ABGII Cement Free Total Hip Replacement System

Transcription

1 Cement Free Total Hip Replacement System Efficacy Innovation

2 Cement Free Hip System The ABG Cement Free Hip System is one of the foremost ranges of cementless total hip replacement prosthesis. Used extensively throughout the world it has demonstrated excellent and consistent clinical results. 1-6 Design Objectives The aims of the ABGII Hip System are to provide total hip replacement that is: 1. Long Lasting 2. Pain Free 3. Fully Functional 4. Easy to implant successfully These are intended to be achieved by re-establishing physiological load transfer in both the acetabulum and the femur through the ABGII Hip System which provides: Anatomical femoral shape with only proximal fixation Hemispherical acetabular component Titanium alloy Hydroxyapatite coating Clinical Objectives 1. Establish Excellent Primary Stability the stem shape is designed to achieve immediate primary stability. 2. Encourage Secondary Biological Fixation the prosthesis has a unique hydroxyapatite coating. This special coating encourages the formation of a biological bond with the bone and promotes the long-term stability of the implant. 3. Optimise Bone Conservation the ABGII implant, instrumentation and surgical technique intend to allow optimum conservation of bone stock. ABGII Stem and Cup System 3

3 Cement Free Femoral Component The ABGII femoral component s anatomical shape follows the natural contours of the femur in all three dimensions. This helps establish: Primary Stability the anatomical shape of the femoral stem allows it to adapt to the contours of the femur. Normal Physiological Loading this close three-dimensional conformity with the femur ensures that the load transfer pattern imitates the natural distribution of stress. Bone stress levels are also maintained within physiological limits, as this keeps the bone in the proximal femur healthy and reduces resorption. Proximal Load Transfer The system s biomechanics are designed to be as close as possible to those of the normal femur. To achieve this, the distal part of the stem is made undersized, purposely, and load transfer is only allowed to occur proximally. Distal contact between stem and bone is also avoided. The distal part of the stem is polished to prevent bone ongrowth in the event of any contact. This reduces stress shielding and prevents proximal bone resorption from occurring. Correct Anteversion the 5 anteversion of the neck and the 7 anteversion in the stem s metaphyseal portion help the implant follow the femur s natural form. The re-establishment of normal anatomical loading of healthy bone encourages bone remodelling around the prosthesis. It also prevents bone resorption. As a consequence, healthy bone stock is maintained around the implant long-term and a stable firmlyfixed total hip replacement is achieved. Anatomic load transfer occurs in the metaphysic The ABG design aims to re-establish anatomic load transfer 4

4 Cement Free Hip System Stem Features TMZF Alloy Further improves stress transfer to the proximal femur over conventional TiAl 6 V 4 alloy. Scales these are incorporated into the stem s anterior, posterior and medial surfaces. They encourage the transmission of vertical loading from the implant to the bone and reduce the dependence on friction at the hydroxyapatite surface. Hydroxyapatite Coating only applied proximally. ABG Stem Range 8 sizes Left and right implants Size (left & right) Stem Length (mm) Neck Length (mm) Distal Diameter (mm) Super-Polished Heads Femoral-head quality is critical in reducing material wear in hip prostheses. All Vitallium ABG heads are: Given a super-polished finish Have an average Ra value (Roughness value) of < 0.016µm Three times smoother than heads finished to current ISO standards Alumina Heads A range of Alumina Heads is also available for use with the ABGII. Made of medical grade alumina (ISO 6474), the heads have a standard V40 taper of 5 40' and 11.3mm/12.5mm spigot diameter. The surface finish and sphericity are tightly controlled to tend to provide optimal articulation with the alumina Insert. Super-Polished Heads V40 Alumina Heads Ø8.5 Ø Ø9 115 Ø Ø11 Ø Ø Ø Femoral Stem ABGII Stem Range 5

5 Acetabular Cup System The principal objectives of the ABGII Cup design are to: 1. Ensure stable fixation coupled with an even transfer of load to the supporting bone. 2. Promote secondary biological bonding between the implant and the surrounding bone. 3. Minimise material wear and debris. The ABGII Cup intends to achieve these objectives as a result of its: Hemispherical Shape preserves bone stock and encourages even transfer of load to the supporting bone. Hydroxyapatite coating encourages strong, biological, secondary fixation. Circular Grooving promotes bone ingrowth. Titanium (TiAl 6 V 4 ) Alloy Shell. Duration Stabilised. Polyethylene reduces wear and increases the insert s strength and durability. ABGII shells are available in two options: ABGII No-Hole Cup The ABGII No-Hole Cup consists of a solid shell without holes. This reduces the number of edges between the shell and the polyethylene cup and reduces potential sources of wear. Rotational stability can be enhanced by means of up to five externally-fixed spikes. Their use is left to the surgeon s discretion. ABGII 5-Hole Cup The ABGII 5-Hole Cup has five clustered screw holes. Fixation is achieved by means of either spikes or screws. Any vacant holes in the cup can be sealed by the surgeon, using the ABG obturator screws. The ABG obturator screw provides a water seal to reduce migration of any wear debris that may exist. ABGII Cup Range 6

