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Circular External Fixation Frames with Divergent Half Pins: A Pilot Biomechanical Study
| Journal | Clinical Orthopaedics and Related Research |
| Publisher | Springer New York |
| ISSN | 0009-921X (Print) 1528-1132 (Online) |
| Category | Symposium: Advances in Limb Lengthening and Reconstruction |
| DOI | 10.1007/s11999-008-0492-0 |
| Subject Collection | Medicine |
| SpringerLink Date | Thursday, September 18, 2008 |
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Symposium: Advances in Limb Lengthening and Reconstruction
Circular External Fixation Frames with Divergent Half Pins: A Pilot Biomechanical Study
Christopher Lenarz1, Gary Bledsoe1 and J. Tracy Watson1, 2 
| (1) |
Department of Orthopaedic Surgery and Biomechanics, St. Louis University, St. Louis, MO, USA
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| (2) |
Division of Orthopaedic Traumatology, Department of Orthopaedic Surgery, Saint Louis University Health Science Center, 3635 Vista Ave., 7th Floor Desloge Towers, St. Louis, MO, 63110-2539, USA
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Published online: 18 September 2008
Abstract The use of hexapod circular external fixators has simplified the ability to correct complex limb deformities without cumbersome
frame reconfigurations. These frames are applied primarily using half pin mountings and may be difficult to utilize given
the constraints of traditional half pin constructs. We compared the biomechanical performance of simplified divergent half
pin frames to mountings currently being utilized for application of hexapod frames. Three 6-mm half pins per limb segment
were placed into sawbones at 60° divergent angles in both the sagittal and coronal planes in a 2-cm diaphyseal fracture gap
model. Pin mountings were attached to a standardized four-ring construct. This was compared to similar four-ring frames with
two differing pin/wire configurations: (1) two tensioned wires per ring placed at 90° angles, a total eight wires; and (2)
two 5-mm half pins per ring placed at 90° angles, a total eight half pins. The divergent 6-mm half pin frames demonstrated
similar performance compared the standardized tensioned wire and 5-mm half pin frames in terms of axial micromotion and angular
deflection. Based on the mechanical performance of these divergent half pin frames we believe they can be used clinically
without detrimental consequences.
One or more of the authors (JTW) has received funding from Smith & Nephew.
References
| 1. |
Augat P, Burger J, Schorlemmer S, Henke T, Peraus M, Claes L. Shear movement at the fracture site delays healing in a diaphyseal
fracture model. J Orthop Res. 2003;21:1011–1017.
|
| |
| 2. |
Augat P, Claes L, Hanselmann KF, Suger G, Fleischmann W. Increase of stability in external fracture fixation by hydroxyapatite-coated
bone screws. J Appl Biomater. 1995;6:99–104.
|
| |
| 3. |
Behrens F. A primer of fixator devices and configurations. Clin Orthop Relat Res. 1989;241:5–14.
|
| |
| 4. |
Behrens F. General theory and principles of external fixation. Clin Orthop Relat Res. 1989;241:15–23.
|
| |
| 5. |
Behrens F, Comfort TH, Searls K, Denis F, Young TJ. Unilateral external fixation for severe open tibial fractures: a preliminary
report of prospective evaluation. Clin Orthop Relat Res. 1983;178:111–120.
|
| |
| 6. |
Behrens F, Johnson WD. Unilateral external fixation: methods to increase and reduce frame stiffness. Clin Orthop
Relat Res. 1989;241:48–56.
|
| |
| 7. |
Behrens F, Johnson WD, Koch TW, Kovacveic N. Bending stiffness of unilateral and bilateral fixator frames. Clin Orthop
Relat Res. 1983;178:103–110.
|
| |
| 8. |
Calhoun JH, Li F, Ledbetter BR, Gill CA. Biomechanics of the Ilizarov fixator for fracture fixation. Clin Orthop
Relat Res. 1992;280:15–22.
|
| |
| 9. |
Chao EYS, Aro HT, Lewallen DG, Kelly PJ. The effect of rigidity on fracture healing in external fixzation. Clin Orthop
Relat Res. 1989;241:24–35.
|
| |
| 10. |
Fischer DA. Skeletal stabilization with a multiplane external fixation device: design rationale and preliminary clinical experience. Clin Orthop Relat Res. 1983;180:50–62.
