Affinis Inverse

Our

reverse shoulder replacement

has been further developed according to the motto «Evolution instead of Revolution». Find out how we have addressed current clinical challenges.

EVOLUTIONARY

No inlay screw notching thanks to two-peg design without inferior screw. Increased impingement-free range of motion due to systematic glenosphere overhang and effective stem inclination of 147°. 1

INVERSE

Inversion of the materials in the tribological pairing eliminates polyethylene wear on the scapula neck and surrounding structures. 2

 

PROVEN

Proven primary treatment with more than ten years of clinical experience and convincing clinical evidence. 3,4

 

PROGRESSIVE

In case of possible hypersensitivity to metal ions, our reverse shoulder Affinis Inverse offers a standard solution for allergy patients.

Inversion of the materials in the tribological pairing eliminates polyethylene wear on the scapula neck

Inversion of the materials in the sliding coupling to a hard inlay of ceramic or metal on the humeral side eliminates polyethylene wear on the scapula neck and surrounding structures. 2 This results in a reduced risk of polyethylene-induced disorders such as osteolysis. 5,6-8

No inlay screw notching thanks to two-peg design without inferior screw

In the Metaglene DP (Double Peg), inlay screw notching was eliminated by metaglene optimisation to a two-peg design without an inferior screw.

Reduced risk of notching thanks to effective mean stem inclination of 147°

By the medial inlay chamfer of 8°, the frequently discussed mean inclination was shifted to the inlay. The original stem inclination of 155° is thus reduced by 8°. This results in an effective mean inclination of 147°, allowing increased adduction without mechanical notching in the neutral position of the humerus and generally a higher range of motion.

Increased impingement-free range of motion thanks to by-design eccentricity of the metaglene

An increased impingement-free range of motion is achieved by a systematic glenosphere overhang. The by-design eccentricity of the metaglene, together with the placement on the inferior edge of the glenoid, reduces the risk of notching.

Good primary stability and permanent secondary stability thanks to coated pegs and compression screws with locking caps

The double coating of the two Metaglene DP pegs with titanium plasma spray and a resorbable calcium phosphate compound, which accelerates osseointegration through its osteoconductive effect, contributes to good primary and lasting secondary stability. Even higher primary stability is provided by the compression screws that press the implant against the bone. In addition, once turned in, the superior screw of the Metaglene DP is eventually locked at a fixed angle with the base plate by means of a locking cap.

Minimised risk of disconnections thanks to snap-in mechanism between metaglene and glenosphere

A snap-in mechanism ensures a stable connection between metaglene and glenosphere. The snap-in fixation of the glenosphere is secured by means of a fixation screw, in order to prevent loosening of the connection between the components. Deliberately, in order to minimise the risk of infection a compact design with only two components (metaglene and glenosphere) was chosen. The rate of infection was reduced from 4.0% with earlier systems 9 to 0.7% with the Affinis Inverse prosthesis. 10

Minimised risk of infection or disconnection thanks to monolithic stems

The Affinis Inverse prosthesis convinces also on the humeral side with its evolutionary design with monolithic press-fit stems. In the same manner as for the glenosphere, the risk of infection was to be minimised by reducing the number of individual parts in the stem. 11 Connection of multiple individual components additionally entails a higher risk of disconnections. 12

T Titanium
V vitamys
K Ceramics
T Titanium
Affinis
Progressive materials

The Affinis Inverse shoulder system is defined by an inverse and evolutionary implant design as well as by use of progressive materials. 

These are vitamys, a highly crosslinked polyethylene enriched with vitamin E, for the glenosphere. The benefits of vitamys are obvious: The good mechanical strength allows long-term mechanical performance of the material. The high wear resistance reduces wear and thus the risk of osteolysis. 6-8 The addition of vitamin E furthermore ensures resistance to oxidation and thus high resistance to ageing as well. 13 

Mathys uses high-quality ceramics for the inlay. Low wear rates, high strength and toughness, good wettability and biologically inert behaviour 5,13,14 argue for this material. These advantages make the ceramics a treatment option not only for young and active patients. 

For the Affinis Inverse stems and the metaglene, the titanium alloy Ti6Al4V is used, which has proven its worth in medical technology for many years. The quality of the alloy is shown by a controlled homogeneous structure and the high strength of the material, and it permits nickel-free anchoring in the bone.

Reduced risk of allergy

Allergic reactions to metal ions in joint replacement are an issue that concerns patients and physicians. Ceramics, titanium and PE/vitamys provide a solution for patients with hypersensitivity to nickel, cobalt, chromium and molybdenum ions. The Affinis Inverse system thus offers implants that are directly available as a standard solution for cases of hypersensitivity.

Reduced wear

The ceramys ceramic inlay as well as the vitamys (PE) glenosphere of the Affinis Inverse prosthesis show significantly lower wear in simulator testing than UHMWPE (PE) or cobalt-chromium (CoCr) components do. The wear reduction of the optimum coupling of vitamys/ceramys compared to the coupling of CoCr/UHMWPE is 82%.15

Wear reduction in % of the Affinis Inverse sliding couplings

100% 75% 50% 25% 0% UHMWPE/CoCr 37% UHMWPE/Ceramics* 67% vitamys/CoCr 82% vitamys/Ceramics* *ceramys
You want to know more about our reverse shoulder arthroplasty solution?
Smart instrumentation

The Affinis Inverse system offers smart instrumentation, and as a result, it allows convenient operation with simple and logical workflows for efficient installation of the prosthesis. In addition, all surgical steps are instrumentally guided. Free-hand manipulations are avoided, hence reproducible results can be achieved.

The instruments are arranged in a straightforward tray concept that ensures and simplifies overview of the entire instrumentation at all times.