6 The ABGII Insert ABGII Alumina Insert Is made from Duration Stabilised Polyethylene, using standard UHMWPE. The unique packaging protects the polyethylene from oxidation and reduces wear. 9 Has a strong snap-fit locking mechanism. This ensures secure shell fixation. Twelve "scallops" provide extra rotational stability. Is available in different head sizes (22.2mm, 28mm and 32mm). These offer surgeons a wider choice of options. Is available in both standard and hooded versions. The cup insert is manufactured from the current highest purity medical grade alumina (Al 2 O 3 ISO6474), selected for its safe clinical history over 20 years of orthopaedic use and its excellent wear characteristics when combined with an alumina head. Excellent wetting and high scratch resistance result in reduced wear rates. Minimal third body wear helps prevent damage of the bearing. Corrosion resistant and bioinert alumina shows excellent long-term in-vivo stability. Alumina insert range Contains the currently maximum possible thickness of polyethylene with every size. V40 Alumina Heads ABGII Obturator, spike and screw ABGII No-Hole Cup ABGII 5-Hole Cup ABGll Cup Duration stabilised polyethylene Insert 7

7 The Ceramic on Ceramic Bearing Quality Assurance The alumina has a very fine grain size (< 2 microns) and high density (> 3.96g/cc) which provides excellent mechanical integrity. This is achieved by using high purity alumina powder and by using Hot Isostatic Pressing (HIPping). The micrographs below show the effectiveness of this process at removing residual pores and increasing the final density of the alumina. All batches are strictly checked at all stages: manufacturing, packaging and sterilisation. All cups and heads are also individually mechanically proof tested to ensure that any risk of mechanical failure is minimised. NON-HIP MATERIAL HIP MATERIAL Alumina Insert prior to proof testing Non-HIP material cut in cross section. Area featured was remote from the edge of the sample. Magnification x4000 HIP material cut in cross section. Area featured was close to the sample edge. Magnification x4000 Material Performance Alumina is well reputed as a high performance structural ceramic for engineering bearings. This is because of its intrinsic properties of hardness and potential for a high surface polish. The hardness of alumina is approximately 2000 Vickers, almost 10 times higher than cobalt chrome (350 Vickers). This makes it very abrasion resistant and can be polished to Ra < 0.02 microns. This results in the excellent wear data shown in the graph below. Conventional polyethylene (PE) on ceramic bearings offer historically low wear due to the scratch resistance of ceramic heads. However ceramic on ceramic couples demonstrate dramatic improvements in wear patterns (some 300 times less wear). This low ceramicceramic wear has also been reported in clinical wear measurements 6. Risk of any fracture has been significantly reduced by careful design of the acetabular system and through repeated mechanical testing (both static and fatigue). 3 6 mm /10 cycles (equivalent to 1 year) Irradiated PE / Metal Irradiated PE / Ceramic Metal / Metal Ceramic / Ceramic 8

8 The Ceramic on Ceramic Bearing The mechanical relationship between the metal cup and alumina insert is fundamental to the long-term stability of the implant. The ABGII Cup s internal shape has been designed to optimise the overall mechanical strength of the system. The conical junction (Morse taper) of the ABGII aluminaalumina cup enables a direct and secure mechanical fit of the two components. The micro-textured interior cup surface helps to distribute stresses evenly across the metal/alumina interface. The ABGII Cup rim has been designed to be elevated above the alumina insert circumference to protect the ceramic from stem impingement. The contact of the stem with the ceramic insert has been seen as a significant reason for failure of other Ceramic-Ceramic systems. 4,11 The Range Of Motion (R.O.M.) of the system has been optimised and a minimum of 126 is achievable. This is in line with physiological requirements to provide full mobility for the patient. The design of the ABGII Cup prevents any impingement with the alumina insert R.O.M. Cup/Insert Size Selection Five Insert sizes are available for combination with eleven ABGII Ceramic-Ceramic cup sizes. An insert size can be used with more than one cup size as shown below. 28mm Reference Alumina Insert ABGII The ABGII Ceramic-Ceramic System provides a minimum Range of Motion (R.O.M.) of 126 Compatible with ABGII cups Outer Diameter (mm) 46, 48, 50 52, 54 56, 58 60, 62 64, 66 32mm Reference Available in a Alumina Insert ABGII specific pack N.A. including both Compatible with ABGII cup and insert cups Outer Diameter (mm) 52, 54 56, 58 60, 62 64, 66 9

