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Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws.

Publication ,  Journal Article
Springer, ER; Lachiewicz, PF; Gilbert, JA
Published in: Clin Orthop Relat Res
June 1991

In a comparative biomechanical study of the stability of experimentally produced femoral neck fractures fixed with Knowles pins or with 6.5-mm cancellous screws, 12 matched pairs of anatomic specimen femurs were divided into four groups of standardized osteotomies. One member of each matched pair was fixed with three or four 6.5-mm cancellous screws, whereas the other member was fixed with the same number of Knowles pins. Mechanical testing was performed on an Instron testing machine. There was no statistically significant difference in maximum load to failure or in fixed stiffness between the two methods of fixation. When examining maximum load to failure, three of either device provided fixation equivalent to four. Although there was a difference in absolute fixed stiffness between specimens fixed with three Knowles pins compared to four, when stiffness was expressed as a percentage of intact stiffness, there was no difference between any fixation group. From an analysis of the observed modes of failure and from calculations of the flexural rigidity provided by the devices, it is proposed that the quality of the trabecular bone of the femoral neck is a major factor in the experimental fixation of femoral neck fractures.

Duke Scholars

Published In

Clin Orthop Relat Res

ISSN

0009-921X

Publication Date

June 1991

Issue

267

Start / End Page

85 / 92

Location

United States

Related Subject Headings

  • Orthopedics
  • Humans
  • Fracture Fixation, Internal
  • Femoral Neck Fractures
  • Bone Screws
  • Bone Nails
  • Biomechanical Phenomena
  • 1103 Clinical Sciences
 

Citation

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Springer, E. R., Lachiewicz, P. F., & Gilbert, J. A. (1991). Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws. Clin Orthop Relat Res, (267), 85–92.
Springer, E. R., P. F. Lachiewicz, and J. A. Gilbert. “Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws.Clin Orthop Relat Res, no. 267 (June 1991): 85–92.
Springer ER, Lachiewicz PF, Gilbert JA. Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws. Clin Orthop Relat Res. 1991 Jun;(267):85–92.
Springer, E. R., et al. “Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws.Clin Orthop Relat Res, no. 267, June 1991, pp. 85–92.
Springer ER, Lachiewicz PF, Gilbert JA. Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws. Clin Orthop Relat Res. 1991 Jun;(267):85–92.
Journal cover image

Published In

Clin Orthop Relat Res

ISSN

0009-921X

Publication Date

June 1991

Issue

267

Start / End Page

85 / 92

Location

United States

Related Subject Headings

  • Orthopedics
  • Humans
  • Fracture Fixation, Internal
  • Femoral Neck Fractures
  • Bone Screws
  • Bone Nails
  • Biomechanical Phenomena
  • 1103 Clinical Sciences