gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie
73. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie
95. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie
50. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

21. - 24.10.2009, Berlin

Cancellous bone osseointegration is enhanced by loading

Meeting Abstract

  • B. Willie - Charité – Universitätsmedizin Berlin, Julius Wolff Institut u. Centrum f. Muskuloskeletale Chir., Berlin, Germany
  • J. Han - Hospital for Special Surgery, Research, New York, United States
  • T. Nair - Hospital for Special Surgery, Research, New York, United States
  • N. Kelly - Hospital for Special Surgery, Research, New York, United States
  • M. van der Meulen - Hospital for Special Surgery, Research, New York, United States
  • M. Bostrom - Hospital for Special Surgery, Research, New York, United States

Deutscher Kongress für Orthopädie und Unfallchirurgie. 73. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 95. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 50. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 21.-24.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocPO20-1130

DOI: 10.3205/09dkou717, URN: urn:nbn:de:0183-09dkou7172

Veröffentlicht: 15. Oktober 2009

© 2009 Willie et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Problem: Biophysical stimuli may be an effective therapy to counteract age-related changes in bone structure, which affect the osseointegration and thus, the primary stability of implants used in joint replacement or fracture fixation. The influence of controlled mechanical loading on osseointegration was investigated using an in vivo device implanted in the distal lateral femur of twelve male rabbits.

Methods: Compressive loads (1 MPa, 1 Hz, 50 cycles/day, 4 weeks) were applied to a porous titanium foam cylindrical implant (5 mm diameter, 2 mm length, 74% porosity, 565 µm mean void intercept length) and the underlying cancellous bone, while the contralateral limbs served as unloaded controls. The amount of bone impacted into the implant during surgery and the basal mineral apposition rate was determined at time zero in two rabbits. A scanning electron microscope with a backscattered electron detector was used to quantify the amount of bone ingrowth and periprosthetic bone in undecalcified sections. The histological characteristics of bone ingrowth and periprosthetic bone were also compared between implants that had undergone loading and bilateral unloaded control implants. A mixed effects model was used to account for the correlation of the outcome measures within rabbits.

Results and conclusion: Backscattered electron imaging indicated that the amount of bone ingrowth was significantly greater in the loaded limb (21±4%) compared to the unloaded control limb (15±5%, p=0.03). The amount of underlying cancellous periprosthetic bone was not significantly different between the loaded (29±8%) and unloaded control limb (25±9%, p=0.37). Fluorescent microscopy indicated that there was no significant difference in the mineral apposition rate of the bone ingrowth or periprosthetic bone measured in the loaded compared to the control limb. Although there was an increased amount of bone ingrowth in the loaded implants, histological analysis demonstrated that the quality of osseointegration was similar. Newly formed woven bone was observed in direct apposition to the coatings in both loaded and unloaded implants. These data indicate that cyclic mechanical loading significantly enhanced the amount of cancellous bone ingrowth into a porous titanium foam implant. These results suggest that biophysical therapy should be further investigated to augment current treatments to enhance long-term cementless fixation.