Sa. Mazzuca et Kd. Brandt, Plain radiography as an outcome measure in clinical trials involving patients with knee osteoarthritis, RHEUM DIS C, 25(2), 1999, pp. 467
The identification of pharmacologic agents that inhibit matrix metalloprote
inase activity and may serve as effective disease-modifying osteoarthritis
drugs (DMOADs) in humans has led to interest in the ability of plain radiog
raphic methods to detect early cartilage damage and assess progressive cart
ilage changes of knee osteoarthritis (OA). Conventional knee radiography la
cks sufficient standardization of key elements of the radioanatomic positio
ning of the knee to avoid significant, probably insurmountable, error varia
tion in the measurement of tibiofemoral joint space width (JSW), the surrog
ate for the thickness of articular cartilage in radiographic images. Recent
ly, several protocols for the use of fluoroscopy to standardize the radioan
atomic position of the knee in a plain radiograph have been shown to afford
notably more precise measurement of medial tibiofemoral JSW than can be de
rived from unstandardized, conventional techniques. A field test of one of
these protocols suggests that DMOAD trials with respect to sample size or d
uration of treatment necessary to detect true OA progression and demonstrat
e a drug effect may be more feasible.