FDA Product Code HSX: Prosthesis, Knee, Femorotibial, Non-constrained, Cemented, Metal/polymer

Under FDA product code HSX, non-constrained cemented femorotibial knee prostheses are cleared for unicompartmental or total knee arthroplasty.

Non-constrained designs rely on the patient's own ligaments — particularly the PCL and collateral ligaments — for joint stability, rather than on mechanical constraint from the implant. They offer more natural kinematics than constrained designs and are used in patients with intact ligamentous support.

HSX devices are Class II medical devices, regulated under 21 CFR 888.3520 and reviewed by the FDA Orthopedic panel.

Leading manufacturers include Smith & Nephew, Inc., Signature Orthopaedics Pty, Ltd. and Medacta International S.A..