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Biomedical subjects

A Wluka

Publications and source records attributed to A Wluka.

7 recordsLinked to original sources
PubMed2005

Comparison of conventional standing knee radiographs and magnetic resonance imaging in assessing progression of tibiofemoral joint osteoarthritis.

OBJECTIVE: Although the current recommendation is to measure radiographic joint space width (JSW) to assess structural change in osteoarthritis (OA), there is increasing interest in direct measurement of cartilage volume from magnetic resonance imaging (MRI). We performed a longitudinal study to compare change in both JSW and articular cartilage volume in subjects with symptomatic knee OA. METHODS: JSW was measured in 28 subjects with knee OA (57% females, mean age 62.8+/-9.8 years) who had standing radiographs in full extension, where both radiographs had satisfactory alignment. Each subject had femoral, tibial and combined femoral and tibial cartilage volumes determined from T1-weighted fat saturated sagittal knee MRI. All subjects had a repeat of the knee radiograph and MRI 1.96+/-0.4 years later. RESULTS: At baseline there was a moderate, but statistically significant, correlation between JSW and femoral and tibial cartilage volumes in the medial tibiofemoral joint, which was strengthened by adjusting for medial tibial bone size (R=0.58-0.66, P=0.001). Although we observed a reduction in JSW and femoral and tibial cartilage volumes over the study period, there was no significant association between reduction in JSW and cartilage volume (R<0.13). There was a trend towards a significant association between change in medial tibiofemoral cartilage volume and joint replacement at 4 years (OR=9.0, P=0.07) but not change in medial tibiofemoral JSW (OR=1.1, P=0.92). CONCLUSIONS: Although there was a modest correlation between cartilage volume and JSW in the medial tibiofemoral compartment, there was no correlation between longitudinal change in these measures. Change in cartilage volume appears to be a better predictor of joint replacement. Further work in larger samples over a longer period of time will be needed to confirm these findings.

Arthroplasty, Replacement, Knee↗
PubMed2004

Association between knee cartilage volume and bone mineral density in older adults without osteoarthritis.

OBJECTIVES: Studies have suggested an inverse association between osteoarthritis (OA) and osteoporosis, based on the presence of osteophytes rather than joint space narrowing (JSN), an indirect measure of joint cartilage. We conducted a cross-sectional study to determine the relationship between knee cartilage volume, a direct measure of joint cartilage, and bone mineral density (BMD) in an adult population. METHODS: 86 adults aged 55.1+/-10.4 years (50% females) had total BMD and bone mineral content (BMC) measured using dual X-ray absorptiometry. Site-specific BMD was performed on men in the study. Tibial and patella cartilage volumes were determined by processing images acquired in the sagittal plane using T(1)-weighted fat saturation magnetic resonance on an independent work station. RESULTS: Tibial knee cartilage volume was positively associated with total body BMD in both men and women after adjusting for age, BMI, tibial bone area and physical activity. In men, tibial cartilage volume was positively associated with proximal femur BMD, but not lumbar spine BMD. No relationship was seen between patellar cartilage volume and BMD at any region. CONCLUSIONS: We have shown a positive association between tibial cartilage volume and total BMD in men and women, but no such association with patellar cartilage volume. The mechanism for this is unclear but may represent a common environmental or genetic component. This study also highlights the need to examine the osteophyte and joint cartilage separately when investigating factors affecting the joint in health and disease since each feature is likely to reflect different aspects of the pathogenic process in OA.

Adult↗
PubMed2004

Longitudinal study of the relationship between knee angle and tibiofemoral cartilage volume in subjects with knee osteoarthritis.

