A radiological technique for the assessment of wear in prosthetic knee replacements

Abstract

This technique allows repeatable, precise measurement of insert thickness. The technique may be adapted to any implant where a reliable calibrating distance is present.

A model-based approach to measure the minimum joint space width of total knee replacements in standard radiographs

“…Several other studies describe alternatives to the radiographic wear measurement. Some studies use fluoroscopy to improve the reproducibility, as the alignment between the tibial tray and the radiographic beam can be optimized before the measurement (Duryea et al, 2001;Hide et al, 2000). A standard deviation of 0.15 mm was found in this measurement, which is similar to the finding in our work, yet fluoroscopy generally comes with a higher radiation dose for the patient and requires a longer imaging time.…”

Fully automated software to monitor wear in prosthetic knees using fluoroscopic images

“…A more detailed discussion of the clinical aspects of this study are given by Hide et al [9]. The high degree of reproducibility and low failure rate indicate that this software can be a powerful tool in assessing wear in knee prostheses.…”

“…The average dose area product (DAP) was193 mGy cm 2 per image. These data and the acquisition methods are described in great detail elsewhere [9]. Figure 1 shows the results of the software.…”

“…al. [9]. The reader made three separate and independent measurements of the data set, giving a total of nine (three readings times three acquisitions) for each knee.…”

“…Previous work, using digital fluoroscopy to position and obtain weight-bearing images of knee prostheses, has shown that measurement of the minimal joint space width (mJSW) on these images provides repeatable, precise measurement of insert thickness [9]. This method utilized manual onscreen measurements provided on the fluoroscopy system.…”