Radiographic Follow-Up for a Knee Implant

Challenge

A pivotal trial of a new total knee replacement system required serial radiographic assessment of implant fixation over two years, including radiolucent lines, osteolysis, and component alignment. Inconsistent patient positioning and variable radiograph quality across sites threatened to obscure subtle changes at the bone–implant interface, and the regulatory submission demanded reproducible, independently adjudicated measurements at every follow-up visit.

Our Solution

Intrinsic Imaging issued a standardized radiographic acquisition manual with positioning guidance and trained every site before first enrollment, then applied prospective quality control so inadequate examinations were flagged and repeated within the visit window. Musculoskeletal radiologists read each time point blinded to visit sequence using zone-based radiolucency scoring and calibrated alignment measurements, with CT adjudication for equivocal cases and formal reader-agreement monitoring throughout the study.

Results

• Radiograph repeat rate reduced to under 3%
• Inter-reader agreement above 90% on radiolucency scoring
• Two-year fixation data supported the regulatory submission