SIGMA® Total Knee System

The SIGMA® Knee System offers one of today’s most comprehensive, integrated knee systems. Based on the clinically successful P.F.C.® Total Knee System introduced in 1984, the SIGMA Knee continues a history on innovation based on clinical evidence.

The SIGMA® Knee embraces a wide variety of surgeon philosophies and surgical techniques, while providing function, clinical results, and a variety of options for today’s patients. Available in posterior cruciate retaining or posterior stabilized femoral component designs, and fixed and mobile-bearing tibial component designs, this knee system is designed to provide surgical solutions for a variety of clinical indications.

The SIGMA Knee System

Features & Benefits

Fixed Bearing Technology

Highly polished cobalt chrome tibial tray provides smooth surface to reduce polyethylene wear.1 i2 locking mechanism with an interference fit for decreased micromotion.2 Features XLK polyethylene, a moderately cross-linked, oxidatively stable material.

MBT Rotating Platform Technology

Rotational freedom to actively diffuse loosening forces.3 Self-aligning bearing is designed to decouple flexion-extension and rotation into two unidirectional motions. Rotating platform tibial inserts available in AOX™ Antioxidant Polyethylene, featuring COVERNOX™ Antioxidant.

AOX™ Antioxidant Polyethylene

COVERNOX Antioxidant stabilizes free radicals and prevents oxidation.Addition of an antioxidant eliminates the need for a heat treatment, thus maintains excellent mechanical properties.Moderate levels of cross-linking for wear performance similar to XLK.

High Flexion

SIGMA RP-F Rotating Platform Knee accommodates 155 degrees of flexion with increased contact area in high flexion. SIGMA CR150 Knee, available in fixed bearing or rotating platform options, accommodates 150 degrees of flexion.


Supporting Documentation


SIGMA® Fixed Bearing Knee System Value Brief


1. Data on File at DePuy Orthopaedics, Inc. WR010120.

2. Leisinger, S., S. Hazebrouck and D. Deffenbaugh. "A New Approach to Micromotion Characterization of Modular Tibia Implants." 54th Annual Meeting of the Orthopaedic Research Society, Poster No. 1952, March 2-5, 2008, San Francisco, CA.

3. Bottlang, M., K.E. Oliver, E. Lacatusu, M.B. Sommers, O. Kessler. "A Mobile-bearing Knee Prosthesis Can Reduce Strain at the Proximal Tibia." Clinical Orthopaedics and Related Research. No. 447, pp. 105-111.

4. King, R. et al "Characterization of Gamma-Irradiated UHMWPE Stabilized with a Hindered Phenol Antioxidant." ORS Annual Meeting, 2009; Poster #19.

Indications for Use

Total Knee Arthroplasty (TKA) and Unicompartmental Knee Replacement are intended to provide increased patient mobility and reduce pain by replacing the damaged knee joint articulation in patients where there is evidence of sufficient sound bone to seat and support the components. The SIGMA® Cruciate Retaining Knee femoral components with POROCOAT® Porous Coating are intended for cemented or cementless use as the femoral component of a Total Knee Replacement System. TKA is indicated for: a severely painful and/or disabled joint from osteoarthritis, post-traumatic arthritis, rheumatoid arthritis or a failed previous implant. Unicompartmental Knee Replacement is indicated in these conditions if only one side of the joint (medial or lateral) is affected.