Computed tomography assisted osteodensitometry in total hip arthroplasty.
BACKGROUND
Periprosthetic bone remodelling is an important issue in total hip arthroplasty, which can compromise long-term outcomes. The aim of this study was to evaluate bone remodelling of the proximal femur with an uncemented hydroxyapatite-coated taper stem.


METHODS
Twenty-three patients (27 hips) were included in this study. The mean age of the patients at the index operation was 57.2 years. There were 15 men and 8 women. Bone remodelling was assessed with quantitative computed tomography and the clinical outcome determined using the Harris Hip Scores. The mean preoperative Harris Hip Score was 38 points and at the 1-year follow up, it was rated 96 points. All hips were radiologically stable.


RESULTS
At the 1-year follow up, we found a greater bone-density loss of the cancellous bone (ranging from 16.7 to 28.2%) compared with the cortical bone (ranging from 5.3 to 7.8%). A strong correlation was found between the low density of the cortical bone at the index operation and a higher loss of bone density at the follow up.


CONCLUSIONS
The newly designed tapered stem showed good clinical and radiological outcomes with a proximal femoral bone loss that compares favourably with other studies.
Pandit
Salil
S
Department of Orthopaedic Surgery, Middlemore Hospital, South Auckland Clinical School, University of Auckland, Auckland, New Zealand. spandit@middlemore.co.nz
Graydon
Andrew
A
Bradley
Lyndon
L
Walker
Cameron
C
Pitto
Rocco
R
D019644:Arthroplasty, Replacement, Hip; D015519:Bone Density; D016723:Bone Remodeling; D003720:Densitometry / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed