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The Utility of the Tip-Apex Distance in Predicting Axial Migration and Cutout With the Trochanteric Fixation Nail System Helical Blade. J Orthop Trauma 2016 06;30(6):e207-11 PMID: 26655519

Pubmed ID





OBJECTIVES: To determine whether a tip-apex distance (TAD) <20 mm is associated with a higher rate of axial migration and perforation with the Trochanteric Fixation Nail (TFN) System helical blade implant.

DESIGN: Retrospective.

SETTING: Level I Trauma Center.

PARTICIPANTS: Four hundred forty-three patients surgically treated for proximal femur fractures were identified through a query of Current Procedural Terminology code 27245 from January 2009 to February 2013. A total of 258 patients treated with the TFN helical blade system were included in the study.

MAIN OUTCOME MEASURED: The association of axial migration and perforation with the measured TAD.

RESULTS: The overall rate of mechanical complications was 10.1%. The average TAD was 20.4 mm. Axial perforation occurred in 8 patients (3.4%). Axial migration up to subchondral bone without perforation occurred in 3 patients (1.1%). Only 1 fracture failed in varus (0.38%). There was a significant difference in the rates of combined axial migration and perforation with a TAD <20 mm (P = 0.03). Logistic regression model demonstrated increased odds for combined axial cutout and migration with TAD less than 20 (odds ratio = 1.15, P = 0.01).

CONCLUSIONS: A TAD <20 mm was associated with an increased frequency of axial migration and cutout with the TFN helical blade.

LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Author List

Flores SA, Woolridge A, Caroom C, Jenkins M


Adam Neal Wooldridge MD, MPH Assistant Professor in the Orthopaedic Surgery department at Medical College of Wisconsin


2-s2.0-84949604308   6 Citations

MESH terms used to index this publication - Major topics in bold

Age Factors
Aged, 80 and over
Bone Nails
Equipment Design
Equipment Failure
Follow-Up Studies
Foreign-Body Migration
Fracture Fixation, Intramedullary
Fracture Healing
Hip Fractures
Injury Severity Score
Logistic Models
Middle Aged
Odds Ratio
Predictive Value of Tests
Retrospective Studies
Risk Assessment
Sex Factors
Tomography, X-Ray Computed
Trauma Centers
jenkins-FCD Prod-336 69ef4a6b262d135130251597d5d39873903802b5