Prevention of fracture at the distal locking site of the gamma nail. A biomechanical study.
To investigate the origin of fractures at the distal locking site of the Gamma nail, we loaded ten paired human cadaver femora fixed with a Gamma nail in torsion until they fractured. When an awl was hammered in to start the hole for distal locking a fissure appeared in the lateral cortex of all the femora, and the mean torsional load to create a fracture was reduced by 57.8% compared with that in a control group in which the distal locking hole had been started with a centre drill. When an additional drill hole was made, the mean failure load in torsion decreased by 35.7%. We strongly recommend that an awl should not be used at the distal locking site of the Gamma nail; we recommend the use of a centre drill. Additional drill holes should be avoided because they act as stress raisers.
Lacroix
H
H
University Hospital-Dijkzigt, Rotterdam, The Netherlands.
Arwert
H
H
Snijders
C J
CJ
Fontijne
W P
WP
D005264:Femoral Fractures / Q000209:etiology / Q000517:prevention & control*; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects* / Q000379:methods; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D013314:Stress, Mechanical; D013525:Surgical Instruments