9 ABG Clinical and Radiological Results The design of the ABGII Femoral Stem is based on the well established ABG HA-Coated Femoral Stem. Clinical studies of the ABG Hip System show excellent results in both the short and medium term. 1-6 As many as 95% of patients were found to be completely painfree after 6-7 years. In one followup study (at 6-7 years), 98% of the patients achieved Merle d Aubigné scores of 17 or above (18 = maximum score) when assessed for total function. In nearly 95% of cases, radiological analysis of the acetabulum confirmed the presence of normal bone in all zones. These successful outcomes fully support the rationale behind the design of the ABG implant. Radiological analysis of the femur showed cancellous densification occurring in the metaphyseal area (particularly in Gruen zones 2 and 6); minimal proximal bone resorption; the presence of reactive lines (in Gruen zones 3, 4 and 5), and and the absence of radiolucent line at the interface bone/implant in the zones covered by the HA coating. These findings suggest that ABG stems achieve strong proximal fixation with no distal load transfer, resulting in strong healthy bone in the metaphyseal region. Considering the cup side, nothing has been detected on X-rays, with the absence of radiolucent line at the interface bone/implant in the 3 zones of Charnley. ABGII French Clinical Study: Total Merle d Aubigné score for the cup (with Duration PE) at 5 year follow-up (765 cases) 6 X-rays featuring the ABGII cup and stem at 5 years postop 10 ABGII French Clinical Study: Total Merle d Aubigné score for the stem at 5 year follow-up (1364 cases) 6

10 Densitometry Densitometry analysis of hips implanted with the ABG Hip System, compared with their contralateral hips shows that bone density around the prosthesis remains relatively unchanged compared to the unoperated side (b and d). This demonstrates that the design objectives to establish physiological load transfer have been achieved. Any significant change in load transfer would result in a difference in bone density. 3,12 a Densitometry (Lunar) at 5 years. Comparison with nonoperated opposite side. Metaphyseal region: - 10% calcium loss in the trochanteric region, Zone 1; 25% loss at the calcar, Zone % increase in calcium content in Zones 2 and 6 b c d Densitometry (Lunar) at 5 years. Diaphyseal region: - Very little change in Zones 3, 4, and 5 A consecutive study has been realised on the ABGII, comparing it with the original ABG design. This study has shown a substantial improvement of the proximal bone stock preservation (zones 1 and 7), confirming the philosophy behind the design change. 19 Mean perioprosthetic bone loss from baseline for distal, proximal and all Green zones combined 11

11 Acetabular Components ABGII 5-HOLE CUP MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM ABGII NO-HOLE CUP MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM FOR USE WITH ABGII NO-HOLE CUPS CATALOGUE NUMBER ABGII NO-HOLE SPIKE FOR USE WITH ABGII 5-HOLE CUPS CATALOGUE NUMBER ABG OBTURATOR SCREW ABG CUP SPIKE 7MM ABG CUP SPIKE 9MM ABG CUP SCREW 12MM ABG CUP SCREW 15MM ABG CUP SCREW 20MM ABG CUP SCREW 25MM ABG CUP SCREW 30MM ABG CUP SCREW 35MM ABG CUP SCREW 40MM ABG CUP SCREW 45MM ABG CUP SCREW 50MM ABG CUP SCREW 55MM ABGII INSERTS, DURATION STABILISED UHMWPE (Only for use with ABGII Cups) 22.2MM STANDARD MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM STANDARD MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM STANDARD MM MM MM MM MM MM MM MM MM MM MM MM MM MM HOODED MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM HOODED MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM MM HOODED MM MM MM MM MM MM MM MM MM MM MM MM MM

12 ABGII Ceramic-Ceramic Components CUP (CERAMIC) NO HOLE AND HOLED CUPS FOR CERAMIC REFERENCE REFERENCE TRIAL SIZE HOLED NO HOLE MM MM MM MM MM MM MM MM MM MM MM CERAMIC (ALUMINA) INSERTS 28MM REFERENCE TRIAL SIZE FOR OD 46, 48, 50MM FOR OD 52, 54MM FOR OD 56, 58MM FOR OD 60, 62MM FOR OD 64, 66MM CERAMIC (ALUMINA) INSERTS 32MM REFERENCE TRIAL SIZE FOR OD 56, 58MM FOR OD 60, 62MM FOR OD 64, 66MM FOR OD 52MM (PACK INSERT + HOLED CUP) FOR OD 52MM (PACK INSERT + NON HOLED CUP) FOR OD 54MM (PACK INSERT + HOLED CUP) FOR OD 54MM (PACK INSERT + NON HOLED CUP) Please note that Cr-Co stems such as the EON (127 and 132 ), the Definition PM, the Reliance PF and Reliance CM are not compatible with the ABGII cups with ceramic (alumina) inserts. 13

