*Yu HJ, *Zhang Y, *Morges S, *Dawson E, *Galante N, *Belaroussi B, **Hoover KB, *Miller CG.
*BioClinica, Inc., Newtown, PA 18940
**Department of Radiology, VCU Medical Center, Richmond, PA 23219
BACKGROUND: Joint space width (JSW) and joint space narrowing on plain radiographs are used to evaluate the severity and progression of osteoarthritis and for monitoring the impact of osteoarthritis therapies in clinical trials. The minimal joint space width (mJSW) is defined as the narrowest point between the cortical surface of the acetabulum and the femoral head. The use of manual calipers is prone to operator error for reasons including manual selection of the narrowest point, ensuring measurement is perpendicular to the cortical edge and that measurement does not overlap with cortical bone. To our knowledge, there were no commercial software packages available for measuring mJSW of the hip.
OBJECTIVE: A semi-automated software to evaluate mJSW was developed for improved precision and higher throughput analysis in clinical trials and is presented here.
METHODS: The mJSW in millimeters (mm) was measured on both right and left hips by 2 techniques: 1) manually using a caliper tool and 2) using the semi-automated software (Figure 1). Measurements were made by 2 experienced observers on AP pelvis radiographs from 30 subjects. Each observer measured the mJSW using both techniques, twice over a minimum interval of 15 days. The mJSW values from both methods were compared and presented as mean (SD). Intra- and inter-observer reproducibility was assessed using the intra-class correlation coefficient (ICC).
RESULTS: The manually measured mJSW were lower than semi-automatically measured mJSW for observer A, but were higher for observer B (Table 1). The overall intra-observer ICC value, for observers 1 and 2, were higher than the overall ICC from manual measurement (Table 2). The inter-observer ICC value, for read session 1 and 2 using the semi-automated method were also higher than manual measurement (Table 3). Both Intra- and Inter-observer bias were higher for manually measured mJSW compared to semi-automated measured mJSW (Table 2 and 3).
CONCLUSION: This technique provided good intra- and inter-observer reproducibility and provided superior precision from mJSW obtained from manual measurements. This new technique for mJSW measurement is suitable for use in clinical trials where assessment of the hip joint maybe required.
SPONSOR: BioClinica Inc.
DICLOSURE STATEMENT: None
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