M-SERIES. Modular Femoral Stem AN ACCURATE MATCH EVERY TIME

Transcription

1 M-SERIES Modular Femoral Stem AN ACCURATE MATCH EVERY TIME

2 54 Extension 114 Flexion High How do you ensure optimal post-operative joint stability? MECHANICAL RANGE OF MOTION Cup Position: 45 degrees abduction, 20 degrees anteversion 5,6 Low Joint stability can be affected by many factors, including offset and leg length. When the selected primary stem provides adequate leg length but the joint requires additional offset, the concern is potential post-operative dislocation. Do you sacrifice leg length or offset? With the AcuMatch M-Series, you sacrifice neither. The M-Series uncouples offset and leg length, providing surgeons a unique way to restore joint stability in complex total hip arthroplasty. Leg length and offset challenges are easily overcome by selecting from two offsets, each with multiple vertical height options. 41.2mm 41.2mm 36.2mm THE NECK SEGMENT High and low offset necks predictably restore normal anatomy. 1,2,3,4 Length 25mm 35mm Multiple vertical height options provide for leg length adjustment. Machined neck flats decrease neck cross section resulting in an increase in range of motion. 5,6,7,8 Adjust leg length without affecting offset Adjust offset without affecting leg length Low Plasticity Burnishing increases fatigue strength of neck segment by more than 30 percent. 14

3 How do you deal with unpredictable bone loss? 100% INTERCHANGEABILITY Nothing is routine about revision total hip surgery. It is an art. Frequently, unpredictable bone loss results from retrieval of the previously implanted stem. What do you do? The AcuMatch M-Series patented three-segment stem design* gives you more than 33,000 possible neck/metaphyseal/stem constructions. Customize your solutions to a wide range of proximal bone-loss situations. METAPHYSEAL FLARE SIZES L M S XS THE METAPHYSEAL SEGMENT Trapezoidal shape provides excellent rotational stability for proximal loading and ensures greater bone surface contact. 9 Optimized interference fit and 1mm of pure titanium plasma spray achieve the goal of biologic attachment. Available in diameters of 21-31mm and x-small (21, 23 and 25mm only), small, medium and large flare options. Calcar replacing segments are available for instances where the medial flare of the metaphysis is deficient. PROXIMAL/DISTAL MISMATCH *Combined with Exactech s five femoral head lengths A B A: Smallest stem coupled with largest metaphyseal segment B: Largest stem coupled with smallest metaphyseal segment

4 CROSS SECTION OF STEM SEGMENT Longitudinal flutes provide rotational stability How do you establish neck version when using a long curved stem? In some patients, the bow of the femur is lateral. In others, the acetabulum is slightly anteverted or retroverted. If you need a long curved stem for a patient with atypical anatomy, do you choose neck version or stem placement? With the M-Series, you don t have to choose. Stem segment rotated to match anatomy without affecting neck version The M-Series allows independent neck version and stem placement to minimize the potential for femoral fractures and post-operative dislocation. THE STEM SEGMENT Sharp flutes provide a solid fit in the canal resulting in rotational stability. Infinite placement of neck segment Coronal slot and patented distal tip geometry decrease the incidence of thigh pain. 10 Forged titanium more closely matches the modulus of elasticity of bone.

5 What do you want most from your prosthesis? Confidence in design and construction is an important factor in prosthesis selection. Exactech optimized the AcuMatch M-Series design using Finite Element Analysis and extensive mechanical testing. Its taper integrity and strength have been validated at a respected independent laboratory. 11 Testing including bending and torsion simulated physiological loading which represented activities of daily living. 12,13 The results categorized taper wear as mild at loads of 6.4 times body weight. Percentage of damage area was categorized as mild with only 5.9 percent to 7 percent of total taper surface area affected. 12,13 Continuous product improvement is a priority at Exactech, and when new technology was identified that could enhance the fatigue strength of metals, the M-Series was selected as a logical first application. Low Plasticity Burnishing (LPB) is a patented process that increases the fatigue strength of the M-Series neck segment by more than 30 percent. 14 From joint stability to bone loss to atypical anatomy, the AcuMatch M-Series is the answer for difficult surgical situations. Load (lbs) Finite Element Analysis of M-Series Taper M-SERIES NECK FATIGUE STRENGTH 14 M-Series Neck featuring LPB Technology Fatigue Strength (approx lbs.) per ASTM E ASTM Standard - Femoral Prosthesis Head / Neck Region Fatigue Strength per ASTM F Cycles (millions) REFERENCES Medical illustrations 2002 Neill Biomedical Art Co. 1. Davey JR, O Connor DO, Burke DW, Harris WH. Femoral component offset. J Arthroplasty Feb;8(1): Oh I, Harris WH. Anatomic basis of femoral component design for total hip replacement. Proceedings of the 24th Annual Meeting of the Orthopaedic Research Society, Dallas, Robinson RP, Simonian PT, Gradisar IM, Ching RP. Joint motion and surface contact area related to component position in total hip arthroplasty. J Bone Joint Surg Br Jan;79(1): Robinson RP. Evaluation of offset variation in 192 consecutive hips. Unpublished data. 5. Amstutz HC, Lodwig RM, Schurman DJ, Hodgson AG. Range of motion studies for total hip replacements. Clin Orthop Relat Res Sep;(111): Krushell RJ, Burke DW, Harris WH. Range of motion in contemporary total hip arthroplasty. J Arthroplasty Jun;6(2): Vaughn BK. Management of dislocation in total hip arthroplasty. Operative Techniques in Orthopaedics Oct;5(4): Yamaguchi M, Akisue T, Bauer TW, Hashimoto Y. The spatial location of impingement in total hip arthroplasty. J Arthroplasty Apr;15(3): Joshi MG, Advani SG, Miller F, Santare MH. Analysis of a femoral hip prosthesis designed to reduce stress shielding. J Biomech Dec;33(12): Petty W. Thigh pain following cementless total hip implantation addressed by new femoral design. Orthopedic: Special Edition. Vol. 2, No Postak PD. The Orthopaedic Research Laboratories, Cleveland, OH, May Krygier JJ, Dujovne AR, Bobyn JD. Fatigue behavior of titanium femoral hip prosthesis with proximal sleeve-stem modularity. J Appl Biomater. 1994;5(3): Bobyn JD, Dujovne AR, Krygier AR, Young DL. Surface analysis of the taper junctions of retrieved and in-vitro tested modular prosthe ses. In (Morrey BF, ed): State-of-the-Art in Total Hip Arthroplasty. Raven Press, Ltd., New York, 1993, pp Data on file at Exactech, Inc EXACTECH, INC. ISO CERTIFIED EXACTECH Rev. B AcuMatch M-Series 0309 U.S. Pat. # 5,152,799, 6,319,286, 6,911,048. European Patent # Other foreign patents pending.