Sawbones in Biomechanical Settings - a Review

Abstract

The use of sawbone material in biomechanical testing is controversial. Real bone has a unique internal architecture and viscoelastic properties. Clinically relevant data can only be obtained by the use of genuine material of fresh or preserved cadaveric bone. Sawbone material, in contrast, offers different advantages. It is consistent in size, shape and density and can be modelled to nearly any form. Special storage techniques or ethic committee approval are not required and costs are low. Comparability and reproducibility of results remain the most important factors. This review surveys papers advocating the use of sawbone material to enhance biomechanical test set-up accuracy. In these studies, the results mostly were used to give suggestions to orthopaedic surgeons for clinical situations. For better contrast, nearly every study mentioned is compared to an analogous study using cadaver bones. Studies comparing similar operation techniques, or implants, seem designated for the use of artificial bone. An ideal study design could consist of synthetic and real bone in a two-phase test set-up. This paper may help authors to decide whether to use sawbones for their experiments or not.

Key words

sawbones - biomechanical testing - comparison

References

• 1 Acevedo J I, Sammarco V J, Boucher H R. et al . Mechanical comparison of cyclic loading in five different first metatarsal shaft osteotomies.  Foot & Ankle International. 2002;  23 711-716
• 2 Cachia V V, Culbert B, Warren C. et al . Mechanical and structural characteristics of the new BONE-LOK cortical-cancellous internal fixation device.  J Foot & Ankle Surg. 2003;  42 15-20
• 3 Dalton S K, Bauer G R, Lamm B M. et al . Stability of the offset V osteotomy: effects of fixation, orientation, and surgical translocation in polyurethane foam models and preserved cadaveric specimens.  J Foot & Ankle Surg. 2003;  42 53-62
• 4 Ellis T, Bourgeault C A, Kyle R F. Screw position affects dynamic compression plate strain in an in vitro fracture model.  J Orthop Trauma. 2001;  15 333-337
• 5 Gardner M J, Brophy R H, Campbell D, Mahajan A, Wright T M, Helfet D L, Lorich D G. The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model.  J Orthop Trauma. 2005;  19 597-603
• 6 Lauge-Pedersen H, Aspenberg P, Ryd L. et al . Arch-shaped versus flat arthrodesis of the ankle joint: strength measurements using synthetic cancellous bone.  Proc Inst Mech Engineers Part H - J Engin Med. 2002;  216 43-49
• 7 Melamed E A, Schon L C, Myerson M S. et al . Two modifications of the Weil osteotomy: analysis on sawbone models.  Foot & Ankle International. 2002;  23 400-405
• 8 Miller R A, Firoozbakhsh K, Veitch A J. A biomechanical evaluation of internal fixation for ankle arthrodesis comparing two methods of joint surface preparation.  Orthopedics. 2000;  23 457-460
• 9 Nasson S, Shuff C, Palmer D. et al . Biomechanical comparison of ankle arthrodesis techniques: crossed screws vs. blade plate.  Foot & Ankle International. 2001;  22 575-580
• 10 Nyska M, Trnka H J, Parks B G. et al . Proximal metatarsal osteotomies: a comparative geometric analysis conducted on sawbone models.  Foot & Ankle International. 2002;  23 938-945
• 11 Pommer A, David A, Hahn M P. et al . Biomechanische Untersuchung zur initialen Stabilitat verschiedener Arthrodesetechniken des oberen Sprunggelenks.  Unfallchirurg. 1995;  98 535-539
• 12 Richter M GT, Zech S, Allami M, Geerling J, Droste P, Krettek C. A comparison of plates with and without locking screws in a calcaneal fracture model.  Foot & Ankle International. 2005;  26 309-319
• 13 Sanders D W, Milne A D, Dobravec A. et al . Cyclic testing of flexor tendon repairs: an in vitro biomechanical study [see comment].  J Hand Surg [Am]. 1997;  22 1004-1010
• 14 Sanders R, Haidukewych G J, Milne T. et al . Minimal versus maximal plate fixation techniques of the ulna: the biomechanical effect of number of screws and plate length.  J Orthop Trauma. 2002;  16 166-171
• 15 Sedlin E D, Hirsch C. Factors affecting the determination of the physical properties of femoral cortical bone.  Acta Orthop Scand. 1966;  37 29-48
• 16 Stoffel K, Stachowiak G, Forster T. et al . Oblique screws at the plate ends increase the fixation strength in synthetic bone test medium.  J Orthop Trauma. 2004;  18 611-616
• 17 Tornkvist H, Hearn T C, Schatzker J. The strength of plate fixation in relation to the number and spacing of bone screws.  J Orthop Trauma. 1996;  10 204-208
• 18 Trnka H J, Nyska M, Parks B G. et al . Dorsiflexion contracture after the Weil osteotomy: results of cadaver study and three-dimensional analysis.  Foot & Ankle International. 2001;  22 47-50
• 19 Trnka H J, Parks B G, Ivanic G. et al . Six first metatarsal shaft osteotomies: mechanical and immobilization comparisons.  Clin Orthop Relat Res. 2000;  381 256-265
• 20 Wolf J H. Julius Wolff und sein „Gesetz der Transformation der Knochen”.  Orthopäde. 1995;  24 378-386