Surgical neck fractures of the proximal humerus: a laboratory evaluation of ten fixation techniques.
OBJECTIVE
A biomechanical cadaver study was performed to compare the stability and ultimate strength of ten standard fixation techniques used for the treatment of surgical neck fractures of the proximal humerus.


METHODS
One hundred twenty (60 fresh frozen, 60 embalmed) proximal humerus specimens were selected and divided into two groups: fresh frozen specimens represented a nonosteopenic group and embalmed specimens an osteopenic group. Simulated fractures were created at the level of the surgical neck, reduced, and randomly assigned to one of ten methods of fixation (six fresh frozen and six embalmed specimens per fixation group). These constructs were then mechanically tested with the humeri oriented to create primarily shear loading of the fixation.


CONCLUSIONS
The T-plate and screws provided significantly stronger fixation (p < 0.005) in the fresh frozen specimens than all other methods. The Ender nails/tension band construct was the second strongest fixation technique, providing significantly stronger fixation (p < 0.01) than all the remaining techniques. Four Schanz pins with one pin placed through the greater tuberosity followed by the T-plate and screws provided the strongest fixation in embalmed specimens. Tension band fixation in both humeral groups was shown to provide the least effective fixation.
Koval
K J
KJ
Department of Orthopaedics, Hospital for Joint Diseases, New York 10003, USA.
Blair
B
B
Takei
R
R
Kummer
F J
FJ
Zuckerman
J D
JD
D001696:Biomechanical Phenomena; D001851:Bone Diseases, Metabolic / Q000150:complications; D001858:Bone Nails / Q000592:standards*; D001860:Bone Plates / Q000592:standards*; D001863:Bone Screws / Q000592:standards*; D002102:Cadaver; D004615:Embalming; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D011897:Random Allocation; D012784:Shoulder Fractures / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*