Biomedical subjects

J C Buckland-Wright

Publications and source records attributed to J C Buckland-Wright.

At least 19 recordsLinked to original sources

PubMed2006

A 2 yr longitudinal radiographic study examining the effect of a bisphosphonate (risedronate) upon subchondral bone loss in osteoarthritic knee patients.

OBJECTIVES: To determine whether risedronate (RIS) slows down trabecular bone loss in the medial compartment of the proximal tibia, a characteristic of patients with progressive knee osteoarthritis (OA). METHODS: Initially, 100 patients were randomly selected from each treatment group (each N approximately 300) comprising placebo and RIS 5 mg/day, 15 mg/day and 50 mg/week from a double blind, multi-centre, placebo-controlled, 2 yr investigation of OA knee patients in North America. Using fluoroscopic semi-flexed standard radiography, baseline and exit knee radiographs were digitized by laser scanner. Following computerized measurement of minimum medial compartment joint space width, each group was subdivided into joint space narrowing (JSN) non-progressor or JSN-progressor (JSN >or=0.6 mm measured at any point post-baseline). Computerized method of fractal signature analysis (FSA) quantified longitudinal changes separately in horizontal and vertical trabeculae in region of interest (three-fourth width of tibial compartment x 6 mm height) in the medial compartment. Following the initial study, all JSN-progressor knees within the entire patient cohort (N = 1232) were similarly analysed. RESULTS: OA knees in JSN non-progressor group had a slight decrease in FSA for vertical and horizontal trabeculae and showed no drug effect. In JSN-progressor knees, bone loss was greater in both placebo and RIS 5 mg/day groups compared with those in RIS 15 mg/day group in which trabeculae were retained, and in the RIS 50 mg/week group in which the vertical trabecular number increased significantly (P < 0.05). CONCLUSION: This preliminary study showed that patients with marked cartilage loss (JSN>or=0.6 mm) receiving RIS 15 mg/day retained vertical trabecular structure, and those receiving RIS 50 mg/week increased vertical trabecular number, thereby preserving the structural integrity of subchondral bone in knee OA.

Adult↗

PubMed2005

A novel mathematical model identifies potential factors regulating bone apposition.

The development of pharmaceutical treatments for bone disease can be enhanced by mathematical models that predict their effects on matrix apposition during cancellous bone remodelling. Therefore, a mathematical model was constructed to simulate the rate of focal bone formation from the number of osteoid-forming osteoblasts at one microsite and their rate of activity. The number of mature osteoid-forming cells was simulated from a relationship describing the proliferation of preosteoblasts. Osteoblast activity was described by Michaelis-Menten enzyme kinetic equations adapted to describe cellular activity. The model incorporates the negative feedback effects on the rates of bone apposition due to the reduction in size of mature osteoblasts with continuing differentiation and the reduction in number of osteoid-forming cells with apoptosis and osteocyte formation. In addition, the rate of mineralisation is limited according to osteoid substrate availability. Results of sensitivity analysis revealed the amount of bone formed at one microsite to be more sensitive to changes in factors that controlled cell growth during proliferation and the number of mature osteoid-forming osteoblasts than to those that determined cellular activity. Matrix and osteocyte signalling were shown to have potentially important roles in controlling rates of osteoid apposition in normal, healthy bone. This simple model supports the critical role of controlled mitotic growth in normal bone apposition. It can also help to explain how the homeostatic processes of bone resorption and apposition during remodelling can be disrupted by growth factors that affect the mitotic fraction and division time of proliferative preosteoblast cells.

Cell Proliferation↗

PubMed2005

Fractal analysis of trabecular bone in knee osteoarthritis (OA) is a more sensitive marker of disease status than bone mineral density (BMD).

