Fuechtmeier, B. and May, R. and Hente, R. and Maghsudi, M. and Voelk, M. and Hammer, J. and Nerlich, M. and Prantl, L. (2007) Proximal humerus fractures: a comparative biomechanical analysis of intra and extramedullary implants. ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY, 127 (6). pp. 441-447. ISSN 0936-8051,
Full text not available from this repository. (Request a copy)Abstract
Introduction The biomechanical stability of a newly developed humerus nail (Sirus (TM)) for the treatment of fractures of the proximal humerus was analyzed in comparison to established systems. In total, three randomized groups were formed (n = 4 pairs) from 12 matched pairs of human cadaver humeri. Materials and methods All intact bones were mechanically characterized by five subsequent load cycles under bending and torsional loading. The bending moment at the osteotomy was 7.5 N m the torsional moment was 8.3 N m over the hole specimen length. Loading was consistently initiated at the distal epiphysis and the deformation at the distal epiphysis was continuously recorded. Prior to implant reinforcement, a defect of 5 mm was created to simulate an unstable subcapital humerus fracture. For paired comparison, one humerus of each pair was stabilized with the Sirus proximal humerus nail while the counterpart was stabilized by a reference implant. In detail, the following groups were created: Sirus versus Proximal humerus nail (PHN) with spiral blade (group I); Sirus versus PHILOS plate (group II); Sirus versus 4.5 mm AO T-plate (group III). Results The Sirus nail demonstrated significantly higher stiffness values compared to the reference implants for both bending and torsional loading. The following distal epiphyseal displacements were recorded for a bending moment of 7.5 N m at the osteotomy: Sirus I: 8.8 mm, II: 8.4 mm, III: 7.7 mm (range 6.9-10.9), PHN 21.1 mm (range 15.7-25.2) (P = 0.005), PHILOS plate 27.5 mm (range 21.6-35.8) (P < 0.001), 4.5 AO T-plate 26.3 mm (range 24.3-33.9) (P = 0.01). The rotations corresponding to 8.3 N m torsional moment were: Sirus I: 9.1 degrees, II: 9.3 degrees, III: 10.6 degrees (range 7.5-12.2), PHN 13.5 degrees (range 10.3-15.6) (P = 0.158), PHILOS plate 15.6 degrees (range 13.7-20.8) (P = 0.007), 4.5 AO T-Platte 14.1 degrees (range 11.5-19.7) (P = 0.158). Conclusion The intramedullary load carriers were biomechanically superior when compared to the plating systems in the fracture model presented here. Supplementary, the Sirus Nail showed higher stiffness values than the PHN. However, the latter are gaining in importance due to the possibility of minimal invasive implantation. Whether this will be associated with functional advantages requires further clinical investigation.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | INTERNAL-FIXATION; SHAFT FRACTURES; HEAD FRACTURES; INTRAMEDULLARY; proximal humerus fractures; biomechanical analysis; proximal humeral nail |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Unfallchirurgie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Dec 2020 06:41 |
| Last Modified: | 02 Dec 2020 06:41 |
| URI: | https://pred.uni-regensburg.de/id/eprint/32412 |
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