Femoral stem fracture and in vivo corrosion of retrieved modular femoral hips.
A series of 78 retrieved modular hip devices were assessed for fretting and corrosion. Damage was common at both the head-neck junction (54% showing corrosion; 88% showing fretting) and at the stem-sleeve junction (88% corrosion; 65% fretting). Corrosion correlated to in vivo duration, patient activity, and metal (vs ceramic) femoral heads but did not correlate to head carbon content. Femoral stem fatigue fracture was observed in seven retrievals; all had severe corrosion, were under increased stress, and were in vivo longer than the non-fractured cohort. This study emphasizes the potential for stem fracture when small diameter femoral stems with large offsets are used in heavy and active patients. Designs which reduce fretting and corrosion in modular implants is warranted as patients demand longer lasting implants.
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
J Caitlin
JC
Huot Carlson
Douglas W
DW
Van Citters
John H
JH
Currier
Amber M
AM
Bryant
Michael B
MB
Mayor
John P
JP
Collier
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000032:analysis; D003343:Corrosion; D020878:Device Removal; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D005264:Femoral Fractures / Q000209:etiology*; D005270:Femur Head / Q000737:chemistry; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000209:etiology*; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D012189:Retrospective Studies; D013314:Stress, Mechanical
D002244:Carbon