Precision and Accuracy Measurement of Radiostereometric Analysis Applied to Movement of the Sacroiliac Joint

Abstract

Background Different techniques have been used to quantify the movement of sacroiliac (SI) joints. These include radiostereometric analysis (RSA), but the accuracy and precision of this method have not been properly evaluated and it is unclear how many markers are required and where they should be placed to achieve proper accuracy and precision. Purpose The purpose of this study was to test accuracy and precision of RSA, applied to the SI joint, in a phantom model and in patients. Methods We used a plastic phantom attached to a micrometer to obtain a true value of the movement of the SI joint and compared this value with the measured value obtained by RSA; the difference represented the accuracy. The precision of the system was measured by double examination in the phantom and in six patients, and was expressed by a limit of significance (LOS). We analyzed different marker distributions to find optimal marker placement and number of markers needed. Results The accuracy was high and we identified no systematic errors. The precision of the phantom was high with a LOS less than 0.25°and 0.16 mm for all directions, and in patients, the precision was less than 0.71°for rotations and 0.47 mm translations. No markers were needed in the pubic symphysis to obtain good precision. Conclusions The accuracy and precision are high when RSA is used to measure movement in the SI joint and support the use of RSA in research of SI joint motion.

Physiological in vitro sacroiliac joint motion: a study on three‐dimensional posterior pelvic ring kinematics

“…A number of studies have made attempts to describe SIJ movements both qualitatively and quantitatively (Weisl, 1955;Egund et al 1978;Lavignolle et al 1983;Miller et al 1987;Rothk€ otter & Berner, 1988;Sturesson et al 1989Sturesson et al , 1999Sturesson et al , 2000aVleeming et al 1989Vleeming et al , 1992aSimonian et al 1994a;Jacob & Kissling, 1995;Kissling & Jacob, 1996;Wang & Dumas, 1998;Kibsg ard et al 2012Kibsg ard et al , 2014bLindsey et al 2014). The common observation is that its overall movement is multi-dimensional and held within a small range, but to a highly variable extent among individuals.…”

“…One underlying assumption for these therapies is that they influence SIJ pain as a consequence of altering motion. Sound scientific evidence of such alterations is still pending, and there is conflicting data for reference values of physiological movement (Weisl, 1955;Lavignolle et al 1983;Jacob & Kissling, 1995;Kissling & Jacob, 1996;Sturesson et al 1999Sturesson et al , 2000aKibsg ard et al 2012Kibsg ard et al , 2014bEgund & Jurik, 2014).…”

Authors' response to the letter to the Editors by Professor M. T. Cibulka: a critical interpretation of sacroiliac joint movement studies

“…However, combining all the data from published studies employing RSA and appropriate markers, the maximum sagittal rotation of the SIJ never exceeds 3.6°and translation of the joint never exceeds 2 mm (Kibsg ard et al 2012). Amalgamating these data with the observation that osteophytosis in women, regardless of age, is rare (1.83% of females) and not very common in men (12.27%; Dar et al 2008), it therefore appears that small SIJ movements are present, even at an advanced age (Vleeming et al 1992).…”

“…Sturesson responded to the critique by explaining that the RSA technique enables optimal spatial contribution of the implanted markers, resulting in highly precise measurements. Moreover, a recent article has reported that when RSA is applied correctly, the method is reproducible and can be regarded as the gold standard in measuring small joint movements in orthopedic research (Kibsg ard et al 2012). …”

Innominate movement patterns, rotation trends and range of motion in individuals with low back pain of sacroiliac joint origin

“…Several techniques have been used to accurately quantify the innominate bone kinematics, while using either multiple radiographs (Mens et al, 1999) or roentgen stereophotogrammetric analysis with implantation of radio-opaque markers (Sturesson et al, 1989;Kibsgard et al, 2012). While these techniques are highly accurate for investigating joint ranges of motion (ROM) between the two test positions, they are not appropriate for investigation of patterns or trends of joint motion as they cannot be performed in real time.…”