Design Rationale

Supporting healthcare professionals

Design surgeon listSmith & Nephew thanks the following surgeons for their participation as part of the REDAPT™ Revision Acetabular System design team:

Dr. Robert BourneLondon, OntarioLondon Health Sciences, Univ.of Western Ontario

Dr. Richard McCalden London, OntarioLondon Health Sciences, Universityof Western Ontario

Dr. Andrew Shinar Nashville, TNVanderbilt Orthopaedics

Dr. Scott MarwinNew York, NYNYU-Hospital JointDiseases

Dr. Steven Weeden Fort Worth, TXThe Texas Hip & Knee Center

Dr. Mathias BostromNew York, NYHospital for Special Surgery

Dr. John Masonis Charlotte, NCOrthoCarolina

Dr. James WaddellToronto, OntarioUniversity of Toronto, St.Michael’s Hospital

Dr. Craig Della ValleChicago, ILMidwest Orthopaedics at RUSH

Mr. Stephen JonesCardiff, UKUniv. Hosp. of Wales andUniv. Hosp. Llandough

Dr. David CampbellAdelaide, South AustraliaWakefield Orthopaedic Clinic

Prof. Christian Götze Bad Oeynhausen, GermanyAuguste-Viktoria-Klinik

Our pioneering approach to the design of our products is vividly displayed through the REDAPT Acetabular Augments, developed for use in revision total hip arthroplasty cases where bone voids exist that may not be able to be addressed solely through placement of an acetabular shell. Augments can aid in the restoration of the native hip center where using a cup alone may produce a “high hip center”.¹ To allow ingrowth, an additive, or 3D printing manufacturing process is used to produce an entirely porous implant that is intended to mimic the structure of cancellous bone. Bone conserving shapes designed to help mitigate the need to remove excessive native bone stock. Additionally, new variable-angle locking screws can be used in addition to standard spherical head screws to enhance implant stability and minimize micromotion after surgery.

CONCELOC at 25x magnification

CONCELOC at 80x magnification

Please utilize the QR Code here to view the Additive Manufacturing Video.

REDAPT™ Acetabular Augments – Design Rationale

REDAPT™ Acetabular Augments

CONCELOC™ Advanced Porous TitaniumMaterial composition: Titanium Alloy CONCELOC is made from Ti-6Al-4V and meets the ASTM and ISO standards for that alloy, which has been shown to be biocompatible and has an excellent clinical history with over 40 years of use in medical devices.²

Porosity: Up to 80% CONCELOC Advanced Porous Titanium has an interconnected network of pores with a porosity of up to 80% in the near-surface regions, where the initial fixation will occur and an overall porosity of up to about 67%.³ These porosities are similar to the wide range of 60 – 80% porosity reported for other advanced porous structures currently on the market.⁴-⁸

Pore size: 202μm to 934μm The literature suggests that pore sizes greater than about 100μm benefit biological fixation.⁹,¹⁰ CONCELOC Advanced Porous Titanium has an average pore size that ranges from 202 to 342m overall and from 484 to 934μm at the surfaces of the porous structure.³,¹¹

Three dimensional model before and after application of friction bumps.

REDAPT™ Acetabular Augments – Design Rationale

Stability Variable angle locking screws For bone ingrowth to occur, it is critical that implants

remain stable. It has been reported that as little as 150 microns of motion can interrupt the process of bone ingrowth.¹²

Screws have historically been used as a means to provide adjunctive fixation. The introduction of REDAPT Variable Angle Locking Screws gives the surgeon the option to further enhance the rigidity of the construct. Traditional, spherical head screws or REDAPT Variable Angle Locking Screws can be used in any of the available screw holes on the REDAPT Acetabular Augments.

• Variable angle lock up to 12˚ (included angle)

• Increased stiffness in static bending compared to non-locking screws¹³

• 6.5mm cancellous thread

• Lengths: 15mm – 50mm

High friction surface The high friction surface of the CONCELOC Advanced

Porous Titanium is designed to aid in achieving the initial stability needed to hold the implant in place upon insertion.

