Quadsense (Quadsense and Quadsense Pro)

The Quadsense and Quadsense Pro Systems are intraoperative orthopaedic assessment devices that measure patellofemoral joint forces during total knee arthroplasty (TKA) with patellar resurfacing. A sensor attaches to the patella to record medial, lateral, superior, and inferior loads during range-of-motion trials, allowing surgeons to compare forces before and after trial component insertion. The system displays real-time data on a Panel PC outside the sterile field, and surgeons control it via a sterile control puck.

The Quadsense and Quadsense Pro retain identical intended use, measurement methods, and core technological principles as the predicate. Minor physical differences include geometric changes to sensor interface and shim design for the Pro version to expand configuration options. Software version 2.1.0 adds quantitative load comparisons (absolute and percentage changes), two new warnings (insufficient data peaks and low patella thickness alerts), optional surgeon-input workflow for arithmetic calculations, graphical auto-scaling, and signal noise filtering—all based on existing acquired data without new measurement hardware or automated clinical decision-making.

ISO 14971:2019 (risk management); IEC 62304:2006+A1:2015 (software verification and validation); IEC 62366-1:2015/AMD1:2020 (human factors); FDA Guidance on Cybersecurity in Medical Devices; FDA Guidance on Applying Human Factors and Usability Engineering to Medical Devices; accelerated aging protocol simulating 3 years shelf life.

The device shares identical intended use, indications, sterilization method, operating principle, and electromagnetic compatibility with predicate K241298. The minor technological modifications—geometric shim changes and software usability enhancements—do not alter core measurement capabilities or introduce automated clinical decisions; they only provide supplementary numerical and visual outputs from data already acquired by the predicate system. Comprehensive design controls, verification, validation, and human factors testing confirm performance equivalence and that no new or increased risks are introduced.