The purpose of this study was to determine whether fractal analysis (FSA) of macroradiographs or bone mineral density (BMD) is more sensitive in detecting disease-related cancellous bone alterations in knee osteoarthritis (OA). Differences in BMD between 11 OA (6 females) and 11 non-OA reference (7 females) tibiae were compared with differences in trabecular organization measured by computerized method of fractal signature analysis (FSA) of digitized macroradiographs (x3.5 to x5). OA knees had anatomic and radiographic evidence of medial compartment disease. FSA measured cancellous bone organization at 4 regions of interest (ROI): medial and lateral subchondral (Sc) and subarticular (Sa) sites, dual X-ray absorptiometry (DXA) measured BMD at the same ROIs. Compared to non-OA, OA tibiae had significant increased (P < 0.05) in FSA of vertical trabeculae in the medial Sa region (trabecular size range: 0.42-0.54; 0.90-1.98 mm) and significant decrease (P < 0.05) in FSA for some horizontal trabeculae in the Sc region (trabecular size range: medial side 0.12-0.18 mm; lateral side 0.12-0.24 mm). Compared to non-OA, BMD of OA tibiae was not significantly different at any ROI. BMD was not sensitive to changes in trabecular organization detected by FSA. The increase in FSA of vertical trabeculae in the medial Sa region was consistent with trabecular fenestration and thinning, which may have been detected as decreased BMD in a larger sample. For studies involving small sample sizes, quantifying changes in trabecular organization is more sensitive than BMD for detecting bone alterations in knee OA.

Absorptiometry, Photon↗

PubMed2004

Cancellous bone changes in the radius of patients with rheumatoid arthritis: a cross-sectional quantitative macroradiographic study.

OBJECTIVE: Fractal signature analysis (FSA), a computerized method of textural analysis, permits the separate measurement of changes in vertical and horizontal trabeculae based on the fractal dimension over a range of trabecular widths (fractal signature). We determined whether the FSA of high-definition macroradiographs (x5 magnification) quantified radiographic changes at sites of osteopenia and erosion formation in the rheumatoid arthritis (RA) hand. METHODS: Sixty-seven RA patients had macroradiographs of the left wrist and hand. The distal radius was scored and grouped from very mild (RA1) to moderate (RA4) disease. Macroradiographs were digitized and FSA of horizontal and vertical trabecular organization was performed in the radius at sites of periarticular osteopenia, erosion formation and at a mid-metaphyseal site. The RA groups were compared with 11 healthy non-arthritic subjects using ANOVA and Dunnett's tests. RESULTS: Compared to the non-arthritic hands, FSA at the distal radius in groups RA1 to RA4 measured significantly lower (P<0.05) fractal signatures. The fractal signatures were lowest in RA4 involving small, medium to large sized vertical trabeculae at the periarticular osteopenic (0.18 to 0.84 mm, P<0.01) and mid-metaphyseal sites (0.12 to 0.60 and 0.84 to 1.02 mm, P </= 0.04), and small to medium sized vertical trabeculae at the periarticular erosion site (0.24 to 0.84 mm, P<0.01). CONCLUSION: FSA quantified radiographic bone loss in the distal radius of RA patients with increasing radiographic severity in terms of lower fractal signatures compared with the non-arthritics. Disease-related bone loss was demonstrated by FSA to involve mainly vertical trabeculae at the periarticular osteopenic, periarticular erosion and the mid-metaphyseal sites indicating directionality of bone resorption in RA.

Arthritis, Rheumatoid↗

PubMed2004

Quantitative radiographic assessment of cancellous bone changes in the proximal tibia after total knee arthroplasty: a 3-year follow-up study.

The objective of this study was to determine whether fractal signature analysis (FSA) of digitized macroradiographs of knees with prosthetic implants quantifies alterations in tibial trabecular structure surrounding the implant over a 3-year period. Nineteen knees (16 patients) with arthroplasty had macroradiographs (x4) at baseline and annually for 3 years. The regions of interest (ROIs) were located in the medial and lateral plateau, midstem, and apical sites. FSA of horizontal and vertical trabecular organization was measured at each ROI, and the changes at the yearly visits were compared to the baseline values. Compared to the baseline values, FSA of the first-year radiographs detected a significant ( P < 0.05) decrease in the number of vertical trabeculae in the medial compartment, and vertical, and horizontal trabeculae in the lateral compartment. During the second year, bone remodeling led to an increase in the number of horizontal trabeculae in the medial compartment, and vertical, and horizontal trabeculae in the lateral compartment. During the third year, there was a significant increase ( P < 0.05) in the number of vertical and some horizontal trabeculae in both the medial and lateral compartments. Overall trabecular changes were significantly greater in the lateral than in the medial compartment. Following total knee arthroplasty, the response of bone showed that the first year was characterized by trabecular loss in response to posttraumatic osteopenia following surgery. By the third year, this process had reversed, with a significant increase in mainly vertical and some horizontal trabeculae in both the medial and lateral compartments, with only the lateral compartment showing an overall loss in small- and medium-sized trabeculae by the end of the study period.

Aged↗

PubMed2004

Sensitivity analysis of a novel mathematical model identifies factors determining bone resorption rates.

