A biomechanical comparison of the two- and four-hole side-plate dynamic hip screw in an osteoporotic composite femur model

BACKGROUND: Dynamic hip screw (DHS) is a common implant used to treat stable-type intertrochanteric hip fractures. There are many factors that can affect the success rate of the surgery, including the length of side plates. It is therefore important to investigate the biomechanical effect of different DHS side plates on bones. OBJECTIVE: In order to reduce the likelihood of an implant failure, the aim of this study was to use finite element analysis (FEA) to investigate and understand the effect of side plates with different lengths in DHS. METHODS: In this FEA study, a 3D model with cortical bone, cancellous bone, side plate, lag screw, and cortical screws to simulate the implantation of DHS with different lengths of side plate (2-hole, 4-hole, and 6-hole) for intertrochanteric hip fractures was constructed. The loading condition was used to simulate the force (400 N) on the femoral head and the stress distribution on the lag screw, side plate, cortical screws, and femur was measured. RESULTS: The highest stress points occured around the region of contact between the screw and the cortical bones. The stress on the femur at the most distal cortical screw was the greatest. The shorter the length of the side plate, the greater the stress on the cortical screws, resulting in an increased stress on the femur surrounding the cortical screws. CONCLUSIONS: The use of DHS with 2-hole side plate may increase the risk of side plate pull-out. The results of this study provide a biomechanical analysis for selection of DHS implant lengths that can be useful for orthopaedic surgeons.

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Comparison between Conventional and Minimally Invasive Dynamic Hip Screws for Fixation of Intertrochanteric Fractures of the Femur

ISRN Orthopedics ◽

10.1155/2013/484289 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

A. Mahmood ◽

M. Kalra ◽

M. K. Patralekh

Keyword(s):

Surgical Technique ◽

Minimally Invasive ◽

Early Mobilization ◽

Dynamic Hip Screw ◽

Minimally Invasive Technique ◽

Invasive Technique ◽

Intertrochanteric Fractures ◽

Tissue Destruction ◽

Side Plate ◽

Hip Screw

Background. Intertrochanteric fractures of the proximal femur are one of the most common fractures encountered, and dynamic hip screw with a side plate is the standard treatment. We compared a minimally invasive surgical technique with the conventional surgical technique used in the fixation of intertrochanteric fractures with the dynamic hip screw (DHS) device. Methods. Thirty patients with such fractures were treated with the conventional open technique and 30 with a new minimally invasive technique. Patients in both groups were followed up for 1 year. Results. There was less blood loss, minimal soft tissue destruction, shorter hospital stay, and early mobilization with the minimally invasive technique. Conclusion. The present study finds minimally invasive technique superior to conventional (open) DHS.

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Identification of the medial femoral safe zone for drilling during dynamic hip screw side plate fixation: A CT angiogram tracing of the profunda femoris artery

Injury ◽

10.1016/j.injury.2019.01.010 ◽

2019 ◽

Vol 50 (3) ◽

pp. 720-726 ◽

Cited By ~ 1

Author(s):

Samer S.S. Mahmoud ◽

Bessam Ahmed ◽

Khalid Hamid ◽

Simon Milburn ◽

Paul Baker

Keyword(s):

Plate Fixation ◽

Safe Zone ◽

Dynamic Hip Screw ◽

Side Plate ◽

Profunda Femoris Artery ◽

Ct Angiogram ◽

Hip Screw ◽

Profunda Femoris

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Two-hole versus four-hole plate dynamic hip screw: a systematic review of current evidence

Irish Journal of Medical Science (1971 -) ◽

10.1007/s11845-020-02184-9 ◽

2020 ◽

Vol 189 (4) ◽

pp. 1317-1322

Author(s):

Martin S. Davey ◽

Sean O. Flynn ◽

Joshua Hayes ◽

Iain Feeley ◽

Marc C. Grant Freemantle ◽

...

Keyword(s):

Systematic Review ◽

Dynamic Hip Screw ◽

Current Evidence ◽

Hip Screw ◽

Plate Dynamic

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Surgical Treatment for Stable 2-Part Intertrochanteric Femur Fracture Using Dynamic Hip Screw with 2-Hole Side Plate in Elderly Patients

Journal of the Korean Fracture Society ◽

10.12671/jkfs.2016.29.3.192 ◽

2016 ◽

Vol 29 (3) ◽

pp. 192

Author(s):

Kyung-Hoon Lee ◽

Suk Ku Han ◽

Seung-Jae Chung ◽

Jongho Noh ◽

Kee-Haeng Lee

Keyword(s):

Surgical Treatment ◽

Elderly Patients ◽

Femur Fracture ◽

Dynamic Hip Screw ◽

Side Plate ◽

Hip Screw ◽

Intertrochanteric Femur Fracture

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BIOMECHANICAL EFFECT OF DIFFERENT LAG SCREW LENGTHS WITH DIFFERENT BARREL LENGTHS IN DYNAMIC HIP SCREW SYSTEM: A FINITE ELEMENT ANALYSIS STUDY

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519417500087 ◽

2017 ◽

Vol 17 (01) ◽

pp. 1750008 ◽

Cited By ~ 2

Author(s):

CHUNG-YUH TZENG ◽

KUI-CHUO HUANG ◽

YUN-CHE WU ◽

CHU-LING CHANG ◽

KUAN-RONG LEE ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Intertrochanteric Fracture ◽

High Stress ◽

Dynamic Hip Screw ◽

Element Analysis ◽

Side Plate ◽

Lag Screw ◽

Hip Screw ◽

Biomechanical Effect

The dynamic hip screw (DHS) system is commonly used to treat intertrochanteric fracture of the hip joint. Breakage of the lag screw was noted in clinical practice and the length of lag screw as well as the length of the side plate in the DHS system appeared to play a role in the risk of breakage. Thus, the aim of this study was to investigate the biomechanical effect of different lag screw lengths and barrel plate lengths in the DHS implant system by finite element analysis (FEA). Four FEA simulation models were created according to different lengths of lag screw (79[Formula: see text]mm and 63[Formula: see text]mm) and different lengths of barrel side plate (43[Formula: see text]mm and 37[Formula: see text]mm). The von Mises stress was used as the observation indicator. The results showed that the maximum tensile stress on the long lag screw was slightly greater than that of the shorter lag screw. Use of a shorter barrel side plate may also cause high stress between the lag screw and the barrel side plate. This finding provides biomechanical reference data that may be of value to orthopedic surgeons with respect to choice of implant size and length in the treatment of intertrochanteric fracture with a DHS system to prevent complications such as implant failure caused by broken lag screws.

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