Hip fracture implants increase serum metal levels.
OBJECTIVE
Hip fractures are disabling accidents in the elderly. The purpose of this prospective study was to investigate systemic exposure to metals from hip implants used for fracture fixation.


METHODS
Serum levels of Cr, Ni and Mo in patients with compression hip screws (n = 22) or cervical fracture screws (n = 23) were measured by inductively coupled plasma mass spectrometry. Blood samples were collected before surgery and at 3 and 12 months postoperatively.


RESULTS
At 3 months, patients with compression hip screws showed higher concentrations of Cr and Ni than did those with cervical screws. Both types of screws led to a 2-fold increase in serum Mo, which was not expected for the freestanding cervical screws. After 12 months, the levels had decreased, but the compression hip screw was still associated with higher values for Cr and Mo.


CONCLUSIONS
The difference between the screws is most likely due to the potential for fretting and crevice corrosion between components in the compression hip screws. The apparent short-term systemic elevation of stainless steel elements in patients with hip screws does not support routine removal of asymptomatic hip fracture implants.
Høl
P J
PJ
Orthopaedic Biomaterials-Innovest AS, Bergen, Norway. paul.hol@odont.uib.no
Mølster
A
A
Gjerdet
N R
NR
Bell
K
K
Saetersdal
C
C
Gjertsen
J-E
JE
D000368:Aged; D000369:Aged, 80 and over; D002857:Chromium / Q000097:blood*; D005260:Female; D005265:Femoral Neck Fractures / Q000601:surgery; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D008982:Molybdenum / Q000097:blood*; D009532:Nickel / Q000097:blood*; D011446:Prospective Studies
D002857:Chromium; D009532:Nickel; D008982:Molybdenum