Proximal loading of the femur leads to low subsidence rates: first clinical results of the CR-stem.
BACKGROUND
A new femoral stem was developed with a design that leads to compression of cancellous bone in the calcar region which results in proximal loading. The cross-sectional design of the implant provides rotational stability.


METHODS
In the first clinical investigation ten patients underwent uncemented total hip arthroplasty between January 1999 and May 1999 using the CR-stem((R)) (Implantcast GmbH, Buxtehude, Germany). Results were investigated using the Harris-hip-score (HHS) and antero-posterior and lateral radiographs. Migration was evaluated with the EBRA-FCA-method with a follow-up of 7 years.


RESULTS
We demonstrated a mean subsidence rate of 2.23 +/- 1.13 mm 7 years after implantation thus providing basic data for extensive testing in a clinical environment.


CONCLUSIONS
As small subsidence rates are regarded as predictor for superior long-term results in uncemented total hip arthroplasty according to the literature, the CR-stem shows promise for excellent long-term results.
Mazoochian
F
F
Department of Orthopaedics, Universitätsklinikum Grosshadern, Ludwig-Maximilians-University of Munich, Marchioninistr. 15, 81377 Munich, Germany. farhad.mazoochian@med.uni-muenchen.de
Schrimpf
F M
FM
Kircher
J
J
Mayer
W
W
Hauptmann
S
S
Fottner
A
A
Müller
P E
PE
Pellengahr
C
C
Jansson
V
V
D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008875:Middle Aged; D011474:Prosthesis Design; D012399:Rotation; D016896:Treatment Outcome