The development of pharmaceutical treatments for bone disease can be enhanced by computational models that predict their effects on resorption and rates of remodeling. Therefore, a simple mathematical model was formulated to simulate erosion depth and duration of resorption, using Michaelis-Menten (M-M) equations to describe changing rates of cellular activity during the two phases of bone resorption. The model was based on histomorphometric data and cellular interactions that occur in the bone microenvironment cited from the literature. Availability of bone substrate for osteoclastic activity during Phase I was assumed to be limited by the ratio of RANKL (ligand for receptor activator for nuclear factor kappaB) to osteoprotegerin (OPG) ('effective RANKL'). The required presence of marrow stromal cell produced macrophage-colony stimulating factor (M-CSF) for osteoclast action was represented as a factor equal to 1 for healthy bone. Growth factors released from the matrix during Phase I were assumed to cause two negative feedback effects: (1) the inhibitory effect of transforming growth factor-beta1 (TGFbeta1)-induced production of OPG by marrow osteoblast stromal cells, reducing effective RANKL; (2) the apoptosis of osteoclast nuclei assumed to occur at high concentrations of TGFbeta. This signaled the end of Phase I. During Phase II, cellular activity to remove the collagen fibrils left behind by osteoclasts was also simulated by Michaelis-Menten kinetic equations. Results of sensitivity analysis revealed variation in resorption depth and duration to fluctuate within 6% and 7% of the baseline value for changes in most input parameters. However, resorption depth was reduced and the duration of resorption lengthened by both a decrease in matrix TGFbeta and an increase the apoptotic threshold. Furthermore, the duration of resorption, but not erosion depth, was sensitive to changes in the maximum rate of cellular activity during removal of collagen fibrils. This mathematical model, which simulates the changing rates of cellular activity, has identified factors that reduce the duration and depth of resorption. It also suggests new targets for modeling therapeutic intervention to slow the rate of bone remodeling.

Bone Resorption↗

PubMed2002

Meniscal and articular cartilage changes in knee osteoarthritis: a cross-sectional double-contrast macroradiographic study.

OBJECTIVE: In knee osteoarthritis (OA) damage to meniscal cartilage is associated with the changes in articular cartilage. Using double-contrast macroradiographs we determined whether the degree of meniscal cartilage damage was similar to or different from that at the corresponding regions of the articular cartilage on the tibia and femur. DESIGN: Double-contrast microfocal macroradiographs,x7-x9 magnification, were obtained of the tibio-femoral joint in 20 osteoarthritic knee patients with medial compartment disease (Kellgren and Lawrence grades I-III). The appearance of the meniscus and the femoral and tibial articular cartilage were graded separately using a 5-point scale. RESULTS: In the medial diseased compartment, articular cartilage damage on the tibia was similar to that of the meniscus, which had significantly greater (P<0.02) degenerative changes than the cartilage on the femur. In the lateral compartment, meniscal damage was significantly worse than in either tibial (P<0.04) or femoral articular cartilages (P<0.01), respectively; none was as severe as that in the medial osteoarthritic compartment. CONCLUSION: Although the cross-sectional nature of this study precluded definite aetiological inferences, this study showed that degenerative changes in the meniscal and articular cartilages were not totally variable. Because of its larger articular surface, changes in the medial femoral cartilage were less marked than at the meniscal and tibial cartilages in the osteoarthritic compartment. In the lateral compartment, meniscal damage precedes tibial and femoral articular cartilage changes. In knees with medial compartment OA, combined meniscal and articular cartilage damage would account for detection of radiographic joint space loss and not meniscal extrusion only.

Adult↗

PubMed2000

Imaging. Radiological assessment of hand OA.

OBJECTIVE: The different radiographic procedures and methods for reading films and assessing the status and progression of hand osteoarthritis (OA) were reviewed. METHODS: The methods that relate to each of the above procedures were assigned to categories upon which there was or was not general agreement. RESULTS: It was agreed that the radiographic method should use published standardized radiographic protocols; that X-ray features should be graded separately for determining the extent of the disease and that changes in osteophyte size was the most sensitive indicator of progression. For epidemiological studies films should be read blind and randomly, but for assessing progression films should be read in pairs and in sequence. No agreement was obtained on the value of the lateral radiographic view of the hand nor on which radiographic atlas would be best for long-term longitudinal studies. CONCLUSIONS: Further work was required to evaluate the role of MRI and scintigraphy in hand OA; radiographic atlases could be improved by incorporating diagrams to illustrate the change in grade for each feature; validation was required for methods of assessment in long-term trials.

