Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-11T02:19:13.698Z Has data issue: false hasContentIssue false

Optimal Distal Screw Alignment in the Gamma Nail

Published online by Cambridge University Press:  05 May 2011

Ching-Kong Chao*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
Chun-Ching Hsiao*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
Po-Quang Chen*
Affiliation:
Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan 100, R.O.C.
*
* Professor
** Graduate student
** Graduate student
Get access

Abstract

The effect of stress distribution due to the changes of the distal screw alignment in relation to the Gamma nail and the femoral shaft is thoroughly studied in this paper. Failure of the Gamma nail composite occurs through the cranial aperture of the distal screws and the insertion hole for the lag screw due to nonunion, delayed-union and continued weight-bearing. A three-dimensional finite element model was used to study the fractured femur, the Gamma nail, the lag screw and the distal locking screws. The first and the second distal screws were inserted into the Gamma nail in four different configurations. We found that the stress of the Gamma nail composite was substantially reduced with the two screws configured in the anterior to posterior direction. This alignment can bear greater loading in the more demanding fracture types. In the subtrochanteric fracture or the comminuted fractures at the proximal femur, the optimal alignment of the two distal screws was in the anterior to posterior direction.

Type
Articles
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Gaebler, C., Stanzl-Tschegg, S., Tschegg, E. K., Kukla, C., Menth-Chiari, W. A., Wozasek, G. E. and Heinz, T., “Implant Failure of the Gamma Nail,” Injury, 30(2), pp. 9199 (1999).Google Scholar
[2]Valverde, J. A., Alonso, M. G., Porro, J. G., Rueda, D., Larrauri, P. M. and Soler, J. J., “Use of the Gamma Nail in the Treatment of Fractures of the Proximal Femur,” Clinical Orthopaedics & Related Research, 350, pp. 5661 (1998).CrossRefGoogle Scholar
[3]van den Brink, W. A. and Janssen, I. M. C., “Failure of the Gamma Nail in a Highly Unstable Proximal Femur Fracture: Report of Four Cases Encountered in the Netherlands,” Journal of Orthopaedic Trauma, 9(1), pp. 5356 (1995).Google Scholar
[4]Leung, K. S., So, W. S., Shen, W. Y. and Hui, P. W., “Gamma Nails and Dynamic Hip Screws for Peritrochanteric Fractures, A Randomised Prospective Study in Elderly Patients,” Journal of Bone & Joint Surgery — British Volume, 74(3), pp. 345351 (1992).Google Scholar
[5]Lentz, W., “Pohl's Sliding Screw,” in: Maatz, R, Lentz, W, Arens, W, Beck, H, eds., Intramedullary Nailing and Other Intramedullary Osteosyntheses, Philadelphia, etc: W. B. Saunders, pp. 198207 (1986).Google Scholar
[6]Davis, T. R. C., Sher, J. L. and Horsman, A., et al. “Intertrochanteric Femoral Fractures: Mechanical Failure after Internal Fixation,” Journal of Bone & Joint Surgery—British Volume, 72(B), pp. 2631 (1990).Google Scholar
[7]Simpson, A. H. R. W., Varty, K. and Dodd, C. A. F., “Sliding Hip Screws: Modes of Failure,” Injury, 20, pp. 227231 (1989).Google Scholar
[8]Amis, A. A., Bromage, J. D. and Larvin, M., “Fatigue Fracture of a Femoral Sliding Compression Screw-Plate Device after Bone Union,” Biomaterials, 8, pp. 153157 (1987).Google Scholar
[9]Manoli, A., “Malassembly of the Sliding Screw-Plate Device,” Journal of Trauma, 26, pp. 916922 (1986).CrossRefGoogle ScholarPubMed
[10]Haynes, R. C., Poll, R. G., Miles, A. W. and Weston, R. B., “An Experimental Study of the Failure Modes of the Gamma Locking Nail and AO Dynamic Hip Screw Under Static Loading: a Cadaveric Study,” Medical Engineering & Physics, 19(5), pp. 446453 (1997).Google Scholar
[11]Mahomed, N., Harrington, I., Kellam, J., Maistrelli, G., Hearn, T. and Vroemen, J., “Biomechanical Analysis of the Gamma Nail and Sliding Hip Screw,” Clinical Orthopaedics & Related Research, 304, pp. 280288 (1994).Google Scholar
[12]Wang, C. J., Yettram, A. L., Yao, M. S. and Procter, P., “Finite Element Analysis of a Gamma Nail Within a Fractured Femur,” Medical Engineering & Physics, 20(9), pp. 677683 (1998).CrossRefGoogle ScholarPubMed
[13]Rosenblum, S. F., Zuckerman, J. D., Kummer, F. J. and Tam, B. S., “A Biomechanical Evaluation of the Gamma Nail,” Journal of Bone & Joint Surgery —British Volume, 74(3), pp. 352357 (1992).Google Scholar
[14]Taylor, M. E., Tanner, K. E., Freeman, M. A. and Yettram, A. L., “Stress and Strain Distribution Within the Intact Femur: Compression or Bending,” Medical Engineering & Physics, 18(2), pp. 122131 (1996).Google Scholar
[15]Prendergast, P. J. and Taylor, D., “Stress Analysis of the Proximo-Medial Femur after Total Hip Replacement,” Journal of Biomedical Engineering, 12(5), pp. 379382 (1990).CrossRefGoogle ScholarPubMed
[16]Voor, M. J., Verst, D. A., Mladsi, S. W., Khalily, C. and Seligson, D., “Fatigue Properties of a Twelve-Hole Versus a Five-Hole Intramedullary Supracondylar Nail,” Journal of Orthopaedic Trauma, 11(2), pp. 98102 (1997).Google Scholar
[17]Zimmerman, K. W. and Klasen, H. J., “Mechanical Failure of Intramedullary Nails after Fracture Union,” Journal of Bone & Joint Surgery—British Volume, 65(3), pp. 274275 (1983).Google ScholarPubMed