Radiographic assessment

Radiographic assessment and progression of disease

Grading assessments of knee (baseline/5 & 10 years), spine (baseline and 9 years), hand (baseline & 11 years), hip (baseline & year 8) and feet (year 6) are available. Radiographs were read by investigators, using an atlas of radiographic features with good reproducibility (Spector 1993, Hart 1994, Hassett 2003). A summary or global degeneration score of all affected joints is possible from the acquired data. We have used this method for calculating a total hand score (Spector TD, 1996). In addition, we have recently analysed data comparing progression at the hand, spine and knee showing the sites are closely correlated. Lumbar spine OA progression predicted 67% of progression of knee OA. Progression of JSN in knee OA was predicted by progression in lumbar spine disc space narrowing (OR 2.9, 95% CI 1.2 – 7.5) and hip OA (JSN) (OR 2.0, 95% CI 1.0 – 4.2) predicting 41 and 49% of knee progression respectively. This study demonstrated that progression of knee OA can be predicted by studying progression of lumbar spine and hip OA. This is of particular importance as it suggests that global scores of total joint damage may be more informative for longitudinal studies. The progression data from this cohort is very unique. We have reproducibility of over 70% Kappas with less than 3% improvers.

Current OA Status of Cohort

In 1989 200 cases of radiographic OA were identified in the cohort. In the knee, 25% developed progressive disease, and 95 new cases of OA were identified after 4 years. There are now 150 progressors with knee OA, and 100 non-progressors. There are also 115 incident knee OA cases, with an incident rate of new knee OA of approximately 3% per year.

Joint group

Non-progressors

Progressors

Knee

OP
JSN

11%
7%

15%
8%

Hand

OP
JSN

8%
13%

20%
24%

Hip

OP
JSN

15%
2%

15%
2%

Spine

OP
JSN

58%
46%

31%
19%