Clinical Protocols↗

PubMed2000

Degenerative changes at the scaphotrapezial joint following Herbert screw insertion: a radiographic study comparing patients with scaphoid fracture and primary hand arthritis.

One method of Herbert screw insertion is to mobilize the scaphotrapezial joint and insert the screw through the articular surface of the distal scaphoid. Because of concern that this might predispose to osteoarthritis in the scaphotrapezial joint, we have investigated joint space width and the presence of osteophytes adjacent to the scaphotrapezial joint using high definition macroradiography.Twenty-eight patients with symptomatic primary osteoarthritis of their hands, 23 with a scaphoid fracture successfully treated conservatively and 18 treated with a Herbert screw were studied. The patients with primary osteoarthritis of their hands had more narrowing of the scaphotrapezial joint compared with the other two groups, but patients treated with a Herbert screw had a significantly higher incidence of osteophytosis on the distal scaphoid than the other two groups. With Herbert screw fixation, osteophytosis on the distal scaphoid may cause impingement and pain, and be a predictor of further degenerative joint changes.

Adult↗

PubMed2000

Early radiographic features in patients with anterior cruciate ligament rupture.

OBJECTIVE: To determine, in a preliminary cross sectional study of patients with anterior cruciate ligament (ACL) ruptured knees, which of the radiographic features-subchondral cortical plate thickness, trabecular sclerosis, and osteophytosis-appears before or in association with changes in joint space width (JSW) as a surrogate for articular cartilage thickness in patients with ruptured knees. METHODS: 19 patients (14 men), mean (95% CI) age 28.7 (23.6 to 33.8) years, had ACL rupture in one knee only, confirmed by arthroscopy. Anterior draw, Lachman's test, and pivot shift tests were performed and x5 posteroanterior macroradiographs of both knees in a standing semiflexed view were taken at a mean (95% CI) time from injury of 34. 3 (26.9 to 41.7) months. In each radiograph, computerised methods were used to measure minimum JSW and fractal signature analysis (FSA) to quantify the vertical and horizontal trabecular organisation, osteophyte area, and the subchondral cortical plate thickness, in the medial and lateral tibial compartments of all knees. RESULTS: Physical examination confirmed the presence of joint laxity in the injured knees. No statistical difference in either medial or lateral JSW and subchondral cortical plate thickness was detected between ACL ruptured and uninjured knees. FSA showed a significant decrease in fractal dimension for the horizontal trabeculae (size 0.42 mm) in the medial compartment of the ACL ruptured knees compared with the uninjured knees (p<0.01, multivariate analysis of variance). There was an inverse correlation (R -0.74) between the time since knee injury and the difference in FSA values for ACL ruptured and uninjured knees in medial compartment horizontal trabeculae (size 0.4 mm). No significant changes were detected in the lateral compartment. Osteophytes were detected in the medial compartment of nine ACL injured knees. CONCLUSION: Compared with the uninjured knee, ACL rupture leads to thickening of subchondral horizontal trabeculae (decreased FSA) in the medial tibial compartment of all knees, reaching significance at about four years after injury. Osteophytes were present in the same compartment in 9/19 knees. No changes in JSW and subchondral cortical plate thickness were detected. Whether the bony changes detected in these ACL ruptured knees presage those of early osteoarthritis requires further study.

Adult↗

PubMed1999

Field test of the reproducibility of automated measurements of medial tibiofemoral joint space width derived from standardized knee radiographs.

OBJECTIVE: To estimate the reproducibility of computerized measurements of minimum joint space width (JSW) in the medial tibiofemoral compartment in knee radiographs (semiflexed AP view) obtained from clinical radiology units. METHODS: Technologists from 5 clinical radiology units were trained in the performance of the fluoroscopically assisted semiflexed AP knee examination. Each of 44 subjects (34 with knee osteoarthritis, OA, 10 with bilaterally normal knees) were examined within 7 days in 2 of the 5 units. The examination in each unit was repeated 1 week later. Minimum JSW was measured on digitized radiographic images with computer software that corrected for radiographic magnification. RESULTS: Despite ongoing quality control by technologists, 11% of radiographs were flawed with respect to the protocol standard for knee rotation and 36% with respect to the standard for knee flexion. The standard error of measurement (SEm) of JSW in 174 knees that were examined twice in the same unit was 0.32 mm (SEm = 0.25 mm for the subset of 76 paired radiographs with uniformly high quality). The overall between-unit SEm was 0.45 mm. Within-unit, but not between-unit, precision was related to the technical quality of the radiographs. Precision was unrelated to subject age, sex, race, weight, and radiographic severity of knee OA. CONCLUSION: The within-unit precision of JSW measurements from all pairs of semiflexed views (irrespective of technical quality) represented a notable improvement over that observed in radiographs with flawed knee rotation or flexion (as would be the case in conventional extended knee views). In future applications of this technique, assurance of technical quality by an independent observer should result in a level of measurement precision that will permit the design of clinical trials of disease modifying OA drugs with fewer subjects and/or shorter duration of treatment than is possible with conventional knee radiography.

