Triathlon® Hinge Knee System

The Triathlon® Hinge Knee System is a constrained rotating hinge prosthesis for total knee replacement, intended for cemented implantation in patients with severely unstable knees, particularly those with loss of collateral ligament support. It is used in both primary and revision cases, and is compatible with modular rotating hinge (MRH) and global modular replacement system (GMRS) components for distal femoral and proximal tibial replacements in tumor treatment.

The new Triathlon® Small Proximal Tibial Bearing Component and End Cap are manufactured from ASTM F1537 cobalt-chromium alloy, identical to predicate devices. The bearing component has smaller anteroposterior and mediolateral dimensions than prior versions to prevent overhang during tibial rotation. The End Cap is identical to the existing Triathlon Universal Baseplate End Cap (5560-S-016) and is now offered as a standalone saleable part. Both components utilize the same basic mechanical principles as predicate devices.

ASTM F1223-20 (range of motion analysis), ASTM F2052-15 and F2213-17 (MRI magnetic displacement and torque), ASTM F2119-07 (MRI image artifacts), ASTM F2182-191ae (RF heating), ISO 10993-1:2020 (biocompatibility), ISO 11607-1:2019 and 11607-2:2019 (sterilization validation), ASTM F1980-21 (shelf-life), ANSI/AAMI ST72:2019 (bacterial endotoxin testing), and ASTM F1886/F1886M-16, F88/88M-21, F2096-11(2019) (materials and sterilization testing).

The subject components are substantially equivalent because they use identical materials (ASTM F1537) and identical or nearly identical designs to predicate devices (primarily K223528, K230416, K053514, K141056, K172326), operate on the same mechanical principles, and have undergone comparable non-clinical testing including fatigue, wear, biomechanical, and MRI safety analyses. The only design difference—smaller tibial bearing dimensions—is a minor modification to prevent mechanical interference, not a functional change. Compatibility with MRH and GMRS systems is based on established predicate data for those systems (K994207, K002552, K023087, K222056).