Mode of Fixation Failures of Dynamic Hip Screw with TSP in the Treatment of Unstable Proximal Femur Fracture: Biomechanical Analysis and a Report of 3 Cases.
10.4055/jkoa.2006.41.1.176
- Author:
Soo Yong KANG
1
;
Eun Woo LEE
;
Ki Ser KANG
;
Kwang Sup SONG
;
Sang Hak LEE
;
Young Uk PARK
;
Seung Hwan CHANG
Author Information
1. Department of Orthopaedic Surgery, College of Medicine, Chung-Ang University, Seoul, Korea. osewlee@hanmail.net
- Publication Type:Case Report
- Keywords:
Unstable intertrochanteric fracture;
Trochanteric stabilizing plate;
Metal failure
- MeSH:
Femur*;
Fractures, Stress;
Hip Fractures;
Hip*;
Incidental Findings
- From:The Journal of the Korean Orthopaedic Association
2006;41(1):176-180
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
There are few reports of the failure mode of a dynamic hip screw with a trochanteric stabilizing plate (TSP) in the treatment of unstable proximal femur fractures. We present 3 cases of fixation failure of a TSP used to treat unstable intertrochanteric fractures. All cases had the same type of failure mode, which represented a fatigue fracture of the distal screw at the junction of a plate and screw. Non-union occurred in 2 cases, and one case was an incidental finding 4 years after union. Biomechanical analysis and SEM (scanning electron micrograph) examination was also performed. Adding TSP to the plate might increase the level of shear stress and slip motion in the distal screw followed by a fatigue fracture. SEM of the surface of the broken screw revealed a multiple cycle and low stress fatigue fracture. Recommendations are made regarding the implant design and surgical technique.