Female↗

PubMed1999

Substantial superiority of semiflexed (MTP) views in knee osteoarthritis: a comparative radiographic study, without fluoroscopy, of standing extended, semiflexed (MTP), and schuss views.

OBJECTIVE: To improve the radiographic assessment of cartilage loss, as measured by joint space width (JSW) in patients with osteoarthritis (OA) of the knees required to detect the effect of structure modifying drugs in OA trials. This was achieved by determining which of 3 nonfluoroscopic radiographic views--standing extended, semiflexed, and schuss--produced the most accurate radioanatomic positioning of the joint and greater reproducibility in joint repositioning and JSW measurement. METHODS: Knees from 74 patients with OA of the knees who had medial tibiofemoral compartment JSW > or =2 mm in all views were studied. For all 3 radiographic views, accuracy in the radioanatomic positioning of the knee was determined for both joint rotation and flexion. Reproducibility in joint repositioning and JSW measurement were determined from the difference between repeat examinations taken within 2 h. RESULTS: About 86% of knees in the 3 views had accurate rotational position of the joint at each visit. Radioanatomically, knees in the semiflexed view were significantly more accurately positioned in regard to knee flexion (p<0.0005) than in the schuss view, which in turn was better (p<0.014) than in the extended knee view. Joint repositioning was significantly more reproducible in the semiflexed (p<0.0001) than in the extended knee, which was better (p<0.013) than in the schuss position. JSW measurement was significantly more reproducible in the semiflexed (p<0.014) than both schuss and extended knee positions, which were not significantly different from each other. CONCLUSION: Protocols defining the nonfluoroscopic radiographic procedures for the semiflexed view provide the most accurate radioanatomic joint positioning, and the most reproducible joint repositioning and JSW measurement. Using this method significantly fewer knees would be required to detect significant JSW changes in a structure modifying drug trial compared to the schuss and the extended knee positions.

Adult↗

PubMed1996

Quantitative radiography in osteoarthritis: microfocal radiography.

Quantitative macroradiography of patients with hand and knee OA, employing standardized radiographic and mensural procedures, permit: accurate and reproducible measurements of all radiographic features. significant changes in JSW and osteophyte number and size to be detected within as short a period as 18 months. therapeutic effects upon articular cartilage to be determined from changes in JSW. a better understanding of the disease process from an evaluation of the relative changes in the different radiographic features of OA.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1996

Microfocal techniques in quantitative radiography: measurement of cancellous bone organization.

Microfocal radiography records, with unusually good resolution, the detailed structural organization of cancellous bone. A textural imaging method, fractal signature analysis (FSA), was used to quantify the horizontal and vertical trabecular organization recorded within macroradiographic images of the spine of post-menopausal women and the tibia in osteoarthritic knees, and the analysis of variance method was applied to the wrist and hand of rheumatoid patients. Changes in trabecular structure were found to correlate with (i) body weight, age and bone mineral density in the lumbar spine of post-menopausal women; (ii) the degree of cartilage loss and age in the tibia of patients with knee OA; and (iii) analysis of variance quantified the extent of 'normal', osteopaenic and eroded bone in rheumatoid joints. Quantitation of cancellous bone organization can add significantly to our understanding of disease processes and effect of therapy in diseased joints.

Aged↗

PubMed1996

Fractal signature analysis measures cancellous bone organisation in macroradiographs of patients with knee osteoarthritis.

