Tartrate-resistant acid phosphatase 5b (TRAP 5b) as a marker of osteoclast activity in the early phase after cementless total hip replacement.
BACKGROUND
After total hip replacement, increased bone metabolism is seen. A local periprosthetic osteopenia can be measured by dual-energy X-ray absorptiometry (DXA), but it is still unkown whether biochemical markers can be used to monitor the local remodeling at an earlier stage.


METHODS
In this prospective study we compared the biochemical markers tartrate-resistant acid phosphatase 5b (TRAP 5b), bone ALP, osteocalcin and CrossLaps with periprosthetic DXA in 17 consecutive patients after uncemented total hip replacement.


RESULTS
We found a highly significant early increase in TRAP 5b after 2 weeks and 6 weeks, which was followed by a densitometrically detectable decrease in bone mineral density after 26 weeks, especially in periprosthetic section Gruen zone 7. Bone ALP and osteocalcin levels as markers of osteoblast activity, and also Cross-Laps as a further marker of osteoclast activity, did not appear to allow any significant prediction of local bone remodeling.


CONCLUSIONS
Our findings show that TRAP 5b is a sensitive parameter for monitoring of osteoclast activity after cementless total hip replacement, and may predict local osteopenia.
Habermann
Bjoern
B
Department of Orthopaedic Surgery, University Hospital, Frankfurt/Main, Germany. B.Habermann@Friedrichsheim.de
Eberhardt
Christian
C
Feld
Matthias
M
Zichner
Ludwig
L
Kurth
Andreas A
AA
D000135:Acid Phosphatase / Q000032:analysis*; D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000032:analysis; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods; D015415:Biomarkers / Q000032:analysis*; D015519:Bone Density; D016723:Bone Remodeling; D001862:Bone Resorption; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000032:analysis; D010010:Osteoclasts / Q000201:enzymology*; D011446:Prospective Studies; D011475:Prosthesis Failure; D013644:Tartrates
D015415:Biomarkers; D013644:Tartrates; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase