Anatomic stem design reduces risk of thin cement mantles in primary hip replacement.
OBJECTIVE
To analyse the influence of femoral stem design in the lateral plane (anatomic vs. straight) on the cement mantle quality.


METHODS
In this consecutive multi-surgeon radiographic study we determined, Dorr grading, cement mantle quality (Barrack) and mantle thickness using Gruen zones 1–14 in 280 primary cemented total hip replacements, divided into two groups (140 anatomic Biomet Olympia, 140 straight Exeter Universal Series).


RESULTS
Twenty-three per cent of the straight Exeter Universal stems had a cement mantle of <2 mm thickness in Gruen zone 8 and 25% in Gruen zone 9, compared to 0.7% of the anatomical Olympia stems in Gruen zone 8 and 1.4% in Gruen zone 9. The difference between the two groups was statistically significant (P < 0.001). In all other zones no significant differences were found.


CONCLUSIONS
This radiological study confirms that femoral stems with an anatomical curve in the lateral plane carry a lower risk of thin cement mantles (especially in Gruen zones 8 and 9) than straight stems. Cement mantle analysis in one radiographic plane only is insufficient.
Hank
Christian
C
Department of Orthopaedic Surgery, New Royal InWrmary at Little France, University of Edinburgh, Old Dalkeith Road, Edinburgh EH16 4SU, Scotland.
Schneider
Michael
M
Achary
Cheryl S
CS
Smith
Leslie
L
Breusch
Steffen J
SJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D001843:Bone Cements; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography
D001843:Bone Cements