TY - JOUR
T1 - Dual small fragment plating improves screw-to-screw load sharing for mid-diaphyseal humeral fracture fixation
T2 - A finite element study
AU - Kosmopoulos, Victor
AU - Luedke, Colten
AU - Nana, Arvind D.
N1 - Publisher Copyright:
© 2015-IOS Press and the authors.
PY - 2015
Y1 - 2015
N2 - BACKGROUND: A smaller humerus in some patients makes the use of a large fragment fixation plate difficult. Dual small fragment plate constructs have been suggested as an alternative. OBJECTIVE: This study compares the biomechanical performance of three single and one dual plate construct for mid-diaphyseal humeral fracture fixation. METHODS: Five humeral shaft finite element models (1 intact and 4 fixation) were loaded in torsion, compression, posterior-anterior (PA) bending, and lateral-medial (LM) bending. A comminuted fracture was simulated by a 1-cm gap. Fracture fixation was modelled by: (A) 4.5-mm 9-hole large fragment plate (wide), (B) 4.5-mm 9-hole large fragment plate (narrow), (C) 3.5-mm 9-hole small fragment plate, and (D) one 3.5-mm 9-hole small fragment plate and one 3.5-mm 7-hole small fragment plate. RESULTS: Model A showed the best outcomes in torsion and PA bending, whereas Model D outperformed the others in compression and LM bending. Stress concentrations were located near and around the unused screw holes for each of the single plate models and at the neck of the screws just below the plates for all the models studied. Other than in PA bending, Model D showed the best overall screw-to-screw load sharing characteristics. CONCLUSION: The results support using a dual small fragment locking plate construct as an alternative in cases where crutch weight-bearing (compression) tolerance may be important and where anatomy limits the size of the humerus bone segment available for large fragment plate fixation.
AB - BACKGROUND: A smaller humerus in some patients makes the use of a large fragment fixation plate difficult. Dual small fragment plate constructs have been suggested as an alternative. OBJECTIVE: This study compares the biomechanical performance of three single and one dual plate construct for mid-diaphyseal humeral fracture fixation. METHODS: Five humeral shaft finite element models (1 intact and 4 fixation) were loaded in torsion, compression, posterior-anterior (PA) bending, and lateral-medial (LM) bending. A comminuted fracture was simulated by a 1-cm gap. Fracture fixation was modelled by: (A) 4.5-mm 9-hole large fragment plate (wide), (B) 4.5-mm 9-hole large fragment plate (narrow), (C) 3.5-mm 9-hole small fragment plate, and (D) one 3.5-mm 9-hole small fragment plate and one 3.5-mm 7-hole small fragment plate. RESULTS: Model A showed the best outcomes in torsion and PA bending, whereas Model D outperformed the others in compression and LM bending. Stress concentrations were located near and around the unused screw holes for each of the single plate models and at the neck of the screws just below the plates for all the models studied. Other than in PA bending, Model D showed the best overall screw-to-screw load sharing characteristics. CONCLUSION: The results support using a dual small fragment locking plate construct as an alternative in cases where crutch weight-bearing (compression) tolerance may be important and where anatomy limits the size of the humerus bone segment available for large fragment plate fixation.
KW - Finite element analysis
KW - bone plates
KW - humerus
KW - internal fracture fixation
KW - mechanical stress
UR - http://www.scopus.com/inward/record.url?scp=84922645031&partnerID=8YFLogxK
U2 - 10.3233/THC-140875
DO - 10.3233/THC-140875
M3 - Article
C2 - 25408282
AN - SCOPUS:84922645031
VL - 23
SP - 83
EP - 92
JO - Technology and Health Care
JF - Technology and Health Care
SN - 0928-7329
IS - 1
ER -