Surgical technique

Affinis Inverse
Reverse shoulder prosthesis
LC system with SMarT instruments

  • 1. Humeral resection
  • 2. Humerus preparation and stem implantation
  • 3. Glenoid preparation
  • 4. Metaglene implantation
1. Humeral resection
Step 01
Humeral resection

Completely instrument-guided humeral resection for the delto-pectoral and lateral access

2. Humerus preparation and stem implantation
Step 02
Humerus preparation and stem implantation

Step-by-step preparation of the humerus for the final stem implantation

3. Glenoid preparation
Step 03
Glenoid preparation

Kirschner wire-guided glenoid preparation for inferior-aligned implant placement

4. Metaglene implantation
Step 04
Metaglene implantation

Eccentric implantation of the two-peg metaglene DP and fixation with A/P compression screws and fixed-angle superior screw

Affinis shoulder system

The Affinis Shoulder system covers a wide range of indications: Whether primary treatment, fracture or revision prosthesis – the prostheses solve orthopaedic challenges systematically and uncompromisingly and are defined by a sophisticated implant design as well as by use of advanced materials.

Further information about the Affinis shoulder system can be found on the Mathys website

mathysmedical.com

Affinis Short

Stemless anatomical

Osteoarthritis of the shoulder

Affinis Classic

Anatomical

Osteoarthritis of the shoulder

Affinis Inverse

Inverse

Rotator defect arthropathy

Affinis Fracture Inverse

Fracture Inverse

Proximal humerus fracture

Affinis Fracture

Fracture Hemi

Proximal humerus fracture

Learn more

You can learn about the reverse total shoulder implant and the surgical technique at congresses and workshops.

Events

Event

Challenges and Controversies in Shoulder Arthroplasty – Challenges and possible Solutions

Downloads
Document

Affinis Inverse – Brochure

Document

Affinis Inverse Metaglene LC System – Brochure

Document

Affinis Inverse Metaglene DP – Surgical technique

Document

Affinis Inverse Metaglene CP – Surgical technique

Document

Affinis Inverse Metaglene DP – Instructions for technical surgical assistance

Document

Affinis Inverse Metaglene CP – Instructions for technical surgical assistance

Document

Affinis Inverse Bone Grafting instruments – Instructions for technical surgical assistance

Document

Affinis Inverse Bone Grafting Instruments – Brochure

We provide you with the current version of the existing documents. Older versions of the surgical techniques, guidelines and processing instructions are listed in our overview Overview_IFU and can be requested at marketing@mathysmedical.com.

Documents in other languages can be found on the Mathys website:
mathysmedical.com

References
  • 1 de Wilde L F, Poncet D, Middernacht B, Ekelund A. Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis. Acta Orthop. 2010;81(6):719-26.
  • 2 Kohut G, Dallmann F, Irlenbusch U. Wear-induced loss of mass in reversed total shoulder arthroplasty with conventional and inverted bearing materials. J Biomech. 2012;45(3):469-73.
  • 3 ODEP Rating: http://www.odep.org.uk/products.aspx, last access 29.10.2020.
  • 4 Irlenbusch U, Kaab M, Kohut G, Proust J, Reuther F, Joudet T. Reversed shoulder arthroplasty with inversed bearing materials: 2-year clinical and radiographic results in 101 patients. Arch Orthop Trauma Surg. 2015;135(2):161-9.
  • 5 Alexander J J, Bell S N, Coghlan J, Lerf R, Dallmann F. The effect of vitamin E-enhanced cross-linked polyethylene on wear in shoulder arthroplasty-a wear simulator study. J Shoulder Elbow Surg. 2019;28(9):1771-1778.
  • 6 Boileau P, Moineau G, Morin-Salvo N, Avidor C, Godeneche A, Levigne C, Baba M, Walch G. Metal-backed glenoid implant with polyethylene insert is not a viable long-term therapeutic option. J Shoulder Elbow Surg. 2015;24(10):1534-43.
  • 7 Harris W H. Wear and periprosthetic osteolysis: the problem. Clin Orthop Relat Res. 2001(393):66-70.
  • 8 Huang C H, Lu Y C, Chang T K, Hsiao I L, Su Y C, Yeh S T, Fang H W, Huang C H. In vivo biological response to highly cross-linked and vitamin e-doped polyethylene--a particle-Induced osteolysis animal study. J Biomed Mater Res B Appl Biomater. 2016;104(3):561-7.
  • 9 Wall B, Nove-Josserand L, O'Connor D P, Edwards T B, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am. 2007;89(7):1476-85.
  • 10 National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR). Summary Report SP Humeral Affinis Inverse (Reverse Total) 23-11-20. Data valid to 21 March 2021.
  • 11 Walter G, Gramlich Y. Periprothetische InfektionenInfektionperiprothetische. In: Orthopädie und Unfallchirurgie. Springer Berlin Heidelberg. ISBN 978-3-642-54673-0. 2019;1-25.
  • 12 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty: 2020 Annual Report, Adelaide; AOA, 2020: 1-474. [Accessed from: https://aoanjrr.sahmri.com/annual-reports-2020]. Table ST48, page 368.
  • 13 Willmann G. Improving Bearing Surfaces of Artificial Joints. Advanced Engineering Materials. 2001;2(3):135-41.
  • 14 Barnes D H, Moavenian A, Sharma A, Best S M. Biocompatibility of Ceramics. ASM Handbook. 2012;23.
  • 15 Lerf R, Wuttke V, Reimelt I, Dallmann F, Delfosse D. Tribological Behaviour of the “Reverse” Inverse Shoulder Prosthesis. 7th International UHMWPE Meeting. Philadelphia 2015.
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