Systematic Reviews
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jul 18, 2018; 9(7): 92-99
Published online Jul 18, 2018. doi: 10.5312/wjo.v9.i7.92
Systematic review of dynamization vs exchange nailing for delayed/non-union femoral fractures
Jacob E Vaughn, Ronit V Shah, Tarek Samman, Jacob Stirton, Jiayong Liu, Nabil A Ebraheim
Jacob E Vaughn, Ronit V Shah, Tarek Samman, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43614, United States
Jacob Stirton, Jiayong Liu, Nabil A Ebraheim, Department of Orthopedic Surgery, University of Toledo Medical Center, Toledo, OH 43614, United States
Author contributions: Vaughn JE, Shah RV and Samman T performed the research and analyzed the data and wrote the paper; Stirton J, Liu J and Ebraheim NA provided structure for the article as well as edited and revised the paper.
Conflict-of-interest statement: The authors report no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Jiayong Liu, MD, Assistant Professor, Department of Orthopedic Surgery, University of Toledo Medical Center, 3065 Arlington Avenue, Toledo, OH 43614, United States.
Telephone: +1-800-5865336 Fax: +1-419-3835362
Received: February 3, 2018
Peer-review started: February 6, 2018
First decision: March 2, 2018
Revised: April 24, 2018
Accepted: May 30, 2018
Article in press: May 30, 2018
Published online: July 18, 2018

To analyze the literature on efficacy of dynamamization vs exchange nailing in treatment of delayed and non-union femur fractures.


Ultimately, 31 peer-reviewed articles with 644 exchanged nailing patients and 131 dynamization patients were identified and analyzed. The following key words were inputted in different combinations in order to search the field of publications in its entirety: “non-union”, “delayed union”, “ununited”, “femur fracture”, “femoral fracture”, “exchange nailing”, “dynaiz(s)ation”, “secondary nailing”, “dynamic”, “static”, and “nail revision”. The initial search yielded over 150 results, and was refined based on the inclusion criteria: Only studies reporting on humans, non-unions and delayed unions, and the usage of exchange nailing and/or dynamization as a secondary treatment after failed IM nailing. The resulting 66 articles were obtained through online journal access. The results were filtered further based on the exclusion criteria: No articles that failed to report overall union rates, differentiate between success rates of their reported techniques, or articles that analyzed less than 5 patients.


Exchange nailing lead to fracture union in 84.785% of patients compared to the 66.412% of dynamization with statistically comparable durations until union (5.193 ± 2.310 mo and 4.769 ± 1.986 mo respectively). Dynamically locking exchange nails resulted in an average union time of 5.208 ± 2.475 mo compared to 5.149 ± 2.366 mo (P = 0.8682) in statically locked exchange nails. The overall union rate of the two procedures, statically and dynamically locked exchange nailing yielded union rates of 84.259% and 82.381% respectively. Therefore, there was no significant difference between the different locking methods of exchange nailing for union rate or time to union at a significance value of P < 0.05. The analysis showed exchange nailing to be the more successful choice in the treatment of femoral non-unions in respect to its higher success rate (491/567 EN, 24/57 dynam, P < 0.0001). However, there was no significant difference between the success rates of the two procedures for delayed union fractures (25/27 EN, 45/55 dynam, P = 0.3299). Nevertheless, dynamization was more efficient in the treatment of delayed unions (at rates comparable to exchange nailing) than in the treatment of non-unions.


In conclusion, after examination of factors, dynamization is recommended treatment of delayed femur fractures, while exchange nailing is the treatment of choice for non-unions.

Keywords: Non-union, Delayed union, Dynamization, Femoral fracture, Exchange nailing

Core tip: Information from previously published articles investigating patients treated for delayed union and non-union femur fractures by either dynamization or exchange nailing was combined and analyzed to better understand which technique was more efficient at achieving osseous union. When treating femoral non-unions, exchange nailing was shown to achieve osseous union in a higher percentage of patients than dynamization with comparable recovery times. However, dynamization appears to be equally as effective as exchange nailing in the treatment of delayed unions.