Periprosthetic bone remodeling after 12 years differs in cemented and uncemented hip arthroplasties.
BACKGROUND
Different patterns of stress shielding may lead to differences in periprosthetic bone preservation around cemented and uncemented hips in the long term?


OBJECTIVE
The purpose of this study is to compare the difference in periprosthetic bone density between cemented Charnley total hip and uncemented hydroxyapatite-coated Furlong THAs at a minimum followup of 12 years (mean, 16 years; range, 12-24 years).


METHODS
We studied a cohort of 17 patients who had bilateral THAs with a cemented Charnley THA on one side and an uncemented Furlong hydroxyapatite-coated THA on the other side. At a minimum followup of 12 years, Harris and Oxford hip scores were used to determine the function, and dual-energy x-ray absorptiometry was used to quantify bone mineral density adjacent to the prosthesis. The results of the dual-energy x-ray absorptiometry scan for cemented and uncemented hips were analyzed using paired-sample two-tailed t-tests. To compare the Harris hip scores, a nonparametric Wilcoxon test was used.


RESULTS
Bone mineral density was higher on the uncemented Furlong side in Gruen Zones 2, 3, 5, and 6 of the proximal femur and DeLee and Charnley Zone 1 of the acetabulum. In all other zones, there was no difference. Comparison of Harris and Oxford hip scores showed no differences between the two hips.


CONCLUSIONS
Bone density is better preserved around the uncemented hydroxyapatite-coated Furlong stem compared with the Charnley cemented stem.


METHODS
Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Trauma and Orthopaedics, Scarborough General Hospital, Scarborough, West Yorkshire, UK. prakachandran@yahoo.co.uk
Prakash
P
Chandran
Mohammed
M
Azzabi
Mark
M
Andrews
John G
JG
Bradley
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000534:rehabilitation*; D001843:Bone Cements; D015519:Bone Density / Q000502:physiology; D016723:Bone Remodeling / Q000502:physiology*; D002484:Cementation; D015331:Cohort Studies; D004185:Disability Evaluation; D017886:Durapatite; D005260:Female; D006304:Health Status; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000378:metabolism*; D011859:Radiography
D001843:Bone Cements; D017886:Durapatite