Biomechanics of a cemented short stem: Standard vs. line-to-line cementation techniques. A biomechanical in-vitro study involving six osteoporotic pairs of human cadaver femurs. (February 2018)

• Record Type: Journal Article
• Authors: Kutzner, Karl Philipp; Freitag, Tobias; Bieger, Ralf; Reichel, Heiko; Pfeil, Joachim; Ignatius, Anita; Dürselen, Lutz
• Is Part Of: Clinical biomechanics. Volume 52(2018)
• Page Start: 86
• Page End: 94
• Publication Date: 2018-02
• Subjects: Cemented total hip arthroplasty -- Short stem -- Biomechanics -- Optimys -- French paradox -- Cement-mantle thickness -- Migration -- Micromotion -- Primary stability; Biomechanics -- Periodicals; Osteopathic medicine -- Periodicals; Biomechanics -- Periodicals; Osteopathic Medicine -- Periodicals; 612.76
• DOI: 10.1016/j.clinbiomech.2018.01.004
• Languages: English
• ISSNs: 0268-0033

Abstract

Abstract: Background: Short-stem total hip arthroplasty (THA) potentially offers advantages compared to conventional THA, including sparing bone and soft tissue and being a facilitated and less traumatic implantation. However, the indication is limited to patients with sufficient bone quality. Cemented short-stem THA might provide an alternative to conventional cemented THA. To date, no cemented short stem is available on the market. Methods: In the present in vitro study, primary stability of a new cemented short stem was evaluated, comparing standard (undersized stem) versus line-to-line (same-sized stem) cementing techniques, using six pairs of human cadaver femurs. Primary stability, including reversible micromotion and irreversible migration, was assessed in a dynamic material-testing machine. Fracture load was tested and fracture pattern analyzed. Findings: Both cementation techniques (standard vs. line-to-line) displayed comparable results with respect to primary stability without any statistical differences (micromotion: 17.5 μm vs. 9.6 μm ( p = 0.063); migration: 9.5 μm vs. 38.2 μm ( p = 0.188)). Regarding fracture load, again, no difference was observed (3670 N vs. 3687 N ( p = 0.063)). In all cases, proximal fractures of Vancouver type B3 occurred. Interpretation: The present in vitro study demonstrates that the line-to-line cementation technique, which is favourable regarding the philosophy of short stem THA, can be further pursued in the course of the development of a cemented short stem. Further investigations should address how well the cemented short stem compares to well-established cemented straight-stem designs. Highlights: In the course of the development of a cemented short stem a biomechanical in-vitro study was conducted. Standard and line-to-line cementation techniques were compared by testing biomechanical properties. The two cementation techniques showed no significant differences regarding primary stability and maximum fracture load. Line-to-line cementation technique can be considered favourable in regard to the short-stem philosophy.