The flat, tapering prosthesis neck allows a large scope of movement between prosthesis stem and acetabular cup.2 The 12/14 taper is designed for the use of modular LINK prosthesis heads made of ceramic or metal with various lengths and diameters. Furthermore, the highly polished neck region reduces abrasion in the event of unintentional contact with the acetabular cup9.
Meta-diaphyseal support and fixation provided by a large medial curvature with a 100 mm radius of curvature for anatomical adaptation is the prerequisite for primary and secondary stability.
The primary stability of the implant is additionally enhanced by the characteristic metaphyseal V-shape, while the rectangular cross-section neutralizes torsion forces.1,5
A tapered distal end reduces distal bone contact and facilitates introduction of the stem into the medullary canal.1,5,6
The self-anchoring shape of the stem is an optimization of the standard design in the proximal region in order to promote mechanical stability and favorable load transmission to the bone surface. The horizontal ribs in the proximal section of the stem serve to counteract subsidence of the stem and to promote primary stability. The distal region has vertical ribs to counteract the rotational forces.7
The hip prosthesis stems of the LCU System follow the concept of a straight stem with tapered lateral shoulder and an osteoconductive coating.4 The straight profile with rectangular cross-section provides the implant with proximal stability. The HX coating promotes bone integration.1 Two types of stem are available for the purpose of adaptation to the patient’s anatomy2:
Standard stem with 130º CCD angle
Lateralizing stem with 125º CCD angle
The following materials and coatings are used for the hip prosthesis stems of the LCU System:
The stem is made from Ti6Al4V forged alloy.
The micro-roughness of the metal surface is created by corundum-blasting, which produces an even and uniform surface structure with pore sizes and roughness values for osseointegration.2,3
The HX coating with a thickness of 20 +/- 10 µm is applied by LEP (LINK Electrochemical Process) to the entire length of the prosthesis, and promotes bone ongrowth.4
LCU – Hip System cementless & cemented
Size: 1 MB
Khanuja H, Vakil J, Goddard M, Mont M. Current Concepts Review: Cementless Femoral Fixation in Total Hip Arthroplasty. J Bone Joint Surg Am. 2011;93:500-9.
Internal documentation W. LINK
Garcia-Rey E, Garcia-Cimbrelo E. Grit-Blasted Implant Bone Interface in Total Joint Arthroplasty. In: Karachalios T, editor. Bone-Implant Interface in Orthopedic Surgery: Basic Science to Clinical Applications. London: Springer; 2014. p. 83-9.
Yang C., Effect of calcium phosphate surface coating on bone ingrowth onto porous-surfaced titanium alloy implants in rabbit tibiae, J Oral Maxillofac Surg. 2002 Apr;60(4):422-5.
Hwang KT, Kim YH, Kim YS, Choi IY. Total hip arthroplasty using cementless grit-blasted femoral component: a minimum 10-year follow-up study. The Journal of arthroplasty. 2012;27(8):1554-61.
Jones DL, Westby MD, Greidanus N, Johanson NA, Krebs DE, Robins L, et al. Update on Hip and Knee Arthroplasty: Current State of Evidence. Arthritis care & research. 2005;53:772-80.
Vidalain, Jean-Pierre. Twenty-year results of the cementless Corail stem. International orthopaedics, 2011, 35. year, No. 2, p. 189-194.
General information on Corail-type femoral stems: Hallan, G., et al. "Medium-and long-term performance of 11 516 uncemented primary femoral stems from the Norwegian arthroplasty register." Bone & Joint Journal 89.12 (2007): 1574-1580."
International Orthopedics, Volume 41, Number 3, March 2017, Page 611-618