OBJECTIVE: To determine whether fractal signature analysis (FSA) of digitised macroradiographs of knees quantifies alterations in trabecular structure in the tibial cancellous bone of osteoarthritic patients with either early or definite joint space narrowing compared with non-arthritic subjects. METHODS: 90 osteoarthritic knees had macroradiographs at x5 magnification. Joint space width and FSA of horizontal and vertical trabecular organisation in the tibial subarticular cancellous bone were measured in the medial and lateral tibio-femoral compartments and compared to reference values obtained from the knees of 14 healthy non-arthritic volunteers, and to the subject's age and weight. RESULTS: Compared to the non-arthritic joints, FSA of the trabecular structure of the medial diseased compartment of the tibia was significantly different and correlated with the degree of joint space narrowing (P < 0.003); FSA of horizontal trabecular structures decreased (P < 0.001) in knees with early osteoarthritis (joint space > 3 mm) and vertical trabecular FSA increased in knees with marked joint space narrowing (joint space < 3 mm). In the lateral compartment of the tibia, FSA did not show a difference between any of the categories. With increasing age of all subjects, the changes in FSA indicated a significant increase in the number of fine horizontal and vertical trabeculae. No correlation was found between the subjects' body weight and changes in the subarticular cancellous bone organisation. CONCLUSIONS: FSA quantifies changes in cancellous bone organisation in knee osteoarthritis. In the diseased compartment, increased horizontal trabecular thickness occurred early and preceded the later changes in the vertical structures.

Age Factors↗

PubMed1995

Radio-anatomic position for the lateral radiographic view of the human patello-femoral joint.

Recent clinical and epidemiological studies have emphasised the importance of the patello-femoral joint (P-FJ) in osteoarthritis. X-ray examination of this joint for joint space width (JSW) assessment using the standard medio-lateral view is difficult. In 26 femora, the mean angle of inclination between the medial and lateral condyles measured at their inferior and anterior surfaces, relative to a line passing between the medial and lateral femoral epicondyles, was used to define the optimum alignment of the x-ray tube. The results showed that for medio-lateral radiography of the P-FJ, the central ray of the x-ray beam should be directed cranially, in a upward projection by 5 degrees and then anteriorly by 4 degrees, resulting in superimposition of the inferior and anterior condylar surfaces respectively. The value of these angles was confirmed by radiographs of the 26 femora and 10 post mortem joints. The margins for joint space width measurement were identified by embedding lead balls, within the cartilage of the cadaveric knees, and were defined as the median vertical ridge of the patella and the middle of the patella groove on the femur.

Aged↗

PubMed1995

Pattern of scaphoid fracture union detected by macroradiography.

Stereoscopic macroradiography was used to study the pattern of union of scaphoid fractures. Of 21 patients who had partial union of a scaphoid fracture, 13 united on the ulnar side and five on the radial side only. In three it was on both sides but delayed in the centre. Where there was initial union on the ulnar side, all progressed to complete union, including two patients with displaced fractures. Four out of five patients with initial union on the radial side had displaced fractures, and three of these went on to non-union. We conclude that in those patients with partial union of a scaphoid fracture, if union is seen on the ulnar side, the fracture is likely to unite completely, whereas if there is partial union on the radial side, there is a high risk of non-union.

Adolescent↗

PubMed1995

Accuracy and precision of joint space width measurements in standard and macroradiographs of osteoarthritic knees.

OBJECTIVES: To improve the reproducibility and accuracy of joint space width (JSW) measurement as an assessment of cartilage loss in patients with osteoarthritis (OA) of the knee by determining how precision and accuracy of JSW measurement were altered by a computerised method of measurement, correction for radiographic magnification, radiography of the knee in the standing semiflexed view, and high definition macroradiography of the knee in the semiflexed view--taking JSW measurements from standard radiographs of OA knees in the extended view as the standard for comparison. METHODS: Twenty five OA and 10 nonarthritic knees were radiographed in the extended view and minimum JSW was measured manually. Conventional and x5 macroradiographs were taken in the semiflexed view. All radiographs were taken twice on the same day and repeated two weeks later. Automated computerised measurement of minimum JSW was obtained from digitally stored images of all radiographs. RESULTS: For medial compartment JSW measurements, computerised was more accurate than manual, correction for radiographic magnification improved precision and accuracy, measurements in the semiflexed view were more precise and accurate, and macroradiography increased measurement precision. For the lateral compartment JSW measurements, correction for radiographic magnification improved precision and accuracy, and the semiflexed view improved precision only. CONCLUSIONS: Protocols defining radiographic and mensural procedures are essential for quality control of knee radiography in the semiflexed view to permit accurate and reproducible measurement of JSW. Macroradiography provides greater precision of JSW measurement.

Adult↗