Femoral component positioning in resurfacing arthroplasty--effects on cortical strains.
Previous studies have suggested that femoral component positioning in resurfacing arthroplasty may affect strains in the femoral neck that could lead to decreased implant longevity. A strain gaged, Sawbones model was used to determine the femoral neck strains for a variety of resurfacing head translations and angulations. We found that head positions affected strain distributions, most positions leading to increased neck strains, often over 100%, with the exception being a varus head position where the superior neck strains decreased over 50%. Although the clinical meaning of these findings is unclear, it could be of concern for stress-shielding or fatigue fracture of the femoral neck.
Kummer
Frederick J
FJ
NYU School of Medicine, New York, New York, USA. fkummer@yahoo.com
Pereira
Gavin
G
Schachter
Aaron K
AK
Jaffe
William L
WL
D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D002102:Cadaver; D019544:Equipment Failure Analysis; D005265:Femoral Neck Fractures / Q000209:etiology; D005269:Femur / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013314:Stress, Mechanical