[Femoral periprosthetic bone remodelling to the proximal femur after implantation of custom made anatomic and standard straight stem hip prostheses].
OBJECTIVE
As a result of stress shielding bone resorption occurs around straight femoral stems following total hip replacement (THR). The question arises whether this pattern of periprosthetic bone loss is altered with use of custom made anatomic femoral stems.


METHODS
DEXA method was used to examine proximal femora of two groups of patients after cementless THR. Data of 16 patients with a standard straight femoral stem and 15 patients with a custom made anatomic stem were acquired at 1 week and 2, 4, 6, 9, 12 and 24 months postoperatively. Periprosthetic bone density was recorded in regions of interest (ROI).


RESULTS
Similar pattern of periprosthetic bone changes were seen in femora with straight and anatomic hip stems at 24 months postoperatively. Femoral bone loss, up to 36 % in the calcar ROI, was seen with straight and anatomic stems.


CONCLUSIONS
Custom designed anatomic femoral hip stems were unable to prevent periprosthetic bone resorption. However it is concluded, that implantation of custom made stems in grossly distorted femoral anatomy induces transmission of forces similar to standard femoral stems implanted in normal medullary anatomy.
Arabmotlagh
M
M
Abteilung für Rheumaorthopädie der Johann-Wolfgang-Goethe-Universität Frankfurt/M. m.arabmotlagh@t-online.de
Hennigs
T
T
Rittmeister
M
M
D015502:Absorptiometry, Photon / Q000379:methods*; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D016723:Bone Remodeling; D001862:Bone Resorption / Q000000981:diagnostic imaging* / Q000209:etiology*; D019544:Equipment Failure Analysis; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging* / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D016896:Treatment Outcome