteoporosis within the femoral head in OA patients.

Female↗