13 Femoral Components ABGII FEMORAL STEMS WITH HA COATING LEFT IMPLANT SIZE REFERENCE HEADS V40 (5 40 ) Vitallium REFERENCE HEAD NECK DIAMETRE DIAMETRE (MM) (MM) * * RIGHT IMPLANT SIZE REFERENCE RETENTIVE TRIAL HEAD REFERENCE DIAMETRE NECK (MM) LENGTH (MM) Ceramic REFERENCE HEAD NECK DIAMETRE DIAMETRE (MM) (MM) * +8 Heads can be used only with stem sizes 2 to 8. 14

14 Biography 1. Short-term results of Hydroxyapatite-coated primary total hip arthroplasty. Rossi P, et al. Clinical Orthopaedics. 310: pp Hydroxyapatite-coated hip prostheses. Early results from an international study. Tonino A.J, et al. Clinical Orthopaedics 312: pp , ABG Prosthesis - Results at 5 years. Nourissat C, et al. Cahiers d'enseignement de la SOFCOT 50pp (French) 1994 or Cahiers d'enseignment de la SOFCOT 51: pp (English) The histology of the interface between bone and Hydroxyapatite in the ABG hip prosthesis. Adrey J, et al. Cahiers d'enseignment de la SOFCOT 50 pp (French) or Cahiers d'enseignment de la SOFCOT 51: pp (English) ABG Cement free hip international multicentre study 5 year follow up Stryker publication. 6. ABG II Cementless system ABG Group data, publication pending. 7. Hydroxyapatite treatment and properties. The P-factors. Doyle C. Cahiers d'enseignment de la SOFCOT 50 pp (French) 1994 or Cahiers d'enseignment de la SOFCOT 51: pp (English) TMZF A Beta Titanium Alloy for Orthopaedic Implants. Stryker publication DURATION A stabilised UHMWPE with superior oxidation, creep and wear resistance - technical development and scientific evaluation. Stryker publication The Histology around Hydroxyapatite coated Total Hip Implants. Tonino A. Efort Barcelona 97 abstract. 11. Histological analysis of the bone-prosthesis interface after implantation in humans of prostheses coated with Hydroxyapatite. Frassinet P, et al. J Orthop Surg 7: pp , Bone remodelling around uncemented femoral hip implants with Hydroxyapatite coating. Massari L, et al. Stryker publication On the Material and Tribology of Alumina-Alumina Coupling for Hip Joint Prostheses - A. Walter - Clinical Orthopaedics and Related Research 282 p31-46, Role of Ceramic Implants Design & Clinical Success with Total Hip Prosthetic Ceramic-to-Ceramic Bearings - I.C. Clarke - Clinical Orthopaedics and Related Research 282 p , September Analysis of Retrieved Alumina Ceramic Components from Mittelmeier Total Hip Prostheses -J. Nevelos, E. Ingham, C. Doyle, J. Fisher, A. Nevelos - J Biomaterials (20), , Wear of Ultra-High Molecular Weight Polyethylene Acetabular Cups in a Physiological Hip Joint Simulator in the Anatomical Position using Serum as a Lubricant - R.Y. Bigsby, C.S. Hardaker, J. Fisher - Proc Inst Mech Eng H, 211(3):265-9, Influence of Acetabular Cup Angle on the Wear of Biolox forte Alumina/Alumina Hip Joints in a Physiological Hip Stimulator - J. Nevelos, E. Ingham, C. Doyle, A. Nevelos, J. Fisher - Trans 45th ORS - USA, Hip Simulator Wear Evaluation of Metal Total Hip Replacement Systems - V. Krishna Polieni, Aiguo Wang - Cas Stark RD September 3, The Influence of Implant Design on Periprosthetic Bone, Remodelling of two types of Uncemented HA-Coated Hip Stems. A Two-Year Follow-Up Study using dexa A. Tonino et al Publication pending Stryker SA Cité-Centre Grand-Rue Montreux Switzerland t : f : This document is intended solely for the use of healthcare professionals. The information presented in this brochure is intended to demonstrate the breadth of Stryker product offerings. Always refer to the package insert, product label and/or user instructions before using any Stryker product. Products may not be available in all markets. Product availability is subject to the regulatory or medical practices that govern individual markets. Please contact your Stryker representative if you have questions about the availability of Stryker products in your area. Products referenced with designation are trademarks of Stryker. Products referenced with designation are registered trademarks of Stryker. Literature Number: ABGBR02E03 MTX/GS 09/06 Copyright 2006 Stryker

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