OBJECTIVES: There is emerging evidence that knee alignment is associated with progression of osteoarthritis (OA). The aim of this study was to examine the relationship between baseline knee angle and the rate of cartilage loss in subjects with knee OA. METHODS: One hundred and seventeen subjects with knee OA had standing radiographs and MRI on their symptomatic knee at baseline and at the 1.9+/-0.2 yr follow-up. Knee cartilage volume was measured at baseline and follow-up. Knee angle was defined as the angle subtended by a line drawn through the mid-shaft of the femur with respect to one drawn through the mid-shaft of the tibia. RESULTS: At baseline, in the medial compartment, as the angle decreased (i.e. was less varus) the tibial and femoral cartilage volume increased. In the lateral compartment, as the angle became more valgus, there was a reduction in tibial and femoral cartilage volume. In the longitudinal study, for every 1 degrees increase in baseline varus angulation there was an average annual loss of medial femoral cartilage of 17.7 micro l [95% confidence interval (CI) 6.5-28.8]. Although not statistically significant, there was a trend for a similar relationship between loss of medial tibial cartilage volume and baseline knee angle. In the lateral compartment, there was an average loss of tibial cartilage volume of 8.0 micro l (95% CI 0.0-16.0) for every 1 degrees increase in valgus angle. CONCLUSIONS: Baseline knee angle is associated with the rate of cartilage loss in the knee. Further work will be needed to determine whether therapies aimed at modifying the knee angle will reduce the progression of knee OA.

Aged↗
PubMed2003

Factors affecting knee cartilage volume in healthy men.

OBJECTIVES: To understand the factors that influence joint cartilage in health and disease as they are important for the prevention and management of osteoarthritis. METHODS: We conducted a cross-sectional study to determine factors influencing knee cartilage volume in 45 males aged (mean+/-S.D.) 52.5+/-13.2 yr. RESULTS: Total and medial tibial volumes were inversely associated with age, body mass index (BMI) and amount of physical activity and positively associated with total bone content. BMI explained the largest amount of the variation in tibial cartilage volume (18.7%). There were similar findings at the lateral tibial cartilage, but for age and total bone content this did not reach statistical significance. There was a positive association with serum testosterone at all tibial cartilage sites, but this only reached statistical significance for medial tibial cartilage, where serum testosterone explained up to 8% of the variation in cartilage volume. CONCLUSIONS: Modifiable risk factors of osteoarthritis also appear to be significant determinants of tibial cartilage volume. Serum testosterone may provide one possible explanation for gender differences in tibial cartilage volume and prevalence of tibiofemoral osteoarthritis. The proposed link between osteoarthritis and knee cartilage volume and the effect of testosterone will need to be confirmed in longitudinal studies.

Adult↗
PubMed2000

Longterm methotrexate use in rheumatoid arthritis: 12 year followup of 460 patients treated in community practice.

OBJECTIVE: To extend our observations on the longterm tolerability of methotrexate (MTX) and reasons for discontinuation in a cohort of 460 patients with rheumatoid arthritis (RA). METHODS: We studied all patients with RA who started MTX before June 1986 and attended the community based private practices of 6 rheumatologists in Melbourne. Information to at least April 1, 1995, or within one year of death was updated from the patient's medical records to include MTX discontinuation and reasons for discontinuation. Addition of disease modifying antirheumatic drugs (DMARD) concomitant with MTX was noted. Survival analyses based upon life table methods were used with MTX discontinuation as the observable endpoint. Three different definitions of MTX discontinuation were used (1) according to whether the patient was taking the drug at last followup irrespective of any periods of temporary discontinuation; (2) MTX discontinuation for > 3 months considered to be a treatment endpoint; and (3) addition of concomitant DMARD considered to be only partial success of MTX (as a need for additional therapy to meet treatment goals). RESULTS: At 12 years, 53% of patients were continuing to take MTX (irrespective of any periods of temporary discontinuation). If discontinuation of the drug for 3 or more months was considered a treatment termination then 38% were still taking the drug at 12 years, and if addition of concomitant DMARD was regarded as a treatment endpoint only 17% of patients were continuing MTX at 12 years. Withdrawal for gastrointestinal toxicity declined over time but the risk of other adverse effects appeared to persist over time. CONCLUSION: MTX in RA is well tolerated over the longer term, with > 50% of patients starting MTX in a community based rheumatology private practice continuing to take it 12 years later. However, a substantial number of patients had 2nd line therapies added over this time. Monitoring for toxicity should continue throughout the course of therapy.

Antirheumatic Agents↗