Key features and benefits

The Atlas System is an implantable joint unloader for patients with medial knee osteoarthritis

Placed subcutaneously alongside the knee joint, the Atlas System incorporates advanced biomaterials designed to provide a clinically beneficial 13 kg (30 lbs.) of unloading. Importantly, the Atlas System absorbs excess joint load rather than transfer load to otherwise healthy areas of the joint.

Key benefits

Atlas materials

Streamlined surgical technique

The Atlas System features a streamlined surgical technique based on the patient’s own anatomy and allows the surgeon to visually confirm functional joint unloading during the procedure.

Trial placement and evaluation


Identify femoral ­medial epicondyle


Identify medial edge of tibia


Select absorber length


Determine tibial fixation point


Introduce trial and confirm implant function

Device placement


Place guide pins


Introduce final implant


Confirm free movement and device function

Visual confirmation of functional unloading during surgery from full extension through deep flexion (1-2)

Proven durability

The Atlas System has successfully passed rigorous durability testing, including simulated use testing, load testing, and material biocompatibility testing.


1. Escobar A, Quintana JM, Bilbao A, Arostegui I, Lafuente I, Vidaurreta I. Responsiveness and clinically important differences for the WOMAC and SF-36 after total knee replacement. Osteoarthritis Cartilage. 2007;15(3):273–80.

2. Brander VA. Predicting total knee replacement pain: a prospective, observation study. Clin Orthop Relat Res. 2003;416:27–36.

3. Tay KS, Lo NN, Yeo SJ, Chia S, Tay DKJ, Chin PL. Revision total knee arthroplasty: causes and outcomes. Ann Acad Med Singapore. 2013;42(4):178–83.

4. Kostecki K. PEEK usage climbs for devices. Med Des. 2011. Available from: Accessed July 2, 2014.

5. Scholes SC, Unsworth A. The wear properties of CFR-PEEK-OPTIMA articulating against ceramic assessed on a multidirectional pin-on-pin machine. Proc Inst Mech Eng H. 2007;221(3):281–9.

6. Scholes SC, Unsworth A. Wear studies on the likely performance of CFR-PEEK/CoCrMo for use as artificial joint bearing materials. J Mater Sci Mater Med. 2009;20(1):163–70.

7. Scholes SC, Unsworth A. Pitch-based carbon-fibre-reinforced poly(ether-ether-ketone) OPTIMA® assessed as a bearing material in a mobile bearing unicondylar knee joint. Proc Inst Mech Eng H. 2009;223(1):13–25.

8. Steinberg EL, Rath E, Shlaifer A, Chechik O, Maman E, Salai M. Carbon fiber reinforced PEEK Optima-A composite material biomechanical properties and wear/debris characteristics of CF-PEEK composites for orthopedic trauma implants. J Mech Behav Biomed Mater. 2013;17:221–8.

9. Nakahara I, Takao M, Bandoh S, Bertollo N, Walsk WR, Sugano N. In vivo implant fixation of carbon fiber-reinforced PEEK hip prostheses in an ovine model. J Orthop Res. 2013;31(3):485–92.

10. Brockett CL, John G, Williams S, Jin Z, Isacc GH, Fisher J. Wear of ceramic-on-carbon fiber-reinforced poly-ether ether ketone hip replacements. J Biomed Mater Res B Appl Biomater. 2012;100(6):1459–65.

11. Grupp TM, Utzschneider S, Schröder C, et al. Biotribology of alternative bearing materials for unicompartmental knee arthroplasty. Acta Biomater. 2010;6(9):3601–10.

12. MoxiMed. Absorber Durability, KineSpring PEEK System [Benchmark Report-Product Design]. Released January 2, 2013.

13. Anthrex Medizinische Instrumente GmbH. PEEKPower High Tibial Osteotomy Plate. [White Literature]; 2013.

14. Dickinson AS, Taylor AC, Browne M. The influence of acetabular cup material on pelvis cortex surface strains, measured using digital image correlation. J Biomech. 2012;45(4):719–23.

15. Latif AM, Mehats A, Elcocks M, Rushton N, Field RE, Jones E. Pre-clinical studies to validate the MITCH PCR Cup: a flexible and anatomically shaped acetabular component with novel bearing characteristics. J Mater Sci Mater Med. 2008;19(4):1729–36.

16. Maharaj G, Bleser S, Albert K, Lambert R, Jani S, Jamison R. Characterization of wear in composite material orthopedic implants. Part I: the composite trunnion/ceramic head interface. Biomed Mater Eng. 1994;4(3):193–8.

17. Pace N, Marinelli M, Spurio S. Technical and histologic analysis of a retrieved carbon fiber-reinforced poly-ether-ether-ketone composite alumina-bearing liner 28 months after implantation. J Arthroplasty. 2008;23(1):151–5.

18. Scholes SC, Inman IA, Unsworth A, Jones E. Tribological assessment of a flexible carbon-fibre-reinforced poly(ether-ether-ketone) acetabular cup articulating against an alumina femoral head. Proc Inst Mech Eng H. 2008;222(3):273–83.

19. Wang A, Lin R, Stark C, Dumbleton JH. Suitability and limitations of carbon fiber reinforced PEEK composites as bearing surfaces for total joint replacements. Wear. 1999;225–9:724–7.

20. Brown SA, Hastings RS, Mason JJ, Moet A. Characterization of short-fibre reinforced thermoplastics for fracture fixation devices. Biomaterials. 1990;11(8):541–7.

21. Bruner HJ, Guan Y, Yoganandan N, Pintar FA, Maiman DJ, Slivka MA. Biomechanics of polyaryletherketone rod composites and titanium rods for posterior lumbosacral instrumentation. Presented at the 2010 Joint Spine Section Meeting. Laboratory investigation. J Neurosurg Spine. 2010;13(6):766–72.

22. Cadossi, M., et al., Erratum: A comparison of hemiarthroplasty with a novel polycarbonate- urethane acetabular component for displaced intracapsular fractures of the femoral neck: A randomised controlled trial in elderly patients (Bone and Joint Journal (2013) 95-B (609–615)). (Journal Article).

23. Molinari, G.P., V. Galmarini, and R.M. Capelli, Tribofit hip system in the surgical treatment of the medial femoral neck fractures in elderly patients. 96th National Congress of the Italian Society of Orthopaedics and Traumatology Rimini Italy, 2011. 12(Journal Article): p. S110.

24. Moroni, A., et al., Cushion bearings versus large diameter head metal-on-metal bearings in total hip arthroplasty: A short-term metal ion study. Archives of orthopaedic and trauma surgery, 2012. 132(1): p. 123–129.

25. Siebert, W.E., et al., A two-year prospective and retrospective multi-center study of the TriboFit Hip System. Journal of long-term effects of medical implants, 2009. 19(2): p. 149–155.

26. Smith, R.A. and N.J. Hallab, In vitro macrophage response to polyethylene and polycarbonate-urethane particles. Journal of Biomedical Materials Research – Part A, 2010. 93(1): p. 347–355.

27. Wippermann, B., et al., Explantation and analysis of the first retrieved human acetabular cup made of polycarbonate urethane: A case report. Journal of long-term effects of medical implants, 2008. 18(1): p. 75–83.