• Topographically mapped “bumps” on all bone-interfacing surfaces

• Patented design feature

• Benefit of additive manufacturing

Adaptability Two styles to address varying defects • Staple – Allows the Augment to span around a screw that is

placed through the cup into the acetabulum

• Slice – Provides additional support where defects may be present in the more medial aspects of the acetabulum

Optimized screw hole pattern (Slice implants only)

Augment Holding Forceps • Allows placement of REDAPT Acetabular Augments

with minimal tissue interference

Four thickness options – 8, 12, 18 and 24mm • Addresses wide range of defect sizes

• Helps restore anatomic hip center

OneAugmentfitsmultipleshelldiameters

Compatability Chart (mm)

Augment ID 50 56 62 68 74

Shell OD 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80

REDAPT Acetabular Augments – Design Rationale

Staple Slice

8mm 12mm 18mm 12mm 18mm 24mm

50mm

56mm

62mm

68mm

74mm

REDAPT™ Acetabular Augments – Design Rationale

Reproducibility Trials • Exact replica of each implant size

Driver Platform • Designated surface for light impaction if necessary

Steinmann Pin Holes (size permitting)

• Allow for implants to be positioned exactly where trialing is completed

Cement Troughs • Simplifies unitization of Augments to the acetabular shell

• Allows cement injection technique or traditional manual spreading of cement

Cement Troughs

Steinmann Pin Hole

Driver Platform

Implant overview REDAPT™ Acetabular Augments

Staple: 8mm – 18mm thickness

Slice: 12mm – 24mm thickness

Spherical Head Screws 15mm – 50mm

REDAPT Locking Screws 15mm – 50mm

Instrument overview Trials

REDAPT™ Drill Guide

Torque Limiting Driver

Straight Drills 15mm – 35mm

Augment Holding Forceps

References:

1. Siegmeth A, Duncan CP, Masri BA, Kim WY, Garbuz DS, "Modular tantalum augments for acetabular defects in revision hip arthroplasty," Clin Orthop Relat Res. 2009 Jan;467(1):199-205. doi: 10.1007/s11999-008-0549-0. Epub 2008 Oct 16. 2. D.F. Williams, “Titanium and Titanium Alloys,” in Biocompatibility of Clinical Implant Materials, D. F. Williams, Eds., Boca Raton, FL: CRC Press, Inc., 1981. 3. Smith & Nephew Research report. OR-14-091A. 4. J.E. Minter, K. Rivard and B. Aboud, "Characterization of a new rougher porous coating for revision reconstructive surgery," Orthop Res Soc, San Francisco, CA, Mar 2-5, 2008, 1870. 5. N. Patil, K. Lee and S.B. Goodman, "Porous tantalum in hip and knee reconstructive surgery," J Biomed Mater Res B, 2009;89(1):242-251. 6. H. Liu, "Porous metal foam structures and methods," USA Patent 2008/0199720, 2008. 7. "Tritanium primary acetabular shells," Stryker, 2008, SODTR-SS. 8. D. Scholvin, D. Linton and J. Moseley, "Bonding of titanium foam to cobalt chrome substrates," Orthop Res Soc, San Antonio, TX, Jan 26-29, 2013, 0459. 9. J.D. Bobyn, R.M. Pilliar, H.U. Cameron and G.C. Weatherly, "The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone," Clin Orthop Relat Res, 1980;150):263-270. 10. V. Karageorgiou and D. Kaplan, "Porosity of 3D biomaterial scaffolds and osteogenesis," Biomaterials, 2005;26(27):5474-5491. 11. Smith & Nephew Research report. OR-15-119. 12. R.M. Pilliar, J.M. Lee and C. Maniatopoulos, "Observations on the effect of movement on bone ingrowth into porous-surfaced implants," Clin Orthop Relat Res, 1986;208:108-113. 13. Smith & Nephew Research report. TM-15-043.

Smith & Nephew, Inc. 1450 Brooks RoadMemphis, TN 38116 USA Telephone: 1-901-396-2121 Information: 1-800-821-5700 Orders/Inquiries: 1-800-238-7538 Supporting healthcare professionals for over 150 years

www.smith-nephew.com

™Trademark of Smith & Nephew©2018 Smith & Nephew10864 V1 07/18