|
| |
| 11. |
Fitzpatrick DC, Sommers MB, Kam BC, Marsh JL, Bottlang M. Knee stability after articulated external fixation. Am J Sports Med. 2005;33:1735–1741.
|
| |
| 12. |
Gasser B, Boman B, Wyder D, Schneider E. Stiffness characteristics of the circular Ilizarov device as opposed to conventional
external fixators. J Biomech Eng. 1990;112:15–21.
|
| |
| 13. |
Green SA. The Ilizarov method: Rancho technique. Orthop Clin North Am. 1991;22:677–688.
|
| |
| 14. |
Green SA, Harris L, Wall DM, Ishkanian J, Marinow H. The Rancho mounting technique for the Ilizarov method. A preliminary
report. Clin Orthop Relat Res. 1992;280:104–116.
|
| |
| 15. |
Kabata T, Tsuchiya H, Sakurakichi K, Yamashiro T, Watanabe K, Tomita K. Reconstruction with distraction osteogenesis for juxta-articular
nonunions with bone loss. J Trauma. 2005;58:1213–1222.
|
| |
| 16. |
Kenwright J, Goodship AE. Controlled mechanical stimulation in the treatment of tibial fractures. Clin Orthop Relat Res. 1989;241:36–47.
|
| |
| 17. |
Kershaw CJ, Cunningham JL, Kenwright J. Tibial external fixation, weight bearing, and fracture movement. Clin Orthop Relat Res. 1993;293:28–36.
|
| |
| 18. |
Kummer FJ. Biomechanics of the Ilizarov external fixator. Clin Orthop Relat Res. 1992;280:11–14.
|
| |
| 19. |
Metcalfe AJ, Saleh M, Yang L. Techniques for improving stability in oblique fractures treated by circular fixation with particular
reference to the sagittal plane. J Bone Joint Surg Br. 2005;87:868–872.
|
| |
| 20. |
Podolsky A, Chao EY. Mechanical performance of Ilizarov circular external fixators in comparison with other external fixators.
Clin Orthop Relat Res. 1993;293:61–70.
|
| |
| 21. |
Pugh KJ, Wolinsky PR, Dawson JM, Stahlman GC. The biomechanics of hybrid external fixation. J Orthop Trauma. 1999;13:20–26.
|
| |
| 22. |
Pugh KJ, Wolinsky PR, Pienkowski D, Banit D, Dawson JM. Comparative biomechanics of hybrid external fixation. J Orthop Trauma. 1999;13:418–425.
|
| |
| 23. |
Roberts CS, Dodds JC, Perry K, Beck D, Seligson D, Voor MJ. Hybrid external fixation of the proximal tibia: strategies to
improve frame stability. J Orthop Trauma. 2003;17:415–420.
|
| |
| 24. |
Rozbruch SR, Fragomen AT, Ilizarov S. Correction of tibial deformity with use of the Ilizarov-Taylor spatial frame. J Bone Joint Surg Am. 2006;88 Suppl 4:156–174.
|
| |
| 25. |
Shearer J, Egan J. Computerized analysis of pin geometry. In: Coombs R, Green SA, Sarmeinto A, eds. External Fixation and Functional Bracing. London, UK: Orthotext; 1989:129–135.
|
| |
| 26. |
Watson JT. Principles of External Fixation and Bone Transport. In: Rockwood CA, Green DP, Bucholz RW, eds. Rockwood and Green’s Fractures in Adults. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006:258–296.
|
| |
| 27. |
Watson JT. Distraction osteogenesis. J Am Acad Orthop Surg. 2006;14:S168–S174.
|
| |
| 28. |
Watson JT, Anglen J. Infected fractures In: Stannard JP, Schmidt AH, Kregor PJ, eds. Surgical Treatment of Orthopaedic Trauma. New York, NY: Thieme; 2006:20–24.
|
| |
| 29. |
Watson JT, Kuldjanov D. Bone defects. In: Rozbruch SR, Ilizarov S, eds. Limb Lengthening and Reconstruction Surgery. New York, NY: Informa Healthcare; 2006:185–201.
|
| |
|
|
|
|
|
|